Epilepsy

Epilepsy

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Epilepsy is a common chronic
Chronic (medicine)
A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...

 neurological disorder
Neurological disorder
A neurological disorder is a disorder of the body's nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord, or in the nerves leading to or from them, can result in symptoms such as paralysis, muscle weakness, poor coordination, loss of sensation, seizures,...

 characterized by seizure
Seizure
An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...

s. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

.
About 50 million people worldwide have epilepsy, and nearly two out of every three new cases are discovered in developing countries.
Epilepsy becomes more common as people age. Onset of new cases occur most frequently in infants and the elderly. As a consequence of brain surgery, epileptic seizures may occur in recovering patients.

Epilepsy is usually controlled, but not cured, with medication. However, over 30% of people with epilepsy do not have seizure control even with the best available medications. Surgery
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...

 may be considered in difficult cases. Not all epilepsy syndromes are lifelong – some forms are confined to particular stages of childhood. Epilepsy should not be understood as a single disorder, but rather as syndromic with vastly divergent symptoms, all involving episodic abnormal electrical activity in the brain and numerous seizures.

Classification



Epilepsies are classified in five ways:
  1. By their first cause (or etiology
    Etiology
    Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....

    ).
  2. By the observable manifestations of the seizures, known as semiology.
  3. By the location in the brain where the seizures originate.
  4. As a part of discrete, identifiable medical syndrome
    Syndrome
    In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...

    s.
  5. By the event that triggers the seizures, such as reading or music


In 1981, the International League Against Epilepsy (ILAE) proposed a classification scheme for individual seizures that remains in common use. This classification is based on observation (clinical and EEG) rather than the underlying pathophysiology or anatomy and is outlined later on in this article. In 1989, the ILAE proposed a classification scheme for epilepsies and epileptic syndromes. This can be broadly described as a two-axis scheme having the cause on one axis and the extent of localization within the brain on the other. Since 1997, the ILAE have been working on a new scheme that has five axes: ictal phenomenon, (pertaining to an epileptic seizure), seizure type, syndrome, etiology, impairment.

Seizure types


Seizure types are organized firstly according to whether the source of the seizure within the brain is localized (partial or focal
Focal seizures
Partial seizures are seizures which affect only a part of the brain at onset. The brain is divided into two hemispheres, each consisting of four lobes - the frontal, temporal, parietal and occipital lobes...

 onset seizures) or distributed (generalized seizures). Partial seizures are further divided on the extent to which consciousness is affected. If it is unaffected, then it is a simple partial
Simple partial seizure
Simple partial seizures are seizures which affect only a small region of the brain, often the temporal lobes and/or hippocampi. People who have simple partial seizures retain consciousness...

seizure; otherwise it is a complex partial
Complex partial seizure
A complex partial seizure is an epileptic seizure that is associated with bilateral cerebral hemisphere involvement and causes impairment of awareness or responsiveness, i.e. loss of consciousness.-Presentation:...

(psychomotor) seizure. A partial seizure may spread within the brain - a process known as secondary generalization. Generalized seizures are divided according to the effect on the body but all involve loss of consciousness. These include absence
Absence seizure
Absence seizures are one of several kinds of seizures. These seizures are sometimes referred to as petit mal seizures ....

 (petit mal), myoclonic
Myoclonus
Myoclonus is brief, involuntary twitching of a muscle or a group of muscles. It describes a medical sign and, generally, is not a diagnosis of a disease. Brief twitches are perfectly normal. The myoclonic twitches are usually caused by sudden muscle contractions; they also can result from brief...

, clonic
Clonus
Clonus is a series of involuntary muscular contractions and relaxations. Clonus is a sign of certain neurological conditions, and is particularly associated with upper motor neuron lesions such as in stroke, multiple sclerosis, spinal cord damage and hepatic encephalopathy...

, tonic, tonic-clonic
Tonic-clonic seizure
Tonic–clonic seizures are a type of generalized seizure that affects the entire brain...

 (grand mal), and atonic
Atonic seizure
Atonic seizures , are a type of seizure. They consist of a brief lapse in muscle tone that are caused by temporary alterations in brain function. The seizures are brief - usually less than fifteen seconds. They begin in childhood and may persist into adulthood...

 seizures.

Children may exhibit behaviors that are easily mistaken for epileptic seizures but are not caused by epilepsy. These include:
  • Inattentive staring
  • Benign shudders (among children younger than age 2, usually when they are tired or excited)
  • Self-gratification behaviors (nodding, rocking, head banging)
  • Conversion disorder
    Conversion disorder
    Conversion disorder is a condition in which patients present with neurological symptoms such as numbness, blindness, paralysis, or fits without a neurological cause. It is thought that these problems arise in response to difficulties in the patient's life, and conversion is considered a psychiatric...

     (flailing and jerking of the head, often in response to severe personal stress such as physical abuse)


Conversion disorder can be distinguished from epilepsy because the episodes never occur during sleep and do not involve incontinence or self-injury.

Epilepsy syndromes


Just as there are many types of seizures, there are many types of epilepsy syndromes. Epilepsy classification includes more information about the person and the episodes than seizure type alone, such as clinical features (e.g., behavior during the seizure) and expected causes.

There are four main groups of epileptic syndrome which can be further divided into: benign Rolandic epilepsy
Rolandic epilepsy
In neurology and pediatrics, benign rolandic epilepsy or benign epilepsy with centrotemporal spikes is the most common epilepsy syndrome in childhood. Most children will outgrow the syndrome , hence the label benign...

, frontal lobe epilepsy
Frontal lobe epilepsy
Frontal lobe epilepsy, or FLE, is a neurological disorder that is characterized by brief, recurring seizures that arise in the frontal lobes of the brain, often while the patient is sleeping...

, infantile spasms, juvenile myoclonic epilepsy
Juvenile myoclonic epilepsy
Juvenile myoclonic epilepsy , also known as Janz syndrome, is a fairly common form of idiopathic generalized epilepsy, representing 5-10% of all epilepsies. This disorder typically first manifests itself between the ages of 12 and 18 with myoclonus occurring early in the morning. Most patients also...

, juvenile absence epilepsy, childhood absence epilepsy
Childhood absence epilepsy
Childhood absence epilepsy , also known as pyknolepsy, is an idiopathic generalized epilepsy which occurs in otherwise normal children. The age of onset is between 4–10 years with peak age between 5–7 years. Children have absence seizures which although brief , they occur frequently, sometimes in...

 (pyknolepsy), hot water epilepsy, Lennox-Gastaut syndrome
Lennox-Gastaut syndrome
Lennox–Gastaut syndrome , also known as Lennox syndrome, is a difficult-to-treat form of childhood-onset epilepsy that most often appears between the second and sixth year of life, and is characterized by frequent seizures and different seizure types; it is often accompanied by developmental delay...

, Landau-Kleffner syndrome
Landau-Kleffner syndrome
Landau–Kleffner syndrome , also called infantile acquired aphasia, acquired epileptic aphasia or aphasia with convulsive disorder, is a rare, childhood neurological syndrome....

, mitochondrial disorders, progressive myoclonic epilepsy
Progressive myoclonic epilepsy
Progressive myoclonic epilepsy is a rare epilepsy syndrome caused by a variety of genetic disorders. It consists of both myoclonic seizures and tonic-clonic seizures together with progressive neurological decline....

, reflex epilepsy
Reflex epilepsy
Reflex Epilepsy is the cognomen to seizures which are generated by a person’s acuteness to sensor stimulation caused by the environment. Possibly the best-known type of reflex epilepsy to the general public is photosensitive epilepsy.-External links:* International League Against Epilepsy....

, Rasmussen's syndrome, temporal lobe epilepsy
Temporal lobe epilepsy
Temporal lobe epilepsy a.k.a. Psychomotor epilepsy, is a form of focal epilepsy, a chronic neurological condition characterized by recurrent seizures. Over 40 types of epilepsies are known. They fall into two main categories: partial-onset epilepsies and generalized-onset epilepsies...

, limbic epilepsy, status epilepticus
Status epilepticus
Status epilepticus is a life-threatening condition in which the brain is in a state of persistent seizure. Definitions vary, but traditionally it is defined as one continuous unremitting seizure lasting longer than 5 minutes, or recurrent seizures without regaining consciousness between seizures...

, abdominal epilepsy
Abdominal epilepsy
Abdominal epilepsy is a rare condition consisting of gastrointestinal disturbances caused by epileptiform seizure activity. While a causal relationship between seizure activity and the GI symptoms has not been proven, the GI symptoms cannot be explained by other pathophysiological mechanisms, and...

, massive bilateral myoclonus
Myoclonus
Myoclonus is brief, involuntary twitching of a muscle or a group of muscles. It describes a medical sign and, generally, is not a diagnosis of a disease. Brief twitches are perfectly normal. The myoclonic twitches are usually caused by sudden muscle contractions; they also can result from brief...

, catamenial epilepsy
Catamenial epilepsy
Catamenial epilepsy is a subtype of epilepsy, which is a chronic neurological condition characterized by recurrent seizures. Catamenial epilepsy is a subset of this population, which includes women of whom their seizure exacerbation is aligned with their menstrual cycle. Women with catamenial...

, Jacksonian seizure disorder, Lafora disease
Lafora disease
Lafora disease, also called Lafora progressive myoclonic epilepsy or MELF , is a fatal autosomal recessive genetic disorder characterized by the presence of inclusion bodies, known as Lafora bodies, within neurons and the cells of the heart, liver, muscle, and skin.Most patients with this disease...

, photosensitive epilepsy
Photosensitive epilepsy
Photosensitive epilepsy is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights, bold, regular patterns, or regular moving patterns.-Symptoms:...

, etc.

