Disconnexion Syndromes in Animals and Man: Part I

The early successes of the views of Broca and Wernicke led the classical neurologists to a mode of analysis of the disturbances of the higher neurological functions subsequently to be labelled with the derisive term “diagrammaking.” Starting from the picture of the brain as a collection of sets of more or less specialized groups of cells connected by relatively discrete fibre pathways, these classical neurologists deduced a series of symptom complexes. On the basis of this model clinical syndromes could be divided into those resulting from lesions of grey matter and those which resulted from lesions of the white matter interconnecting specialized regions. Thus, cortical syndromes were distinguished from “conduction” syndromes. Basically it was this mode of analysis which dominated the literature until the First World War. An interest in the connexions between different parts of the speech region and between the speech region and the remainder of the brain dated back to almost the earliest of the classical writings. Wernicke (1874) had already predicted the existence of a particular aphasic syndrome resulting from disconnexion of the sensory speech zone from the motor speech area by a single lesion in the left hemisphere. Subsequent developments showed him correct in principle although probably at least partially incorrect in his assumption as to the location of the pathway between these regions. These earliest studies concentrated on lesions of white matter separating regions within a single hemisphere. Dejerine (1892) in describing the pathology of pure alexia without agraphia probably was the first to show definite clinical symptomatology as the result of a lesion of the corpus callosum. Hugo Liepmann carried the analysis of syndromes resulting from the disconnexion of specialized regions of grey matter to its most important development. He published the first post-mortem of a case of pure word-deafness from a unilateral lesion (Liepmann 1898; Liepmann and Storch 1902) consistent with if not fully establishing the hypothesis that this syndrome resulted from isolation of the speech area from auditory inputs into both the left and right hemispheres. He described the famous case of the Regierungsrat (Liepmann 1900) in which he carefully analysed this patient’s behaviour and explained it on the basis of a series of disconnexions. In this paper he predicted the sites of the lesions. The post-mortem findings (Liepmann 1906) amply confirmed these published antemortem predictions. One year later he published with Maas the famous case, Ochs (Liepmann and Maas 1907), which showed the effects of callosal disconnexion on motor function. In the immediately following years Liepmann’s results were repeatedly confirmed by such workers as Kurt Goldstein (1908), Bonhoeffer (1914) and a host of other authors. As Liepmann (1914) himself pointed out, those who were apparently his severest critics, such as von Monakow, had indeed fundamentally accepted his point of view; in fact, no really important criticism was ever directed against his analysis. Goldstein’s (1927) monograph This article has been re-typeset for clarity but the content is unchanged from the original version published as Geschwind, N. (1965). Disconnexion syndromes in animals and man. I. Brain 88:237–294. Copyright 1965 by The Oxford University Press.