Twitches & Hemifacial Spasm

Twitches & Hemifacial Spasm

Twitches

Twitches are involuntary muscle spasms that are NOT suppressible or able to be volitionally initiated and there is no compulsion to generate the movement.

Hemifacial Spasm

Unilateral repetitive, paroxysmal, uncontrollable spasmodic contractions of facial nerve innervated musculature: there is a unilateral spasmodic twitch of the eyelid, along with a facial grimace (twitch of the side of the face).
It most commonly secondary to neurovascular compression of the facial nerve; hence microvascular decompression is sometimes done to prevent the twitching.
It typically starts in the orbicularis oculi and then propagates via ephaptic transmission: the impulse passes between facial nerve branches.