Chapter 027. Aphasia, Memory Loss, and Other Focal Cerebral Disorders (Part 3) The correspondence between individual deficits of language function and lesion location does not display a rigid one-to-one relationship and should be conceptualized within the context of the distributed network model. Nonetheless, the classification of aphasias of acute onset into specific clinical syndromes helps to determine the most likely anatomic distribution of the underlying neurologic disease and has implications for etiology and prognosis (Table 27-1). The syndromes listed in Table 27-1 are most applicable to aphasias caused by cerebrovascular accidents (CVA). They can be divided into "central" syndromes, which result from damage to the two epicenters of the language network (Broca's and Wernicke's areas), and "disconnection" syndromes, which arise from lesions that interrupt the functional connectivity of these centers with each other and with the other components of the language network. The syndromes outlined below are idealizations; pure syndromes occur rarely. Table 27-1 Clinical Features of Aphasias and Related Conditions Comprehe nsion Repeti tion of Spoken Language Nami ng Fluen cy Wernicke's Impair ed Impai red Impai red Preser ved or increased Broca's Preserv ed (except grammar) Impai red Impai red Decre ased Global Impair ed Impai red Impai red Decre ased Conduction Preserv ed Impai red Impai red Preser ved Nonfluent (motor) transcortical Preserv ed Preser ved Impai red Impair ed Fluent (sensory) transcortical Impair ed Preser ved Impai red Preser ved Isolation Impair ed Echol alia Impai red No purposeful speech Anomic Preserv ed Preser ved Impai red Preser ved except for word- finding pauses Pure word deafness Impair ed only for spoken Impai red Preser ved Preser ved language Pure alexia Impair ed only for reading Preser ved Preser ved Preser ved Wernicke's Aphasia Comprehension is impaired for spoken and written language. Language output is fluent but is highly paraphasic and circumlocutious. The tendency for paraphasic errors may be so pronounced that it leads to strings of neologisms, which form the basis of what is known as "jargon aphasia." Speech contains large numbers of function words (e.g., prepositions, conjunctions) but few substantive nouns or verbs that refer to specific actions. The output is therefore voluminous but uninformative. For example, a patient attempts to describe how his wife accidentally threw away something important, perhaps his dentures: "We don't need it anymore, she says. And with it when that was downstairs was my teeth-tick . . . a . . . den . . . dentith . . . my dentist. And they happened to be in that bag . . . see? How could this have happened? How could a thing like this happen. . .So she says we won't need it anymore. . .I didn't think we'd use it. And now if I have any problems anybody coming a month from now, 4 months from now, or 6 months from now, I have a new dentist. Where my two . . . two little pieces of dentist that I use . . . that I . . . all gone. If she throws the whole thing away . . . visit some friends of hers and she can't throw them away." . Chapter 027. Aphasia, Memory Loss, and Other Focal Cerebral Disorders (Part 3) The correspondence between individual deficits of language function and lesion location. (Broca's and Wernicke's areas), and "disconnection" syndromes, which arise from lesions that interrupt the functional connectivity of these centers with each other and with the other. determine the most likely anatomic distribution of the underlying neurologic disease and has implications for etiology and prognosis (Table 27-1). The syndromes listed in Table 27-1 are most applicable