Effects of high-dose intravenous corticosteroid therapy in Landau-Kleffner syndrome.

Two children with Landau-Kleffner syndrome were successfully treated with antiepileptic drugs and a high-dose intravenous corticosteroid. A combination of valproate and a benzodiazepine (clonazepam or diazepam) ameliorated epileptic seizures and electroencephalographic spikes and waves, but speech disturbances persisted. Both patients were treated with an intravenous infusion of high-dose methylprednisolone sodium succinate (20 mg/kg daily) for 3 consecutive days. This infusion was repeated three times with a 4-day interval between treatments, which resulted in a rapid improvement in speech ability. After intravenous therapy, prednisolone was given orally (2 mg/kg daily for 1 month, then gradually withdrawn), which maintained the clinical improvement in speech.