Question 6
This patient has infarcted a small region of white matter in the internal capsule on the right side. As a result she cannot smile symmetrically, and has trouble speaking clearly. Her arm is also affected: she has diminished strength, particularly in her hand and forearm, and the biceps and triceps reflexes are brisk. Her leg is much less affected. She has no aphasia or cognitive problems, no other motor problems, and no visual field deficit or other sensory loss.
Question a. Which side of the face and arm is affected, left or right?
a. Anterior cerebral artery on left
b. Anterior cerebral artery on right
Question b. What major cerebral artery is involved?
Question c. What specific (named) arterial branches are involved?
Question d. Is it likely that any cortical tissue is involved in this stroke?
Answer to Question 6
Answer to Question a
a. The left lower part of her face and arm are involved.
Answer to Question b
The internal capsule is in the jurisdiction of the MCA.
Answer to Question c
It is supplied by the deeply penetrating lenticulostriate branches that arise directly from the MCA stem. 
Answer to Question d
The fact that she has no aphasia or cognitive problems and no visual or other sensory deficits all agree with a subcortical localization. Presumably one of the lenticulostriate vessels has collapsed, causing a small region of the internal capsule to lose its blood supply and die. The resulting tiny cavity in the internal capsule is described as a lacune.