Clinical Classification of Stroke

Definition and Diagnosis

The American Heart Association defines lacunar infarcts as subcortical strokes measuring <1.5 cm in diameter affecting penetrating arteries in the basal ganglia, brain stem, or deep white matter 1, 2, 3
Patients with lacunar infarcts present with classical lacunar syndromes (pure motor hemiparesis, pure sensory syndrome, sensorimotor stroke, ataxic hemiparesis, or dysarthria-clumsy hand) without cortical signs 1, 2
Cortical dysfunction (aphasia) is a defining feature of anterior circulation infarcts, such as Partial Anterior Circulation Infarct (PACI) 3
Motor deficits with cortical signs distinguish PACI from pure lacunar syndromes 3

Vascular imaging (CTA or MRA) must be obtained urgently to exclude large vessel occlusion, even with presumed cortical stroke 1
Transthoracic echocardiography at minimum and extended cardiac rhythm monitoring are mandatory given the aphasia and cortical presentation 1
MRI is superior to CT for detecting acute cortical infarcts and distinguishing them from chronic lacunar infarcts 5, 6

Misclassification of stroke subtype has therapeutic consequences, as antiplatelet therapy alone may be inadequate for patients with atrial fibrillation, and anticoagulation may be required 1
The presence of multiple small chronic infarcts with cerebral atrophy on CT suggests underlying vascular cognitive impairment and small vessel disease burden, but does not change the acute stroke classification 4, 5