Bell Palsy
PAGE 123
Bell Palsy
http://www.emedicine.com/emerg/topic56.htm
Last Updated: November 28, 2005
Synonyms and related keywords: Bell's palsy, facial nerve
paralysis, facial paralysis, idiopathic facial paralysis,
unilateral facial paralysis, cranial nerve VII paralysis, seventh
cranial nerve paralysis, neurologic disorder, paralysis on one side
of face, weakness on one side of face, drooling, tearing from eyes,
upper respiratory infection, URI, viral infection, herpes simplex
virus, HSV, Bell palsy
AUTHOR INFORMATION Section 1 of 10
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Author: Michael Lambert, MD, Fellowship Director of Emergency
Ultrasound, Clinical Assistant Professor, Department of Emergency
Medicine, Resurrection Medical Center
Michael Lambert, MD, is a member of the following medical
societies: American Academy of Emergency Medicine, American College
of Emergency Physicians, American Institute of Ultrasound in
Medicine, and Society for Academic Emergency Medicine
Editor(s): Edward Bessman, MD, Chairman, Department of Emergency
Medicine, John Hopkins Bayview Medical Center; Assistant Professor,
Department of Emergency Medicine, Johns Hopkins University;
Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine;
J Stephen Huff, MD, Associate Professor of Emergency Medicine and
Neurology, Department of Emergency Medicine, University of Virginia
Health System; John Halamka, MD, Chief Information Officer,
CareGroup Healthcare System, Assistant Professor of Medicine,
Department of Emergency Medicine, Beth Israel Deaconess Medical
Center; Assistant Professor of Medicine, Harvard Medical School;
and Jonathan Adler, MD, Attending Physician, Department of
Emergency Medicine, Massachusetts General Hospital; Division of
Emergency Medicine, Harvard Medical School
INTRODUCTION Section 2 of 10
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Background: Bell palsy is one of the most common neurologic
disorders affecting the cranial nerves. It is an abrupt,
unilateral, peripheral facial paresis or paralysis without a
detectable cause. This syndrome of idiopathic facial paralysis was
first described more than a century ago by Sir Charles Bell, yet
much controversy still surrounds its etiology and management. Bell
palsy is certainly the most common cause of facial paralysis
worldwide.
Keeping in mind that Bell palsy is a diagnosis of exclusion is
imperative. Other disease states or conditions that present with
facial palsies are often misdiagnosed as idiopathic.
Patients with Bell palsy frequently present to the ED before
seeing any other health care professional. The appearance of a
distorted face and the abrupt functional impairment are the driving
forces that prompt emergency evaluation. Patients often fear they
have had a stroke or have a tumor and that their distorted facial
appearance will be permanent.
The emergency physician's role consists of the following:
Exclude other causes of facial paralysis.
Initiate appropriate treatment.
Protect the eye.
Arrange appropriate medical follow-up care.
Pathophysiology: Actual pathophysiology is unknown; this is an
area of interminable debate. A popular theory champions
inflammation of the facial nerve. During this process, the nerve
increases in diameter and becomes compressed as it courses through
the temporal bone.
The facial nerve courses through a portion of the temporal bone
commonly referred to as the facial canal. The first portion of the
facial canal (the labyrinthine segment) is narrowest. The tiny
opening (about 0.66 mm in diameter) in this segment is known as the
meatal foramen.
The facial nerve is subjected to tight confines on its journey
through the facial canal. It seems logical that various
inflammatory, demyelinating, ischemic, or compressive processes may
impair neural conduction at this unique anatomic site.
Anatomy
The facial nerve (seventh cranial nerve) has 2 components. The
larger portion comprises efferent fibers that stimulate the muscles
of facial expression. The smaller portion contains taste fibers to
the anterior two thirds of the tongue, secretomotor fibers to the
lacrimal and salivary glands, and some pain fibers.
Pathway
The path of the facial nerve is very complex; this may be the
reason the nerve is vulnerable to injury. Two portions of the
facial nerve leave the brain at the cerebellopontine angle,
traverse the posterior cranial fossa, dive into the internal
acoustic meatus, pass through the facial canal in the temporal
bone, then angle sharply backwards, where they pass behind the
middle ear and exit the cranium at the stylomastoid foramen. From
here, the facial nerve bisects the parotid gland, and then terminal
branches burst out from the parotid plexus to supply the muscles of
facial expression.
Frequency: In the US: The incidence of Bell palsy in the United
States is approximately 23 cases per 100,000 persons. The condition
affects approximately 1 person in 65 in a lifetime.
Internationally: The incidence is the same as in the United
States.
Mortality/Morbidity: Bell palsy can cause aesthetic, functional,
and psychological disturbances in patients who have residual nerve
dysfunction during their recovery phase or in patients with
incomplete healing.
Partial paralysis
Motor synkinesis (involuntary movement accompanying a voluntary
movement)
Autonomic synkinesis (involuntary lacrimation after a voluntary
muscle movement)
Race: Incidence of Bell palsy appears to be slightly higher in
persons of Japanese descent.
Sex: No difference exists in sex distribution in patients with
Bell palsy.
Age: Age affects the probability of contracting Bell palsy. The
incidence is highest in persons aged 15-45 years. Bell palsy is
less common in those younger than 15 years and in those older than
60 years. CLINICAL Section 3 of 10
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History: Most patients presenting to the ED suspect they have
suffered a stroke or have an intracranial tumor. The most common
complaint is of weakness on one side of their face.
Postauricular pains: Almost 50% of patients experience pain in
the mastoid region. The pain frequently occurs simultaneously with
the paresis, but precedes the paresis by 2-3 days in about 25% of
patients.
Tear flow: Two thirds of patients complain about tear flow. This
is due to the reduced function of the orbicularis oculi in
transporting the tears. Fewer tears arrive at the lacrimal sac and
overflow occurs. The production of tears is not accelerated.
Altered taste: While only one third of patients complain about
taste disorders, four fifths of patients show a reduced sense of
taste. This may be explained by only half the tongue being
involved.
Dry eyes
Hyperacusis: Impaired tolerance to typical levels of noise due
to an increased irritability to the sensory neural mechanism.
Physical: Findings of facial paralysis are easily recognizable
on physical examination. A careful, complete examination excludes
other possible causes of facial paralysis. Strongly consider other
etiologies if all branches of the facial nerve are not
affected.
The classic definition of Bell palsy describes mononeuric
involvement of the facial nerve, yet other cranial nerves are
probably affected. The facial nerve is the only cranial nerve
eliciting obvious findings on physical examination because of its
unique anatomical course from the brain to the lateral face.
Remember that weakness and/or paralysis from involvement of the
facial nerve manifests as weakness of the entire face (upper and
lower) on the affected side. Focus attention on the voluntary
movement of the upper part of the face on the affected side.
In supranuclear lesions such as a cortical stroke (upper motor
neuron; above the facial nucleus in the pons), the upper third of
the face is spared while the lower two thirds are paralyzed. The
orbicularis, frontalis, and corrugator muscles are innervated
bilaterally, which explains the pattern of facial paralysis.
Test other cranial nerves; their examination results should be
normal.
Tympanic membranes should not be inflamed; presence of infection
raises possibility of complicated otitis media.
Causes: "All that glitters is not gold" (William
Shakespeare)
The etiology of Bell palsy remains unclear, although vascular,
infectious, genetic, and immunologic causes have all been proposed.
Patients with other diseases or conditions sometimes develop a
peripheral facial nerve palsy, but these are not classified as Bell
palsy (see Differentials). Viral infections: Clinical and
epidemiologic data lend credence to an infectious origin, which
triggers an immunologic response, resulting in damage to the facial
nerve. Pathogens leading the list include herpes simplex virus type
1 (HSV-1); herpes simplex virus type 2 (HSV-2); human herpesvirus
(HHV); varicella zoster virus (VZV); Mycoplasma pneumoniae;
Borrelia burgdorferi; influenza B; adenovirus; coxsackievirus;
Ebstein-Barr virus; hepatitis A, B, and C; cytomegalovirus (CMV);
and rubella virus.
Pregnancy: Bell palsy is uncommon in pregnancy; however, the
prognosis is significantly worse in pregnant women with Bell palsy
than among nonpregnant women with palsy.
Genetics: Recurrence rates (4.5-15%) and familial incidence
(4.1%) have been addressed in various studies. Genetics may have a
role in Bell palsy, but which factors are inherited is unclear.
DIFFERENTIALS Section 4 of 10
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Diabetes Mellitus, Type 1 - A Review Diabetes Mellitus, Type 2 -
A Review Fractures, Mandible Herpes Zoster Multiple Sclerosis
Tick-Borne Diseases, Lyme
Other Problems to be Considered: Herpes zosterPregnancy
(especially third trimester)PolyneuritisAcute otitisChronic
otitisTemporal bone fractureInfectious mononucleosisParotid
tumorsSarcoidosisCholesteatoma of the middle earAneurysm of
vertebral, basilar artery, or carotid arteriesCarcinomatous
meningitisFacial trauma (blunt, penetrating, iatrogenic)Leukemic
meningitisLeprosyMelkersson-Rosenthal syndromeMiddle ear
surgeryOsteomyelitis of the skull baseSkull base tumorWORKUP
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Lab Studies: No specific laboratory tests exist to confirm the
diagnosis of Bell palsy. Clinical setting determines tests that may
be of value. Other potential causes in the differential diagnosis
may be confirmed or suspected based on the following diagnostic
laboratory tests:
Complete blood count
Erythrocyte sedimentation rate
Thyroid function studies
Lyme titer
Serum glucose level
Rapid plasma reagin (RPR) or Venereal Disease Research
Laboratory (VDRL) test
Human immunodeficiency virus (HIV)
Cerebral spinal fluid analysis
Immunoglobulin M (IgM), immunoglobulin G (IgG), and
immunoglobulin A (IgA) titers for CMV, rubella, HSV, hepatitis A,
hepatitis B, hepatitis C, VZV, M pneumoniae, and B burgdorferi.
