Acute facial nerve paralysis
Encyclopedia
Facial nerve paralysis is a common problem that involves the paralysis
of any structures innervated by the facial nerve
. The pathway of the facial nerve is long and relatively convoluted, and so there are a number of causes that may result in facial nerve paralysis. The most common is Bell's palsy
, an idiopathic
disease that may only be diagnosed by exclusion.
A thorough medical history
and physical examination
are the first steps in making a diagnosis.
During the physical examination, a distinction must first be made between paralysis and paresis
(incomplete paralysis). Not surprisingly, paralysis is far more serious and requires immediate treatment.It must also be determined whether the forehead
is involved in the motor defect or not. This is usually accomplished by assessing how well a patient can raise his or her eyebrow
s. The question is an important one because it helps determine if the lesion is in the upper motor neuron
component of the facial nerve, or in its lower motor neuron
component. If the mimetic muscles do not contract anymore, facial nerve surgery is indicated, for example smile surgery
.
Laboratory investigations include an audiogram
, nerve conduction studies
(ENoG
), computed tomography
(CT) or magnetic resonance imaging (MRI).
can be caused by a lacunar infarct affecting fibers in the internal capsule
going to the nucleus.
The facial nucleus itself can be affected by infarcts of the pontine arteries
.
is the most common cause of acute facial nerve paralysis (>80%). Previously considered idiopathic
, it has been recently linked to herpes simplex infection. Another more severe form of facial palsy, called Ramsay-Hunt syndrome, is linked to herpes zoster
infection of the facial nerve. Other, less common, etiologies are Lyme disease
polio, TB.
Bell's palsy is an exclusion diagnosis. Some factors that tend to rule out Bell's palsy include:
Bell's palsy is believed in the most recent studies to be due to herpes virus. Other proposed etiologies include vascular problems in the inner ear. Treatment includes steroids and antivirals.
, especially fracture
s of the temporal bone
, may also cause acute facial nerve paralysis. Understandably, the likelihood of facial paralysis after trauma depends on the location of the trauma. Most commonly, facial paralysis follows temporal bone fractures, though the likelihood depends on the type of fracture.
Transverse fractures in the horizontal plane present the highest likelihood of facial paralysis (40-50%). Patients may also present with hemotympanum
(blood behind the tympanic membrane), sensory deafness, and vertigo
– the latter two symptoms due to damage to vestibulocochlear nerve
(cranial nerve VIII) and the inner ear. Longitudinal fracture in the vertical plane present a lower likelihood of paralysis (20%). Patients may present with hematorrhea (blood
coming out of the external auditory meatus), tympanic membrane tear, fracture of external auditory canal, and conductive hearing loss
.
Traumatic injuries can be assessed by computed tomography
(CT) and nerve conduction studies (ENoG). In patients with mild injury, management is the same as with Bell's palsy – protect the eye
s and wait. In patients with severe injury, progress is followed with nerve conduction studies. If nerve conduction studies show a large (>90%) change in nerve conduction, the nerve should be decompressed. The facial paralysis can follow immediately the trauma due to direct damage to the facial nerve, in such cases a surgical treatment may be attempted. In other cases the facial paralysis can occur a long time after the trauma due to oedema and inflammation. In those cases steroids can be a good help.
infection
that affects cranial nerves VII (facial nerve
) and VIII (vestibulocochlear nerve
).
Patients present with facial paralysis, ear pain, vesicle
s, sensorineural hearing loss
, and vertigo
.
Management includes Antiviral drug
s and oral steroid
s.
is an infection in the middle ear, which can spread to the facial nerve and inflame it, causing compression of the nerve in its canal.
Antibiotic
s are used to control the otitis media, and other options include a wide myringotomy
(an incision in the tympanic membrane) or decompression if the patient does not improve.
Chronic otitis media usually presents in an ear with chronic discharge (otorrhea), or hearing loss, with or without ear pain (otalgia
). Once suspected, there should be immediate surgical exploration to determine if a cholesteatoma
has formed as this must be removed if present. Inflammation from the middle ear can spread to the canalis facialis of the temporal bone - through this canal travels the facial nerve together with the steatoacoustisus nerve. In the case of inflammation the nerve is exposed to edema and subsequent high pressure, resulting in a periferic type palsy.
