Fasciculation
Encyclopedia
A fasciculation fəˌsɪkjʉˈleɪʃən, or "muscle twitch", is a small, local, involuntary muscle contraction
and relaxation visible under the skin arising from the spontaneous discharge of a bundle of skeletal muscle
fibers (muscle fascicle
). Fasciculations have a variety of causes, the majority of which are benign
, but can also be due to disease of the motor neurons.
The most effective way to detect fasciculations may be surface electromyography (EMG). Surface EMG is more sensitive than needle electromyography and clinical observation in the detection of fasciculation in people with ALS.
drugs over long periods, in particular ethanolamine
s such as Benadryl
, used as an antihistamine and sleep aid, and Dramamine
for nausea and motion sickness. Persons with benign fasciculation syndrome
(BFS) may experience paraesthesia shortly after taking such medication; fasciculation episodes begin as the medication wears off.
Stimulant
s can cause fasciculations directly. These include caffeine
, pseudoephedrine
(Sudafed), amphetamines, and the asthma
bronchodilator
s salbutamol
(e.g. Proventil, Combivent, Ventolin). Medications used to treat attention deficit disorder often contain stimulants as well, and are common causes of benign fasciculations.
The depolarizing neuromuscular blocker, succinylcholine, causes fasciculations. It is a normal side effect of the drug's administration, and can be prevented with a small dose of a nondepolarizing neuromuscular blocker prior to the administration of succinylcholine, often 10% of a nondepolarizing NMB's induction dose.
Fasciculations can happen in any muscle in the body.
intake can cause fasciculations, especially after a magnesium loss due to severe diarrhea
. Over-exertion is another risk factor for magnesium loss. As 70-80% of the adult population does not consume the recommended daily amount of magnesium, inadequate intake may also be a common cause. Treatment consists of increased intake of magnesium, such as nuts (especially almonds) and bananas. Magnesium supplements may also be taken, however too much magnesium may cause diarrhea, causing dehydration and nutrient loss (including magnesium).
Fasciculation also often occurs during a rest period after sustained stress, such as that brought on by unconsciously tense muscles. Reducing stress and anxiety is therefore another useful treatment. Relieving bodily stress through sexual intercourse has proven to be an effective form of treatment.
There is no proven treatment for fasciculations in people with ALS. Among patients with ALS, fasciculation frequency is not associated with the duration of ALS and is independent of the degree of limb weakness and limb atrophy. No prediction of ALS disease duration can be made based on fasciculation frequency alone.
Muscle contraction
Muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten, or remain the same...
and relaxation visible under the skin arising from the spontaneous discharge of a bundle of skeletal muscle
Skeletal muscle
Skeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth muscle...
fibers (muscle fascicle
Muscle fascicle
In anatomy, a fascicle is a bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue.Specialized muscle fibers in the heart that transmit electrical impulses from the Atrioventricular Node to the Purkinje Fibers are fascicles, also referred to as bundle branches...
). Fasciculations have a variety of causes, the majority of which are benign
Benign
A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
, but can also be due to disease of the motor neurons.
Conditions
- The origin of most cases is at present unknown and usually inconclusive, has therefore been given the title benign fasciculation syndromeBenign fasciculation syndromeBenign fasciculation syndrome is a neurological disorder characterized by fasciculation of various voluntary muscles in the body. The twitching can occur in any voluntary muscle group but is most common in the eyelids, arms, legs, and feet. Even the tongue may be affected. The twitching may be...
. - NeuromyotoniaNeuromyotoniaNeuromyotonia , also known as Isaacs' syndrome, is a form of peripheral nerve hyperexcitability that causes spontaneous muscular activity resulting from repetitive motor unit action potentials of peripheral origin.-Causes:...
, also known as Isaacs' syndrome - Lower motor neuron lesion
- Werdnig-Hoffman disease
- Amyotrophic lateral sclerosisAmyotrophic lateral sclerosisAmyotrophic lateral sclerosis , also referred to as Lou Gehrig's disease, is a form of motor neuron disease caused by the degeneration of upper and lower neurons, located in the ventral horn of the spinal cord and the cortical neurons that provide their efferent input...
- Kennedy diseaseKennedy diseaseKennedy's disease or X-linked Spinal and Bulbar Muscular Atrophy or Spinobulbar Muscular Atrophy or X-Linked Bulbo-Spinal Atrophy is an X-linked recessive, slow progressing, neurodegenerative disease associated with mutation of the androgen receptor...
- Organophosphate poisoningOrganophosphate poisoningOrganophosphate poisoning results from exposure to organophosphates , which cause the inhibition of acetylcholinesterase leading to the accumulation of acetylcholine in the body. Organophosphate poisoning most commonly results from exposure to insecticides or nerve agents...
- Benzodiazepine withdrawal
- Magnesium deficiencyMagnesium deficiency (medicine)Magnesium deficiency refers to an intake of dietary magnesium below minimal levels, which can result in numerous symptoms and diseases. These can generally be remedied by an increase of magnesium in diet or oral supplements...