Imaging Studies: Bell palsy remains a clinical diagnosis.
Imaging studies are not indicated in the ED. Excluding other causes
of facial palsy may require one of the following imaging studies
depending on clinical setting.
Facial CT scan or plain radiographs: Perform to rule out
fractures or bony metastasis.
CT scan is indicated when stroke, or acquired immunodeficiency
syndrome (AIDS)-CNS involvement is considered in differential
diagnosis
MRI: For a suspected neoplasm of the temporal bone, brain,
parotid gland, or other structure, or to evaluate for multiple
sclerosis, MRI is the superior method of imaging. The course of the
facial nerve through the intratemporal and extratemporal regions
from the brain to the facial muscles and glands can be followed on
MRI. MRI also may be considered in lieu of CT scan.
Other Tests: Electrodiagnosis of the facial nerve: These studies
assess the function of the facial nerve. These tests are rarely
performed on an emergent basis.
Electromyography (EMG) and nerve conduction velocities produce a
graphic readout of the electrical currents displayed by stimulating
the facial nerve and recording the excitability of the facial
muscles it supplies. Comparison to the contralateral side helps
determine the extent of nerve injury and has prognostic
implications. This is not part of the acute workup.
In the nerve excitability test, the threshold of the electrical
stimulus producing visible muscle twitching is determined.
Electroneurography (ENoG) compares evoked potentials on the
paretic side versus the healthy side.
TREATMENT Section 6 of 10
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Emergency Department Care: The primary treatment of patients
with Bell palsy in the ED is pharmacologic management. The
remainder of care focuses on reassurance, eye care instructions,
and appropriate follow-up care. Steroids
Treatment of Bell palsy with steroids remains controversial.
Numerous research articles have been written on the benefit or
uselessness of steroids to treat patients with Bell palsy.
Researchers seem to lean more toward using steroids as a means
to optimize outcomes. Once the decision to use steroids is made,
the consensus is to start immediately. Antiviral agents: Although
there is insufficient research evaluating the efficacy of antiviral
medicines in Bell palsy, most experts believe in a viral etiology.
Therefore, antiviral agents seem a logical choice for pharmacologic
management and are commonly recommended.
Eye care: The eyes are frequently unprotected in patients with
Bell palsy. This leaves the eyes at risk for corneal drying and
foreign body exposure. Manage with tear substitutes, lubricants,
and eye protection.
Artificial tears: Use these during waking hours to replace
diminished or absent lacrimation.
Lubricants are used during sleep. They may be used during waking
hours if artificial tears cannot provide adequate protection. One
disadvantage is blurred vision during waking hours.
Eyeglasses or shields protect the eye from injury and reduce
drying by decreasing the air currents that come directly in contact
with the exposed cornea.
Consultations: The patient's primary care physician or
consultant should provide close follow-up care. Documentation
should chart the progress of the patient's recovery.
Opinions vary widely on referral to a specialist. Some specific
referral indications are listed below:
Neurologist: When other neurologic signs are identified on
physical examination and for an atypical presentation of Bell
palsy, referral is indicated.
Ophthalmologist: For any unexplained ocular pain or abnormal
findings on physical examination of the eyes, the patient should be
referred for further workup.
Otolaryngologist: In patients with persistent paralysis,
prolonged weakness of the facial muscles, or recurrent weakness,
referral is warranted.
Surgeon: Surgery to decompress the facial nerve is recommended
occasionally for patients with Bell palsy. Patients with a poor
prognosis identified by facial nerve testing or persistent
paralysis appear to benefit the most from surgical
intervention.
Since most patients recover without medication, physicians may
be able to manage patients without prescribing medication. This
watchful waiting plan is an option; however, some individuals with
Bell palsy never completely recover. Both medications listed below
have clinical trials that support and dispute their efficacy.
Drug Category: Corticosteroids -- Have anti-inflammatory
properties and cause profound and varied metabolic effects. Modify
the body's immune response to diverse stimuli.
Drug NamePrednisone (Deltasone, Orasone, Sterapred) --
Pharmacologic success may be the result of anti-inflammatory
effect, which presumably decreases compression of the facial nerve
in the facial canal.
Adult Dose1 mg/kg/d PO for 7 d
Pediatric DoseAdminister as in adults
ContraindicationsDocumented hypersensitivity; viral, fungal,
connective tissue, and tubercular skin infections; peptic ulcer
disease; hepatic dysfunction; GI disease
Interactions Coadministration with estrogens may decrease
prednisone clearance; concurrent use with digoxin may cause
digitalis toxicity secondary to hypokalemia; phenobarbital,
phenytoin, and rifampin may increase metabolism of glucocorticoids
(consider increasing maintenance dose); monitor for hypokalemia
with coadministration of diuretics
PregnancyB - Usually safe but benefits must outweigh the
risks.
PrecautionsAbrupt discontinuation of glucocorticoids may cause
adrenal crisis; hyperglycemia, edema, osteonecrosis, myopathy,
peptic ulcer disease, hypokalemia, osteoporosis, euphoria,
psychosis, myasthenia gravis, growth suppression, and infections
may occur with glucocorticoid use
Drug Category: Antiviral -- Herpes simplex infections may be a
common cause of Bell palsy. Acyclovir is the most-used treatment,
but other antiviral agents may be appropriate.
Drug NameAcyclovir (Zovirax) -- Has demonstrated inhibitory
activity directed against both HSV-1 and HSV-2, and infected cells
selectively take it up.
Adult Dose4000 mg/24 h PO for 7-10 d
Pediatric Dose2 years: 1000 mg PO qid for 10 d
ContraindicationsDocumented hypersensitivity
InteractionsConcomitant use of probenecid or zidovudine prolongs
half-life and increases CNS toxicity of acyclovir
PregnancyC - Safety for use during pregnancy has not been
established.
PrecautionsCaution in renal failure or when using nephrotoxic
drugs
FOLLOW-UP Section 8 of 10
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In/Out Patient Meds: Consider prednisone at an initial dose of 1
mg/kg/day.
Prednisone is a potent drug with a high risk of side effects.
The evidence of its usefulness continues to come under scrutiny in
the literature. Until efficacy can be clearly defined, it should
not be perceived as a standard of care.
With no contraindications and if the physician chooses to
administer steroids, the best choice is prednisone at a high dose,
as early as possible in the disease course. (Consider tapering on
day 5 to 5 mg bid for 5 d.)
Administer acyclovir (Zovirax) 800 mg PO 5 times/d for 10 d; 20
mg/kg in patients younger than 2 years. Recent evidence supports
HSV as the presumed cause in more than 70% of Bell palsy cases.
Complications: Most patients with Bell palsy recover without any
cosmetically obvious deformities; however, approximately 5% are
left with an unacceptably high degree of sequelae.
Incomplete motor regeneration
The largest portion of the facial nerve comprises efferent
fibers that stimulate muscles of facial expression. If the motor
portion achieves suboptimal regeneration, paresis of all or some of
these facial muscles results.
This manifests as (1) oral incompetence, (2) epiphora (excessive
tearing), and (3) nasal obstruction.
Incomplete sensory regeneration
Dysgeusia (impairment of taste) may result.
Ageusia (loss of taste) may result.
Dysesthesia (impairment of sensation or disagreeable sensation
to normal stimuli) may result.
Aberrant reinnervation of the facial nerve
After the impaired neural conduction of the facial nerve begins
the regeneration and repair process, some nerve fibers take an
unusual course and connect to neighboring fibers. This aberrant
reconnection produces unusual neurologic pathways.
When voluntary movements are initiated, they are accompanied by
involuntary movements (eg, the movement of a closed eye following
that of the uncovered one). These involuntary movements
accompanying voluntary movement are termed synkinesis.
Prognosis: The natural course of Bell palsy varies from early
complete recovery to substantial nerve injury with permanent
sequelae. Prognostically, patients fall into 3 groups with roughly
equal numbers in each group.
Group 1 regains complete recovery of facial motor function
without sequelae.
Group 2 experiences incomplete recovery of facial motor
function, but no cosmetic defects are apparent to the untrained
eye.
Group 3 experiences permanent neurologic sequelae that are
cosmetically and clinically apparent.
Most patients develop an incomplete facial paralysis during the
acute phase. This group has an excellent prognosis for full
recovery. Patients demonstrating complete paralysis are at higher
risk for severe sequelae.
Of patients with Bell palsy, 85% achieve complete recovery. Ten
percent are bothered by some asymmetry of facial muscles, while 5%
experience severe sequelae.
Patient Education: Eye care
Protect the eye from foreign objects and sunlight.
Keep the eye well lubricated.
Educate the patient to report new ocular findings such as pain,
discharge, or visual changes.
For excellent patient education resources, visit eMedicine's
Brain and Nervous System Center. Also, see eMedicine's patient
education article Bell Palsy.
PICTURES Section 9 of 10
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Caption: Picture 1. The facial nerve.
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BIBLIOGRAPHY Section 10 of 10
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Adams RD, Victor M, eds: Diseases of the spinal cord, peripheral
nerve, and muscle. In: Principles of Neurology. 5th ed. NY: McGraw
Hill; 1993:1175-1177.
Cousin GC: Facial nerve palsy following intra-oral surgery
performed with local anaesthesia. J R Coll Surg Edinb 2000 Oct;
45(5): 330-3[Medline].
English JB, Stommel EW, Bernat JL: Recurrent Bell's palsy.
Neurology 1996 Aug; 47(2): 604-5[Medline].
Helling TD, Neely JG: Validation of objective measures for
facial paralysis. Laryngoscope 1997 Oct; 107(10):
1345-9[Medline].
