Which syndrome is classically lacunar and can present as pure motor hemiparesis, pure sensory syndrome, or ataxic hemiparesis?

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Lacunar infarcts from small penetrating arteries cause syndromes that are pure in their deficits and lack cortical signs. When such an infarct produces a pure motor deficit, a pure sensory deficit, or a combination with ataxia (ataxic-hemiparesis), these classic presentations are grouped under a single label. That umbrella term for these lacunar presentations is Classic Lacunar Syndrome. It reflects the idea that these deficits arise from small, deep infarcts in structures like the internal capsule, thalamus, or adjacent pathways, leading to specific, localized symptoms without higher-order cortical involvement. While each presentation can be described individually—pure motor stroke, pure sensory stroke, or sensorimotor/ataxic-hemiparesis—the collective designation that best fits all of them is Classic Lacunar Syndrome. Central pain syndrome can occur after thalamic involvement, but it is not a typical initial lacunar presentation like the ones described here.