Lacunar strokes commonly cause which type of deficits, and what underlying pathology causes lacunar infarcts?

• A. Pure motor or pure sensory deficits; lipohyalinosis of small penetrating arteries from hypertension/diabetes
• B. Aphasia and neglect; large vessel atherosclerosis
• C. Visual field loss; venous sinus thrombosis
• D. Ataxia with tremor; cardioembolic disease

Answer: (A)

Lacunar strokes stem from disease of the small deep penetrating arteries that supply subcortical structures like the internal capsule, thalamus, and basis pontis. Chronic hypertension and diabetes promote lipohyalinosis and microatheroma formation in these vessels, leading to occlusion and small, deep infarcts called lacunes. Because these infarcts affect deep brain areas rather than the cortex, the typical clinical picture is pure motor deficits (such as hemiparesis) or pure sensory deficits (numbness), with cortical signs like aphasia or neglect usually absent. The underlying pathology explains both the small size of the infarcts and the characteristic deep, pure-sensorimotor presentation.