Aphasias are disturbances in the comprehension or production of spoken or written language. Clinical examination should assess spontaneous speech (fluency), comprehension, repetition, naming, reading, and writing. A classification scheme is presented in Table 55-1. In nearly all right-handed individuals and many left-handed pts, language localization is in the left hemisphere.
TABLE 55-1CLINICAL FEATURES OF APHASIAS AND RELATED CONDITIONS COMMONLY SEEN IN CEREBROVASCULAR ACCIDENTS ||Download (.pdf) TABLE 55-1CLINICAL FEATURES OF APHASIAS AND RELATED CONDITIONS COMMONLY SEEN IN CEREBROVASCULAR ACCIDENTS
| ||Comprehension ||Repetition of Spoken Language ||Naming ||Fluency |
|Wernicke’s ||Impaired ||Impaired ||Impaired ||Preserved or increased |
|Broca’s ||Preserved (except grammar) ||Impaired ||Impaired ||Decreased |
|Global ||Impaired ||Impaired ||Impaired ||Decreased |
|Conduction ||Preserved ||Impaired ||Impaired ||Preserved |
|Nonfluent (anterior) transcortical ||Preserved ||Preserved ||Impaired ||Impaired |
|Fluent (posterior) transcortical ||Impaired ||Preserved ||Impaired ||Preserved |
|Isolation ||Impaired ||Echolalia ||Impaired ||No purposeful speech |
|Anomic ||Preserved ||Preserved ||Impaired ||Preserved except for word-finding pauses |
|Pure word deafness ||Impaired only for spoken language ||Impaired ||Preserved ||Preserved |
|Pure alexia ||Impaired only for reading ||Preserved ||Preserved ||Preserved |
Although speech sounds grammatical, melodic, and effortless (fluent), it is virtually incomprehensible due to errors in word usage, structure, and tense and the presence of paraphasic errors and neologisms (“jargon”). Comprehension of written and spoken material is severely impaired, as are reading, writing, and repetition. The pt usually seems unaware of the deficit and is not frustrated. Associated symptoms can include parietal lobe sensory deficits and homonymous hemianopia. Motor disturbances are rare.
Lesion is located in posterior perisylvian region. Most common cause is embolism to the inferior division of dominant middle cerebral artery (MCA); less commonly intracerebral hemorrhage, severe head trauma, or tumor is responsible.
Speech output is sparse (nonfluent), slow, labored, interrupted by many word-finding pauses, and usually dysarthric; output may be reduced to a grunt or single word. Naming and repetition also impaired. Most pts have severe writing impairment. Comprehension of written and spoken language is relatively preserved. The pt is often aware of and visibly frustrated by deficit. With large lesions, a dense hemiparesis may occur, and eyes may deviate toward side of lesion. More commonly, lesser degrees of contralateral face and arm weakness are present. Sensory loss is rarely found, and visual fields are intact.
Lesion involves dominant inferior frontal gyrus (Broca’s area), although cortical and subcortical areas along superior sylvian fissure and insula are often involved. Commonly caused by vascular lesions involving the superior division of the MCA; less commonly due to tumor, intracerebral hemorrhage, or abscess.
All aspects of speech and language are impaired. Pt cannot read, write, or repeat and has poor auditory comprehension. Speech output is minimal and nonfluent. Hemiplegia, hemisensory loss, and homonymous hemianopia are usually present. ...