Norman Geschwind and the use of history in the (re)birth of behavioral neurology.

When Norman Geschwind (1926-1984) attended medical school in the 1940s, his psychiatry professors taught as if behavior were unrelated to neuropathology. The focus of neurology remained the diagnosis and treatment of aphasias and epilepsies, while cognitive impairments and developmental disorders were classified as functional (psychological) disorders. Geschwind was troubled by the fact that many of the patients he saw with neurological deficits also presented with behavioral (developmental) disorders. Geschwind's generation also had been taught that aphasias resulted from global rather than localized or focal neurological lesions. These holists, including the prepsychoanalytic Sigmund Freud, targeted the work of aphasiologist Carl Wernicke as an exemplar of the flaws of the localizationist hypothesis. Reading Wernicke in the original, Geschwind discovered a complex and multilayered explanation for aphasias that implicated lesions located in association pathways that, when extensive, resulted in behavioral disorders. Geschwind also reread the works of the holists, discovering that, while their rhetoric rejected Wernicke, their explanations of aphasias actually reinforced Wernicke's hypothesis. Building on his reading of these historical documents and his clinical experiences, Geschwind urged the resurrection of Wernicke's disconnection syndromes that Geschwind labeled as Behavioral Neurology.