Phenobarbital-induced dyskinesia in a neurologically-impaired child

A 2-year-old child with known neurologic impairment developed a dyskinesia soon after starting phenobarbital therapy for seizures. Known causes of movement disorders were eliminated after evaluation. On repeat challenge with phenobarbital, the dyskinesia recurred. Phenobarbital should be added to the list of anticonvulsant drugs that can cause movement disorders.