Landau-Kleffner syndrome (LKS), or acquired epileptiform aphasia, is an epilepsy syndrome involving progressive neuropsychological impairment related to the appearance of paroxysmal electroencephalograph (EEG) activity.
History
Frank R Kleffner [1925-2015William Landau & Frank Kleffner in 1957 [Landau W & Kleffner F, 1957] described six patients who were diagnosed with “acquired largely receptive aphasia, sometimes recurrent with some association with a convulsive disorder.” These attacks began as partial, myoclonic, or absence seizures, which they called “petit mal,” but were not closely correlated with the aphasic symptoms.
In cases with an epileptiform pattern, “a severe paroxysmal EEG abnormality” was seen, usually diffuse. Any EEG improvement paralleled the speech improvement, and the general prognosis was good with appropriate treatment.
William M Landau 1924-2017EEGs in five cases showed “generalized spikes” in three patients, spikes on the right hemisphere in one patient, and, for the fifth patient, only slow waves in the left temporal area that later became generalized.