Where is this patient’s lesion most likely located? A 65-year-old obese man with a 60-pack-year smoking history presents with partial loss of vision after suffering a stroke. Physical examination reveals a bilateral defect in the upper left visual quadrants.

Loop of Meyer in the right temporal lobe

The correct answer is E. The loop of Meyer is located in the temporal lobe. It carries fibers from the inferior retina that are responsible for the contralateral upper quadrant of vision. The fibers first pass through the ipsilateral optic tract. Damage to the loop of Meyer on the right temporal lobe would result in bilateral left upper quadrant anopsia Answer A is incorrect. The dorsal optic radiation carries fibers from the superior retina that are responsible for the contralateral lower quadrant of vision. Damage to the left dorsal optic radiation causes bilateral right lower quadrant anopsia Answer B is incorrect. The dorsal optic radiation carries fibers from the superior retina that are responsible for the contralateral lower quadrant of vision. Damage to the right dorsal optic radiation causes bilateral left lower quadrant anopsia Answer C is incorrect. The optic tract carries fibers from the temporal retina of the ipsilateral eye and from the nasal retina of the contralateral eye. Damage to the left optic tract would cause right homonymous hemianopia Answer D is incorrect. Damage to the loop of Meyer in the left temporal lobe would result in bilateral right upper quadrant anopsia Answer F is incorrect. The optic tract carries fibers from the temporal retina of the ipsilateral eye and from the nasal retina of the contralateral eye. Damage to the right optic tract would cause left homonymous hemianopia.