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Bell's Palsy - Idiopathic Unilateral Facial Paralylsis                       bell_palsy2007.pdf    Editorial: bell_palsy2007-2.pdf

SX:
Global unilateral facial muscle weakness is the hall mark of this condition.
It may develop rapidly within a few hours or evolve over 1-2 days, & is often accompanied by pain behind the ipsilateral ear and excess tearing.  Numbness of the face is also a common complaint, but inevitably refers to a proprioceptive sensation that accompanies weakness.  Hyperacusis, diminished lacrimation, and abnormal taste sensation are present to variable degress.
Untreated, 80-85% of all patients with Bell's palsy recover completely or almost so.  In a smaller number, persistent facial weakness ensues.  Rarely, motor recovery fails completely.

The cause of Bell's palsy is uncertain:  A viral neuritis caused by such agents as herpes simplex or herpes zoster is a possible mechanism, even in patients who do not have a skin eruption.

Bell's palsy or idiopathic palsy is the most common disorder affecting the facial nerve. Diagnosis is primarily one of exclusion. There is typically an acute unilateral facial paresis that evolves in 24 to 48 hours. Etiology and pathophysiology are heavily disputed, and as of yet unknown. The natural history of Bell's palsy is favorable. Eight-four percent show satisfactory recovery without any treatment, however 16% suffer moderate to severe sequelae.

Prognosis is influenced by degree of paresis, age of patient, and time until first signs of recovery. Prognostic testing currently involves various electrophysiological tests. More than 90% degeneration of the facial nerve carries a poor prognosis for recovery; these are the patients who may benefit from facial nerve decompression surgery. If surgery is performed it should be done early (< 21 days from onset of palsy) and should include a middle cranial fossa decompression.

Suggested Rx of potential benefit:

• Prednisone 25 mg bid x 10days.
• Acylovir 400 mg 5x/day for about 10 days. (No additional benefit in combination with prednisolone.   NEJM Oct 18, 2007 Vol 357:1598-1607)

· Local eye care - artificial tears during day, lacrilube or celluvisc ointment at night, tape eye diagonally avoiding contact with cornea.

* Ramsay Hunt Synd = Herpes zoster oticus results from involvement of the facial & auditory nerves.  Presenting features include vesicles in the external ear & ipsilateral facial paralysis.  This localization of zoster may be accompanied by hearing loss, vertigo, loss' of taste, tongue vesicles, & other signs consistent with involvement of additional cranial ganglia, esp. those of the 9th & 10th cranial nerves.

Results Final outcomes were assessed for 496 of 551 patients who underwent randomization. At 3 months, the proportions of patients who had recovered facial function were 83.0% in the prednisolone group as compared with 63.6% among patients who did not receive prednisolone 25 mg PO BID  x 10 days (P<0.001) and 71.2% in the acyclovir  400 mg 5x/day group as compared with 75.7% among patients who did not receive acyclovir (adjusted P=0.50). After 9 months, these proportions were 94.4% for prednisolone and 81.6% for no prednisolone (P<0.001) and 85.4% for acyclovir and 90.8% for no acyclovir (adjusted P=0.10). For patients treated with both drugs, the proportions were 79.7% at 3 months (P<0.001) and 92.7% at 9 months (P<0.001). There were no clinically significant differences between the treatment groups in secondary outcomes. There were no serious adverse events in any group.

Conclusions In patients with Bell's palsy, early treatment with prednisolone significantly improves the chances of complete recovery at 3 and 9 months.
There is no evidence of a benefit of acyclovir given alone or an additional benefit of acyclovir in combination with prednisolone.  
REF: NEJM Volume 357:1598-1607 October 18, 2007.  Comment: ACP Journal Club. 2008 Mar-Apr;148:29.

Although the antiviral agent acyclovir is currently used for the treatment of Ramsay Hunt syndrome, its effects on facial nerve and hearing recovery remain controversial. We retrospectively analyzed the effects of acyclovir-prednisone treatment in 80 Ramsay Hunt patients. Of 28 patients for whom treatment was begun within 3 days of the onset of facial paralysis, the recovery from paralysis was complete in 21 (75%). By comparison, of 23 patients for whom treatment was begun more than 7 days after onset, recovery from facial paralysis was complete in only 7 (30%). A significant difference in facial nerve recovery was found between these groups. Early (within 3 days) administration of acyclovir-prednisone was proved to reduce nerve degeneration by nerve excitability testing. Hearing recovery also tended to be better in patients with early treatment. There was no significant difference in facial nerve outcome between intravenous and oral acyclovir treatment.

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):371-378
Adour KK, Ruboyianes JM, Von Doersten PG, Byl FM, Trent CS, Quesenberry CP Jr, Hitchcock T
Department of Head and Neck Surgery, Kaiser Permanente Medical Center, Oakland, CA 94611-5693, USA.

In a double-blind study, we compared the final outcome of 99 Bell's palsy patients treated with either acyclovir-prednisone (53 patients) or placebo-prednisone (46 patients).

For patients receiving acyclovir 2,000 mg (400 mg 5 times daily) for 10 days. Electrical tests included electroneurography and the maximal stimulation test.

Treatment with acyclovir-prednisone was statistically more effective in returning volitional muscle motion (recovery profile of 10; p = .02) and in preventing partial nerve degeneration (p = .05) than placebo-prednisone treatment. The t-tests indicated that the recovery profile and index means were significantly better for the acyclovir-treated group (recovery profile t = 1.99, p = .051; recovery index t = 2.10, p = .040).
We conclude that acyclovir-prednisone is superior to prednisone alone in treating Bell's palsy patients and suggest that herpes simplex is the probable cause of Bell's palsy.

          2008