Karl Kleist

Karl Kleist was a German neurologist and psychiatrist who made notable advances in descriptive psychopathology and neuropsychology. Kleist coined the terms unipolar (‘einpolig’) and bipolar (‘zweipolig’) that are now used in the concepts of unipolar depression and bipolar disorder. His main publications were in the field of neurology, and he is particularly known for his work on the localisation of function in the cerebral cortex of man including mapping of cortical functions on brain maps. The work is based on several hundred cases of shot wounded patients of World War I, whose functional deficits Kleist deliberately studied and described in detail during their lifetime. Later on, by means of brain autopsy, he documented the lesion and was, thus, able to localize brain function in each single case doing this also on cytoarchitectonical grounds. Kleist was a student of Carl Wernicke and his work was closely associated with the Wernicke tradition. Among his students were Edda Neele and Karl Leonhard, who further developed the Kleist-Leonhard classification system of psychosis.