Table 1.

Classification schemes for lacunar stroke and cerebral small vessel disease.

LS Classification	Assessment	Definition	Reference
TOAST	Clinical	CT/MRI unremarkable or with subcortical lesion <15mm that explains acute symptoms, No cardioembolism, No ipsilateral large vessel stenosis >50%	(34)
CCS	Clinical	CT/MRI with lesion in territory of penetrating vessel and <20mm that explains acute symptoms, No focal pathology in parent artery	(36)
ASCOD	Clinical	CT/MRI with small/deep lesion <15mm that explains acute symptoms, Stuttering symptoms, CT/MRI evidence of chronic LS/WMH/CMB/PVS	(37)
STRIVE	Radiographic	Recent small subcortical infarcts are DWI hyperintensities <20mm, Chronic lacunes are T2 hypointensities with hyperintense rim <15mm	(38)
Poirier and Derouesné	Pathologic	Type Ia old infarcts <20mm with pan-necrotic cavitation and scattered macrophages, Type Ib incomplete infarcts with selective loss of vulnerable elements	(92)
cSVD Disease Process	Vessel Size	Definition	Reference
Arteriosclerosis/atherosclerosis	200-800 μm	Microatheromatous plaques with foam cells	(11)
Arteriolosclerosis	40-150 μm	Concentric hyaline thickening of vessel wall	(59)
Lipohyalinosis	40-300 μm	Non-inflammatory lipid and protein aggregation	(60)