A stroke which results in only LEFT leg weakness most likely involves which of the following arteries?

A stroke which results in only LEFT leg weakness most likely involves which of the following arteries?

• A. right ACA
• B. right PCA
• C. right vertebral artery
• D. right posterior communicating artery

Answer: (A)

The correct answer is the right anterior cerebral artery (ACA). This artery supplies the medial portions of the frontal lobes and the superior medial parietal lobes, which are responsible for controlling motor functions of the lower extremities, particularly the legs. When a stroke occurs affecting the right ACA, it can lead to weakness or paralysis on the contralateral side of the body, which in this case is the left leg. In this scenario, the left leg weakness is a strong indicator that the damage is located in the right hemisphere of the brain, as the motor pathways cross over. The anterior circulation of the brain, which includes the ACA, is particularly involved in the motor control of the lower limbs. Other arteries listed do not typically result in isolated left leg weakness. The right posterior cerebral artery (PCA) primarily supplies areas that are involved with vision and might affect other functions rather than isolated motor control of the leg. The right vertebral artery deals with the posterior circulation and is more related to supplying blood to the brainstem and cerebellum, while the right posterior communicating artery is involved in linking the anterior and posterior circulations of the brain and does not typically correlate with isolated limb weakness.

The correct answer is the right anterior cerebral artery (ACA). This artery supplies the medial portions of the frontal lobes and the superior medial parietal lobes, which are responsible for controlling motor functions of the lower extremities, particularly the legs. When a stroke occurs affecting the right ACA, it can lead to weakness or paralysis on the contralateral side of the body, which in this case is the left leg.

In this scenario, the left leg weakness is a strong indicator that the damage is located in the right hemisphere of the brain, as the motor pathways cross over. The anterior circulation of the brain, which includes the ACA, is particularly involved in the motor control of the lower limbs.

Other arteries listed do not typically result in isolated left leg weakness. The right posterior cerebral artery (PCA) primarily supplies areas that are involved with vision and might affect other functions rather than isolated motor control of the leg. The right vertebral artery deals with the posterior circulation and is more related to supplying blood to the brainstem and cerebellum, while the right posterior communicating artery is involved in linking the anterior and posterior circulations of the brain and does not typically correlate with isolated limb weakness.