Dystonia associated with carbamazepine administration: experience in brain-damaged children.

Carbamazepine is an anticonvulsant most effective in treating complex partial and generalized tonic-clonic seizures. We have cared for three children in whom four episodes of dystonia proceeding to opisthotonus occurred in association with carbamazepine use. The patients, a 4-year-old with microcephaly and severe retardation, a 1-year-old with cerebral dysgenesis, and a 5-year-old with spastic quadriplegia and mild retardation, all had seizures unresponsive to multiple anticonvulsant combinations. In all three patients carbamazepine was introduced and gradually increased to a maximum dosage of 25 mg/kg of body weight per day. Dystonic symptoms began two to three weeks after introduction of therapy and subsided within three weeks after discontinuation. In one child, a second course of carbamazepine resulted in a return of the dystonia. The currently available clinical and neuropharmacologic data suggest that carbamazepine may be an antagonist of dopamine and that this property is responsible for the production of dystonia.