Familial Hemiplegic Migraine

Familial hemiplegic migraine is a rare autosomal dominant subtype of migraine associated with transient hemiparesis. Mutations in CACNA1A, ATP1A2, or SCN1A affect neuronal ion channels, leading to cortical spreading depression. Clinical manifestations include unilateral weakness, headache, visual aura, and ataxia. Diagnosis is clinical and supported by genetic testing. Management includes avoidance of triggers, prophylactic medications, and acute migraine therapy; prognosis is generally favorable, though attacks can be debilitating.