Landau-Kleffner syndrome: Consistent response to repeated intravenous gamma-globulin doses: A case report

Purpose: Although several treatments have been tried for Landau-Kleffner syndrome (LKS) too many patients are refractory to known therapies. We report an 8-year-old girl who failed other therapies but who had a consistent response after treatment with intravenous (i.v.) gamma-globulin. Methods: We monitored the girl from the age of 6 years, when she presented with a 6-month history of loss of language with normal hearing, normal brain magnetic resonance imaging (MRI), increased cerebrospinal fluid (CSF) IgG index, and an EEG showing almost continuous, pre dominantly left-sided spike- and slow-wave complexes. She had no clinical seizures and did not respond to consecutive trials of valproate (VPA), clonazepam (CZP), prednisone, and carbamazepine (CBZ). She received three courses of intravenous (i.v.) gamma-globulin; after each course, clinical and electrographic improvement lasted a few months. After each of the initial two courses, clinical improvement lasted 3-4 months but was followed by recurrence of the spikes on the EEG and by speech deterioration. Results: However, her last remission has been continuous for the past 16 months. Her CSF IgG index became normal after the first i.v, gamma-globulin infusion. Conclusions: Based on our experience with this patient and on other investigators' experience, we believe that further research into immunologic mechanisms and therapies of this syndrome are warranted.