Chapter 027. Aphasia, Memory Loss, and Other Focal Cerebral Disorders (Part 3) pot

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-

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

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

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."