Each type of epilepsy presents with its own unique combination of seizure type, typical age of onset, EEG findings, treatment, and prognosis. The most widespread classification of the epilepsies divides epilepsy syndromes by location or distribution of seizures (as revealed by the appearance of the seizures and by EEG
EEG
EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

) and by cause. Syndromes are divided into localization-related epilepsies, generalized epilepsies, or epilepsies of unknown localization.

Localization-related epilepsies, sometimes termed partial or focal epilepsies, arise from an epileptic focus, a small portion of the brain that serves as the irritant driving the epileptic response. Generalized epilepsies, in contrast, arise from many independent foci (multifocal epilepsies) or from epileptic circuits that involve the whole brain. Epilepsies of unknown localization remain unclear as to whether they arise from a portion of the brain or from more widespread circuits.

Epilepsy syndromes are further divided by presumptive cause: idiopathic, symptomatic, and cryptogenic
Cryptogenic disease
A cryptogenic disease is a disease of which the cause is unknown. It may be used in a particular case, when the nature of the patient's condition is known but the cause has not been found . The word cryptogenic also appears in the names of some disease entities, when the situation is sufficiently...

. In general, idiopathic epilepsies are thought to arise from genetic abnormalities that lead to alteration of basic neuronal regulation. Symptomatic epilepsies arise from the effects of an epileptic lesion, whether that lesion is focal, such as a tumor, or a defect in metabolism causing widespread injury to the brain. Cryptogenic epilepsies involve a presumptive lesion that is otherwise difficult or impossible to uncover during evaluation.

The genetic component to epilepsy is receiving particular interest from the scientific community. Conditions such as ring chromosome 20 syndrome
Ring chromosome 20 syndrome
Ring chromosome 20, ring-shaped chromosome 20 or r syndrome is a rare human chromosome abnormality where the two arms of chromosome 20 fuse to form a ring chromosome. The syndrome is associated with epileptic seizures, behaviour disorders and mental retardation.When only one copy of chromosome 20...

 (r(20)) are gaining acknowledgment, and although only 60 cases have been reported in the literature since 1976, "more widespread cytogenetic chromosomal karyotyping in nonetiological cases of epilepsy" is likely.

Some epileptic syndromes are difficult to fit within this classification scheme and fall in the unknown localization/etiology category. People with seizures that occur only after specific precipitants ("provoked seizures"), have "epilepsies" that fall into this category. Febrile convulsions are an example of seizures bound to a particular precipitant. Landau-Kleffner syndrome
Landau-Kleffner syndrome
Landau–Kleffner syndrome , also called infantile acquired aphasia, acquired epileptic aphasia or aphasia with convulsive disorder, is a rare, childhood neurological syndrome....

 is another epilepsy that, because of its variety of EEG
EEG
EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

 distributions, falls uneasily in clear categories. What can be even more confusing is that certain syndromes, such as West syndrome
West syndrome
West syndrome or West's Syndrome is an uncommon to rare epileptic disorder in infants. It is named after the English physician, William James West , who first described it in an article published in The Lancet in 1841. The original case actually described his own son, James Edwin West...

, featuring seizures such as infantile spasms, can be classified as idiopathic, syndromic, or cryptogenic depending on cause and can arise from both focal or generalized epileptic lesions.

Below are some common seizure syndromes:
  • Autosomal dominant nocturnal frontal lobe epilepsy
    Autosomal dominant nocturnal frontal lobe epilepsy
    Autosomal dominant nocturnal frontal lobe epilepsy is a rare epileptic disorder that causes frequent violent seizures during sleep. These seizures often involve complex motor movements, such as hand clenching, arm raising/lowering, and knee bending. Vocalizations such as shouting, moaning, or...

    (ADNFLE) is an idiopathic localization-related epilepsy that is an inherited epileptic disorder that causes seizures during sleep. Onset is usually in childhood. These seizures arise from the frontal lobes and consist of complex motor movements, such as hand clenching, arm raising/lowering, and knee bending. Vocalizations such as shouting, moaning, or crying are also common. ADNFLE is often misdiagnosed as nightmares. ADNFLE has a genetic basis. These genes encode various nicotinic acetylcholine receptor
    Nicotinic acetylcholine receptor
    Nicotinic acetylcholine receptors, or nAChRs, are cholinergic receptors that form ligand-gated ion channels in the plasma membranes of certain neurons and on the postsynaptic side of the neuromuscular junction...

    s.

  • Benign centrotemporal lobe epilepsy of childhood or benign Rolandic epilepsy
    Rolandic epilepsy
    In neurology and pediatrics, benign rolandic epilepsy or benign epilepsy with centrotemporal spikes is the most common epilepsy syndrome in childhood. Most children will outgrow the syndrome , hence the label benign...

     is an idiopathic localization-related epilepsy that occurs in children between the ages of 3 and 13 years, with peak onset in prepubertal late childhood. Apart from their seizure disorder, these patients are otherwise normal. This syndrome features simple partial seizures that involve facial muscles and frequently cause drooling. Although most episodes are brief, seizures sometimes spread and generalize. Seizures are typically nocturnal and confined to sleep. The EEG
    EEG
    EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

     may demonstrate spike discharges that occur over the centrotemporal scalp over the central sulcus of the brain (the Rolandic sulcus) that are predisposed to occur during drowsiness or light sleep. Seizures cease near puberty. Seizures may require anticonvulsant
    Anticonvulsant
    The anticonvulsants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder, since many seem to act as mood stabilizers, and in the treatment of neuropathic pain. The goal of an...

     treatment, but sometimes are infrequent enough to allow physicians to defer treatment.

  • Benign occipital epilepsy of childhood (BOEC) is an idiopathic localization-related epilepsy and consists of an evolving group of syndromes. Most authorities include two subtypes, an early subtype with onset between three and five years, and a late onset between seven and 10 years. Seizures in BOEC usually feature visual symptoms such as scotoma or fortifications (brightly colored spots or lines) or amaurosis (blindness or impairment of vision). Convulsions involving one half the body, hemiconvulsions, or forced eye deviation or head turning are common. Younger patients typically experience symptoms similar to migraine with nausea and headache, and older patients typically complain of more visual symptoms. The EEG
    EEG
    EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

     in BOEC shows spikes recorded from the occipital (back of head) regions. The EEG and genetic pattern suggest an autosomal dominant transmission as described by Ruben Kuzniecky
    Ruben Kuzniecky
    Ruben Kuzniecky, M.D. is a professor of Neurology specializing in the field of epilepsy and Magnetic Resonance Imaging . He was the first to recognize and prove that mesial temporal sclerosis, a common cause for difficult to control temporal lobe epilepsy, can be identified with MRI.-Bio:Dr...

    , et al. Lately, a group of epilepsies termed Panayiotopoulos syndrome
    Panayiotopoulos syndrome
    Panayiotopoulos syndrome is a common idiopathic childhood-related seizure disorder that occurs exclusively in otherwise normal children and manifests mainly with autonomic epileptic seizures and autonomic status epilepticus. An expert consensus has defined Panayiotopoulos syndrome as "a benign...

     that share some clinical features of BOEC but have a wider variety of EEG findings are classified by some as BOEC.

  • Catamenial epilepsy
    Catamenial epilepsy
    Catamenial epilepsy is a subtype of epilepsy, which is a chronic neurological condition characterized by recurrent seizures. Catamenial epilepsy is a subset of this population, which includes women of whom their seizure exacerbation is aligned with their menstrual cycle. Women with catamenial...

    (CE) is when seizures cluster around certain phases of a woman's menstrual cycle.

  • Childhood absence epilepsy
    Childhood absence epilepsy
    Childhood absence epilepsy , also known as pyknolepsy, is an idiopathic generalized epilepsy which occurs in otherwise normal children. The age of onset is between 4–10 years with peak age between 5–7 years. Children have absence seizures which although brief , they occur frequently, sometimes in...

    (CAE) is an idiopathic generalized epilepsy that affects children between the ages of 4 and 12 years of age, although peak onset is around five to six years old. These patients have recurrent absence seizures, brief episodes of unresponsive staring, sometimes with minor motor features such as eye blinking or subtle chewing. The EEG finding in CAE is generalized 3 Hz spike and wave discharges. Some go on to develop generalized tonic-clonic seizures. This condition carries a good prognosis because children do not usually show cognitive decline or neurological deficits, and the seizures in the majority cease spontaneously with onging maturation.

  • Dravet's syndrome, previously known as severe myoclonic epilepsy of infancy (SMEI), is a neurodevelopmental disorder beginning in infancy and characterized by severe epilepsy that does not respond well to treatment. This syndrome was described by Charlotte Dravet, French psychiatrist and epileptologist
    Epileptologist
    An epileptologist is a neurologist who specializes in the treatment of epilepsy. Epileptologists are experts in seizures and seizure disorers, anticonvulsants, and special situations involving seizures, such as cases in which all treatment intended to stop seizures has failed and epilepsy in...

     (born July 14, 1936). Dravet described this syndrome while working at the Centre Saint Paul at the University of Marseille
    Marseille
    Marseille , known in antiquity as Massalia , is the second largest city in France, after Paris, with a population of 852,395 within its administrative limits on a land area of . The urban area of Marseille extends beyond the city limits with a population of over 1,420,000 on an area of...

    . At Centre Saint Paul, one of her supervisors was Henri Gastaut, who described the Lennox-Gastaut syndrome
    Lennox-Gastaut syndrome
    Lennox–Gastaut syndrome , also known as Lennox syndrome, is a difficult-to-treat form of childhood-onset epilepsy that most often appears between the second and sixth year of life, and is characterized by frequent seizures and different seizure types; it is often accompanied by developmental delay...

    . She described this condition in 1978 Estimates of the prevalence of this rare disorder have ranged from 1:20,000 to 1:40,000 births, though the incidence may be found to be greater as the syndrome becomes better recognized and new genetic evidence is discovered. It is thought to occur with similar frequency in both genders, and knows no geographic or ethnic boundaries.

