transcortical motor aphasia
A type of non-fluent aphasia characterized by preserved repetition abilities despite impaired spontaneous speech production.
Full Definition
Transcortical motor aphasia is a specific form of non-fluent aphasia that results from lesions in the supplementary motor area or adjacent prefrontal cortex, typically sparing Broca's area itself. Patients exhibit severely reduced spontaneous speech output with preserved ability to repeat words and phrases, distinguishing it from Broca's aphasia. The condition is often associated with frontal lobe strokes or degenerative processes affecting the premotor cortex. In neuropathological examination, the arcuate fasciculus and perisylvian language areas remain intact, while damage is typically found in the dorsolateral prefrontal or supplementary motor regions. This preservation pattern creates the characteristic clinical presentation of intact repetition with severely impaired verbal fluency.
Usage
Usage note: Distinguished from Broca's aphasia by preserved repetition; ensure clinical correlation is documented in pathological reports.
In Context
- "The autopsy revealed focal cortical atrophy in the supplementary motor area consistent with the patient's transcortical motor aphasia." — Autopsy report
- "Histological examination showed neuronal loss in Brodmann areas 6 and 8, correlating with the transcortical motor aphasia observed clinically." — Neuropathological assessment