conduction aphasia

n. Aphasia characterized by relatively good spontaneous language, good comprehension, and poor repetition with a significant number of phonological paraphasias (words incorrect from the point of view of the phonological composition). Three basic and five secondary characteristics are usually included in the definition of conduction aphasia. The three basic characteristics are (1) fluent but paraphasic conversational language, (2) nearnormal language comprehension, (3) significant difficulties in language repetition. Conduction aphasia very often also includes (secondary characteristics) (1) defective naming with significant number of phonological paraphasias; (2) reading difficulties (reading aloud is defective, whereas reading understanding may be near normal); (3) writing defects, ranging from mild spelling errors to severe agraphia; (4) ideomotor apraxia; and (5) neurological abnormalities, including loss of cortical sensitivity and some degree of right hemiparesis. Language repetition defects in conduction aphasia have been explained in two different ways: (1) as a disconnection between Wernicke's and Broca's areas and (2) as a segmentary ideomotor apraxia, specifically a verbal apraxia. The first explanation was proposed by Wernicke when this aphasia syndrome was initially described. The second explanation was first proposed by Luria.

-AA