(sarcoidosis
of the nervous system), itself a rare condition.
compressing the facial nerve anywhere along its complex pathway can result in facial paralysis. Common culprits are facial neuromas, congenital cholesteatoma
s, hemangioma
s, acoustic neuroma
s, parotid gland
neoplasms, or metastases of other tumours.
Patients with facial nerve paralysis resulting from tumours usually present with a progressive, twitching paralysis, other neurological signs, or a recurrent Bell's palsy-type presentation.
The latter should always be suspicious, as Bell's palsy should not recur. A chronically discharging ear must be treated as a cholesteatoma until proven otherwise; hence, there must be immediate surgical
exploration.
Computed tomography (CT) or magnetic resonance (MR) imaging should be used to identify the location of the tumour, and it should be managed accordingly.
Often, since facial neoplasms have such an intimate relationship with the facial nerve, removing tumors in the this region becomes perplexing as the physician is unsure how to manage the tumor without causing even more palsy. Typically, benign tumors should be removed in a fashion that preserves the facial nerve, while malignant tumors should always be resected along with large areas of tissue around them, including the facial nerve. While this will inevitably lead to heightened paralysis, safe removal of a malignant neoplasm is worth the often treatable palsy that follows. In the best case scenario, paralysis can be corrected with techniques including hypoglossal-facial nerve anastomosis, end-to-end nerve repair, cross facial nerve grafting, or muscle transfer/transposition techniques, such as the gracilis free muscle transfer.
Paralysis
Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...
of any structures innervated by the facial nerve
Facial nerve
The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...
. The pathway of the facial nerve is long and relatively convoluted, and so there are a number of causes that may result in facial nerve paralysis. The most common is Bell's palsy
Bell's palsy
Bell's palsy is a form of facial paralysis resulting from a dysfunction of the cranial nerve VII that results in the inability to control facial muscles on the affected side. Several conditions can cause facial paralysis, e.g., brain tumor, stroke, and Lyme disease. However, if no specific cause...
, an idiopathic
Idiopathic
Idiopathic is an adjective used primarily in medicine meaning arising spontaneously or from an obscure or unknown cause. From Greek ἴδιος, idios + πάθος, pathos , it means approximately "a disease of its own kind". It is technically a term from nosology, the classification of disease...
disease that may only be diagnosed by exclusion.
A thorough medical history
Medical history
The medical history or anamnesis of a patient is information gained by a physician by asking specific questions, either of the patient or of other people who know the person and can give suitable information , with the aim of obtaining information useful in formulating a diagnosis and providing...
and physical examination
Physical examination
Physical examination or clinical examination is the process by which a doctor investigates the body of a patient for signs of disease. It generally follows the taking of the medical history — an account of the symptoms as experienced by the patient...
are the first steps in making a diagnosis.
During the physical examination, a distinction must first be made between paralysis and paresis
Paresis
Paresis is a condition typified by partial loss of voluntary movement or by impaired movement. When used without qualifiers, it usually refers to the limbs, but it also can be used to describe the muscles of the eyes , the stomach , and also the vocal cords...
(incomplete paralysis). Not surprisingly, paralysis is far more serious and requires immediate treatment.It must also be determined whether the forehead
Forehead
For the Arsenal striker see GervinhoIn human anatomy, the forehead is the fore part of the head. It is, formally, an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp...
is involved in the motor defect or not. This is usually accomplished by assessing how well a patient can raise his or her eyebrow
Eyebrow
The eyebrow is an area of thick, delicate hairs above the eye that follows the shape of the lower margin of the brow ridges of some mammals. Their main function is to prevent sweat, water, and other debris from falling down into the eye socket, but they are also important to human communication and...
s. The question is an important one because it helps determine if the lesion is in the upper motor neuron
Upper motor neuron
Upper motor neurons are motor neurons that originate in the motor region of the cerebral cortex or the brain stem and carry motor information down to the final common pathway, that is, any motor neurons that are not directly responsible for stimulating the target muscle...
component of the facial nerve, or in its lower motor neuron
Lower motor neuron
Lower motor neurons are the motor neurons connecting the brainstem and spinal cord to muscle fibers, bringing the nerve impulses from the upper motor neurons out to the muscles...
component. If the mimetic muscles do not contract anymore, facial nerve surgery is indicated, for example smile surgery
Smile surgery
Smile surgery or smile reconstruction is a surgical procedure that restores the smile for people with facial nerve paralysis. Facial nerve paralysis is a relatively common condition with a yearly incidence of 0.25% leading to function loss of the mimic muscles. The facial nerve gives off several...
