Which one of the following patterns of visual disturbance would be predicted to be demonstrable on examination of this patient?
**Core Concept**
Visual disturbances can be categorized based on the location of the lesion in the visual pathway. Each pattern of visual disturbance is associated with a specific type of lesion, such as optic nerve, optic chiasm, optic tract, or occipital lobe.
**Why the Correct Answer is Right**
The correct answer is associated with a lesion of the optic chiasm. This is typically seen in conditions such as pituitary tumors or craniopharyngiomas that compress the optic chiasm from below. The characteristic visual disturbance in this case is bitemporal hemianopia, where there is a loss of the outer half of the visual field in both eyes. This is due to the compression of the crossing nasal fibers of the optic nerves at the optic chiasm.
**Why Each Wrong Option is Incorrect**
* **Option A:** This is typically associated with a lesion of the optic nerve, such as optic neuritis, which would result in a loss of vision in one eye.
* **Option B:** This is typically associated with a lesion of the occipital lobe, such as a stroke or tumor, which would result in a loss of vision in one eye or a homonymous hemianopia.
* **Option C:** This is typically associated with a lesion of the optic tract or lateral geniculate body, which would result in a homonymous hemianopia.
**Clinical Pearl / High-Yield Fact**
Bitemporal hemianopia is a characteristic visual disturbance associated with lesions of the optic chiasm, such as pituitary tumors. This is an important clinical correlation to remember when evaluating patients with visual disturbances.
**Correct Answer: D. Bitemporal hemianopia**