Landau-Kleffner syndrome (LKS)
is a rare, childhood neurological disorder characterized by the sudden or gradual development of aphasia (the inability to understand or express language) and an abnormal electro-encephalogram (EEG). The disorder usually occurs in children between age 5 and 7. Typically, children with LKS develop normally but then lose their language skills for no apparent reason. While many of the affected individuals have seizures, 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. Some affected children may have a permanent severe language disorder, while others may regain much of their language abilities (although it may take months or years). Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.