.
Laboratory investigations include an audiogram
Audiogram
An audiogram is a standard way of representing a person's hearing loss . Most audiograms cover the limited range 100 Hz to 8000 Hz which is most important for clear understanding of speech, and they plot the threshold of hearing relative to a standardised curve that represents 'normal'...
, nerve conduction studies
Nerve conduction study
A nerve conduction study is a test commonly used to evaluate the function, especially the ability of electrical conduction, of the motor and sensory nerves of the human body.Nerve conduction velocity is a common measurement made during this test...
(ENoG
Electroneuronography
Electroneuronography is a neurological non-invasive test that was first described by Esslen and Fisch in 1979 and is used to examine the integrity and conductivity of a peripheral nerve...
), computed tomography
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
(CT) or magnetic resonance imaging (MRI).
Supranuclear and nuclear lesions
Central facial palsyCentral facial palsy
Central facial palsy, is a symptom or finding characterized by paralysis or paresis of the lower half of one side of the face...
can be caused by a lacunar infarct affecting fibers in the internal capsule
Internal capsule
The internal capsule is an area of white matter in the brain that separates the caudate nucleus and the thalamus from the lenticular nucleus. The internal capsule contains both ascending and descending axons....
going to the nucleus.
The facial nucleus itself can be affected by infarcts of the pontine arteries
Pontine arteries
The pontine arteries are a number of small vessels which come off at right angles from either side of the basilar artery and supply the pons and adjacent parts of the brain....
.
Bell's palsy
Bell's palsyBell's palsy
Bell's palsy is a form of facial paralysis resulting from a dysfunction of the cranial nerve VII that results in the inability to control facial muscles on the affected side. Several conditions can cause facial paralysis, e.g., brain tumor, stroke, and Lyme disease. However, if no specific cause...
is the most common cause of acute facial nerve paralysis (>80%). Previously considered idiopathic
Idiopathic
Idiopathic is an adjective used primarily in medicine meaning arising spontaneously or from an obscure or unknown cause. From Greek ἴδιος, idios + πάθος, pathos , it means approximately "a disease of its own kind". It is technically a term from nosology, the classification of disease...
, it has been recently linked to herpes simplex infection. Another more severe form of facial palsy, called Ramsay-Hunt syndrome, is linked to herpes zoster
Herpes zoster
Herpes zoster , commonly known as shingles and also known as zona, is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body, often in a stripe...
infection of the facial nerve. Other, less common, etiologies are Lyme disease
Lyme disease
Lyme 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...
polio, TB.
Bell's palsy is an exclusion diagnosis. Some factors that tend to rule out Bell's palsy include:
- Recurrent paralysis
- Slowly progressive paralysis (The onset of Bell's palsy is very sudden, usually within 24 hours all the symptoms have been manifested)
- Twitching
- Associated symptoms (either cochleaCochleaThe cochlea is the auditory portion of the inner ear. It is a spiral-shaped cavity in the bony labyrinth, making 2.5 turns around its axis, the modiolus....
r or neurologic)
Bell's palsy is believed in the most recent studies to be due to herpes virus. Other proposed etiologies include vascular problems in the inner ear. Treatment includes steroids and antivirals.
Trauma
Physical traumaPhysical trauma
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
, especially fracture
Fracture
A fracture is the separation of an object or material into two, or more, pieces under the action of stress.The word fracture is often applied to bones of living creatures , or to crystals or crystalline materials, such as gemstones or metal...
s of the temporal bone
Temporal bone
The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebrum.The temporal bone supports that part of the face known as the temple.-Parts:The temporal bone consists of four parts:* Squama temporalis...
