Question

A 67-year-old man with a history of hypertension and diabetes mellitus presents to the emergency department with sudden onset left leg weakness. His examination is notable for 3/5 strength in his left lower extremity as well as diminished sensation to temperature and light touch. Which of the following vascular territories is most likely affected in this patient?

a) Left lenticulostriate arteries
b) Left posterior cerebral artery
c) Right anterior cerebral artery
d) Right middle cerebral artery

Answer 1

A 67-year-old man with sudden onset left leg weakness and diminished sensation likely has a stroke affecting the right anterior cerebral artery, leading to symptoms on the opposite side of his body.

Step-by-step explanation:

The sudden onset of left leg weakness and diminished sensation to temperature and light touch in a 67-year-old man with a history of hypertension and diabetes suggests a cerebrovascular accident or stroke. Given the unilateral weakness and sensory deficits, the vascular territory most likely affected is the one supplying the region of the central nervous system that controls these functions. For left leg weakness and sensory changes, the right side of the brain is usually involved due to the crossing of motor and sensory pathways within the CNS.

The correct answer is c) Right anterior cerebral artery. This artery supplies the medial portion of the frontal lobe and the superior medial parietal lobes. These areas are involved in the control of the lower extremity motor function and sensation on the contralateral (opposite) side of the body. Thus, a stroke affecting the right anterior cerebral artery would likely manifest as weakness and sensory loss in the left leg.