The course of Dravet syndrome is highly variable from person to person. Seizures begin during the first year of life and development is normal prior to their onset. In most cases, the first seizures occur with fever and are generalized tonic-clonic (grand mal) or unilateral (one-sided) convulsions. These seizures are often prolonged, and may lead to status epilepticus, a medical emergency. In time, seizures increase in frequency and begin to occur without fever. Additional seizure types appear, most often these are myoclonic, atypical absence, and complex-partial seizures.

Additional features that are seen in significant numbers of patients with Dravet syndrome may include sensory integration disorders and other autism spectrum
Autism spectrum
The term "autism spectrum" is often used to describe disorders that are currently classified as pervasive developmental disorders. Pervasive developmental disorders include autism, Asperger syndrome, Childhood disintegrative disorder, Rett syndrome and Pervasive Developmental Disorder Not Otherwise...

 characteristics, orthopedic or movement disorders, frequent or chronic upper respiratory and ear infections, sleep disturbance, dysautonomia
Dysautonomia
Dysautonomia is a broad term that describes any disease or malfunction of the autonomic nervous system. This includes postural orthostatic tachycardia syndrome , inappropriate sinus tachycardia , vasovagal syncope, mitral valve prolapse dysautonomia, pure autonomic failure, neurocardiogenic...

, and problems with growth and nutrition.

  • Frontal lobe epilepsy
    Frontal lobe epilepsy
    Frontal lobe epilepsy, or FLE, is a neurological disorder that is characterized by brief, recurring seizures that arise in the frontal lobes of the brain, often while the patient is sleeping...

    , usually a symptomatic or cryptogenic localization-related epilepsy, arises from lesions causing seizures that occur in the frontal lobes of the brain. These epilepsies can be difficult to diagnose because the symptoms of seizures can easily be confused with nonepileptic spells and, because of limitations of the EEG, be difficult to "see" with standard scalp EEG
    EEG
    EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

    .

  • Juvenile absence epilepsy is an idiopathic generalized epilepsy with later onset than CAE, typically in prepubertal adolescence, with the most frequent seizure type being absence seizures. Generalized tonic-clonic seizures can occur. Often, 3 Hz spike-wave or multiple spike discharges can be seen on EEG. The prognosis is mixed, with some patients going on to a syndrome that is poorly distinguishable from JME.

  • Juvenile myoclonic epilepsy
    Juvenile myoclonic epilepsy
    Juvenile myoclonic epilepsy , also known as Janz syndrome, is a fairly common form of idiopathic generalized epilepsy, representing 5-10% of all epilepsies. This disorder typically first manifests itself between the ages of 12 and 18 with myoclonus occurring early in the morning. Most patients also...

    (JME) is an idiopathic generalized epilepsy that occurs in patients aged 8 to 20 years. Patients have normal cognition and are otherwise neurologically intact. The most common seizures are myoclonic jerks, although generalized tonic-clonic seizures and absence seizures may occur as well. Myoclonic jerks usually cluster in the early morning after awakening. The EEG reveals generalized 4–6 Hz spike wave discharges or multiple spike discharges. Interestingly, these patients are often first diagnosed when they have their first generalized tonic-clonic seizure later in life, when they experience sleep deprivation (e.g., freshman year in college after staying up late to study for exams). Alcohol withdrawal can also be a major contributing factor in breakthrough seizure
    Breakthrough seizure
    A breakthrough seizure is an epileptic seizure that occurs, despite the use of anticonvulsants that have otherwise successfully prevented seizures in the patient...

    s, as well. The risk of the tendency to have seizures is lifelong; however, the majority have well-controlled seizures with anticonvulsant medication and avoidance of seizure precipitants.

  • Lennox-Gastaut syndrome
    Lennox-Gastaut syndrome
    Lennox–Gastaut syndrome , also known as Lennox syndrome, is a difficult-to-treat form of childhood-onset epilepsy that most often appears between the second and sixth year of life, and is characterized by frequent seizures and different seizure types; it is often accompanied by developmental delay...

    (LGS) is a generalized epilepsy that consists of a triad of developmental delay or childhood dementia, mixed generalized seizures, and EEG
    EEG
    EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

     demonstrating a pattern of approximately 2 Hz "slow" spike-waves. Onset occurs between two and 18 years. As in West syndrome, LGS result from idiopathic, symptomatic, or cryptogenic causes, and many patients first have West syndrome
    West syndrome
    West syndrome or West's Syndrome is an uncommon to rare epileptic disorder in infants. It is named after the English physician, William James West , who first described it in an article published in The Lancet in 1841. The original case actually described his own son, James Edwin West...

    . Authorities emphasize different seizure types as important in LGS, but most have astatic seizures (drop attacks), tonic seizures, tonic-clonic seizures, atypical absence seizures, and sometimes, complex partial seizures. Anticonvulsants are usually only partially successful in treatment.

  • Ohtahara syndrome is a rare, but severe epilepsy syndrome usually starting in the first few days or weeks of life. The seizures are often in the form of stiffening spasms but other seizures including unilateral ones may be seen. The electroencephalogram (EEG) is characteristic. The prognosis is poor with about half of the infants dying in the first year of life; most if not all surviving infants are severely intellectually disabled and many have cerebral palsy. There is no effective treatment. A number of children have underlying structural brain abnormalities.
  • Primary reading epilepsy is a reflex epilepsy
    Reflex epilepsy
    Reflex Epilepsy is the cognomen to seizures which are generated by a person’s acuteness to sensor stimulation caused by the environment. Possibly the best-known type of reflex epilepsy to the general public is photosensitive epilepsy.-External links:* International League Against Epilepsy....

     classified as an idiopathic localization-related epilepsy. Reading in susceptible individuals triggers characteristic seizures.

  • Progressive myoclonic epilepsies define a group of symptomatic generalized epilepsies characterized by progressive dementia
    Dementia
    Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...

     and myoclonic seizures. Tonic-clonic seizures may occur as well. Diseases usually classified in this group are Unverricht-Lundborg disease
    Unverricht-Lundborg disease
    Unverricht-Lundborg disease is the most common form of an uncommon group of genetic epilepsy disorders called progressive myoclonic epilepsy. It is caused due to a mutation in the cystatin B gene...

    , myoclonus epilepsy with ragged red fibers (MERRF syndrome
    MERRF syndrome
    MERRF syndrome is a mitochondrial disease. It is extremely rare, with an estimated prevalence of 1/400,000 in Europe, and has varying degrees of expressivity owing to heteroplasmy-Presentation:...

    ), Lafora disease
    Lafora disease
    Lafora disease, also called Lafora progressive myoclonic epilepsy or MELF , is a fatal autosomal recessive genetic disorder characterized by the presence of inclusion bodies, known as Lafora bodies, within neurons and the cells of the heart, liver, muscle, and skin.Most patients with this disease...

    , neuronal ceroid lipofucinosis, and sialdosis.

  • Rasmussen's encephalitis
    Rasmussen's encephalitis
    Rasmussen's encephalitis, also known as chronic focal encephalitis , is a rare inflammatory neurological disorder, characterized by frequent and severe seizures, loss of motor skills and speech, hemiparesis , encephalitis , and dementia...

    is a symptomatic localization-related epilepsy that is a progressive, inflammatory lesion affecting children with onset before the age of 10. Seizures start as separate simple partial or complex partial seizures and may progress to epilepsia partialis continua
    Epilepsia partialis continua
    Epilepsia partialis continua is a rare type of brain disorder in which a patient experiences recurrent motor epileptic seizures that are focal , and recur every few seconds or minutes for extended periods .-Presentation:During these seizures, there is repetitive focal myoclonus or Jacksonian...

     (simple partial status epilepticus). Neuroimaging shows inflammatory encephalitis on one side of the brain that may spread if not treated. Dementia and hemiparesis are other problems. The cause is hypothesized to involve an immulogical attack against glutamate receptors, a common neurotransmitter in the brain.

  • Symptomatic localization-related epilepsies are divided by the location in the brain of the epileptic lesion, since the symptoms of the seizures are more closely tied to the brain location rather than the cause of the lesion. Tumors, atriovenous malformations, cavernous malformations, trauma, and cerebral infarcts can all be causes of epileptic foci in different brain regions.

  • Temporal lobe epilepsy
    Temporal lobe epilepsy
    Temporal lobe epilepsy a.k.a. Psychomotor epilepsy, is a form of focal epilepsy, a chronic neurological condition characterized by recurrent seizures. Over 40 types of epilepsies are known. They fall into two main categories: partial-onset epilepsies and generalized-onset epilepsies...

    (TLE), a symptomatic localization-related epilepsy, is the most common epilepsy of adults who experience seizures poorly controlled with anticonvulsant
    Anticonvulsant
    The anticonvulsants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder, since many seem to act as mood stabilizers, and in the treatment of neuropathic pain. The goal of an...

     medications. In most cases, the epileptogenic region is found in the midline (mesial) temporal structures (e.g., the hippocampus
    Hippocampus
    The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...

    , amygdala
    Amygdala
    The ' are almond-shaped groups of nuclei located deep within the medial temporal lobes of the brain in complex vertebrates, including humans. Shown in research to perform a primary role in the processing and memory of emotional reactions, the amygdalae are considered part of the limbic system.-...

    , and parahippocampal gyrus
    Parahippocampal gyrus
    The parahippocampal gyrus is a grey matter cortical region of the brain that surrounds the hippocampus. This region plays an important role in memory encoding and retrieval....

    ). Seizures begin in late childhood and adolescence. Most of these patients have complex partial seizures sometimes preceded by an aura
    Aura (symptom)
    An aura is a perceptual disturbance experienced by some migraine sufferers before a migraine headache, and the telltale sensation experienced by some people with epilepsy before a seizure. It often manifests as the perception of a strange light, an unpleasant smell or confusing thoughts or...

