Magnetoencephalography in children with Landau-Kleffner syndrome and acquired epileptic aphasia.

BACKGROUND AND PURPOSE: Landau-Kleffner syndrome (LKS) is epileptiform aphasia acquired during childhood and occurring in children with previously normal language development. The epileptiform activity in these children is thought to result in a functional ablation of eloquent speech areas. The purpose of this study was to investigate the usefulness of magnetoencephalography (MEG) for localizing the source of epileptiform activity in these patients.

METHODS: Nineteen patients with acquired aphasia and a suspected diagnosis of LKS were referred for MEG evaluation. Patients ranged in age from 4 to 14 years. Fourteen MEG studies were performed on a 74-channel system, four on a 148-channel whole-head system, and one on a 37-channel system.

RESULTS: Thirteen of the 19 patients had perisylvian MEG spikes. In 10 of the patients, the spikes were bilateral, and in three they were unilateral. Four other patients had non-sylvian spikes, and two patients had no spikes recorded. The results of MR imaging were normal or noncontributory for all 19 patients.

CONCLUSIONS: MEG can play a useful role in evaluating children with LKS and acquired epileptiform aphasia, both in diagnosis and in aiding presurgical localization of epileptiform activity when surgery is being considered.