Landau-Kleffner syndrome diagnosed after 9 years of age: Another Landau–Kleffner syndrome?

Abstract

We report five cases of Landau-Kleffner syndrome with onset of language disorders after the age of 9. Epileptic phenomena had common features with those typically described in cases of Landau–Kleffner with earlier onset. However, patterns of linguistic deficits differed. Massive comprehension disorder with auditory agnosia was found in only one subject. For the other subjects the aphasia was primarily expressive with dysfluency and word-finding difficulties. The data suggest that the prevalence of massive receptive disorders in Landau–Kleffner syndrome varies according to the age at onset. The time of onset of a complete syndrome (aphasia + epilepsy) could also be of some critical importance since epileptic phenomena in our cases occurred long before the onset of linguistic impairments. An alternative to the ‘perceptive theory’ must be found, as it does not apply to children who do not display comprehension difficulties.