    , and some TLE patients also suffer from secondary generalized tonic-clonic seizures. If the patient does not respond sufficiently to medical treatment, epilepsy surgery may be considered.

  • Tuberous Sclerosis
    Tuberous sclerosis
    Tuberous sclerosis or tuberous sclerosis complex is a rare multi-system genetic disease that causes non-malignant tumors to grow in the brain and on other vital organs such as the kidneys, heart, eyes, lungs, and skin. A combination of symptoms may include seizures, developmental delay, behavioral...

    (TSC) is a genetic disorder that causes tumors to form in many different organs, primarily in the brain, eyes, heart, kidney, skin and lungs. Several types of brain lesions can occur in individuals with TSC and 60% - 90% of people with TSC develop epilepsy.

  • West syndrome
    West syndrome
    West syndrome or West's Syndrome is an uncommon to rare epileptic disorder in infants. It is named after the English physician, William James West , who first described it in an article published in The Lancet in 1841. The original case actually described his own son, James Edwin West...

    is a triad of developmental delay, seizures termed infantile spasms, and EEG
    EEG
    EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

     demonstrating a pattern termed hypsarrhythmia
    Hypsarrhythmia
    Hypsarrhythmia is an abnormal interictal pattern, consisting of high amplitude and irregular waves and spikes in a background of chaotic and disorganized activity seen on electroencephalogram , frequently encountered in an infant diagnosed with infantile spasms, although it can be found in other...

    . Onset occurs between three months and two years, with peak onset between eight and 9 months. West syndrome may arise from idiopathic, symptomatic, or cryptogenic causes. The most common cause is tuberous sclerosis. The prognosis varies with the underlying cause. In general, most surviving patients remain with significant cognitive impairment and continuing seizures and may evolve to another eponymic syndrome, Lennox-Gastaut syndrome.

Causes


The diagnosis of epilepsy usually requires that the seizures occur spontaneously. Nevertheless, certain epilepsy syndromes require particular precipitants or triggers for seizures to occur. These are termed reflex epilepsy
Reflex epilepsy
Reflex Epilepsy is the cognomen to seizures which are generated by a person’s acuteness to sensor stimulation caused by the environment. Possibly the best-known type of reflex epilepsy to the general public is photosensitive epilepsy.-External links:* International League Against Epilepsy....

. For example, patients with primary reading epilepsy have seizures triggered by reading. Photosensitive epilepsy
Photosensitive epilepsy
Photosensitive epilepsy is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights, bold, regular patterns, or regular moving patterns.-Symptoms:...

 can be limited to seizures triggered by flashing lights. Other precipitants can trigger an epileptic seizure in patients who otherwise would be susceptible to spontaneous seizures. For example, children with childhood absence epilepsy
Childhood absence epilepsy
Childhood absence epilepsy , also known as pyknolepsy, is an idiopathic generalized epilepsy which occurs in otherwise normal children. The age of onset is between 4–10 years with peak age between 5–7 years. Children have absence seizures which although brief , they occur frequently, sometimes in...

 may be susceptible to hyperventilation
Hyperventilation
Hyperventilation or overbreathing is the state of breathing faster or deeper than normal, causing excessive expulsion of circulating carbon dioxide. It can result from a psychological state such as a panic attack, from a physiological condition such as metabolic acidosis, can be brought about by...

. In fact, flashing lights and hyperventilation
Hyperventilation
Hyperventilation or overbreathing is the state of breathing faster or deeper than normal, causing excessive expulsion of circulating carbon dioxide. It can result from a psychological state such as a panic attack, from a physiological condition such as metabolic acidosis, can be brought about by...

 are activating procedures used in clinical EEG
EEG
EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

 to help trigger seizures to aid diagnosis. Finally, other precipitants can facilitate, rather than obligately trigger, seizures in susceptible individuals. Emotional stress, sleep deprivation, sleep itself, heat stress, alcohol and febrile illness are examples of precipitants cited by patients with epilepsy. Notably, the influence of various precipitants varies with the epilepsy syndrome. Likewise, the menstrual cycle
Menstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....

 in women with epilepsy can influence patterns of seizure recurrence. Catamenial epilepsy is the term denoting seizures linked to the menstrual cycle
Menstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....

.

There are different causes of epilepsy that are common in certain age groups.
  • During the neonatal period and early infancy the most common causes include hypoxic-ischemic encephalopathy, CNS infections, trauma, congenital CNS abnormalities, and metabolic disorders.
  • During late infancy and early childhood, febrile seizures are fairly common. These may be caused by many different things, some thought to be things such as CNS infections and trauma.
  • During childhood, well-defined epilepsy syndromes are generally seen.
  • During adolescence and adulthood, the causes are more likely to be secondary to any CNS lesion. Further, idiopathic epilepsy is less common. Other causes associated with these age groups are stress, trauma, CNS infections, brain tumors, illicit drug use and alcohol withdrawal.
  • In older adults, cerebrovascular disease is a very common cause. Other causes are CNS tumors, head trauma, and other degenerative diseases that are common in the older age group, such as dementia
    Dementia
    Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...

    .

Pathophysiology



Mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

s in several gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

s have been linked to some types of epilepsy. Several genes that code for protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 subunits of voltage-gated
Voltage-gated ion channel
Voltage-gated ion channels are a class of transmembrane ion channels that are activated by changes in electrical potential difference near the channel; these types of ion channels are especially critical in neurons, but are common in many types of cells....

 and ligand-gated
Ligand-gated ion channel
Ligand-gated ion channels are one type of ionotropic receptor or channel-linked receptor. They are a group of transmembrane ion channels that are opened or closed in response to the binding of a chemical messenger , such as a neurotransmitter.The binding site of endogenous ligands on LGICs...

 ion channel
Ion channel
Ion channels are pore-forming proteins that help establish and control the small voltage gradient across the plasma membrane of cells by allowing the flow of ions down their electrochemical gradient. They are present in the membranes that surround all biological cells...

s have been associated with forms of generalized epilepsy and infantile seizure syndromes.

One speculated mechanism for some forms of inherited epilepsy are mutations of the genes that code for sodium channel proteins; these defective sodium channels stay open for too long, thus making the neuron hyper-excitable. Glutamate, an excitatory neurotransmitter
Neurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...

, may, therefore, be released from these neurons in large amounts, which — by binding with nearby glutamatergic neurons — triggers excessive calcium (Ca2+) release in these post-synaptic cells. Such excessive calcium release can be neurotoxic to the affected cell. The hippocampus
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...

, which contains a large volume of just such glutamatergic neurons (and NMDA receptors, which are permeable to Ca2+ entry after binding of both glutamate and glycine), is especially vulnerable to epileptic seizure, subsequent spread of excitation, and possible neuronal death. Another possible mechanism involves mutations leading to ineffective GABA
Gabâ
Gabâ or gabaa, for the people in many parts of the Philippines), is the concept of a non-human and non-divine, imminent retribution. A sort of negative karma, it is generally seen as an evil effect on a person because of their wrongdoings or transgressions...

 (the brain's most common inhibitory neurotransmitter) action. Epilepsy-related mutations in some non-ion channel genes have also been identified.

Much like the channelopathies
Channelopathy
Channelopathies are diseases caused by disturbed function of ion channel subunits or the proteins that regulate them. These diseases may be either congenital or acquired .There are a large number of distinct dysfunctions known to be caused by ion channel...

 in voltage-gated ion channels, several ligand-gated ion channels have been linked to some types of frontal and generalized epilepsies.

Epileptogenesis
Epileptogenesis
Epileptogenesis is a process by which a normal brain develops epilepsy, a chronic condition in which seizures occur. The process, which is gradual, occurs in symptomatic epilepsy, in which seizures are caused by an identifiable lesion in the brain. It results from acute brain insults such as...

 is the process by which a normal brain develops epilepsy after trauma, such as a lesion on the brain. One interesting finding in animals is that repeated low-level electrical stimulation to some brain sites can lead to permanent increases in seizure susceptibility: in other words, a permanent decrease in seizure "threshold." This phenomenon, known as kindling
Kindling model
Kindling is a commonly used model for the development of seizures and epilepsy in which the duration and behavioral involvement of induced seizures increases after seizures are induced repeatedly. The kindling model was first proposed in the late 1960s by Goddard and colleagues...

 (by analogy with the use of burning twigs to start a larger fire) was discovered by Dr. Graham Goddard in 1967. It is important to note that these "kindled" animals do not experience spontaneous seizures. Chemical stimulation can also induce seizures; repeated exposures to some pesticides have been shown to induce seizures in both humans and animals. One mechanism proposed for this is called excitotoxicity
Excitotoxicity
Excitotoxicity is the pathological process by which nerve cells are damaged and killed by excessive stimulation by neurotransmitters such as glutamate and similar substances. This occurs when receptors for the excitatory neurotransmitter glutamate such as the NMDA receptor and AMPA receptor are...

. The roles of kindling and excitotoxicity, if any, in human epilepsy are currently hotly debated.

Other causes of epilepsy are brain lesions, where there is scar tissue or another abnormal mass of tissue in an area of the brain.

The complexity of understanding what seizures are have led to considerable efforts to use computational models of epilepsy to both interpret experimental and clinical data, as well as guide strategies for therapy.

Physical, emotional, and social functioning of youth are interfered specifically if seizures are uncontrolled. Some other noted consequences on repeated seizures are neuronal loss, gliosis, parenhymal microhemorrhages, excess of starch bodies, leptomeningeal thickening, subpial gliosis, perivascular gliosis and periavascular atrophy.

Management


Epilepsy is usually treated with medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...

 prescribed by a physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...