Morgan M, Moffat M, Ritchie L, et al: Is Bell's palsy a
reactivation of varicella zoster virus? J Infect 1995 Jan; 30(1):
29-36[Medline].
Morrow MJ: Bell's Palsy and Herpes Zoster Oticus. Curr Treat
Options Neurol 2000 Sep; 2(5): 407-416[Medline].
Niparko JK, Mattox DE: Bell's palsy and herpes zoster oticus.
In: Current Therapy in Neurologic Disease. 4th ed. Philadelphia: BC
Decker; 1993:355-361.
O'Halloran HS, Sen HA, Baker RS: Accidental ocular perforation
from self-inflicted facial palsy. Retina 1997; 17(2):
164-6[Medline].
O'Rahilly R, Muller F: Basic Human Anatomy: A regional Study of
Human Structure. Philadelphia: WB Saunders Co; 1983:391-98.
Olson WH, Brumback RA, Christoferson LA: Practical Neurology for
the Primary Care Physician. Springfield, Ill: Thomas Books;
1981:262.
Peitersen E: Bell's palsy: the spontaneous course of 2,500
peripheral facial nerve palsies of different etiologies. Acta
Otolaryngol Suppl 2002; 4-30[Medline].
Pulec JL: New horizons in facial nerve therapy. Ear Nose Throat
J 1997 Jun; 76(6): 360[Medline].
Qiu WW, Yin SS, Stucker FJ, et al: Time course of Bell palsy.
Arch Otolaryngol Head Neck Surg 1996 Sep; 122(9):
967-72[Medline].
Sittel C, Sittel A, Guntinas-Lichius O, et al: Bell's palsy: a
10-year experience with antiphlogistic-rheologic infusion therapy.
Am J Otol 2000 May; 21(3): 425-32[Medline].
Smith IM, Cull RE: Bell's palsy--which factors determine final
recovery? Clin Otolaryngol 1994 Dec; 19(6): 465-6[Medline].
Smouha EE, Coyle PK, Shukri S: Facial nerve palsy in Lyme
disease: evaluation of clinical diagnostic criteria. Am J Otol 1997
Mar; 18(2): 257-61[Medline].
Unlu Z, Aslan A, Ozbakkaloglu B, et al: Serologic examinations
of hepatitis, cytomegalovirus, and rubella in patients with Bell's
palsy. Am J Phys Med Rehabil 2003 Jan; 82(1): 28-32[Medline].
Victor M, Martin J: Disorders of the cranial nerves. WJM 2000;
173: 266-268.
Volter C, Helms J, Weissbrich B, et al: Frequent detection of
Mycoplasma pneumoniae in Bell's palsy. Eur Arch Otorhinolaryngol
2004 Aug; 261(7): 400-4[Medline].
Wiederholt WC: Bell's palsy. In: Wiederhold WC, ed. Therapy for
Neurologic Disorders. NY: Wiley; 1992:257.
Williamson IG, Whelan TR: The clinical problem of Bell's palsy:
is treatment with steroids effective? Br J Gen Pract 1996 Dec;
46(413): 743-7[Medline].
Bell Palsy
http://www.emedicine.com/neuro/topic413.htm
Last Updated: June 2, 2005
Synonyms and related keywords: Bell's palsy, idiopathic facial
paralysis, facial nerve compression, acute unilateral facial
paralysis, bilateral facial palsy, Guillain-Barr syndrome, GBS,
sarcoidosis, Lyme disease, meningitis, neoplastic meningitis,
infectious meningitis, bilateral neurofibromas, neurofibromatosis
type 2, ipsilateral facial palsy
AUTHOR INFORMATION Section 1 of 11
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Bibliography
Author: Kim Monnell, DO, Consulting Staff, Department of
Neurology, Sarasota Memorial Hospital Coauthor(s): Sally B
Zachariah, MD, Chief, Department of Neurology, Veteran Affairs
Medical Center of Bay Pines; Director, Associate Professor,
Department of Neurology, Division of Strokes, University of South
Florida College of Medicine; Suzan Khoromi, MD, Fellow, Pain and
Neurosensory Mechanisms Branch, National Institute of Dental and
Cranial Research, National Institutes of Health
Kim Monnell, DO, is a member of the following medical societies:
American Academy of Neurology, and American Osteopathic
Association
Editor(s): Milind J Kothari, DO, Program Director, Associate
Professor, Department of Internal Medicine, Division of Neurology,
Pennsylvania State University Hershey Medical Center; Francisco
Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Florian P
Thomas, MD, MA, PhD, DrMed, Associate Chief of Staff, St Louis VA
Medical Center; Associate Director, Neurology Residency Program;
Professor, Departments of Neurology, Molecular Virology, and
Molecular Microbiology and Immunology, Saint Louis University
School of Medicine; Matthew J Baker, MD, Consulting Staff, Collier
Neurologic Specialists, Naples Community Hospital; and Nicholas
Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting Staff,
Neurology Specialists and Consultants
INTRODUCTION Section 2 of 11
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Background: Facial paralysis is a disfiguring disorder that has
a great impact on the patient. Facial nerve paralysis may be
congenital, neoplastic, or result from infection, trauma, toxic
exposures, or iatrogenic causes. The most common cause of
unilateral facial paralysis is Bell palsy, also known as idiopathic
facial paralysis. Bell palsy is thought to account for
approximately 60-75% of cases of acute unilateral facial
paralysis.
In 1550, Fallopius noted the narrow lumen in the temporal bone
through which a part of the seventh cranial nerve passes. In 1828,
Charles Bell made the distinction between the fifth and seventh
cranial nerves; he noted that the seventh nerve was involved mainly
in the motor function of the face and the fifth nerve was concerned
mainly with the sensory perception of the face.
Even today, controversy still surrounds the etiology and
treatment of Bell palsy. Clinical features of Bell palsy that may
help distinguish it from other causes of facial paralysis include
sudden onset of unilateral facial paralysis (less than 48 hours),
absence of signs and symptoms of CNS disease, and absence of signs
and symptoms of ear or posterior fossa disease.
Pathophysiology: The course of the facial nerve is tortuous,
both centrally and peripherally (see Image 1).
The facial nerve nucleus lies within the reticular formation of
the pons, adjacent to the fourth ventricle. The facial nerve roots
include fibers from the motor, solitary, and salivatory nuclei. The
nervus intermedius comprises fibers from salivatory and solitary
nuclei (it contains sensory fibers from the tongue, mucosa, and
postauricular skin as well as parasympathetic fibers to the
salivary and lacrimal glands). The fibers of the facial nerve then
course around the sixth cranial nerve nucleus and exit the pons at
the cerebellopontine angle. The fibers go through the internal
auditory canal along with the vestibular portion of the eighth
cranial nerve. The narrowest portion of the internal auditory canal
is the labyrinthine segment. This is the location that is thought
to be the most common site of compression of the facial nerve in
Bell palsy.
The seventh cranial nerve contains parasympathetic fibers to the
nose, palate, and lacrimal glands. The preganglionic
parasympathetic fibers that originate in the salivatory nucleus
join the fibers from nucleus solitarius to form the nervus
intermedius. These fibers then synapse with the submandibular
ganglion, which has fibers that supply the sublingual and
submandibular glands. The fibers from the nervus intermedius also
supply the pterygopalatine ganglion, which has parasympathetic
fibers that supply the nose, palate, and lacrimal glands.
The facial nerve passes through the stylomastoid foramen in the
skull and terminates into the zygomatic, buccal, mandibular, and
cervical branches. These nerves serve the muscles of facial
expression, which include frontalis, orbicularis oculi, orbicularis
oris, buccinator, and platysma. Other muscles innervated by the
facial nerve include stapedius, stylohyoid, posterior belly of the
digastric, occipitalis, and anterior and posterior auricular
muscles. All muscles of the facial nerve are derived from the
second brachial arch.
The location of injury of the facial nerve in Bell palsy is
peripheral to the seventh nerve nucleus. The injury is thought to
occur near or at the geniculate ganglion. If the lesion is proximal
to the geniculate ganglion, the motor paralysis is accompanied by
gustatory and autonomic abnormalities. Lesions between the
geniculate ganglion and the origin of the chorda tympani produce
the same effect except that they spare lacrimation. If the lesion
is at the stylomastoid foramen, it may result in facial paralysis
only.
Bell palsy is thought to be caused by edema and ischemia
resulting in compression of the facial nerve in its course through
the bony canal. The cause of the edema and ischemia is still being
debated. In the past, cold exposure (eg chilly wind, cold air
conditioning, or driving with the car window down) were considered
the only triggers to Bell palsy. However, most authors believe that
the herpes simplex virus (HSV) is the most likely cause. Actually
studying the causal relationship between HSV and Bell palsy is
difficult because of the ubiquitous nature of HSV.
In 1972, McCormick first suggested that HSV is responsible for
idiopathic facial paralysis. This was based on the analogy that HSV
was found in cold sores, and he hypothesized that HSV may remain
latent in the geniculate ganglion. Since then, autopsy studies have
shown HSV in the geniculate ganglion of patients with Bell palsy.
Murakami et al performed polymerase chain reaction (PCR) testing
for HSV in the endoneural fluid of the seventh nerve of patients
who underwent surgery for Bell palsy. Eleven of the 14 patients
were found to have HSV in the endoneural fluid.
Assuming that HSV is the etiologic agent in Bell palsy is
reasonable. If this is true, then the virus is most likely to
travel up the axons of the sensory nerves and reside in the
ganglion cells. At times of stress the virus will reactivate,
causing local damage to the myelin. Thus, Bell palsy may be
secondary to viral and/or autoimmune reactions causing the facial
nerve to demyelinate, resulting in unilateral facial paralysis.
