Age of onset and outcome in Landau-Kleffner syndrome (1985).

In 1957 Landau and Kleffner described an unusual childhood disorder which they termed ‘syndrome of acquired aphasia with convulsive disorder’, in which language regresses after a period of normal development and seizures develop. Children with this disorder typically have severe receptive language difficulties and often are at first thought to be deaf. However, pure-tone audiometry shows normal peripheral hearing, and usually there are no abnormal neurological signs. Some children do not have seizures but do have an abnormal EEG, typically with spike activity in one or both temporal lobes. Since the original description by Landau and Kleffner several further cases have been reported ...