A 62-year-old woman after resection of a left temporal lobe glioma has a right superior homonymous quadrantanopia. The structure most likely injured is:
- A Calcarine cortex above the sulcus
- B Optic radiations in the parietal lobe
- C Meyer's loop in the temporal lobe ✓
- D Lingual gyrus
Correct answer: C. Meyer's loop in the temporal lobe
Explanation
Meyer's loop carries fibres from the inferior retina, which subserve the superior visual field, as it sweeps through the temporal lobe toward the inferior bank of the calcarine cortex. C temporal lobe lesion therefore gives a contralateral superior quadrantanopia, classically described as 'pie in the sky'. Parietal lobe lesions interrupt superior retinal fibres and produce an inferior quadrantanopia, which is the discriminating fact against option B.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.