Which statement best describes a pure motor lacunar stroke?

Which statement best describes a pure motor lacunar stroke?

• A. Caused by occlusion of lenticulostriate arteries.
• B. Typically presents with pure sensory loss.
• C. Produces gaze palsy.
• D. Involves cortex causing aphasia.

Answer: (A)

A pure motor lacunar stroke occurs when a small penetrating artery, most classically the lenticulostriate arteries that supply the posterior limb of the internal capsule and nearby subcortical white matter, becomes occluded. This tiny-vessel blockage causes a lacunar infarct in a subcortical motor pathway, so the corticospinal tract is disrupted without involving the cortex. As a result, the presentation is isolated motor weakness (often affecting the face, arm, and leg on one side) without sensory loss, aphasia, neglect, or other cortical signs. This fits best because the clinical picture matches a small deep infarct in subcortical motor pathways due to lenticulostriate artery occlusion. Other options describe different lacunar syndromes or cortical involvement: a pure sensory presentation points to thalamic perforators; gaze palsy suggests brainstem or oculomotor pathway involvement; cortical involvement would lead to aphasia or other higher cortical deficits.

A pure motor lacunar stroke occurs when a small penetrating artery, most classically the lenticulostriate arteries that supply the posterior limb of the internal capsule and nearby subcortical white matter, becomes occluded. This tiny-vessel blockage causes a lacunar infarct in a subcortical motor pathway, so the corticospinal tract is disrupted without involving the cortex. As a result, the presentation is isolated motor weakness (often affecting the face, arm, and leg on one side) without sensory loss, aphasia, neglect, or other cortical signs.

This fits best because the clinical picture matches a small deep infarct in subcortical motor pathways due to lenticulostriate artery occlusion. Other options describe different lacunar syndromes or cortical involvement: a pure sensory presentation points to thalamic perforators; gaze palsy suggests brainstem or oculomotor pathway involvement; cortical involvement would lead to aphasia or other higher cortical deficits.