Paroxysmal dystonic choreoathetosis: Clinical features and investigation of pathophysiology in a large family

Paroxysmal dystonic choreoathetosis (PDC) is an unusual hyperkinetic moveme nt disorder characterized by attacks of chorea, dystonia, and ballism with onset in childhood. We report a large British family with dominantly inheri ted PDC linked to chromosome 2q and describe the clinical features in 20 af fected family members. Attacks were precipitated by a variety of factors, i ncluding caffeine, alcohol, or emotion, and could be relieved by short peri ods of sleep in most subjects. The clinical features in the family are comp ared with those of 11 other PDC families in the literature and a core pheno type for PDC suggested. CSF monoamine metabolites measured at baseline and during an attack in one subject were found to increase during the attack. M agnetic resonance spectroscopy of brain and basal ganglia performed both du ring and between attacks was normal. Positron emission tomography using the D-2 receptor ligand, C-11-raclopride, showed no abnormalities.