A 48-year-old man presents with headaches and a right-sided visual field defect. MRI shows a tumour in the left temporal lobe involving the deep white matter. Which pattern of visual field loss is expected?
- A Right superior homonymous quadrantanopia ✓
- B Right inferior homonymous quadrantanopia
- C Left superior homonymous quadrantanopia
- D Bitemporal hemianopia
Correct answer: A. Right superior homonymous quadrantanopia
Explanation
Meyer's loop carries fibres from the inferior retina (superior visual field) as it sweeps through the temporal lobe before reaching the calcarine cortex. B left temporal lobe lesion therefore damages fibres representing the contralateral (right) superior quadrant, producing the classic 'pie in the sky' defect. An inferior quadrantanopia would point to parietal lobe involvement, where the superior retinal fibres travel, so option B is the tempting distractor that lateralises incorrectly.
Reference: Gray's Anatomy for Students / Snell's Neuroanatomy, Clinical Neuroanatomy 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.