- Myalgic Encephalomyelitis
- DehydrationDehydrationIn physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
- Fatigue
- Lyme DiseaseLyme diseaseLyme disease, or Lyme borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi sensu stricto is the main cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii cause most...
- Myasthenia GravisMyasthenia gravisMyasthenia gravis is an autoimmune neuromuscular disease leading to fluctuating muscle weakness and fatiguability...
- RabiesRabiesRabies is a viral disease that causes acute encephalitis in warm-blooded animals. It is zoonotic , most commonly by a bite from an infected animal. For a human, rabies is almost invariably fatal if post-exposure prophylaxis is not administered prior to the onset of severe symptoms...
- FibromyalgiaFibromyalgiaFibromyalgia is a medical disorder characterized by chronic widespread pain and allodynia, a heightened and painful response to pressure. It is an example of a diagnosis of exclusion...
The most effective way to detect fasciculations may be surface electromyography (EMG). Surface EMG is more sensitive than needle electromyography and clinical observation in the detection of fasciculation in people with ALS.
Medications
Other risk factors may include the use of anticholinergicAnticholinergic
An anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. An example of an anticholinergic is dicycloverine, and the classic example is atropine....
drugs over long periods, in particular ethanolamine
Ethanolamine
Ethanolamine, also called 2-aminoethanol or monoethanolamine , is an organic chemical compound that is both a primary amine and a primary alcohol . Like other amines, monoethanolamine acts as a weak base...
s such as Benadryl
Diphenhydramine
Diphenhydramine hydrochloride is a first-generation antihistamine possessing anticholinergic, antitussive, antiemetic, and sedative properties which is mainly used to treat allergies. Like most other first-generation antihistamines, the drug also has a powerful hypnotic effect, and for this reason...
, used as an antihistamine and sleep aid, and Dramamine
Dimenhydrinate
Dimenhydrinate is an over-the-counter drug used to prevent nausea and motion sickness...
for nausea and motion sickness. Persons with benign fasciculation syndrome
Benign fasciculation syndrome
Benign fasciculation syndrome is a neurological disorder characterized by fasciculation of various voluntary muscles in the body. The twitching can occur in any voluntary muscle group but is most common in the eyelids, arms, legs, and feet. Even the tongue may be affected. The twitching may be...
(BFS) may experience paraesthesia shortly after taking such medication; fasciculation episodes begin as the medication wears off.
Stimulant
Stimulant
Stimulants are psychoactive drugs which induce temporary improvements in either mental or physical function or both. Examples of these kinds of effects may include enhanced alertness, wakefulness, and locomotion, among others...
s can cause fasciculations directly. These include caffeine
Caffeine
Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...
, pseudoephedrine
Pseudoephedrine
Pseudoephedrine is a sympathomimetic drug of the phenethylamine and amphetamine chemical classes. It is used as a nasal/sinus decongestant and stimulant, or as a wakefulness-promoting agent....
(Sudafed), amphetamines, and the asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
bronchodilator
Bronchodilator
A bronchodilator is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lungs. Bronchodilators may be endogenous , or they may be medications administered for the treatment of breathing difficulties...
s salbutamol
Salbutamol
Salbutamol or albuterol is a short-acting β2-adrenergic receptor agonist used for the relief of bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease. It is marketed as Ventolin among other brand names....
(e.g. Proventil, Combivent, Ventolin). Medications used to treat attention deficit disorder often contain stimulants as well, and are common causes of benign fasciculations.
The depolarizing neuromuscular blocker, succinylcholine, causes fasciculations. It is a normal side effect of the drug's administration, and can be prevented with a small dose of a nondepolarizing neuromuscular blocker prior to the administration of succinylcholine, often 10% of a nondepolarizing NMB's induction dose.
Fasciculations can happen in any muscle in the body.
Treatment
Inadequate magnesiumMagnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
intake can cause fasciculations, especially after a magnesium loss due to severe diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
. Over-exertion is another risk factor for magnesium loss. As 70-80% of the adult population does not consume the recommended daily amount of magnesium, inadequate intake may also be a common cause. Treatment consists of increased intake of magnesium, such as nuts (especially almonds) and bananas. Magnesium supplements may also be taken, however too much magnesium may cause diarrhea, causing dehydration and nutrient loss (including magnesium).
Fasciculation also often occurs during a rest period after sustained stress, such as that brought on by unconsciously tense muscles. Reducing stress and anxiety is therefore another useful treatment. Relieving bodily stress through sexual intercourse has proven to be an effective form of treatment.
There is no proven treatment for fasciculations in people with ALS. Among patients with ALS, fasciculation frequency is not associated with the duration of ALS and is independent of the degree of limb weakness and limb atrophy. No prediction of ALS disease duration can be made based on fasciculation frequency alone.