; primary care
Primary care
Primary care is the term for the health services by providers who act as the principal point of consultation for patients within a health care system...

givers, neurologist
Neurologist
A neurologist is a physician who specializes in neurology, and is trained to investigate, or diagnose and treat neurological disorders.Neurology is the medical specialty related to the human nervous system. The nervous system encompasses the brain, spinal cord, and peripheral nerves. A specialist...

s, and neurosurgeons all frequently care for people with epilepsy. However, it has been stressed that accurate differentiation between generalized and partial seizures is especially important in determining the appropriate treatment. In some cases the implantation of a stimulator of the vagus nerve
Vagus nerve
The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...

, or a special diet can be helpful. Neurosurgical operations for epilepsy can be palliative, reducing the frequency or severity of seizures; or, in some patients, an operation can be curative.

The proper initial response to a generalized tonic-clonic epileptic seizure
Tonic-clonic seizure
Tonic–clonic seizures are a type of generalized seizure that affects the entire brain...

 is to roll the person on the side (recovery position
Recovery position
The recovery position refers to one of a series of variations on a lateral recumbent or three-quarters prone position of the body, in to which an unconscious but breathing casualty can be placed as part of first aid treatment.An unconscious person The recovery position refers to one of a series of...

) to prevent ingestion of fluids into the lungs, which can result in choking and death. Should the person regurgitate
Regurgitation (digestion)
Regurgitation is the expulsion of material from the mouth, pharynx, or esophagus, usually characterized by the presence of undigested food or blood.Regurgitation is used by a number of species to feed their young...

, this should be allowed to drip out the side of the person's mouth. The person should be prevented from self-injury by moving them away from sharp edges, and placing something soft beneath the head. If a seizure lasts longer than 5 minutes, or if more than one seizure occurs without regaining consciousness emergency medical services
Emergency medical services
Emergency medical services are a type of emergency service dedicated to providing out-of-hospital acute medical care and/or transport to definitive care, to patients with illnesses and injuries which the patient, or the medical practitioner, believes constitutes a medical emergency...

 should be contacted.

Medications



The mainstay of treatment of epilepsy is anticonvulsant medications. Often, anticonvulsant medication treatment will be lifelong and can have major effects on quality of life. The choice among anticonvulsants and their effectiveness differs by epilepsy syndrome. Mechanisms, effectiveness for particular epilepsy syndromes, and side-effects differ among the individual anticonvulsant medications. Some general findings about the use of anticonvulsants are outlined below.

Availability - Currently there are 20 medications approved by the Food and Drug Administration for the use of treatment of epileptic seizures in the US: carbamazepine
Carbamazepine
Carbamazepine is an anticonvulsant and mood-stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder, as well as trigeminal neuralgia...

 (common US brand name Tegretol), clorazepate
Clorazepate
Clorazepate , also known as clorazepate dipotassium, is a drug that is a benzodiazepine derivative. It possesses anxiolytic, anticonvulsant, sedative, hypnotic and skeletal muscle relaxant properties. Clorazepate is a prodrug for desmethyldiazepam, which is rapidly produced as an active metabolite...

 (Tranxene), clonazepam
Clonazepam
Clonazepamis a benzodiazepine drug having anxiolytic, anticonvulsant, muscle relaxant, and hypnotic properties. It is marketed by Roche under the trade name Klonopin in the United States and Rivotril in Australia, Brazil, Canada and Europe...

 (Klonopin), ethosuximide
Ethosuximide
Ethosuximide is a succinimide anticonvulsant, used mainly in absence seizures.-Approved:It is approved for absence seizures. Ethosuximide is considered the first choice drug for treating absence seizures in part because it lacks the idiosyncratic hepatotoxicity of the alternative anti-absence...

 (Zarontin), felbamate
Felbamate
Felbamate is an anticonvulsant drug used in the treatment of epilepsy. It is used to treat partial seizures in adults and partial and generalized seizures associated with Lennox-Gastaut syndrome in children...

 (Felbatol), fosphenytoin
Fosphenytoin
Fosphenytoin is a water-soluble phenytoin prodrug used only in hospitals for the treatment of epileptic seizures....

 (Cerebyx), gabapentin
Gabapentin
Gabapentin is a pharmaceutical drug, specifically a GABA analogue. It was originally developed for the treatment of epilepsy, and currently is also used to relieve neuropathic pain...

 (Neurontin), lacosamide
Lacosamide
Lacosamide is a medication developed by UCB for the adjunctive treatment of partial-onset seizures and diabetic neuropathic pain marketed under the trade name Vimpat....

 (Vimpat), lamotrigine
Lamotrigine
Lamotrigine, marketed in the US and most of Europe as Lamictal by GlaxoSmithKline, is an anticonvulsant drug used in the treatment of epilepsy and bipolar disorder. It is also used as an adjunct in treating depression, though this is considered off-label usage...

 (Lamictal), levetiracetam (Keppra), oxcarbazepine
Oxcarbazepine
Oxcarbazepine is a anticholinergic anticonvulsant and mood stabilizing drug, used primarily in the treatment of epilepsy. It is also used to treat anxiety and mood disorders, and benign motor tics...

 (Trileptal), phenobarbital
Phenobarbital
Phenobarbital or phenobarbitone is a barbiturate, first marketed as Luminal by Friedr. Bayer et comp. It is the most widely used anticonvulsant worldwide, and the oldest still commonly used. It also has sedative and hypnotic properties but, as with other barbiturates, has been superseded by the...

 (Luminal), phenytoin
Phenytoin
Phenytoin sodium is a commonly used antiepileptic. Phenytoin acts to suppress the abnormal brain activity seen in seizure by reducing electrical conductance among brain cells by stabilizing the inactive state of voltage-gated sodium channels...

 (Dilantin), pregabalin
Pregabalin
Pregabalin is an anticonvulsant drug used for neuropathic pain and as an adjunct therapy for partial seizures with or without secondary generalization in adults. It has also been found effective for generalized anxiety disorder and is approved for this use in the European Union. It was designed...

 (Lyrica), primidone
Primidone
Primidone is an anticonvulsant of the pyrimidinedione class, the active metabolites of which, phenobarbital and phenylethylmalonamide , are also anticonvulsants...

 (Mysoline), tiagabine
Tiagabine
Tiagabine -Indications:Tiagabine is approved by U.S. Food and Drug Administration as an adjunctive treatment for partial seizures in ages 12 and up. It may also be prescribed to treat anxiety disorders and neuropathic pain . For anxiety and neuropathic pain, tiagabine is used primarily to augment...

 (Gabitril), topiramate
Topiramate
Topiramate is an anticonvulsant drug. It was originally produced by Ortho-McNeil Neurologics and Noramco, Inc., both divisions of the Johnson & Johnson Corporation. This medication was discovered in 1979 by Bruce E. Maryanoff and Joseph F. Gardocki during their research work at McNeil...

 (Topamax), valproate semisodium
Valproate semisodium
Valproate semisodium or divalproex sodium consists of a compound of sodium valproate and valproic acid in a 1:1 molar relationship in an enteric coated form. It is used in the United Kingdom, Canada, and United States for the treatment of the manic episodes of bipolar disorder...

 (Depakote), valproic acid
Valproic acid
Valproic acid is a chemical compound that has found clinical use as an anticonvulsant and mood-stabilizing drug, primarily in the treatment of epilepsy, bipolar disorder, and, less commonly, major depression. It is also used to treat migraine headaches and schizophrenia...

 (Depakene), and zonisamide
Zonisamide
Zonisamide is a sulfonamide anticonvulsant approved for use as an adjunctive therapy in adults with partial-onset seizures for adults; infantile spasm, mixed seizure types of Lennox-Gastaut syndrome, myoclonic, and generalized tonic clonic seizure.-History:...

 (Zonegran). Most of these appeared after 1990.

Medications commonly available outside the US but still labelled as "investigational" within the US are
clobazam
Clobazam
Clobazam , is a drug which is a benzodiazepine derivative. It has been marketed as an anxiolytic since 1975 and an anticonvulsant since 1984...

 (Frisium) and vigabatrin
Vigabatrin
Vigabatrin is an antiepileptic drug that inhibits the catabolism of gamma-aminobutyric acid by irreversibly inhibiting GABA transaminase. It is an analog of GABA, but it is not a receptor agonist...

 (Sabril). Medications currently under clinical trial under the supervision of the FDA include retigabine
Retigabine
Retigabine or ezogabine , codenamed D-23129, is an anticonvulsant used as a treatment for partial epilepsies. The drug was developed by Valeant Pharmaceuticals and GlaxoSmithKline...

, brivaracetam
Brivaracetam
Brivaracetam, the 4-n-propyl analog of levetiracetam, is a racetam derivative with anticonvulsant properties. Brivaracetam is believed to act by binding to the ubiquitous synaptic vesicle protein SV2. Phase II clinical trials in adult patients with refractory partial seizures were promising...

, and seletracetam
Seletracetam
Seletracetam is a drug of the racetam family. It is currently being developed by UCB Pharmaceuticals as an anticonvulsant drug. While similar in structure to so-called nootropic drugs, it is not expected to have cognitive enhancing properties....

.

Other drugs are commonly used to abort an active seizure or interrupt a seizure flurry; these include diazepam
Diazepam
Diazepam , first marketed as Valium by Hoffmann-La Roche is a benzodiazepine drug. Diazepam is also marketed in Australia as Antenex. It is commonly used for treating anxiety, insomnia, seizures including status epilepticus, muscle spasms , restless legs syndrome, alcohol withdrawal,...

 (Valium, Diastat) and lorazepam
Lorazepam
Lorazepam is a high-potency short-to-intermediate-acting 3-hydroxy benzodiazepine drug that has all five intrinsic benzodiazepine effects: anxiolytic, amnesic, sedative/hypnotic, anticonvulsant, antiemetic and muscle relaxant...

