Landau Kleffner syndrome: electroclinical and etiopathogenic heterogeneity.

Landau - Kleffner syndrome is a rare, functional, age-related epilepsy with aphasia and epileptiform discharges on EEG. The heterogenity of clinical presentations, course, long-term outcome and response to treatment suggests multiple underlying etiologies. Normal children abruptly develop deterioration of language functions along with spike and wave discharges on EEG. Clinical seizures may or may not be present. The aphasia responds poorly to most drugs. Valproic acid and benzodiazepines are most effective. Steroids and intravenous immunoglobulins have shown a variable response. Long-term outcome of aphasia is variable, many patients persist with residual impairment. Important questions regarding etiopathogenesis are unanswered.