University of Iowa Family Practice Handbook, Fourth Edition, Chapter 20

Otolaryngology: Facial Nerve Paralysis

Matthew L. Lanternier, MD
Department of Family Medicine
University of Iowa College of Medicine
Peer Review Status: Externally Peer Reviewed by Mosby

1. Bell's palsy (idiopathic) is the most frequent diagnosis but is a diagnosis of exclusion. Bell's palsy (a peripheral seventh cranial nerve lesion) can be differentiated from a central seventh nerve lesion by exam. In Bell's palsy, the motor fibers of all three branches are involved including the ophthalmic branch (forehead weakness). In a central seventh nerve lesion, the forehead is partially spared because of crossed nerve fibers.
2. Symptoms include preceding retroauricular headache, numbness of middle and lower areas or the face (which may not be demonstrable on exam) otalgia, hyperacusis, decreased tearing, altered taste (ante- rior 2/3 of tongue), and facial weakness with equal weakness in all branches of the seventh cranial nerve. Annual incidence is about 25 per 100,000 per year.
3. Onset is rapid over 24-48 hours with maximum paralysis within 5 days. Up to 16% develop sequelae after Bell's palsy.
4. Differential and possible causes. Lyme disease (bilateral in 30%), Mycoplasma, sarcoid (Heerford syndrome), vasculitis, diabetes, rickettsial disease, intracranial pathologic condition (e.g., acoustic neuroma), complication of otologic surgery, HIV, otitis media, multiple sclerosis, and trauma. Herpes zoster oticus (Ramsay-Hunt syndrome) will present with vesicular eruptions. There is some evidence that herpes simplex virus may be an inciting factor in at least some cases of Bell's palsy. Intracranial pathology (tumor, meningitis, CVA) should be ruled out by history, physical exam, and testing as indicated. History of facial twitching, slowly progressing weakness, hearing loss, or additional cranial nerve involvement is suggestive of tumor and should be evaluated with CT or an MRI.
5. Treatment. Characterized by a high rate of spontaneous recovery, up to 86% in two weeks.
   1. If the patient is unable to close the eye, tape or patch the eye with lubricating ointment (such as Lacri-Lube at night and artificial tears during the day) to prevent corneal drying and injury. In severe cases surgery can be done to put a gold weight in the upper eyelid or do a tarsorrhaphy.
   2. Although steroids continue to be widely used, their use is controversial, and there is no good evidence that they change the course of the illness. If you choose to use steroids, a reasonable course is 60 mg PO QD for 5 days with a tapering off over 7 to 10 days. It will certainly be of no benefit if started over 72 hours after onset of symptoms. Over 85% will resolve without treatment within 3 weeks. Many others will improve up to 6 months out.
   3. Acyclovir has been used but again there is no evidence that it is helpful.
   4. Those with a dense paralysis or with evidence of complete muscle denervation by EMG have a worse prognosis. An EMG can be checked during the second week of disease if there is no evidence of improvement. Some recommend surgical decompression of the nerve at this point.
   5. Some evidence suggests a benefit with prednisone/acyclovir combination but this needs further trials to confirm.
   6. Influenza-like symptoms and erythema chronicum migrans should be suggestive of Lyme disease. See Chapter 10 for further information.

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See related Provider Topics Brain and Nervous System, Ear, Nose and Throat, Facial Injuries and Disorders or Injuries and Wounds.

See related Patient Topics Brain and Nervous System, Ear, Nose and Throat or Injuries and Wounds.

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