 (Ativan). Drugs used only in the treatment of refractory status epilepticus
Status epilepticus
Status epilepticus is a life-threatening condition in which the brain is in a state of persistent seizure. Definitions vary, but traditionally it is defined as one continuous unremitting seizure lasting longer than 5 minutes, or recurrent seizures without regaining consciousness between seizures...

 include paraldehyde
Paraldehyde
Paraldehyde is the cyclic trimer of acetaldehyde molecules. Formally, it is a derivative of 1,3,5-trioxane. The corresponding tetramer is metaldehyde. A colourless liquid, it is sparingly soluble in water and highly soluble in alcohol. Paraldehyde slowly oxidizes in air, turning brown and producing...

 (Paral), midazolam
Midazolam
Midazolam is a short-acting drug in the benzodiazepine class developed by Hoffmann-La Roche in the 1970s. The drug is used for treatment of acute seizures, moderate to severe insomnia, and for inducing sedation and amnesia before medical procedures. It possesses profoundly potent anxiolytic,...

 (Versed), and pentobarbital
Pentobarbital
Pentobarbital is a short-acting barbiturate that was first synthesized in 1928. Pentobarbital is available as both a free acid and a sodium salt, the former of which is only slightly soluble in water and ethanol....

 (Nembutal).

Some anticonvulsant medications do not have primary FDA-approved uses in epilepsy but are used in limited trials, remain in rare use in difficult cases, have limited "grandfather" status, are bound to particular severe epilepsies, or are under current investigation. These include acetazolamide
Acetazolamide
Acetazolamide, sold under the trade name Diamox, is a carbonic anhydrase inhibitor that is used to treat glaucoma, epileptic seizures, Idiopathic intracranial hypertension , altitude sickness, cystinuria, and dural ectasia...

 (Diamox), progesterone
Progesterone
Progesterone also known as P4 is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy and embryogenesis of humans and other species...

, adrenocorticotropic hormone
Adrenocorticotropic hormone
Adrenocorticotropic hormone , also known as 'corticotropin', 'Adrenocorticotrophic hormone', is a polypeptide tropic hormone produced and secreted by the anterior pituitary gland. It is an important component of the hypothalamic-pituitary-adrenal axis and is often produced in response to biological...

 (ACTH, Acthar), various corticotropic steroid hormones (prednisone
Prednisone
Prednisone is a synthetic corticosteroid drug that is particularly effective as an immunosuppressant drug. It is used to treat certain inflammatory diseases and some types of cancer, but has significant adverse effects...

), or bromide
Bromide
A bromide is a chemical compound containing bromide ion, that is bromine atom with effective charge of −1. The class name can include ionic compounds such as caesium bromide or covalent compounds such as sulfur dibromide.-Natural occurrence:...

.

Effectiveness - The definition of "effective" varies. FDA approval usually requires that 50% of the patient treatment group had at least a 50% improvement in the rate of epileptic seizures. About 20% of patients with epilepsy continue to have breakthrough epileptic seizures despite best anticonvulsant treatment.

Safety and Side Effects - 88% of patients with epilepsy, in a European survey, reported at least one anticonvulsant related side-effect. Most side effects are mild and "dose-related" and can often be avoided or minimized by the use of the smallest effective amount. Some examples include mood changes, sleepiness, or unsteadiness in gait. Some anticonvulsant medications have "idiosyncratic" side effects that can not be predicted by dose. Some examples include drug rashes, liver toxicity (hepatitis), or aplastic anemia. Safety includes the consideration of teratogenicity (the effects of medications on fetal development) when women with epilepsy become pregnant.

Principles of Anticonvulsant Use and Management - The goal for individual patients is no seizures and minimal side-effects, and the job of the physician is to aid the patient to find the best balance between the two during the prescribing of anticonvulsants. Most patients can achieve this balance best with monotherapy, the use of a single anticonvulsant medication. Some patients, however, require polypharmacy, the use of two or more anticonvulsants.

Serum levels of AEDs can be checked to determine medication compliance
Compliance (medicine)
In medicine, compliance describes the degree to which a patient correctly follows medical advice...

, to assess the effects of new drug-drug interactions upon previous stable medication levels, or to help establish if particular symptoms such as instability or sleepiness can be considered a drug side effect or are due to different causes. Children or impaired adults who may not be able to communicate side-effects may benefit from routine screening of drug levels. Beyond baseline screening, however, trials of recurrent, routine blood or urine monitoring show no proven benefits and may lead to unnecessary medication adjustments in most older children and adults using routine anticonvulsants.

If a person's epilepsy cannot be brought under control after adequate trials of two or three (experts vary here) different drugs, that person's epilepsy is generally said to be medically refractory. A study of patients with previously untreated epilepsy demonstrated that 47% achieved control of seizures with the use of their first single drug. 14% became seizure free during treatment with a second or third drug. An additional 3% became seizure-free with the use of two drugs simultaneously. Other treatments, in addition to or instead of, anticonvulsant medications may be considered by those people with continuing seizures.

Surgery


Epilepsy surgery is an option for people with focal seizures that remain resistant to treatment. The goal for these procedures is total control of epileptic seizures, although anticonvulsant medications may still be required.

The evaluation for epilepsy surgery is designed to locate the "epileptic focus" (the location of the epileptic abnormality) and to determine if resective surgery will affect normal brain function. Physicians will also confirm the diagnosis of epilepsy to make sure that spells arise from epilepsy (as opposed to non-epileptic seizures
Non-epileptic seizures
Non-epileptic seizures are paroxysmal events that mimic an epileptic seizure but do not involve abnormal, rhythmic discharges of cortical neurons. They are caused by either physiological or psychological conditions...

). The evaluation typically includes neurological examination, routine EEG
EEG
EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...

, Long-term video-EEG monitoring
Long-term video-EEG monitoring
Long-term video-EEG monitoring, also known as video telemetry, is a diagnostic technique used in certain patients with epilepsy or seizures. It involves the inpatient hospitalization of the patient for a period of time, typically days to weeks, during which they are continuously monitored and...

, neuropsychological evaluation
Neuropsychology
Neuropsychology studies the structure and function of the brain related to specific psychological processes and behaviors. The term neuropsychology has been applied to lesion studies in humans and animals. It has also been applied to efforts to record electrical activity from individual cells in...

, and neuroimaging such as MRI, Single photon emission computed tomography
Single photon emission computed tomography
Single-photon emission computed tomography is a nuclear medicine tomographic imaging technique using gamma rays. It is very similar to conventional nuclear medicine planar imaging using a gamma camera. However, it is able to provide true 3D information...

 (SPECT), positron emission tomography
Positron emission tomography
Positron emission tomography is nuclear medicine imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide , which is introduced into the body on a...

 (PET). Some epilepsy centers use intracarotid sodium amobarbital test (Wada test
Wada test
The Wada test, named after Canadian neurologist and epileptologist Juhn Atsushi Wada, also known as the "intracarotid sodium amobarbital procedure" , is used to establish cerebral language and memory representation of each hemisphere.-Method:...

), functional MRI or Magnetoencephalography
Magnetoencephalography
Magnetoencephalography is a technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using arrays of SQUIDs...

  (MEG) as supplementary tests.

Certain lesions require Long-term video-EEG monitoring
Long-term video-EEG monitoring
Long-term video-EEG monitoring, also known as video telemetry, is a diagnostic technique used in certain patients with epilepsy or seizures. It involves the inpatient hospitalization of the patient for a period of time, typically days to weeks, during which they are continuously monitored and...

 with the use of intracranial electrodes if noninvasive testing was inadequate to identify the epileptic focus or distinguish the surgical target from normal brain tissue and function. Brain mapping
Brain mapping
Brain mapping is a set of neuroscience techniques predicated on the mapping of quantities or properties onto spatial representations of the brain resulting in maps.- Overview :...

 by the technique of cortical electrical stimulation or Electrocorticography
Electrocorticography
Electrocorticography is the practice of using electrodes placed directly on the exposed surface of the brain to record electrical activity from the cerebral cortex. ECoG may be performed either in the operating room during surgery or outside of surgery...

 are other procedures used in the process of invasive testing in some patients.

The most common surgeries are the resection of lesions like tumors or arteriovenous malformations, which, in the process of treating the underlying lesion, often result in control of epileptic seizures caused by these lesions.

Other lesions are more subtle and feature epilepsy as the main or sole symptom. The most common form of intractable epilepsy in these disorders in adults is temporal lobe epilepsy
Temporal lobe epilepsy
Temporal lobe epilepsy a.k.a. Psychomotor epilepsy, is a form of focal epilepsy, a chronic neurological condition characterized by recurrent seizures. Over 40 types of epilepsies are known. They fall into two main categories: partial-onset epilepsies and generalized-onset epilepsies...

 with hippocampal sclerosis
Hippocampal sclerosis
Ammon's horn sclerosis is the most common type of neuropathological damage seen in individuals with temporal lobe epilepsy . This type of neuron cell loss, primarily in the hippocampus, can be observed in approximately 65% of people suffering from this form of epilepsy.Histopathological hallmarks...

, and the most common type of epilepsy surgery is the anterior temporal lobectomy
Anterior temporal lobectomy
Anterior temporal lobectomy is the complete removal of the anterior portion of the temporal lobe of the brain. It is a treatment option in temporal lobe epilepsy for those in whom anticonvulsant medications do not control epileptic seizures....

, or the removal of the front portion of the temporal lobe including the amygdala
Amygdala
The ' are almond-shaped groups of nuclei located deep within the medial temporal lobes of the brain in complex vertebrates, including humans. Shown in research to perform a primary role in the processing and memory of emotional reactions, the amygdalae are considered part of the limbic system.-...

 and hippocampus
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...

