A 52 year old female complains of sudden visual abnormalities. Her history reveals a 30 pack-year history of smoking, hypeension, and hypercholesterolemia. A head CT shows a lesion in the right occipital lobe and an angiogram reveals an embolic stroke of the right posterior cerebral aery. What type of visual deficit is she most likely experiencing?

## Core Concept
The patient's symptoms and imaging findings suggest a visual deficit due to a lesion in the right occipital lobe, which is supplied by the right posterior cerebral artery (PCA). The occipital lobe is primarily responsible for processing visual information.

## Why the Correct Answer is Right
The right posterior cerebral artery supplies the right occipital lobe, which is crucial for processing visual information from the contralateral visual field. Damage to this area, such as from an embolic stroke, can lead to a **homonymous hemianopia**. This type of visual field defect involves the loss of vision on the opposite side of the lesion in both eyes. Since the lesion is in the right occipital lobe, the patient would experience blindness or loss of vision in the left half of the visual field in both eyes.

## Why Each Wrong Option is Incorrect
* **Option A:** This option is not provided, but generally, any option suggesting a visual deficit not consistent with occipital lobe damage or PCA stroke would be incorrect.
* **Option B:** This option is also not provided, but if it suggested a different type of visual deficit, such as a quadrantanopia (a quarter of the visual field), it would be incorrect because the occipital lobe's involvement typically results in more extensive visual field defects like homonymous hemianopia.
* **Option C:** Similarly, without the specific content, if this option suggested a bilateral visual loss or a different type of visual field defect not associated with occipital lobe lesions, it would be incorrect.
* **Option D:** If this option suggested a condition like amaurosis fugax (transient monocular blindness) or another type of visual disturbance not consistent with a PCA stroke, it would be incorrect.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the **occipital lobe** is responsible for processing visual information, and lesions here typically cause visual field defects. Specifically, a stroke in the **posterior cerebral artery** distribution can cause **homonymous hemianopia**, which is a hallmark of occipital lobe damage.

## Correct Answer: D. Homonymous hemianopia.

✓ Correct Answer: C. Left homonymous hemianopia