A 26-year-old woman with an 8-year history of untreated multiple sclerosis (MS) presented with acute-onset continuous involuntary wavelike movements on the right side of her face (video). Neurologic examination revealed continuous right-sided hemifacial myokymia (CFM), with no concurrent hemifacial spasm. MRI documented a new nonenhancing lesion in the dorsolateral right pontine tegmentum and multiple supratentorial demyelinating lesions (figure, A–D). Symptoms spontaneously resolved 3 weeks later. MS relapses may involve the postnuclear facial nerve course within the pontine tegmentum, producing ipsilateral CFM.1,2 Strict unilaterality and perioral involvement argue against benign eyelid myokymia and should suggest a structural pontic lesion, warranting neuroimaging.