Frequency: In the US: The annual incidence of Bell palsy is
approximately 23 per 100,000.
The right side is affected 63% of the time.
Persons with diabetes have a risk as much as 29% higher than
persons without diabetes of being affected by Bell palsy. Thus,
blood glucose levels at time of diagnosis of Bell palsy may detect
undiagnosed diabetics.
Internationally: The highest incidence was found in a study in
Seckori, Japan, in 1986 and the lowest incidence was found in
Sweden in 1971. Most population studies generally show an annual
incidence of 15-30 per 100,000.
Mortality/Morbidity: The majority of patients who suffer from
Bell palsy have neurapraxia or local nerve conduction block. These
patients are likely to have a prompt and complete recovery of the
nerve. Patients with axonotmesis, with disruption of the axons,
have a fairly good recovery but it is usually not complete. The
risk factors thought to be associated with a poor outcome in
patients with Bell palsy include (1) age greater than 60 years, (2)
complete paralysis, and (3) decreased taste or salivary flow on the
side of paralysis (usually 10-25% compared to the patient's normal
side). Other factors thought to be associated with poor outcome
include pain in the posterior auricular area and decreased
lacrimation.
Patients generally have a good prognosis; approximately 80-90%
of patients recover without noticeable disfigurement within 6 weeks
to 3 months. Patients aged 60 years or older have an approximately
40% chance of complete recovery and have a higher rate of sequelae.
Patients younger than 30 years have only a 10-15% chance of less
than complete recovery and sequelae. If no recovery occurs by 4
months, then the patient is more likely to have sequelae from the
disease, which include synkinesis, crocodile tears, and rarely
hemifacial spasm.
Synkinesis is an abnormal contracture of the facial muscles
while smiling or closing the eyes. It may be mild and result in
slight movement of the chin when the patient blinks, eye closure
with smiling, or contracture around the mouth while blinking.
Crocodile tears are observed; patients shed tears while they
eat.
Facial spasm is a very rare complication of Bell palsy. It
occurs as tonic contraction of one side of the face. Spasms are
more likely to occur during times of stress or fatigue and may
occur during sleep. This condition may occur secondary to
compression of the root of the seventh nerve by an aberrant blood
vessel, tumor, or demyelination of the nerve root. It occurs most
commonly in the fifth and sixth decades of life, and sometimes the
etiology is not found. The presence of progressive facial hemispasm
with other cranial nerve findings indicates a possibility of a
brainstem lesion.
Diabetic patients are 30% more likely than nondiabetic patients
to have only partial recovery; recurrence of Bell palsy is also
more common among diabetic patients.
Bell palsy accounts for only 23% of bilateral facial paralysis.
The majority of patients with bilateral facial palsy have
Guillain-Barr syndrome (GBS), sarcoidosis, Lyme disease, meningitis
(neoplastic or infectious), or bilateral neurofibromas (in patients
with neurofibromatosis type 2).
Bell palsy recurs in 10-15% of patients. It may recur on the
ipsilateral or contralateral side of the initial palsy. Recurrence
usually is associated with a family history of recurrent Bell
palsy. Approximately 30% of patients with recurrent ipsilateral
facial palsy were found to have tumors of the seventh nerve or
parotid gland. Patients with recurrent ipsilateral facial palsy
should undergo MRI or high-resolution CT scan to rule out
neoplastic or inflammatory (eg, multiple sclerosis, sarcoidosis)
cause of recurrence.
Sex: Bell palsy appears to affect the sexes equally. However,
young women aged 10-19 years are more likely to be affected than
men in the same age group.
Pregnant women have a 3.3 times higher risk of being affected by
Bell palsy than nonpregnant women; Bell palsy occurs most
frequently in the third trimester.
Age: The lowest incidence is found in persons younger than 10
years and the highest incidence in persons aged 60 years or
older.
CLINICAL Section 3 of 11
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History: Bell palsy is a diagnosis of exclusion. The diagnosis
must be made on the basis of a thorough history and physical
examination and use of diagnostic testing when necessary.
Symptoms of Bell palsy
Acute onset of unilateral upper and lower facial paralysis (over
a 48-h period)
Posterior auricular pain
Decreased tearing
Hyperacusis
Taste disturbances
The paralysis must include the forehead and lower aspect of the
face. The patient may report inability to close the eye or to smile
on the affected side. He or she also may report increased saliva on
the side of the paralysis. If the paralysis involves only the lower
portion of the face, a central cause should be suspected (ie,
supranuclear). If the patient complains of contralateral weakness
or diplopia in conjunction with the supranuclear facial palsy, a
stroke or intracerebral lesion should be strongly suspected.
Half of the patients affected with Bell palsy may complain of
posterior auricular pain. Ask the patient if he or she has
experienced trauma, which may account for the pain and facial
paralysis.
One third of patients may experience hyperacusis in the ear
ipsilateral to the paralysis, which is secondary to weakness of the
stapedius muscle.
One sixth of patients experience decreased lacrimation.
Many patients report numbness on the side of the paralysis. Some
authors believe that this is secondary to involvement of the
trigeminal nerve, whereas other authors argue that this symptom is
probably due to lack of mobility of the facial muscles and not lack
of sensation.
If a patient has gradual onset of facial paralysis, weakness of
the contralateral side, or history of trauma or infection, other
causes of facial paralysis must be strongly considered. Patients
who have bilateral facial palsy must be evaluated for GBS, Lyme
disease, and meningitis.
If a patient is from the Northeast, Lyme disease should be
considered as a cause of facial paralysis, and serologic testing
should be performed.
Recurrent ipsilateral facial paralysis must raise the suspicion
of a tumor of the seventh nerve or parotid gland. If the patient
reports sudden onset of hearing loss and severe pain with the onset
of facial paralysis, Ramsay Hunt syndrome must be considered.
Symptoms associated with seventh nerve neoplasm include slowly
progressive paralysis, facial hyperkinesis, severe pain, recurrent
palsy, and other cranial nerve involvement. Cerebellopontine tumors
may affect the seventh, eighth, and fifth cranial nerves
simultaneously. Patients with a progressive paralysis of the facial
nerve lasting longer than 3 weeks should be evaluated for
neoplasm.
Physical: Initial inspection of the patient demonstrates
flattening of the forehead and nasolabial fold on the side affected
with the palsy.
When the patient is asked to raise the eyebrows, the side of the
forehead with the palsy will remain flat.
When the patient is asked to smile, the face becomes distorted
and lateralizes to the side opposite the palsy.
The patient is not able to close the eye completely on the
affected side. On attempted eye closure, the eye rolls upward and
inward on the affected side. This is known as Bell phenomenon and
is considered a normal response to eye closure.
A careful examination of the head, ears, eyes, nose, and throat
(HEENT) must be carried out in all patients with facial
paralysis.
The external auditory canal must be inspected for vesicles,
injection, infection, or trauma.
The patient may have decreased sensation to pinprick in the
posterior auricular area.
The patient who has paralysis of the stapedius muscle will
report hyperacusis.
Bell phenomenon is observed on attempted eye closure.
With weakness/paralysis of the orbicularis oculi muscle (facial
nerve innervation) and normal function of the levator muscle
(oculomotor nerve innervation) and Mueller muscle (sympathetic
innervation), eye closure may be partial or absent. The tear reflex
may also be absent in many cases of Bell palsy. For these reasons
the patient may have decreased tearing and susceptibility to
corneal abrasion and dryness of the eye. The patient may appear to
have loss of corneal reflex on the affected side; however, the
contralateral eye blinks when testing the corneal reflex on the
affected side.
A careful oral examination must be performed.
Taste and salivation are affected in many patients with Bell
palsy.
Taste may be assessed by holding the tongue with gauze and
testing each side of the tongue independently with salt, sugar, and
vinegar. The mouth must be washed after testing with different
substances. The affected side has decreased taste as compared to
the normal side.
Careful neurologic examination is necessary in patients with
facial paralysis. A neurologic abnormality warrants neurologic
referral and further testing such as MRI of the brain, lumbar
puncture, and electromyography (EMG) where appropriate.
Causes: See Pathophysiology.
DIFFERENTIALS Section 4 of 11
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Acute Inflammatory Demyelinating Polyradiculoneuropathy Amyloid
Angiopathy Anterior Circulation Stroke Arsenic Basilar Artery
Thrombosis Benign Skull Tumors Brainstem Gliomas Cerebral Aneurysms
Guillain-Barre Syndrome in Childhood Intracranial Hemorrhage
Low-Grade Astrocytoma Lyme Disease Meningioma Meningococcal
Meningitis Multiple Sclerosis Mbius Syndrome Neurofibromatosis,
Type 2 Neurosarcoidosis Neurosyphilis Tuberculous Meningitis
Other Problems to be Considered: Basal skull
fracturesBarotraumaBotulismCarcinomatosisCarotid disease and
strokeDiphtheriaFacial injuriesForceps deliveryHIVIatrogenic (as in
otologic, neurotologic, skull base, or parotid
surgery)IdiopathicInfectionIntratemporal internal carotid artery
aneurysmMalignant otitis externaMeningitisMumpsParotid tumorRamsay
Hunt syndromeSarcomaTeratomaTetanusThalidomide
exposureTraumaToxicVascularWegener vasculitis
WORKUP Section 5 of 11
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Lab Studies: In areas where Lyme disease is endemic, Lyme titers
(IgM and IgG) should be obtained.
Blood glucose or hemoglobin A1c may be obtained to determine if
the patient has undiagnosed diabetes.
Serum titers for HSV may be obtained, but this is usually not
helpful owing to the ubiquitous nature of this virus.
Imaging Studies: If the history and physical examination lead to
a diagnosis of Bell palsy, then immediate imaging is not
necessary.
Imaging is not required because most patients with Bell palsy
improve within 8-10 weeks. If the paralysis does not improve or
worsens, imaging may be useful.