, may also cause acute facial nerve paralysis. Understandably, the likelihood of facial paralysis after trauma depends on the location of the trauma. Most commonly, facial paralysis follows temporal bone fractures, though the likelihood depends on the type of fracture.
Transverse fractures in the horizontal plane present the highest likelihood of facial paralysis (40-50%). Patients may also present with hemotympanum
Hemotympanum
Hemotympanum, or hematotympanum, refers to the presence of blood in the tympanic cavity of the middle ear. Hemotympanum is often the result of basilar skull fracture....
(blood behind the tympanic membrane), sensory deafness, and vertigo
Dizziness
Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
– the latter two symptoms due to damage to vestibulocochlear nerve
Vestibulocochlear nerve
The vestibulocochlear nerve is the eighth of twelve cranial nerves, and is responsible for transmitting sound and equilibrium information from the inner ear to the brain...
(cranial nerve VIII) and the inner ear. Longitudinal fracture in the vertical plane present a lower likelihood of paralysis (20%). Patients may present with hematorrhea (blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
coming out of the external auditory meatus), tympanic membrane tear, fracture of external auditory canal, and conductive hearing loss
Conductive hearing loss
Conductive hearing loss occurs when there is a problem conducting sound waves anywhere along the route through the outer ear, tympanic membrane , or middle ear ....
.
Traumatic injuries can be assessed by computed tomography
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
(CT) and nerve conduction studies (ENoG). In patients with mild injury, management is the same as with Bell's palsy – protect the eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
s and wait. In patients with severe injury, progress is followed with nerve conduction studies. If nerve conduction studies show a large (>90%) change in nerve conduction, the nerve should be decompressed. The facial paralysis can follow immediately the trauma due to direct damage to the facial nerve, in such cases a surgical treatment may be attempted. In other cases the facial paralysis can occur a long time after the trauma due to oedema and inflammation. In those cases steroids can be a good help.
Herpes zoster oticus
Herpes zoster oticus is essentially a herpes zosterHerpes zoster
Herpes zoster , commonly known as shingles and also known as zona, is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body, often in a stripe...
infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
that affects cranial nerves VII (facial nerve
Facial nerve
The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...
) and VIII (vestibulocochlear nerve
Vestibulocochlear nerve
The vestibulocochlear nerve is the eighth of twelve cranial nerves, and is responsible for transmitting sound and equilibrium information from the inner ear to the brain...
).
Patients present with facial paralysis, ear pain, vesicle
Vesicle (biology)
A vesicle is a bubble of liquid within another liquid, a supramolecular assembly made up of many different molecules. More technically, a vesicle is a small membrane-enclosed sack that can store or transport substances. Vesicles can form naturally because of the properties of lipid membranes , or...
s, sensorineural hearing loss
Sensorineural hearing loss
Sensorineural hearing loss is a type of hearing loss in which the root cause lies in the vestibulocochlear nerve , the inner ear, or central processing centers of the brain....
, and vertigo
Dizziness
Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
.
Management includes Antiviral drug
Antiviral drug
Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics for bacteria, specific antivirals are used for specific viruses...
s and oral steroid
Steroid
A steroid is a type of organic compound that contains a characteristic arrangement of four cycloalkane rings that are joined to each other. Examples of steroids include the dietary fat cholesterol, the sex hormones estradiol and testosterone, and the anti-inflammatory drug dexamethasone.The core...
s.
Acute and chronic otitis media
Otitis mediaOtitis media
Otitis media is inflammation of the middle ear, or a middle ear infection.It occurs in the area between the tympanic membrane and the inner ear, including a duct known as the eustachian tube. It is one of the two categories of ear inflammation that can underlie what is commonly called an earache,...
is an infection in the middle ear, which can spread to the facial nerve and inflame it, causing compression of the nerve in its canal.
Antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s are used to control the otitis media, and other options include a wide myringotomy
Myringotomy
Myringotomy is a surgical procedure in which a tiny incision is created in the eardrum, so as to relieve pressure caused by the excessive build-up of fluid, or to drain pus. Myringotomy is often performed as a treatment for acute suppurative otitis media...
(an incision in the tympanic membrane) or decompression if the patient does not improve.
