After an ischemic stroke, which cerebral artery is MOST likely affected if a patient has global aphasia, ideational apraxia, and right homonymous hemianopsia?

The presence of global aphasia, ideational apraxia, and right homonymous hemianopsia indicates that the left hemisphere of the brain has sustained damage. Specifically, global aphasia suggests involvement of the Broca's area and Wernicke's area, which are both located in the left hemisphere and are supplied by the left middle cerebral artery.

Ideational apraxia, which affects the ability to perform tasks or activities in the proper sequence, can also be linked to damage in the left hemisphere. Additionally, the right homonymous hemianopsia indicates a visual field defect due to disruption of the visual pathways, which can occur from lesions affecting the optic radiations that are also primarily located in the left hemisphere when observing right visual field loss.

The combination of these symptoms resulting from an ischemic stroke strongly points to the involvement of the left middle cerebral artery, making it the most likely affected artery in this clinical scenario.