Mesiotemporal atrophy and hippocampal diffusivity distinguish amnestic from non‐amnestic vascular cognitive impairment

BACKGROUND AND PURPOSE The role of clinical factors, cerebral infarcts and hippocampal damage in vascular cognitive impairment (VCI) subtypes remains unclear. METHODS Non-demented patients with carotid stenosis and recent transient ischemic attack/stroke had cognitive assessment and brain magnetic resonance imaging (MRI). Amnestic VCI was defined as memory impairment; non-amnestic VCI was any other subdomain impairment. Associations of MRI metrics [log-transformed total ischemic lesion load (log TILL), mesiotemporal atrophy (MTA) score, hippocampal mean diffusivity (hipMD)] with cognitive performance were assessed. RESULTS A hundred and eight patients, 47 with amnestic VCI and 21 with non-amnestic VCI, were assessed. A higher MTA (odds ratio 12.89, P = 0.001) and left hipMD (odds ratio 4.43, P = 0.003) contributed to amnestic VCI versus normal. Age-adjusted fluency correlated with log TILL (P = 0.002). Age-adjusted memory was associated with left hipMD (P = 0.001), MTA (P < 0.001) but not log TILL (P = 0.14). Left hipMD, MTA and smoking showed classification potential between amnestic VCI versus normal (area 0.859, P < 0.001). CONCLUSIONS Neuroimaging assists stratification in amnestic VCI characterized by hippocampal changes and in non-amnestic VCI by higher ischemic burden. MTA and hippocampal diffusivity show diagnostic biomarker potential.