The MRI of patients with Bell palsy may show enhancement of the
seventh nerve at, or near, the geniculate ganglion. However, if the
paralysis progresses over weeks, the possibility is high of a
neoplasm compressing the seventh cranial nerve. Tumors that
compress or involve the seventh cranial nerve include schwannoma
(most common), hemangioma, meningioma, and sclerosing
hemangioma.
MRI is preferred for imaging the cerebellopontine angle.
If the patient has a history of trauma, CT scan of the temporal
bone may be required.
If the patient has a palpable parotid mass, imaging may be
necessary.
Other Tests: The following tests may be performed in the office
setting. However, they require both the patient's and physician's
time. They may be helpful in assessing the extent of the damage to
the seventh nerve.
The stethoscope loudness test may be used to assess the
functioning of the stapedius muscle. The patient wears the
stethoscope, and the activated tuning fork is placed at the bell of
the stethoscope. The loud sound will lateralize to the side of the
paralyzed stapedius muscle
The Schirmer blotting test may be used to assess tearing
function. The use of benzene will stimulate the nasolacrimal
reflex, and the degree of tearing can be compared between the
paralyzed and normal sides.
Salivary flow also may be tested. The physician places a small
catheter into both the paralyzed and normal submandibular glands.
The patient is then asked to suck on a lemon, and the salivary flow
is compared between the 2 sides. The normal side is the
control.
Useful tests for evaluation of the function of the facial nerve
include nerve conduction testing and EMG.
These tests may aid in assessing the outcome of a patient who
has persistent and severe Bell palsy. This test is most useful when
performed 3-10 days after the onset of paralysis.
Nerve conduction responses are abnormal if a difference of 50%
in amplitude between the paralyzed and normal side is detected; a
difference of 90% between the 2 sides suggests a poorer
prognosis.
May et al demonstrated that prognosis may be favorable if the
motor amplitude of the affected side was greater than 25% of that
of the normal side. An incomplete recovery was observed in patients
whose results demonstrated less than 25% amplitude on the paralyzed
side.
Blink reflexes can be used to measure conduction across the
involved segment but they are commonly absent in Bell palsy.
Brainstem auditory-evoked response (BAER) may be obtained in
patients with peripheral seventh nerve lesions and other neurologic
involvement.
BAER measures the transmission of response through the brain
stem and is effective in detecting, notably, retrocochlear
lesions.
Hendrix and Melnick evaluated BAER of 17 patients with Bell
palsy. They found no evidence of retrocochlear lesions of the
auditory system in any of their patients with Bell palsy.
In another study by Shannon et al, BAER was recorded in 27
patients with Bell palsy; only 6 patients had prolonged brainstem
transmission but normal auditory function.
These studies were small and do not support routine use of BAER
in patients with Bell palsy. However, when a patient presents with
multiple cranial neuropathies, ie, of CN VII and VIII, BAER may be
useful.
Histologic Findings: A review of 12 autopsy cases of patients
with Bell palsy was summarized in Peter Dyck's Peripheral
Neuropathy. This stated that the majority of cases showed
inflammatory changes around the mastoid cells and walls of the
arteries. The most common site of involvement was the geniculate
ganglion.
Surgical findings described constriction of the nerve at the
stylomastoid foramen with swelling of the nerve itself. Microscopic
findings showed an inflammatory reaction with infiltration of
macrophages on the nerve.
TREATMENT Section 6 of 11
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Medical Care: In general, persons with true Bell palsy have an
excellent prognosis. The goals of treatment are to improve function
of the facial nerve and reduce neuronal damage. Many issues must be
addressed in treating patients with Bell palsy. The most important
consideration is the onset of symptoms. Treatment may be considered
for patients who have the onset of paralysis within 1-7 days of the
initial office visit. The American Academy of Neurology published a
practice parameter in 2001 stating that steroids are probably
effective and acyclovir (with prednisone) is possibly effective for
treatment of Bell palsy. There was insufficient evidence for any
recommendation on facial decompression surgery. Because treatment
of Bell palsy is still controversial, a study is currently being
performed in Scotland. It is a placebo-controlled study that will
determine the efficacy of prednisone versus prednisone and
acyclovir versus placebo. The most widely accepted treatment for
Bell palsy is corticosteroids. However, the use of steroids is
still controversial because most patients recover without
treatment.
The recommended dose of prednisone is 1 mg/kg or 60 mg/d for 6
days, followed by a taper, for a total of 10 days.
Many trials have been carried out to study the efficacy of
prednisone in Bell palsy. Early studies had small numbers of
patients and variable outcomes.
In 1972, Adour et al conducted a large, controlled clinical
trial, which found that 89% of patients treated with prednisone had
full recovery as compared to 64% of patients treated with
placebo.
When using corticosteroids for the treatment of Bell palsy,
caution should be used in patients with tuberculosis, peptic ulcer
disease, diabetes mellitus, renal or hepatic dysfunction, or
malignant hypertension.
Since HSV is widely accepted as the likely etiologic agent of
Bell palsy, trials using acyclovir have been conducted. The dose of
acyclovir is 400 mg orally 5 times per day.
A prospective randomized trial with 101 patients comparing
prednisone and acyclovir demonstrated that the prednisone group had
a better clinical recovery. In another prospective randomized trial
with 99 patients, prednisone monotherapy was compared to the
combination of prednisone and acyclovir. This study demonstrated
that combination therapy was more effective in preventing nerve
degeneration as measured by electrodiagnostic tests.
Whether to use prednisone alone or combination therapy is left
to the discretion of the physician. For patients who have a
contraindication to steroid therapy, acyclovir may be given as
solitary treatment.
That eye care is imperative in Bell palsy is accepted
universally. The patient's eye is at risk for drying, corneal
abrasion, and corneal ulcers. Eye care includes artificial tears
for use during the day as well as eyeglasses or shields. At night,
eye lubricants may be used. If artificial tears are not effective
during the daytime, then lubricants may be used; however, they may
cause blurring of vision.
Surgical Care: Surgery for Bell palsy is controversial. In the
past, surgical decompression of the facial nerve was considered for
patients whose facial muscles demonstrated less than 90% of normal
activity on electrophysiologic studies. Surgical decompression of
the facial nerve involves a middle fossa craniotomy with an
extradural approach. However, recent trials suggest this is not
beneficial in patients with Bell palsy.
Consultations: If the initial impression based on the history
and physical examination is not Bell palsy, then a neurologic or
otolaryngologic consultation is needed.
If the paralysis persists for several months, a neurology or
otolaryngology consultation should be sought.
Patients who report persistent dry eye or painful eye should be
referred to an ophthalmologist.
the goals of pharmacotherapy are to reduce morbidity and prevent
complications.
Drug Category: Corticosteroids -- Prednisone can be used but has
many adverse effects including fluid retention, hypokalemia,
myopathy, peptic ulcer, headache (pseudotumor), menstrual
irregularities, cataracts, glaucoma, and manifestation of latent
diabetes mellitus. Signs of infection may also be masked in
patients taking prednisone. Physicians should use caution when
using prednisone in patients with the aforementioned
conditions.
Drug NamePrednisone (Deltasone, Orasone, Meticorten) --
Glucocorticoid absorbed readily from GI tract. It has
anti-inflammatory and immune-modulating effects, and profound and
varied metabolic effects.
Adult Dose1 mg/kg or 60 mg PO qd for 7 d followed by taper for
total of 10 d
Pediatric Dose1 mg/kg PO qd for 6 d followed by taper for total
of 10 d
ContraindicationsDocumented hypersensitivity; severe
uncontrolled diabetes; systemic fungal infections; peptic ulcer
disease; tuberculosis; severe osteoporosis; severe adverse
reactions to corticosteroids
InteractionsDrugs that induce hepatic enzymes may increase
clearancethese include phenobarbital, phenytoin, and rifampin;
patients on aspirin or Coumadin must be monitored closely for GI
bleeding
PregnancyB - Usually safe but benefits must outweigh the
risks.
PrecautionsPatients are at risk for hyperglycemia, electrolyte
abnormalities (especially hypokalemia in patients taking
diuretics), osteoporosis, avascular necrosis, psychosis, and
myopathy or worsening weakness in patients with myasthenia gravis;
abrupt discontinuation of prednisone without taper puts patient at
risk for adrenal crisis
Drug Category: Antiviral medication -- Acyclovir has been used
in the treatment of Bell palsy in combination with prednisone or
used alone in patients who cannot take prednisone.
Drug NameAcyclovir (Zovirax) -- Antiviral drug that has
inhibitory activity against HSV-1, HSV-2, and VZV; selectively
taken up by infected cells.
Adult Dose400 mg PO 5 times/d for 10 d
Pediatric Dose2 years: 20 mg/kg PO for 10 d
ContraindicationsDocumented hypersensitivity
InteractionsProbenecid or zidovudine prolongs half-life and may
increase CNS toxicity
PregnancyC - Safety for use during pregnancy has not been
established.
PrecautionsCaution in renal failure or when using nephrotoxic
drugs
FOLLOW-UP Section 8 of 11
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Further Outpatient Care: If the paralysis is not resolved or is
progressing to complete paralysis, a thorough neurologic and HEENT
examination should be performed to rule out neoplastic causes of
seventh nerve palsy.
The patient should be monitored if the initial EMG shows the
involved facial muscles to have less than 25% of the function of
the normal side.
If the residual paralysis is severe, the patient should be
referred for counseling.
Complications: Approximately 30% of patients with Bell palsy
experience sequelae of the paralysis, which include incomplete
motor recovery, incomplete sensory regeneration, and
parasympathetic impairment.
Incomplete motor recovery may manifest as oral incompetence or
epiphora.
