Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which artery is primarily associated with contralateral face and upper limb deficits?

1. Anterior cerebral artery

2. Middle cerebral artery

3. Posterior cerebral artery

4. Basilar artery

The correct answer is: Middle cerebral artery

The correct choice relates to the middle cerebral artery, which supplies a significant portion of the lateral aspect of the cerebral hemispheres, including the regions that control motor and sensory functions of the face and upper limbs. When there is an occlusion or significant compromise to this artery, it can lead to contralateral deficits, meaning the symptoms manifest on the opposite side of the body from where the brain injury occurred. The motor cortex, which is responsible for movement, is located in the precentral gyrus. The upper limb and facial areas are represented laterally on this part of the cortex. Consequently, if the middle cerebral artery is affected, the area of the brain managing these functions is compromised, resulting in weakness or sensory loss predominantly in the contralateral face and upper limb. Other arteries listed have different primary functions and anatomical territories. The anterior cerebral artery primarily affects the lower limbs and has less impact on the face and upper extremities. The posterior cerebral artery is more involved with the occipital lobe and is primarily associated with visual deficits. The basilar artery supplies the brainstem and cerebellum, which influences more foundational bodily functions such as balance and coordination rather than specifically the face or upper limbs.