Chronic otitis media usually presents in an ear with chronic discharge (otorrhea), or hearing loss, with or without ear pain (otalgia
Otalgia
Otalgia or an earache is ear pain. Primary otalgia is ear pain that originates inside the ear. Referred otalgia is ear pain that originates from outside the ear.Otalgia is not always associated with ear disease...
). Once suspected, there should be immediate surgical exploration to determine if a cholesteatoma
Cholesteatoma
Cholesteatoma is a destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and/or mastoid process.-Signs and symptoms:...
has formed as this must be removed if present. Inflammation from the middle ear can spread to the canalis facialis of the temporal bone - through this canal travels the facial nerve together with the steatoacoustisus nerve. In the case of inflammation the nerve is exposed to edema and subsequent high pressure, resulting in a periferic type palsy.
Neurosarcoidosis
Facial nerve paralysis, sometimes bilateral, is a common manifestation of neurosarcoidosisNeurosarcoidosis
Neurosarcoidosis refers to sarcoidosis, a condition of unknown cause featuring granulomas in various tissues, involving the central nervous system . It can have many manifestations, but abnormalities of the cranial nerves are the most common...
(sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
of the nervous system), itself a rare condition.
Moebius syndrome
Moebius syndrome is a bilateral facial paralysis resulting from the underdevelopment of the VII cranial nerve (facial nerve), which is present at birth. The VI cranial nerve, which controls lateral eye movement, is also affected, so people with Moebius syndrome cannot form facial expression or move their eyes from side to side. Moebius syndrome is extremely rare, and its cause or causes are not known.Tumors
A tumorTumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...
compressing the facial nerve anywhere along its complex pathway can result in facial paralysis. Common culprits are facial neuromas, congenital cholesteatoma
Cholesteatoma
Cholesteatoma is a destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and/or mastoid process.-Signs and symptoms:...
s, hemangioma
Hemangioma
A hemangioma of infancy is a benign self-involuting tumor of endothelial cells, the cells that line blood vessels. It usually appears during the first weeks of life and sometimes resolves by age 10. In more severe case hemangioma may have permanency, if not treated by a physician...
s, acoustic neuroma
Acoustic neuroma
A vestibular schwannoma, often called an acoustic neuroma, is a benign primary intracranial tumor of the myelin-forming cells of the vestibulocochlear nerve . The term "vestibular schwannoma" involves the vestibular portion of the 8th cranial nerve and arises from Schwann cells, which are...
s, parotid gland
Parotid gland
The paired parotid glands are the largest of the salivary glands. They are each found wrapped around the mandibular ramus, and secrete saliva through Stensen's ducts into the oral cavity, to facilitate mastication and swallowing and to begin the digestion of starches.-Location:The parotid glands...
neoplasms, or metastases of other tumours.
Patients with facial nerve paralysis resulting from tumours usually present with a progressive, twitching paralysis, other neurological signs, or a recurrent Bell's palsy-type presentation.
The latter should always be suspicious, as Bell's palsy should not recur. A chronically discharging ear must be treated as a cholesteatoma until proven otherwise; hence, there must be immediate surgical
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...
exploration.
Computed tomography (CT) or magnetic resonance (MR) imaging should be used to identify the location of the tumour, and it should be managed accordingly.
Often, since facial neoplasms have such an intimate relationship with the facial nerve, removing tumors in the this region becomes perplexing as the physician is unsure how to manage the tumor without causing even more palsy. Typically, benign tumors should be removed in a fashion that preserves the facial nerve, while malignant tumors should always be resected along with large areas of tissue around them, including the facial nerve. While this will inevitably lead to heightened paralysis, safe removal of a malignant neoplasm is worth the often treatable palsy that follows. In the best case scenario, paralysis can be corrected with techniques including hypoglossal-facial nerve anastomosis, end-to-end nerve repair, cross facial nerve grafting, or muscle transfer/transposition techniques, such as the gracilis free muscle transfer.
External links
- www.BellsPalsy.ws - Bell's Palsy Information
- www.moebiussyndrome.com - Information about Moebius Syndrome
- www.facialnervepalsy.com - Facial Paralysis Information & Support