. Some neurosurgeons recommend selective amygdalahippocampectomy because of possible benefits in postoperative memory or language function. Surgery for temporal lobe epilepsy is effective, durable, and results in decreased health care costs. Despite the efficacy of epilepsy surgery, some patients decide not to undergo surgery owing to fear or the uncertainty of having a brain operation.

Palliative surgery for epilepsy is intended to reduce the frequency or severity of seizures. Examples are callosotomy or commissurotomy
Commissurotomy
A commissurotomy is a surgical incision of a commissure in the body, as one made in the heart at the edges of the commissure formed by cardiac valves, or one made in the brain to treat certain psychiatric disorders....

 to prevent seizures from generalizing (spreading to involve the entire brain), which results in a loss of consciousness. This procedure can therefore prevent injury due to the person falling to the ground after losing consciousness. It is performed only when the seizures cannot be controlled by other means. Multiple subpial transection
Multiple subpial transection
In the treatment of epilepsy, if partial seizures originate in areas of the brain that cannot be removed safely, multiple subpial transections are an alternative. The surgeon makes a series of shallow cuts into the brain's cerebral cortex...

 can also be used to decrease the spread of seizures across the cortex especially when the epileptic focus is located near important functional areas of the cortex. Resective surgery can be considered palliative if it is undertaken with the expectation that it will reduce but not eliminate seizures.

Hemispherectomy
Hemispherectomy
Hemispherectomy is a very rare surgical procedure where one cerebral hemisphere is removed or disabled. This procedure is used to treat a variety of seizure disorders where the source of the epilepsy is localized to a broad area of a single hemisphere of the brain...

 involves removal or a functional disconnection
Functional disconnection
Functional Disconnection in contradistinction to physical disconnection of the cerebral hemispheres by surgical resection, trauma or lesion, is a concept first described by Leisman. and Sroka, Solsi, and Bornstein , to describe disintegrated function in the brain in the absence of anatomical damage...

 of most or all of one half of the cerebrum. It is reserved for people suffering from the most catastrophic epilepsies, such as those due to Rasmussen syndrome. If the surgery is performed on very young patients (2–5 years old), the remaining hemisphere may acquire some rudimentary motor control of the ipsilateral body; in older patients, paralysis results on the side of the body opposite to the part of the brain that was removed. Because of these and other side-effects, it is usually reserved for patients having exhausted other treatment options.

Other


A ketogenic diet
Ketogenic diet
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control epilepsy in children. The diet mimics aspects of starvation by forcing the body to burn fats rather than carbohydrates...

(high-fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...

, low-carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...

) was first tested in the 1920s, but became less used with the advent of effective anticonvulsants. In the 1990s specialized diets again gained traction within the medical community. The mechanism of action is unknown. It is used mainly in the treatment of children with severe, medically intractable epilepsies, and the New York Times reported that use is supported by peer-reviewed research that found that the diet reduced seizures among drug-resistant epileptics by >50% in 38% of patients and by >90% in 7% of patients.

While far from a cure, operant-based biofeedback based on conditioning of EEG waves has some experimental support (see Professional practice of behavior analysis
Professional practice of behavior analysis
The professional practice of behavior analysis is one domain of behavior analysis: others being behaviorism, experimental analysis of behavior and applied behavior analysis...

). Overall, the support is based on a handful of studies reviewed by Barry Sterman. These studies report a 30% reduction in weekly seizures.

Electrical stimulation methods of anticonvulsant treatment are both currently approved for treatment and investigational uses. A currently approved device is vagus nerve stimulation (VNS). Investigational devices include the responsive neurostimulation system (RNS) and deep brain stimulation (DBS).
  • Vagus nerve stimulation
    Vagus nerve stimulation
    Vagus nerve stimulation is an adjunctive treatment for certain types of intractable epilepsy and treatment-resistant depression.- Mechanism of action :...

    (US manufacturer Cyberonics) consists of a computerized electrical device similar in size, shape and implant location to a heart pacemaker that connects to the vagus nerve
    Vagus nerve
    The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...

     in the neck
    Neck
    The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...

    . The device stimulates the vagus nerve at preset intervals and intensities of current. Efficacy has been tested in patients with localization-related epilepsies, demonstrating 50% of patients experience a 50% improvement in seizure rate. Case series have demonstrated similar efficacies in certain generalized epilepsies, such as Lennox-Gastaut syndrome. Although success rates are not usually equal to that of epilepsy surgery, it is a reasonable alternative when the patient is reluctant to proceed with any required invasive monitoring, when appropriate presurgical evaluation fails to uncover the location of epileptic foci, or when there are multiple epileptic foci.

  • Responsive neurostimulator system (US manufacturer Neuropace) consists of a computerized electrical device implanted in the skull, with electrodes implanted in presumed epileptic foci within the brain. The brain electrodes send EEG signals to the device, which contains seizure-detection software. When certain EEG seizure criteria are met, the device delivers a small electrical charge to other electrodes near the epileptic focus, which disrupt the seizure. The efficacy of the RNS is under current investigation with the goal of FDA approval.

  • Deep brain stimulation
    Deep brain stimulation
    Deep brain stimulation is a surgical treatment involving the implantation of a medical device called a brain pacemaker, which sends electrical impulses to specific parts of the brain...

    (US manufacturer Medtronic) consists of a computerized electrical device implanted in the chest in a manner similar to the VNS, but electrical stimulation is delivered to deep brain structures through depth electrodes implanted through the skull. In epilepsy, the electrode target is the anterior nucleus of the thalamus. The efficacy of the DBS in localization-related epilepsies is currently under investigation.


Noninvasive surgery using the gamma knife or other devices used in radiosurgery is currently being investigated as an alternative to traditional open surgery in patients who would otherwise qualify for anterior temporal lobectomy
Anterior temporal lobectomy
Anterior temporal lobectomy is the complete removal of the anterior portion of the temporal lobe of the brain. It is a treatment option in temporal lobe epilepsy for those in whom anticonvulsant medications do not control epileptic seizures....

.

Avoidance therapy consists of minimizing or eliminating triggers in patients whose seizures are particularly susceptible to seizure precipitants (see above). For example, sunglasses that counter exposure to particular light wavelengths can improve seizure control in certain photosensitive epilepsies.

Canine warning system is where a seizure response dog
Seizure response dog
Seizure response dogs are a special type of service dog, specifically trained to help someone who has epilepsy or a seizure disorder.Due to the differing needs between each case, every potential seizure dog receives specialized training...

, a form of service dog
Service dog
A service dog is a type of assistance dog specifically trained to help people who have disabilities including visual or hearing impairment, and also to help people with mental disabilities including Post Traumatic Stress Disorder and severe depression...

, is trained to summon help or ensure personal safety when a seizure occurs. These are not suitable for everybody, and not all dogs can be so trained. Rarely, a dog may develop the ability to sense a seizure before it occurs. Development of electronic forms of seizure detection systems are currently under investigation.

Seizure prediction
Seizure prediction
Seizure prediction refers to the forecasting of epileptic seizures based on physiological parameters, particularly of the electroencephalogram of epilepsy patients.-Background:...

-based devices
using long-term EEG recordings is presently being evaluated as a new way to stop epileptic seizures before they appear clinically.

Alternative or complementary medicine, including acupuncture
Acupuncture
Acupuncture is a type of alternative medicine that treats patients by insertion and manipulation of solid, generally thin needles in the body....

, psychological interventions, vitamins and yoga
Yoga
Yoga is a physical, mental, and spiritual discipline, originating in ancient India. The goal of yoga, or of the person practicing yoga, is the attainment of a state of perfect spiritual insight and tranquility while meditating on Supersoul...

, was evaluated in a number of systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...

s by the Cochrane Collaboration
Cochrane Collaboration
The Cochrane Collaboration is a group of over 28,000 volunteers in more than 100 countries who review the effects of health care interventions tested in biomedical randomized controlled trials. A few more recent reviews have also studied the results of non-randomized, observational studies...

 into treatments for epilepsy, and found there is no reliable evidence
Evidence-based medicine
Evidence-based medicine or evidence-based practice aims to apply the best available evidence gained from the scientific method to clinical decision making. It seeks to assess the strength of evidence of the risks and benefits of treatments and diagnostic tests...

 to support the use of these as treatments for epilepsy. Exercise or other physical activity
have also been proposed as efficacious strategies for preventing or treating epilepsy.

Epidemiology



Epilepsy is one of the most common of the serious neurological disorders. About 3% of people will be diagnosed with epilepsy at some time in their lives. Genetic
Genetic disorder
A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....

, congenital, and developmental
Developmental disorder
Developmental disorders occur at some stage in a child's development, often retarding the development. These may include,psychological or physical disorders. The disorder is an impairment in the normal development of motor or cognitive skills that are developed before age 18 in which they are...

 conditions are mostly associated with it among younger patients; tumor
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

s are more likely over age 40; head trauma and central nervous system infection
Central nervous system infection
There are four main causes of infections of the central nervous system : bacterial, viral, fungal and protozoal.-Fungal infections:*Cryptococcal meningitis*Brain abscess*Spinal epidural infection-Bacterial infections:*tuberculosis*leprosy...

s may occur at any age. The prevalence
Prevalence
In epidemiology, the prevalence of a health-related state in a statistical population is defined as the total number of cases of the risk factor in the population at a given time, or the total number of cases in the population, divided by the number of individuals in the population...

 of active epilepsy is roughly in the range 5–10 per 1000 people. Up to 5% of people experience non febrile seizure
Febrile seizure
A febrile seizure, also known as a fever fit or febrile convulsion, is a convulsion associated with a significant rise in body temperature...

s at some point in life; epilepsy's lifetime prevalence is relatively high because most patients either stop having seizures or (less commonly) die of it. Epilepsy's approximate annual incidence rate is 40–70 per 100,000 in industrialized countries and 100–190 per 100,000 in resource-poor countries; socioeconomically deprived people are at higher risk. In industrialized countries the incidence rate decreased in children but increased among the elderly during the three decades prior to 2003, for reasons not fully understood.

