hemifacial spasm


hemifacial spasm

a disorder of the facial nerve characterized by unilateral involuntary paroxysmal contractions of the facial muscles, caused by high-frequency bursts of motor units lasting from a few msec to several seconds; reported causes include compression of the ipsilateral facial nerve near its exit from the pons by a vascular malformation, compression of the ipsilateral facial nerve by a posterofossa neoplasm, and idiopathic derivations.

he·mi·fa·cial spasm

(hem'ē-fā'shăl spazm) A facial nerve disorder, with onset in late adult life, characterized by episodes of irregular, sometimes painful, myoclonic contractions of various facial muscles; triggered by voluntary or reflex movements of the face, spasm typically begins in the orbicularis oculi muscle and then spreads; occasionally a sequela of Bell palsy, but more often the result of proximal compression of the facial nerve by an aberrant blood vessel or neoplasm.

he·mi·fa·cial spasm

(hem'ē-fā'shăl spazm) Disorder of facial nerve characterized by unilateral involuntary paroxysmal contractions of facial muscles, caused by high-frequency bursts of motor units lasting from a few milliseconds to several seconds.