Incomplete sensory recovery may result in dysgeusia (impairment
of taste) or ageusia (loss of taste).
Parasympathetic impairment causes aberrant function of lacrimal
glands, which manifests as crocodile tears; patients report
shedding tears while eating.
Prognosis: The natural course of Bell palsy varies from early
complete recovery to substantial nerve injury resulting in
persistent paralysis and synkinesis.
One third of patients regain complete recovery of facial motor
function without sequelae.
One third of patients have incomplete recovery of facial motor
function. These patients do not have any noticeable
abnormalities.
The remainder of patients suffer from permanent neurological and
cosmetic abnormalities, which are apparent.
Patient Education: To prevent corneal abrasions, the patient
should be educated concerning eye care.
They also should be encouraged to do facial muscle exercises
using passive range of motion as well as actively closing their
eyes and smiling.
For excellent patient education resources, visit eMedicine's
Brain and Nervous System Center. Also, see eMedicine's patient
education article Bell Palsy.
MISCELLANEOUS Section 9 of 11
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Medical/Legal Pitfalls: In most cases, the diagnosis of Bell
palsy is straightforward as long as the patient underwent a
thorough history and physical examination. Failure to recognize
structural, infectious, or vascular lesions leading to seventh
nerve damage may result in further deterioration of the patient's
condition. For example, if other cranial nerve, motor, or sensory
symptoms were present at the time, then treatable or preventable
nervous system diseases should be sought. These may include stroke,
GBS, basilar meningitis, or cerebellar pontine angle tumor.
PICTURES Section 10 of 11
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Caption: Picture 1. The facial nerve
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Bibliography
Adour KK, Byl FM, Hilsinger RL, et al: The true nature of Bell's
palsy: analysis of 1,000 consecutive patients. Laryngoscope 1978
May; 88(5): 787-801[Medline].
Adour KK, Ruboyianes JM, Von Doersten PG, et al: Bell's palsy
treatment with acyclovir and prednisone compared with prednisone
alone: a double-blind, randomized, controlled trial. Ann Otol
Rhinol Laryngol 1996 May; 105(5): 371-8[Medline].
Adour KK, Bell DN, Hilsinger RL Jr: Herpes simplex virus in
idiopathic facial paralysis (Bell palsy). JAMA 1975 Aug 11; 233(6):
527-30[Medline].
Adour KK, Wingerd J, Bell DN, et al: Prednisone treatment for
idiopathic facial paralysis (Bell's palsy). N Engl J Med 1972 Dec
21; 287(25): 1268-72[Medline].
Aldrich MS, Beck RW, Albers JW: Familial recurrent Bell's palsy
with ocular motor palsies. Neurology 1987 Aug; 37(8):
1369-71[Medline].
Atlas SW: Magnetic Resonance Imaging of the Brain and Spine. 2nd
ed. Philadelphia: Raven Press; 1996: 988-1001.
Austin JR, Peskind SP, Austin SG, Rice DH: Idiopathic facial
nerve paralysis: a randomized double blind controlled study of
placebo versus prednisone. Laryngoscope 1993 Dec; 103(12):
1326-33[Medline].
Baker RS, Sun WS, Hasan SA, et al: Maladaptive neural
compensatory mechanisms in Bell's palsy-induced blepharospasm.
Neurology 1997 Jul; 49(1): 223-9[Medline].
Baringer JR: Herpes simplex virus and Bell palsy. Ann Intern Med
1996 Jan 1; 124(1 Pt 1): 63-5[Medline].
Blunt MJ: The possible role of vascular changes in the aetiology
of Bell's palsy. J Laryngol Otol 1956 Dec; 70(12):
701-13[Medline].
Boddie HG: Recurrent Bell's palsy. J Laryngol Otol 1972 Nov;
86(11): 117-20[Medline].
Bradley W, Daroff R, Fenichel G: Neurology in Clinical Practice.
2000:274-76.
Conley J, Selfe RW: Occult neoplasms in facial paralysis.
Laryngoscope 1981 Feb; 91(2): 205-10[Medline].
De Diego JI, Prim MP, Madero R, Gavilan J: Seasonal patterns of
idiopathic facial paralysis: a 16-year study. Otolaryngol Head Neck
Surg 1999 Feb; 120(2): 269-71[Medline].
De Diego JI, Prim MP, De Sarria MJ, et al: Idiopathic facial
paralysis: a randomized, prospective, and controlled study using
single-dose prednisone versus acyclovir three times daily.
Laryngoscope 1998 Apr; 108(4 Pt 1): 573-5[Medline].
Dyck PJ, ed: Peripheral Neuropathy. 3rd ed. Philadelphia: WB
Saunders; 1993.
English JB, Stommel EW, Bernat JL: Recurrent Bell's palsy.
Neurology 1996 Aug; 47(2): 604-5[Medline].
Gilden DH: Clinical practice. Bell's Palsy. N Engl J Med 2004
Sep 23; 351(13): 1323-31[Medline].
Grogan PM, Gronseth GS: Practice parameter: Steroids, acyclovir,
and surgery for Bell's palsy (an evidence-based review): report of
the Quality Standards Subcommittee of the American Academy of
Neurology. Neurology 2001 Apr 10; 56(7): 830-6[Medline].
Hammerschlag PE, Cohen NL, Palu R, Brudny JJ: Management of
facial paralysis with jump interposition graft hypoglossal-facial
anastomosis with gold lid weight. Eur Arch Otorhinolaryngol 1994
Dec; S137-9[Medline].
Hato N, Matsumoto S, Kisaki H, et al: Efficacy of early
treatment of Bell's palsy with oral acyclovir and prednisolone.
Otol Neurotol 2003 Nov; 24(6): 948-51[Medline].
Hauser WA, Karnes WE, Annis J, Kurland LT: Incidence and
prognosis of Bell's palsy in the population of Rochester,
Minnesota. Mayo Clin Proc 1971 Apr; 46(4): 258-64[Medline].
Hendrix RA, Melnick W: Auditory brain stem response and
audiologic tests in idiopathic facial nerve paralysis. Otolaryngol
Head Neck Surg 1983 Dec; 91(6): 686-90[Medline].
Holland NJ, Weiner GM: Recent developments in Bell's palsy. BMJ
2004 Sep 4; 329(7465): 553-7[Medline].
Holten KB: How should we manage Bell's palsy?. J Fam Pract 2004
Oct; 53(10): 797-8[Medline].
Jackson CG, von Doersten PG: The facial nerve. Current trends in
diagnosis, treatment, and rehabilitation. Med Clin North Am 1999
Jan; 83(1): 179-95, x[Medline].
Jackson CG: Facial nerve paralysis: Diagnosis of lower motor
neuron facial nerve lesions and facial paralysis. Washington, DC:
American Academy of Otolaryngology, Head and Neck Surgery;
1986.
Keane JR: Bilateral seventh nerve palsy: analysis of 43 cases
and review of the literature. Neurology 1994 Jul; 44(7):
1198-202[Medline].
Lambert R: Medical Management of Facial Paralysis.
Otolaryngology Index 1998; 42: 1-14.
Magaldi JA: Bell's palsy. N Engl J Med 2005 Jan 27; 352(4):
416-8; author reply 416-8[Medline].
Massey EW: Familial Bell's palsy. Ear Nose Throat J 1981 Nov;
60(11): 500-2[Medline].
Matsumoto Y, Pulec JL, Patterson MJ, Yanagihara N: Facial nerve
biopsy for etiologic clarification of Bell's palsy. Ann Otol Rhinol
Laryngol Suppl 1988 Nov-Dec; 137: 22-7[Medline].
May M, Blumenthal F, Klein SR: Acute Bell's palsy: prognostic
value of evoked electromyography, maximal stimulation, and other
electrical tests. Am J Otol 1983 Jul; 5(1): 1-7[Medline].
May M, Hardin WB: Facial palsy: interpretation of neurologic
findings. Laryngoscope 1978 Aug; 88(8 Pt 1): 1352-62[Medline].
McCormick DP: Herpes-simplex virus as a cause of Bell's palsy.
Lancet 1972 Apr 29; 1(7757): 937-9[Medline].
Morgenlander JC, Massey EW: Bell's palsy. Ensuring the best
possible outcome. Postgrad Med 1990 Oct; 88(5): 157-61,
164[Medline].
Murakami S, Mizobuchi M, Nakashiro Y, et al: Bell palsy and
herpes simplex virus: identification of viral DNA in endoneurial
fluid and muscle. Ann Intern Med 1996 Jan 1; 124(1 Pt 1):
27-30[Medline].
Olsen KD: Facial nerve paralysis. 2. 'All that palsies is not
Bell's'. Postgrad Med 1984 Jul; 76(1): 95-7, 100-2,
105[Medline].
Petersen B, LaRouere M, Kartush J: Disorders of the Facial Nerve
. Otolaryngology Index 1998; 40: 1-19.
Robillard RB, Hilsinger RL Jr, Adour KK: Ramsay Hunt facial
paralysis: clinical analyses of 185 patients. Otolaryngol Head Neck
Surg 1986 Oct; 95(3 Pt 1): 292-7[Medline].
Roland L: Merritt's Textbook of Neurology. 9th ed.
1995:467-470.
Ruckenstein MJ: Evaluating facial paralysis. Expensive
diagnostic tests are often unnecessary. Postgrad Med 1998 Jun;
103(6): 187-8, 191-2[Medline].
Shanon E, Himelfarb MZ, Zikk D: Measurement of auditory brain
stem potentials in Bell's palsy. Laryngoscope 1985 Feb; 95(2):
206-9[Medline].
Shaw M, Nazir F, Bone I: Bell's palsy: a study of the treatment
advice given by Neurologists. J Neurol Neurosurg Psychiatry 2005
Feb; 76(2): 293-4[Medline].