Sudden unexpected death in epilepsy


Beyond symptoms of the underlying diseases that can be a part of certain epilepsies, people with epilepsy are at risk for death from four main problems: status epilepticus
Status epilepticus
Status epilepticus is a life-threatening condition in which the brain is in a state of persistent seizure. Definitions vary, but traditionally it is defined as one continuous unremitting seizure lasting longer than 5 minutes, or recurrent seizures without regaining consciousness between seizures...

 (most often associated with anticonvulsant
Anticonvulsant
The anticonvulsants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder, since many seem to act as mood stabilizers, and in the treatment of neuropathic pain. The goal of an...

 noncompliance), suicide
Suicide
Suicide is the act of intentionally causing one's own death. Suicide is often committed out of despair or attributed to some underlying mental disorder, such as depression, bipolar disorder, schizophrenia, alcoholism, or drug abuse...

 associated with depression, trauma from seizures, and sudden unexpected death in epilepsy (SUDEP) Those at highest risk for epilepsy-related deaths usually have underlying neurological impairment or poorly controlled seizures; those with more benign epilepsy syndromes have little risk for epilepsy-related death.

The NICE
NICE
NICE may refer to:* National Independent Cadres and Elites in Iraq* National Institute for Coordinated Experiments, a fictional organisation in C.S...

 National Sentinel Audit of Epilepsy-Related Deaths, led by "Epilepsy Bereaved" drew attention to this important problem. The Audit revealed; "1,000 deaths occur every year in the UK as a result of epilepsy" and most of them are associated with seizures and 42% of deaths were potentially avoidable".

Certain diseases also seem to occur in higher than expected rates in people with epilepsy, and the risk of these "comorbidities" often varies with the epilepsy syndrome. These diseases include depression and anxiety disorders, migraine
Migraine
Migraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea...

 and other headaches, infertility
Infertility
Infertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...

 and low sexual libido. Attention-deficit/hyperactivity disorder (ADHD) affects three to five times more children with epilepsy than children in the general population.
ADHD and epilepsy have significant consequences on a child's behavioral, learning,
and social development. Epilepsy is prevalent in autism
Autism
Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...

.

History


The word epilepsy is derived from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

 ἐπιληψία epilēpsía, which was from ἐπιλαμβάνειν ēpilambánein "to take hold of, to seize", which in turn was combined from ἐπί ēpí "upon" and λαμβάνειν lambánein "to take".

In the past, epilepsy was associated with religious
Religion
Religion is a collection of cultural systems, belief systems, and worldviews that establishes symbols that relate humanity to spirituality and, sometimes, to moral values. Many religions have narratives, symbols, traditions and sacred histories that are intended to give meaning to life or to...

 experiences and even demon
Demon
call - 1347 531 7769 for more infoIn Ancient Near Eastern religions as well as in the Abrahamic traditions, including ancient and medieval Christian demonology, a demon is considered an "unclean spirit" which may cause demonic possession, to be addressed with an act of exorcism...

ic possession
Spiritual possession
Spirit possession is a paranormal or supernatural event in which it is said that spirits, gods, demons, animas, extraterrestrials, or other disincarnate or extraterrestrial entities take control of a human body, resulting in noticeable changes in health and behaviour...

. In ancient times, epilepsy was known as the "Sacred Disease" (as described in a 5th century BC treatise by Hippocrates
) because people thought that epileptic seizures were a form of attack by demon
Demon
call - 1347 531 7769 for more infoIn Ancient Near Eastern religions as well as in the Abrahamic traditions, including ancient and medieval Christian demonology, a demon is considered an "unclean spirit" which may cause demonic possession, to be addressed with an act of exorcism...

s, or that the visions
Vision (religion)
In spirituality, a vision is something seen in a dream, trance, or ecstasy, especially a supernatural appearance that conveys a revelation.Visions generally have more clarity than dreams, but traditionally fewer psychological connotations...

 experienced by persons with epilepsy were sent by the gods
Deity
A deity is a recognized preternatural or supernatural immortal being, who may be thought of as holy, divine, or sacred, held in high regard, and respected by believers....

. Among animist Hmong
Hmong people
The Hmong , are an Asian ethnic group from the mountainous regions of China, Vietnam, Laos, and Thailand. Hmong are also one of the sub-groups of the Miao ethnicity in southern China...

 families, for example, epilepsy was understood as an attack by an evil spirit, but the affected person could become revered as a shaman through these otherworldly experiences.

A chapter from a Babylonian textbook of medicine, dating from about 2000BC and consisting of 40 tablets, records many of the different seizure types we recognize today, and it emphasizes the supernatural nature of epilepsy, while the Ayurvedic text of Charaka Samhita (about 400BC), describes epilepsy as "apasmara", i.e., "loss of consciousness".

In most cultures, persons with epilepsy have been stigmatized, shunned, or even imprisoned; in the Salpêtrière, the birthplace of modern neurology, Jean-Martin Charcot
Jean-Martin Charcot
Jean-Martin Charcot was a French neurologist and professor of anatomical pathology. He is known as "the founder of modern neurology" and is "associated with at least 15 medical eponyms", including Charcot-Marie-Tooth disease and amyotrophic lateral sclerosis...

 found people with epilepsy side-by-side with the mentally retarded, those with chronic syphilis
Syphilis
Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...

, and the criminally insane. In Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...

 to this day, as with other parts of Africa, epilepsy is associated with possession by evil spirits, witchcraft, or poisoning and is believed by many to be contagious. In ancient Rome, epilepsy was known as the Morbus Comitialis ('disease of the assembly hall') and was seen as a curse from the gods.

Stigma continues to this day, in both the public and private spheres, but polls suggest it is generally decreasing with time, at least in the developed world; Hippocrates
Hippocrates
Hippocrates of Cos or Hippokrates of Kos was an ancient Greek physician of the Age of Pericles , and is considered one of the most outstanding figures in the history of medicine...

 remarked that epilepsy would cease to be considered divine the day it was understood.

Legal implications


Many jurisdictions forbid certain activities to persons suffering from epilepsy. The most commonly prohibited activities involve operation of vehicles or machinery, or other activities in which continuous vigilance is required. However, there are usually exceptions for those who can prove that they have stabilized their condition. Those few whose seizures do not cause impairment of consciousness, have a lengthy aura preceding impairment of consciousness, or whose seizures only arise from sleep, may be exempt from such restrictions, depending on local laws. There is an ongoing debate in bioethics
Bioethics
Bioethics is the study of controversial ethics brought about by advances in biology and medicine. Bioethicists are concerned with the ethical questions that arise in the relationships among life sciences, biotechnology, medicine, politics, law, and philosophy....

 over who should bear the burden of ensuring that an epilepsy patient does not drive a car or fly an airplane.

Automobiles



In the U.S., people with epilepsy can drive if their seizures are controlled with treatment and they meet the licensing requirements in their state. The amount of time someone needs to be free of seizures varies in different states, but is most likely to be between three months and a year. The majority of the 50 states place the burden on patients to report their condition to appropriate licensing authorities so that their privileges can be revoked where appropriate. A minority of states place the burden of reporting on the patient's physician. After reporting is carried out, it is usually the driver's licensing agency that decides to revoke or restrict a driver's license.

In the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, it is the responsibility of the patients to inform the Driver and Vehicle Licensing Agency
Driver and Vehicle Licensing Agency
The Driver and Vehicle Licensing Agency is the organisation of the UK Government responsible for maintaining a database of drivers and a database of vehicles in Great Britain; its counterpart in Northern Ireland is the Driver & Vehicle Agency...

 (DVLA) if they have epilepsy. The DVLA rules are quite complex, but in summary, those who continue to have seizures or who are within 6 months of medication change may have their licence revoked. A person must be seizure free of an 'awake' seizure for 12 months (or had only 'sleep' seizures for 3 years or more) before they can apply for a license. A doctor who becomes aware that a patient with uncontrolled epilepsy is continuing to drive has, after reminding the patient of their responsibility, a duty to break confidentiality
Confidentiality
Confidentiality is an ethical principle associated with several professions . In ethics, and in law and alternative forms of legal resolution such as mediation, some types of communication between a person and one of these professionals are "privileged" and may not be discussed or divulged to...

 and inform the DVLA. The doctor should advise the patient of the disclosure and the reasons why their failure to notify the agency obliged the doctor to act.

Aircraft


In many countries, persons with any history of epilepsy are generally disqualified for the medical certifications required for all classes of pilot licenses. In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, FAA
Federal Aviation Administration
The Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...

 regulations disqualify applicants for medical certification with a history of epilepsy, although the final decision is made by FAA headquarters, and rare exceptions are sometimes made for persons who have had only an isolated seizure or two in childhood and have remained free of seizures in adulthood without medication.

In the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, a sub-class of pilots license called the National Private Pilot's License has the same medical requirement standards as the DVLA motoring requirements, hence epilepsy sufferers with one year absence free can, with certain exceptions, fly over UK airspace in certain types of aircraft.

Notable cases



Many notable people, past and present, have carried the diagnosis of epilepsy. In many cases, their epilepsy is a footnote to their accomplishments; for some, it played an integral role in their fame. Historical diagnoses of epilepsy are not always certain; there is controversy about what is considered an acceptable amount of evidence in support of such a diagnosis.

In other animals



Epilepsy occurs in a number of other animals including dogs and cats. It is the most common brain disorder in dogs.

See also



Further reading


  • Morrow, Jim. 2011. Epilepsy a patient's handbook. National Services for Health Improvement. ISBN 978-0-9560921-7-5.
  • Walker, M. & Shorvon, S. Understanding Epilepsy second edition 2000. Family Doctor Pulications. ISBN 1 898205 20 5.