Childhood paroxysmal kinesigenic dyskinesia: report of seven cases with onset at an early age.

We report on seven children who developed abnormal involuntary movements as early as 1.5 years after unremarkable term births. The paroxysmal episodes of abnormal movements were typically precipitated by sudden, voluntary movements, or a startle. The clinical features in each case were consistent with the diagnosis of paroxysmal kinesigenic dyskinesia (PKD). The episodes of abnormal movements are described. EEG was obtained in all cases, and video/electroencephalography (VEEG) monitoring was performed to exclude the possibility of epilepsy in six patients. VEEG studies revealed multiple events consistent with PKD; no ictal epileptiform discharges were recorded. The apparent benign nature of the disorder, as well as treatment options with antiepileptic drugs, was discussed with the parents, and most chose no pharmacologic treatment. We discuss clinical characteristics of PKD, treatment with anticonvulsant therapy, and recent insights into its possible pathophysiology.