Abstract
Background: Hemifacial spasm is diagnosed on a clinical base, with certain atypical features alerting the physician for mimics.
Phenomenology shown: Hemifacial neuromyotonia/myokymia characterized by tonic hemifacial contraction followed by multifocal undulating hemifacial twitches.
Educational value: These features are a red flag for (post-irradiation) facial neuromyotonia/myokymia which generally responds well to low dose carbamazepine.