Review Question - QID 109827

The patient in this vignette presents with multiple vascular risk factors and an inability to see in her superior right visual field suggestive of a contralateral superior quadrantanopia in the setting of a likely stroke. The most common cause of a contralateral superior quadrantanopia is a temporal lobe lesion.

Visual field defects often allow for localization of a lesion to a particular part of the visual pathway. A contralateral superior quadrantopia (i.e., “pie in the sky”) refers to an inability to see the upper left or right quarter of one’s visual field. Given that the inferior optic radiations carry information from the inferior retina (thus, the superior visual field) and pass through the temporal lobe via Meyer’s Loop, a lesion in the temporal lobe will knock out one side of the superior visual field.

Illustration A demonstrates the visual pathway along with associated visual field defects based on lesion location. Note that a contralateral superior quadrantopia stems from a lesion in Meyer's Loop.

Incorrect Answers:
Answer 1: The optic nerve contains visual information from the ipsilateral eye. A lesion in the optic nerve will lead to monocular vision loss.

Answer 2: The optic tract contains visual information from the ipsilateral nasal field. A lesion in the optic tract will lead to a homonymous hemianopia.

Answer 3: The pituitary gland can compress the optic chiasm, the crossing point of the optic nerves of each eye. A lesion arising from the pituitary gland (e.g., pituitary adenoma or craniopharyngioma) will lead to bitemporal hemianopia.

Answer 4: The parietal lobe contains the superior optic radiations. These transmit visual information from the inferior visual fields. A lesion in the parietal lobe will therefore lead to a contralateral inferior quadrantanopia.

Bullet Summary:
Contralateral superior quadrantanopia stems from a lesion in Meyer’s Loop in the temporal lobe.