Landau–Kleffner syndrome also called infantile acquired aphasia, acquired epileptic aphasia or aphasia with convulsive disorder - is a rare childhood neurological syndrome. It is named after William Landau and Frank Kleffner, who characterized it in 1957 with a diagnosis of six children.
A child having previously normal language development losses both expressive and receptive language skills without accompanying cognitive decline, with or without clinical seizures but with abnormal EEG. The cause of epilepsy may be heterogeneous.
It is characterized by the sudden or gradual development of aphasia (the inability to understand or express language) and an abnormal electroencephalogram. LKS affects the parts of the brain that control comprehension and speech (Broca's area and Wernicke's area). The disorder usually occurs in children between the ages of 3 and 7 years. There appears to be a slight male dominance in the diagnosis of the syndrome (ratio of 1.7:1, men to women).