Which vascular territory is implicated in a left hemisphere stroke causing aphasia and right hemiparesis in a right-handed patient?

Which vascular territory is implicated in a left hemisphere stroke causing aphasia and right hemiparesis in a right-handed patient?

• A. Left middle cerebral artery (MCA) territory.
• B. Right MCA territory.
• C. Left posterior cerebral artery territory.
• D. Left basilar artery territory.

Answer: (A)

Language is typically dominant in the left hemisphere for right-handed people, so damage there often disrupts speech and language. The left middle cerebral artery supplies the key language areas (and the adjacent motor cortex for the face and arm). When the left MCA is infarcted, you get aphasia from involvement of Broca’s or Wernicke’s areas and right-sided weakness from the nearby motor pathways. That combination—aphasia plus right hemiparesis in a right-handed person—points to a stroke in the left MCA territory. A stroke in the right hemisphere wouldn’t produce aphasia in a right-handed individual, and strokes in left PCA or the basilar system would yield different patterns (visual/reading problems or brainstem signs, respectively) rather than this specific combination.

Language is typically dominant in the left hemisphere for right-handed people, so damage there often disrupts speech and language. The left middle cerebral artery supplies the key language areas (and the adjacent motor cortex for the face and arm). When the left MCA is infarcted, you get aphasia from involvement of Broca’s or Wernicke’s areas and right-sided weakness from the nearby motor pathways. That combination—aphasia plus right hemiparesis in a right-handed person—points to a stroke in the left MCA territory.

A stroke in the right hemisphere wouldn’t produce aphasia in a right-handed individual, and strokes in left PCA or the basilar system would yield different patterns (visual/reading problems or brainstem signs, respectively) rather than this specific combination.