A 35yo woman presents with visual problems. CT brain reveals pituitary tumor. What is the single most likely defect?

A 35yo woman presents with visual problems. CT brain reveals pituitary tumor. What is the single most likely defect?

a. Homonymous hemianopia
b. Homonymous upper quadrantopia
c. Bitemporal hemianopia
d. Cortical blindness
e. Homonymous lower quadrantopia

Clincher(s) Visual problem,Pituitary tumor A In homonymous hemianopia - literally, a loss of vision on the same side in both eyes - the field loss is usually the result of a lesion in the optic radiation or tract on one side. The visual defect is dependent on the site of the lesion: • right-hand sided lesions lead to left temporal and right nasal field loss • left-hand sided lesions lead to right temporal and left nasal field loss

B upper homonymous quadrantanopia describes the loss of the same upper quadrant from each visual field. Upper homonymous quadrantanopias are usually caused by damage to the optic radiation as it passes throught the temporal lobes. For example a lesion in the left temporal lobe will cause a right homonymous upper quadrantanopia, that is the loss of the upper nasal quadrant from the left eye and the upper temporal quadrant from the right eye.

C Bilateral hemianopia is a loss of temporal field vision in both eyes. This may be caused by a lesion that affects the centre of the optic chiasm and damages fibres from the nasal halves of the retina as they decussate.
Possible causes of this condition include:
• pituitary tumour • craniopharyngioma • suprasellar meningioma

D Bilateral lesions of the primary visual cortex may cause blindness. The cortically blind patient may have no vision but: • pupillary responses are intact: o fibres terminate in the pretectal region of the midbrain and do not involve the cortex • normal fundoscopy • normal visual imagination and dreamin

E Homonymous inferior quadrantanopia is when the lower quadrant of the visual field ceases to function. Homonymy refers to the fact that the same quadrant (meaning both left or both right) is nonfunctional in each eye. For right homonymous inferior quadrantanopia, both lower right quadrants of the visual field experience loss of visual function; the cause of this visual defect is commonly located in the left hemisphere. Left homonymous inferior quadrantanopia involves visual defects in the lower left quadrant of each eye, with the cause usually being located in the right hemisphere of the brain.

KEY C