Spacey et al. (2006) reported a Canadian family of European descent in which 10 members spanning 4 generations had paroxysmal nonkinesigenic dyskinesia (PNKD) inherited in an autosomal dominant pattern. Affected family members presented with episodic dystonia primarily affecting ... Spacey et al. (2006) reported a Canadian family of European descent in which 10 members spanning 4 generations had paroxysmal nonkinesigenic dyskinesia (PNKD) inherited in an autosomal dominant pattern. Affected family members presented with episodic dystonia primarily affecting the hands and feet symmetrically. Age at onset ranged from childhood to age 50 years. Episodes lasted 2 to 5 minutes (up to 10 minutes in 1 patient) and occurred daily or several times per month. Alcohol, caffeine, and excitement were not obvious triggers. Three patients also had migraines, 1 had a grand mal seizure at age 11 years, and 1 had a single infantile seizure.