A 70-year-old man develops a right homonymous hemianopia in which central (macular) vision is preserved. Infarction of which artery is the likely cause?

• A Callosal branch of the anterior cerebral artery
• B Left middle cerebral artery
• C Left anterior choroidal artery
• D Right posterior cerebral artery ✓

Explanation

The primary visual cortex above and below the calcarine sulcus is supplied by the posterior cerebral artery; unilateral infarction gives a contralateral homonymous hemianopia. Macular sparing occurs because the occipital pole, where the macula is represented, also receives collateral supply from terminal branches of the middle cerebral artery. An anterior choroidal artery infarct affects the optic tract and lateral geniculate body and does not characteristically spare the macula.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.