Stankiewicz JA: Steroids and idiopathic facial paralysis.
Otolaryngol Head Neck Surg 1983 Dec; 91(6): 672-7[Medline].
Stankiewicz JA: A review of the published data on steroids and
idiopathic facial paralysis. Otolaryngol Head Neck Surg 1987 Nov;
97(5): 481-6[Medline].
Wolf SM, Wagner JH, Davidson S, Forsythe A: Treatment of Bell
palsy with prednisone: a prospective, randomized study. Neurology
1978 Feb; 28(2): 158-61[Medline].
Yanagihara N: Incidence of Bell's palsy. Ann Otol Rhinol
Laryngol Suppl 1988 Nov-Dec; 137: 3-4[Medline].
Zavlan C, Hou J, Selesnick S: Bell's palsy: an update on causes,
recognition, therapy. The Consultant 1999: 39-48.
Hemifacial Spasm (HFS)
http://emedicine.com/NEURO/topic154.htm
Last Updated: October 11, 2006
Synonyms and related keywords: craniofacial movement disorders,
facial myoclonus, facial dystonia, botulinum toxin, BTX therapy
AUTHOR INFORMATION Section 1 of 10
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Author: Steven Gulevich, MD, Department of Neurology, Swedish
Medical Center of Englewood, Colorado
Steven Gulevich, MD, is a member of the following medical
societies: American Academy of Neurology, American Medical
Association, and Colorado Medical Society
Editor(s): Stephen A Berman, MD, PhD, Professor, Department of
Internal Medicine, Section of Neurology, Dartmouth Medical School;
Chief, Neurology Service, White River Junction Veterans Medical
Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor,
eMedicine; Glenn Lopate, MD, Associate Professor, Department of
Neurology, Division of Neuromuscular Diseases, Washington
University School of Medicine; Chief of Neurology, St Louis
ConnectCare; Selim R Benbadis, MD, Professor, Director of
Comprehensive Epilepsy Program, Departments of Neurology and
Neurosurgery, University of South Florida College of Medicine; and
Nicholas Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting
Staff, Neurology Specialists and Consultants
INTRODUCTION Section 2 of 10
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Background: Facial musculature is subject to the same movement
disorders as muscles of the limbs or trunk. Myoclonus, dystonia,
and other movement disorders present with specific syndromes in the
facial musculature. An understanding of the underlying mechanism
leads to appropriate diagnostic evaluation and potential
treatment.
Although specific treatments are available for many craniofacial
movement disorders, botulinum toxin (BTX) chemodenervation has
proven useful in many of these disorders, supplanting surgery and
medical therapy.
Pathophysiology: First described by Gowers in 1884, hemifacial
spasm (HFS) represents a segmental myoclonus of muscles innervated
by the facial nerve. The disorder presents in the fifth or sixth
decade of life, almost always unilaterally, although bilateral
involvement may occur rarely in severe cases. HFS generally begins
with brief clonic movements of the orbicularis oculi and spreads
over years to other facial muscles (corrugator, frontalis,
orbicularis oris, platysma, zygomaticus).
Clonic movements progress to sustained tonic contractions of
involved musculature. Chronic irritation of the facial nerve or
nucleus, the near-universal cause of HFS, may arise from numerous
underlying conditions.
Irritation of the facial nerve nucleus is believed to lead to
hyperexcitability of the facial nerve nucleus, while irritation of
the proximal nerve segment may cause ephaptic transmission within
the facial nerve. Either mechanism explains the rhythmic
involuntary myoclonic contractions observed in HFS.
Compressive lesions (eg, tumor, arteriovenous malformation,
Paget disease) and noncompressive lesions (eg, stroke, multiple
sclerosis plaque, basilar meningitis) may present as HFS. Most
instances of hemifacial spasm previously thought to be idiopathic
were probably caused by aberrant blood vessels (eg, distal branches
of the anterior inferior cerebellar artery or vertebral artery)
compressing the facial nerve within the cerebellopontine
angle.Race: All races are affected equally.
Sex: A slight female preponderance exists in HFS.
Age: Idiopathic hemifacial spasm typically begins in the fifth
or sixth decade of life.
Onset of hemifacial spasm in patients younger than 40 years is
unusual and often heralds an underlying neurologic illness (eg,
multiple sclerosis). CLINICAL Section 3 of 10
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History: Involuntary facial movement is the only symptom.
Fatigue, anxiety, or reading may precipitate the movements.
Hemimasticatory spasm
Hemimasticatory spasm is analogous to HFS and occurs with
irritation to the motor trigeminal nerve.
This rare condition is a segmental myoclonus and presents with
unilateral involuntary contractions of the trigeminally innervated
muscles of mastication (usually the masseter).
Similar to HFS, hemimasticatory spasm responds to treatment with
medications and BTX.
However, less evidence exists that exploratory surgery benefits
patients with this condition.
Myoclonic movements
Myoclonic movements affecting facial musculature also may arise
from lesions at the brain or brainstem level.
These are distinguished from HFS by the distribution of abnormal
movements (more generalized, possibly bilateral) and possibly by
electrodiagnostic evaluation.
Imaging studies may yield an underlying cause.
Central myoclonus responds to anticonvulsant management.
Oromandibular dystonia
Oromandibular dystonia (OMD) refers to dystonia affecting the
lower facial musculature, predominantly the jaw, pharynx, and
tongue.
When OMD occurs in conjunction with blepharospasm, the disorder
is termed Meige syndrome.
Jaw-opening forms of OMD indicate primary involvement of the
digastric and lateral pterygoid. Jaw-closing OMD involves the
masseter, temporalis, and medial pterygoid.
Jaw deviation, indicating predominant involvement of the lateral
pterygoid, is rare.
BTX is the preferred treatment for OMD and is most effective in
the jaw-closure type.
Medications seldom yield acceptable results. When medications
must be used, employ the same agents as for blepharospasm.
Because of the risk of aspiration, never inject BTX into the
tongue.
Craniofacial tremor
Craniofacial tremor may occur in association with essential
tremor, Parkinson disease, thyroid dysfunction, or electrolyte
disturbance.
It occurs rarely in isolation.
Focal motor seizures must occasionally be distinguished from
other facial movement disorders, particularly HFS.
Postictal weakness and greater involvement of the lower face are
distinguishing features of focal motor seizures.
Facial chorea
Facial chorea occurs in the context of a systemic movement
disorder (eg, Huntington disease, Sydenham chorea).
Chorea is a random, flowing, nonpatterned set of movements.
A related disorder, spontaneous orofacial dyskinesia of the
elderly, is observed primarily in the edentulous. It usually
responds to proper fitting of dentures.
Tics
Facial tics are brief, repetitive, coordinated, semipurposeful
movements of grouped facial and neck muscles.
Tics may occur physiologically or in association with diffuse
encephalopathy.
Some medications (ie, anticonvulsants, caffeine,
methylphenidate, antiparkinsonian agents) are associated with
producing tics.
Single, repetitive, stereotyped movements (eg, repetitive
grimacing, throat clearing, vocalizations) define a simple tic
disorder.
Facial myokymia
Facial myokymia appears as vermicular twitching under the skin,
often with a wavelike spread.
This is distinguished from other abnormal facial movements by
characteristic electromyogram discharges presenting as brief,
repetitive bursts of motor unit potentials firing at 2-60 Hz
interrupted by periods of silence of up to a few seconds.
Facial myokymia may occur with any brainstem process. Severe
cases may benefit from BTX.
Most cases are idiopathic and resolve without treatment over
several weeks.
Physical: The only physical finding in hemifacial spasm is
involuntary facial movements.
Spontaneous HFS manifests with facial spasms that represent
myoclonic jerks and are analogous to segmental myoclonus, which may
affect other body regions.
Postparalytic HFS (following facial nerve trauma such as Bell
palsy) manifests as facial synkinesis and contracture.
Causes: Idiopathic
Vascular compression
Facial nerve compression by mass
Brainstem lesion such as stroke or multiple sclerosis plaque
Secondary to trauma or Bell palsy
DIFFERENTIALS Section 4 of 10
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Other Problems to be Considered: Benign
essentialBlepharospasmOMDCraniofacial tremorFacial choreaTicsFacial
myokymiaWORKUP Section 5 of 10
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Lab Studies: Early cases of HFS may be difficult to distinguish
from facial myokymia, tics, or myoclonus originating in the cortex
or brainstem.
Neurophysiologic testing can be invaluable.
Spread and variable synkinesis on blink reflex testing and
high-frequency discharges on EMG (with appropriate clinical
findings) are diagnostic.
Stimulation of one branch of the facial nerve may spread and
elicit a response in a muscle supplied by a different branch.
Blink reflex studies may reveal synkinesis, which is not present
in essential blepharospasm, dystonia, or seizures.
Needle EMG shows irregular, brief, high-frequency bursts
(150-400 Hz) of motor unit potentials, which correlate with
clinically observed facial movements.
Imaging Studies: Magnetic resonance imaging is the imaging study
of choice, especially if an underlying compressive lesion is
suspected.
Perform angiography and/or magnetic resonance angiography prior
to a vascular decompression surgical procedure.
Other Tests: Cerebral angiography offers little diagnostic value
in HFS. Ectatic blood vessels rarely are identified, and it is
difficult to correlate vessels with the facial nerve. As
angiography may identify an aneurysm or vascular anomaly, it often
is performed prior to decompressive surgery to clarify the vascular
anatomy.
Procedures: In most patients, the treatment of choice is
injection of BTX under EMG guidance.
Chemodenervation safely and effectively treats most patients,
especially those with sustained contractions.
Relief of spasms occurs 3-5 days after injection and lasts
approximately 6 months.
Side effects of BTX injection (eg, facial asymmetry, ptosis,
facial weakness) usually are transient.
Most patients report a highly satisfactory response.
