Neurology · USMLE Step 1 and Step 2

Lacunar Infarcts song

Lacunar Infarcts - Syndromes & Risk Factors, as a song. Hear the short teaser here. The full song is on YouTube and Spotify.

Lacunar Infarcts

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Key points in this song10

Lacunar infarcts are small vessel strokes (<15 mm) caused by lipohyalinosis or microatheroma of penetrating arteries, most commonly associated with chronic hypertension and diabetes.
The most common locations are the putamen, thalamus, internal capsule, pons, and caudate nucleus — all supplied by deep penetrating arteries.
Classic lacunar syndromes include pure motor hemiplegia (posterior limb of internal capsule or pons), pure sensory stroke (thalamus), ataxic hemiparesis, and dysarthria-clumsy hand syndrome.
Pure motor hemiplegia is the most common lacunar syndrome, presenting with contralateral face, arm, and leg weakness without cortical signs (no aphasia, no neglect, no visual field defects).
Lacunar infarcts characteristically lack cortical signs — absence of aphasia, hemineglect, homonymous hemianopia, or seizures helps distinguish them from large vessel or cardioembolic strokes.
MRI with DWI is the imaging modality of choice; CT may miss small lacunar infarcts, especially in the posterior fossa.
Lipohyalinosis — hyaline arteriolosclerosis of small penetrating vessels — is the key pathological mechanism driven by chronic hypertension.
Ataxic hemiparesis presents with ipsilateral limb ataxia and contralateral leg weakness, localizing to the pons or posterior limb of the internal capsule.
Long-term management focuses on aggressive risk factor control — antihypertensives, statins, and antiplatelet therapy (aspirin or clopidogrel); anticoagulation is not indicated unless atrial fibrillation coexists.
Accumulation of multiple lacunar infarcts leads to lacunar state (état lacunaire), presenting clinically as vascular dementia with pseudobulbar palsy, small-stepped gait, and emotional lability.