A 70-year-old man presents to the ER with an acute disturbance of vision and balance. He explains that whilst sitting in his chair at home earlier in the evening the room suddenly began spinning. When he tried to get up, he felt dizzy and kept bumping into furniture. On examination, he has nystagmus and a left homonymous hemianopia. He is noted to be hypeensive (BP 170/80) but all other vital signs are within the normal range. An MRI head reveals an acute ischaemic infarct. According to Bamford classification, what type of stroke has this person suffered?

**Core Concept**
The Bamford classification is a system used to categorize stroke subtypes based on the location and type of brain lesion. It is essential in clinical practice to accurately diagnose stroke subtypes and understand their implications for treatment and outcomes.

**Why the Correct Answer is Right**
The patient presents with symptoms of a left homonymous hemianopia and nystagmus, indicating a lesion in the left occipital lobe or its connections. The acute ischemic infarct on MRI further supports this diagnosis. The Bamford classification categorizes strokes into five subtypes: lacunar, large artery, cardioembolic, small vessel disease, and other causes. Given the patient's symptoms and imaging findings, the most likely subtype is a lacunar stroke, which typically involves small, deep brain lesions resulting from occlusion of small penetrating arteries.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it refers to a large artery stroke, which typically involves a larger territory of brain infarction, such as the middle cerebral artery territory. The patient's symptoms do not suggest a large artery stroke.
**Option B:** This option is incorrect as it refers to a cardioembolic stroke, which typically involves a brain lesion in a more superficial location, often with a more extensive territory of infarction. The patient's symptoms do not suggest a cardioembolic stroke.
**Option C:** This option is incorrect as it refers to small vessel disease, which typically involves a more widespread territory of brain infarction due to chronic small vessel disease. The patient's symptoms do not suggest small vessel disease.
**Option D:** This option is incorrect as it refers to other causes, which would include strokes due to non-atherosclerotic etiologies, such as vasculitis or bleeding. The patient's symptoms and imaging findings do not suggest an other cause.

**Clinical Pearl / High-Yield Fact**
When diagnosing stroke subtypes, it is essential to consider the patient's symptoms, imaging findings, and vascular risk factors. The Bamford classification provides a useful framework for categorizing stroke subtypes and guiding treatment decisions.

**Correct Answer:** C.

✓ Correct Answer: C. Posterior circulation stroke (POCS)