WERNICKE AND ALZHEIMER ON THE LANGUAGE DISTURBANCES OF DEMENTIA AND APHASIA

Signs of language dysfunction in dementia of the Alzheimer's type (DAT ) and in the aphasic syndromes of transcortical sensory aphasia and We rnicke's aphasia are superficially similar. The unresolved question co ncerning the extent to which the language disturbances of DAT are ''ap hasic'' is linked to a more fundamental question concerning the relati on of language to thought, given that aphasia is often defined as lang uage disturbance without disturbance of intellect, and dementia as dis solution of intellectual function, of which language forms an integral part. In this paper we explore the historical roots of today's debate by analyzing the original case studies of Wernicke (1874) and Alzheim er (1907, 1911). Although each of these neurologists described similar patterns of language disturbance, they drew different conclusions. We rnicke argued for a distinction between language and thought and betwe en the language disturbances of aphasia and those of dementia. Alzheim er continued the then dominant paradigm of aphasia in describing the l anguage disturbances of his demented patients as aphasic. Paradoxicall y his conclusion makes him appear, in contrast to Wernicke, to argue f or the identity of the language disturbances of aphasia and dementia. Yet he himself acknowledged that the presence of focal language sympto ms arising from diffuse degenerative pathology was indeed problematic. We conclude that today's discussion could profitably be refocused on the question which emerges from the original works of Wernicke and Alz heimer, which Alzheimer himself asked, and which remains unanswered: H ow can diffuse cerebral pathology give rise to a pattern of language d eficit virtually identical to that of a focal lesion? (C) 1994 Academi c Press, Inc.