What is a Hemifacial Spasm?

It is condition that involves the involuntary contration of the facial muscles on one half of the face. It occurs in most often in indivuduls who are over 40 years of age, but can affect youth.

What are the causes?

Muscle spasming comes from the misfiring of an irritated nerve . The nerves that are generally affected first are the ones that control the eye, spcifically the orbicularis oculi. Eventually other nerves that innevate the facial muscles become irritaed later. Compression of the facial nerves from brain hemorrhaging, the building of plaque in the blood vessels, brain tumors, cysts, or abberrant blood vessels in the brain are some of the physical irritants that cause spasming. These physical irritants wear down the myelin protein sheath that protect the nerve filament, thus short circuiting the nerve causing it to misfire.

 What are the treatment options for this condition?

Anti-convulsant and muscle relaxant drugs are useful in treating this condition, but success is limited. Botox injections can also provide temporary relief for a number of months, but with diminishing results. Eventually, botox injections lose their effectiveness as the body develops antibodies that decrease the desired affect of the toxin. Surgical intervention is the most permanent solution to this condition. Surgery involves the physcial removal or shifting of the physcial matter that is irritating the nerve. In many cases, the nerve irritant causing the issue is an abberrant blood vessel in the brain. If this is the case,  a microvscular decompression procedure provides excellent results.This procedure treates Hemifacial Spasms by shifting the brain vessel(s) that is rubbing against the affected nerve.

Figure A: Intraoperative image of right cerebellum with a loop of anterior inferior cerebellar artery compressing anterior surface of right vestibulo-facialnerve complex. Figure B: Intraoperative image of Teflon® decompressing vestibulo-facial complex from compressing loop of anterior inferior cellebellar artery