Lacunar infarcts are caused by –
**Core Concept**
Lacunar infarcts are a type of small vessel stroke caused by occlusion of the penetrating arteries that supply the deep structures of the brain, such as the basal ganglia, thalamus, and internal capsule. This results in damage to the small blood vessels and subsequent ischemia to the surrounding brain tissue.
**Why the Correct Answer is Right**
Lacunar infarcts are caused by the occlusion of small penetrating arteries, which are branches of the larger cerebral arteries. These small arteries are prone to atherosclerosis, lipohyalinosis, and other forms of vascular disease, leading to their occlusion. The most common causes of lacunar infarcts include hypertension, diabetes mellitus, and atherosclerosis, which damage the small blood vessels and lead to ischemia. The lacunes are typically 1-2 cm in diameter and are often found in the basal ganglia, thalamus, or internal capsule.
**Why Each Wrong Option is Incorrect**
**Option A:** Lacunar infarcts are not typically caused by embolic events, which are more commonly associated with larger vessel strokes.
**Option B:** While hypertension is a risk factor for lacunar infarcts, it is not the direct cause of the infarct itself, but rather contributes to the damage of the small blood vessels.
**Option C:** Lacunar infarcts are not typically caused by vasculitis, which is an inflammatory condition of the blood vessels. Vasculitis can cause a wide range of symptoms, including stroke, but it is not the primary cause of lacunar infarcts.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that lacunar infarcts often present with specific clinical syndromes, such as pure motor stroke, pure sensory stroke, or ataxic hemiparesis, which can help diagnose this type of stroke.
**Correct Answer: C. Atherosclerosis**