Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which artery is implicated in contralateral vision or speech impairments?

1. Anterior cerebral artery

2. Middle cerebral artery

3. Posterior cerebral artery

4. Basilar artery

The correct answer is: Posterior cerebral artery

The artery that is implicated in contralateral vision or speech impairments is the posterior cerebral artery. This artery primarily supplies the occipital lobes, which are responsible for processing visual information. When there is a disruption in blood flow to the areas supplied by the posterior cerebral artery, patients may experience visual field deficits, such as homonymous hemianopsia, where vision is lost in half of the visual field on each side. Moreover, while the posterior cerebral artery is not directly responsible for speech, it can play a role in higher-order visual processing and integration, which can indirectly influence language and communication. The lateralization of cerebral functions means that impairments associated with the posterior cerebral artery can lead to complications in understanding visual stimuli, which are critical for effective communication. Other options are less likely to cause these specific impairments. The anterior cerebral artery mainly supplies the medial portions of the frontal lobes and superior medial parietal areas, which are more associated with lower limb function and judgment rather than vision. The middle cerebral artery provides blood to a large portion of the lateral aspect of the cerebral hemispheres, including areas commonly associated with speech and motor functions, but any resultant speech impairments would generally not be contralateral if both hemispheres are