Is left-sided body weakness with a flat nasolabial fold indicative of a lacunar infarct (LACI) or another condition in an adult or geriatric patient with potential risk factors for cardiovascular disease, such as hypertension and diabetes?

Clinical Classification: Likely Cortical Stroke (PACI), Not LACI

Left-sided body weakness with a flat nasolabial fold indicates a cortical stroke syndrome (most likely Partial Anterior Circulation Infarct/PACI) rather than a lacunar infarct (LACI), because the facial weakness pattern suggests cortical involvement of the motor cortex rather than pure subcortical pathology. 1

Why This is NOT a Lacunar Syndrome

Cortical Signs Present

• A flat nasolabial fold indicates upper motor neuron facial weakness affecting the lower face, which when combined with body weakness suggests involvement of the motor cortex or its immediate projections 1
• Classical lacunar syndromes present with pure motor hemiparesis WITHOUT cortical signs such as aphasia, neglect, or visual field defects 2, 3
• The presence of facial involvement in this pattern (affecting the lower face with nasolabial flattening) combined with body weakness is more consistent with cortical localization 1

Lacunar Infarcts: Defining Features

• Lacunar infarcts are subcortical strokes <1.5 cm in diameter affecting penetrating arteries in the basal ganglia, brainstem, or deep white matter 2, 4
• They present with one of five classical syndromes: pure motor hemiparesis, pure sensory syndrome, sensorimotor stroke, ataxic hemiparesis, or dysarthria-clumsy hand 3, 5
• The key distinguishing feature is the ABSENCE of cortical dysfunction 1

Critical Diagnostic Workup Required

Immediate Imaging

• Non-contrast CT head is mandatory initially to exclude intracranial hemorrhage 2
• Vascular imaging (CTA or MRA) must be obtained urgently to exclude large vessel occlusion, even with presumed cortical stroke, because clinical scores correlate poorly with large vessel occlusion presence 2, 1
• MRI with diffusion-weighted imaging is superior to CT for detecting acute cortical infarcts and distinguishing stroke subtypes 1

Cardiac Evaluation is Mandatory

• Transthoracic echocardiography at minimum to assess for cardioembolic sources 2, 1
• Extended cardiac rhythm monitoring to detect paroxysmal atrial fibrillation 2, 1
• This is critical because misclassification has therapeutic implications: a patient with atrial fibrillation requires anticoagulation, not just antiplatelet therapy 2, 1

Additional Vascular Assessment

• Carotid imaging (duplex ultrasound, CTA, or MRA) within 48 hours to exclude ipsilateral large-artery stenosis >50% 2
• Lipid profile and hemoglobin A1c are essential components 2

Common Pitfall to Avoid

Do not assume this is a benign lacunar stroke based on clinical presentation alone. While lacunar strokes have the best prognosis among stroke subtypes (85% survival at 2 years) 2, 4, this presentation suggests cortical involvement requiring comprehensive workup for cardioembolic and large vessel sources 1. The presence of facial weakness with body weakness in this distribution pattern indicates motor cortex involvement, making this a cortical syndrome that demands full stroke evaluation including cardiac monitoring and anticoagulation consideration if atrial fibrillation is detected 2, 1.