The Landau-Kleffner syndrome or 'acquired aphasia with convulsive disorder'. Long-term follow-up of six children and a review of the recent literature.

We present six patients with acquired aphasia with convulsive disorder (Landau-Kleffner syndrome) and distill the main clinical features from a review of the recent literature. Our series showed that the clinical picture can vary at onset, as well as during the course of the illness, and that the long-term outcome of the aphasia is quite unpredictable, despite the fact that epilepsy and electroencephalographic abnormalities usually regress or disappear with the years. We also call attention to the electroencephalographic phenomenon of electrical status epilepticus during slow sleep, and we suggest that the course of the aphasia may well be linked to the appearance and disappearance of electrical status epilepticus during slow sleep. Therefore, we recommend a sleep electroencephalogram in all children with Landau-Kleffner syndrome. Finally, our findings did not demonstrate the beneficial effect of treatment with anticonvulsants on the aphasia, but recent studies have shown that treatment with corticosteroids, whether combined with anticonvulsants, is effective.