Landau-Kleffner syndrome (LKS), also called acquired epileptiform aphasia, is a rare, childhood neurological disorder characterized by the sudden or gradual development of aphasia (loss of language) and an abnormal electro-encephalogram (EEG). LKS affects the parts of the brain that control speech and comprehension (understanding). The disorder usually occurs in children between the ages of 3 and 7. Typically, these children develop normally and then, for no apparent reason, they lose the ability to understand others and to speak. While many of the affected individuals have seizures (convulsions), some do not. The disorder is difficult to diagnose and may be misdiagnosed as autism, pervasive developmental disorder, hearing impairment, learning disability, auditory/verbal processing disorder, attention deficit disorder, mental retardation, childhood schizophrenia, or emotional/behavioral problems.
Treatment for LKS usually consists of medications, such as anticonvulsants and corticosteroids, and speech therapy, which should be started early. Another controversial treatment option involves a surgical technique called multiple subpial transection in which the pathways of abnormal electrical brain activity are severed.