LKS may also be called infantile acquired aphasia, acquired epileptic aphasia or aphasia with convulsive disorder. This syndrome was first described in 1957 by Dr. William M. Landau and Dr. Frank R. Kleffner, who identified six children with the disorder. LKS occurs most frequently in normally developing children who are between 3 and 7 years of age. For no apparent reason, these children begin having trouble understanding what is said to them. The auditory agnosia may occur slowly or very quickly.
Parents often think that the child is developing a hearing problem or has become suddenly deaf.
Hearing tests, however, show normal hearing. Children may also appear to be autistic or developmentally delayed. Children who have learned to read and write before the onset of auditory agnosia can often continue communicating through written language. Some children develop a type of gestural communication or sign-like language. The communication problems may lead to behavioral or psychological problems.