Hemifacial spasm

Hemifacial spasm (HFS) is a condition that causes transient, involuntary spasms involving all or part of one-half of the face. (1,2) Spontaneous muscle twitching usually begins in one orbicularis oculi, less often the oris. Over months to years, HFS usually spreads to involve all the facial muscles on one side, but remains strictly limited to the muscles supplied by the facial nerve. Fully developed HFS causes repetitive, paroxysmal, involuntary, spasmodic tonic and clonic contractions of the muscles innervated by the facial nerve on the involved side of the face (Video). The spasms persist in sleep, and are often exacerbated by chewing or speaking.

The brow lift sign is co-contraction of the frontalis and orbicularis oculi causing simultaneous eye closure and paradoxical elevation of the eyebrow during a spasm. This movement is impossible to execute voluntarily and does not occur in blepharospasm. It seems very specific for HFS. (3). The brow lift sign was described by Babinski and is one of several signs referred to as “the other Babinski sign.”

Video legend. Left hemifacial spasm, much improved after botulinum toxin injections.

References

1. Chopade TR, Bollu PC. Hemifacial Spasm. 2019 Dec 23. Treasure Island (FL): StatPearls Publishing; 2020 Jan-.

2. Chaudhry N, Srivastava A, Joshi L. Hemifacial spasm: The past, present and future. J Neurol Sci. 2015;356:27-31.

3. Stamey W, Jankovic J. The other Babinski sign in hemifacial spasm. Neurology 2007;69:402-4