Nejm 2007;357:1653

Cause:

Idiopathic (2/3); H. simplex(Ann IM 1996;124:27); Sjogren’s syndrome, hypertension, eclampsia, diabetes, amyloidosis; sarcoid, usually bilateral; Lyme disease (Nejm 1985;312:869); nasal influenza vaccine (Nejm 2004;350:896); H. zoster(10%; called the Ramsay-Hunt syndrome), basilar skull fracture (5%), otitis media (2%), birth (2%), other including syphilis (1%)

Increased incidence in diabetics (Nejm 1982;307:348), or are those diabetic nerve infarcts?

Sx:Facial weakness, acute onset, may also be painful; increased noise sensitivity from diminished stapedial reflex

Si: Cranial nerve VII weakness. Decreased taste on anterior tongue (helpful if absent taste because it distinguishes from primary motor disease, eg, polio); only true occasionally, since often the process is more distal and chorda tympani is spared. Diminished ipsilateral salivation and lacrimation from lesions proximal to geniculate ganglion

80% recover completely, only 50% if Ramsay-Hunt syndrome. If there is some residual motion on affected side, patient always recovers (Nejm 1975;292:748)

Corneal ulceration, prevent by taping lid, esp hs. Misregeneration of the nerve, causing "jaw winking" of orbicularis ori with orbicularis oculi and vice versa; parasympathetics regenerate incorrectly sometimes leading to eye tearing when taste good food ("crocodile tears")

Lab:

Noninv:EMG at 2 weeks if still fibrillation; consider decompression of nerve then

Rx:

Protect eyes w Lacrilube gtts and hs taping

Steroids, as prednisone 60 mg po qd × 10 d (ACP J Club 2008;148:29; Nejm 2007;357;1598) DBCT shows benefit (NNT-9) but valcyclovir (Antiviral Antibiotics) w steroids steroids may be helpful (Jama 2009;302:985 meta analysis), esp if complete paralysis (Nejm 2007;357:1598, 1563)

Surgery no help? (Nejm 1975;292:748), perhaps decompression if flat EMG at 1 wk; physical therapy program no help (Nejm 1982;307:348)