Caution patients that although BTX ablates the muscular spasm,
the sensation of spasm often persists.
TREATMENT Section 6 of 10
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Medical Care: Use medications in patients with noncompressive
lesions and early idiopathic HFS.
Response to medication varies but can be satisfactory in early
or mild cases.
The most helpful agents are carbamazepine and benzodiazepines
(eg, clonazepam).
Often, medication effects attenuate over time, necessitating
more aggressive treatment.
Medications may be used in early HFS (when spasms are mild and
infrequent) or in patients who decline BTX injection.
Surgical Care: Treat compressive lesions surgically.
Ectatic blood vessels cause HFS by compressing the facial nerve
as it exits the brainstem.
Surgical decompression of these blood vessels can yield
excellent results.
Patients with apparently idiopathic HFS may benefit from
posterior fossa exploration and microvascular decompression.
Myectomy rarely is required.
MEDICATION Section 7 of 10
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The goal of pharmacotherapy is reduction of abnormal muscle
contractions. Botulinum toxin type A is the treatment of choice.
Carbamazepine, benzodiazepines, and baclofen also may be used in
patients who refuse BTX injections or who are not surgical
candidates.
Drug Category: Toxins -- Botulinum toxin type A is the drug of
choice. It causes presynaptic paralysis of the myoneural junction
and reduces abnormal contractions. Therapeutic effects may last 3-6
months.
Botulinum toxin type B is useful in reducing excessive, abnormal
contractions associated with blepharospasm; binds to receptor sites
on the motor nerve terminals and after uptake inhibits release of
acetylcholine, blocking transmission of impulses in neuromuscular
tissue; 7-14 d after administering initial dose, assess patients
for a satisfactory response; increase doses 2-fold over previously
administered dose for patients who experience incomplete paralysis
of the target muscle.
Drug NameBotulinum toxin type A (BOTOX) -- Useful in reducing
excessive, abnormal contractions associated with blepharospasm;
binds to receptor sites on the motor nerve terminals and after
uptake inhibits release of acetylcholine, blocking transmission of
impulses in neuromuscular tissue; 7-14 d after administering
initial dose, assess patients for a satisfactory response; increase
doses 2-fold over previously administered dose for patients who
experience incomplete paralysis of the target muscle.
Adult DoseInitial dosing: Inject 1.25-2.5 U (0.05-0.1 mL) IM
into abnormally contracting muscles via hollow EMG needle; not to
exceed 25 U when given as a single injection or 200 U when given as
a cumulative dose in a 30 d period
Pediatric Dose12 years: Administer as in adults
ContraindicationsDocumented hypersensitivity
InteractionsCaution in patients taking aminoglycoside
antibiotics or any other drug that interferes with neuromuscular
transmission as they may potentiate effect of botulinum toxin
PregnancyC - Safety for use during pregnancy has not been
established.
PrecautionsDo not exceed recommended dosages and frequencies of
administration; presence of antibodies may reduce effectiveness of
therapy
Drug NameBotulinum toxin type B (Myobloc) -- When botulinum
toxin injection is indicated and type A toxin is ineffective,
injection with type B (Myobloc) should be considered.
Adult DoseNot established: This author suggests starting dose of
500-1000 U IM, divided among abnormally contracting muscles
Pediatric DoseNot established
ContraindicationsDocumented hypersensitivity to drug; patients
with hypersensitivity to type A toxin, hypersensitivity to type B
is significant concern, and use of type B in these patients is not
recommended
InteractionsCaution in patients taking aminoglycoside
antibiotics or any other drug that interferes with neuromuscular
transmission because they may potentiate effect of botulinum
toxin
PregnancyC - Safety for use during pregnancy has not been
established.
PrecautionsLikely to cause pain at injection site for a few
seconds immediately following administration
Drug Category: Benzodiazepines -- May potentiate effects of GABA
and facilitate inhibitory GABA neurotransmission. May act in the
spinal cord to induce muscle relaxation. Individualize treatment
for each patient.
Drug NameClonazepam (Klonopin) -- Useful in suppressing muscle
contractions by facilitating inhibitory GABA neurotransmission and
other inhibitory transmitters.
Adult DoseInitial dose: 1.5 mg PO in 3 divided doses Maintenance
dose: Increase initial dose by 0.5-1 mg PO q3d to a dose range of
0.05-0.2 mg/kg Alternative maintenance dose: 7-12 mg/d PO; not to
exceed 20 mg/d
Pediatric Dose70 kg = 1500-2100 mg/kg/d
ContraindicationsDocumented hypersensitivity
InteractionsMay decrease levels of dihydropyridine calcium
antagonists and oral contraceptives; can reduce serum
concentrations of carbamazepine, phenobarbital, phenytoin and
valproic acid; when oxcarbazepine is given in doses above 1200 mg/d
may increase phenytoin and phenobarbital serum concentrations
significantly; oxcarbazepine can reduce serum concentrations of
oral contraceptives and make oral contraceptives ineffective; can
increase clearance of felodipine
PregnancyC - Safety for use during pregnancy has not been
established.
PrecautionsMay decrease levels of dihydropyridine calcium
antagonists and oral contraceptives; can reduce serum
concentrations of carbamazepine, phenobarbital, phenytoin and
valproic acid; when oxcarbazepine is given in doses above 1200 mg/d
may increase phenytoin and phenobarbital serum concentrations
significantly; oxcarbazepine can reduce serum concentrations of
oral contraceptives and make oral contraceptives ineffective; can
increase clearance of felodipine
FOLLOW-UP Section 8 of 10
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Prognosis: HFS is a progressive, nonfatal illness. It almost
always responds favorably to treatment.
Patient Education: For excellent patient education resources,
visit eMedicine's Procedures Center. Also, see eMedicine's patient
education article BOTOX Injections.
MISCELLANEOUS Section 9 of 10
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Medical/Legal Pitfalls: At initial evaluation, consider HFS a
symptom, not a diagnosis.
An abnormal neurologic examination (except for the facial
movements) should prompt the search for an underlying cause (eg,
compressive lesion, tumor, stroke).
Look for demyelinating disease as a cause when HFS presents
before 50 years.
BIBLIOGRAPHY Section 10 of 10
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MERGEFORMATINET
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Treatment Medication Follow-up Miscellaneous Bibliography
Adler CH, Zimmerman RA, Savino PJ, et al: Hemifacial spasm:
evaluation by magnetic resonance imaging and magnetic resonance
tomographic angiography. Ann Neurol 1992 Oct; 32(4):
502-6[Medline].
Colosimo C, Chianese M, Giovannelli M, et al: Botulinum toxin
type B in blepharospasm and hemifacial spasm. J Neurol Neurosurg
Psychiatry 2003 May; 74(5): 687[Medline].
Cruccu G, Inghilleri M, Berardelli A, et al: Pathophysiology of
hemimasticatory spasm. J Neurol Neurosurg Psychiatry 1994 Jan;
57(1): 43-50[Medline].
Elston JS: The management of blepharospasm and hemifacial spasm.
J Neurol 1992 Jan; 239(1): 5-8[Medline].
Jankovic J, Schwartz K, Donovan DT: Botulinum toxin treatment of
cranial-cervical dystonia, spasmodic dysphonia, other focal
dystonias and hemifacial spasm. J Neurol Neurosurg Psychiatry 1990
Aug; 53(8): 633-9[Medline].
Jannetta PJ, Abbasy M, Maroon JC, et al: Etiology and definitive
microsurgical treatment of hemifacial spasm. Operative techniques
and results in 47 patients. J Neurosurg 1977 Sep; 47(3):
321-8[Medline].
Kraft SP, Lang AE: Cranial dystonia, blepharospasm and
hemifacial spasm: clinical features and treatment, including the
use of botulinum toxin. CMAJ 1988 Nov 1; 139(9):
837-44[Medline].
Mauriello JA, Leone T, Dhillon S, et al: Treatment choices of
119 patients with hemifacial spasm over 11 years. Clin Neurol
Neurosurg 1996 Aug; 98(3): 213-6[Medline].
Moller AR: The cranial nerve vascular compression syndrome: I. A
review of treatment. Acta Neurochir (Wien) 1991; 113(1-2):
18-23[Medline].
Moller AR: The cranial nerve vascular compression syndrome: II.
A review of pathophysiology. Acta Neurochir (Wien) 1991; 113(1-2):
24-30[Medline].
Reimer J, Gilg K, Karow A, et al: Health-related quality of life
in blepharospasm or hemifacial spasm. Acta Neurol Scand 2005 Jan;
111(1): 64-70[Medline].
NOTE:
Medicine is a constantly changing science and not all therapies
are clearly established. New research changes drug and treatment
therapies daily. The authors, editors, and publisher of this
journal have used their best efforts to provide information that is
up-to-date and accurate and is generally accepted within medical
standards at the time of publication. However, as medical science
is constantly changing and human error is always possible, the
authors, editors, and publisher or any other party involved with
the publication of this article do not warrant the information in
this article is accurate or complete, nor are they responsible for
omissions or errors in the article or for the results of using this
information. The reader should confirm the information in this
article from other sources prior to use. In particular, all drug
doses, indications, and contraindications should be confirmed in
the package insert. FULL DISCLAIMER
Hemifacial Spasm excerptEyelid Myokymia
http://www.emedicine.com/oph/topic607.htm
Last Updated: August 4, 2005
Synonyms and related keywords: eyelid twitching, eyelid jumping,
muscle contractions, blepharospasm, Meige syndrome, hemifacial
spasm, spastic-paretic facial contracture, botulinum toxin A,
BOTOX, BOTOX injections
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Author: Byron L Lam, MD, Professor, Department of Ophthalmology,
Bascom Palmer Eye Institute, University of Miami School of
Medicine
Byron L Lam, MD, is a member of the fol