Abstract
AIMS: To investigate the characteristics of hypoperfusion and structural impairment in patients with transient ischemic attack (TIA) or minor stroke (MS) with intracranial atherosclerotic stenosis (ICAS) and evaluate its impact on cognitive decline. METHODS: Cognitive function in 47 patients and 33 health controls (HC) was assessed using the Montreal Cognitive Assessment (MoCA) tool. Arterial spin labeling with two distinct postlabeling delays and 3D T1 imaging was conducted to assess cerebral blood flow (CBF), morphometric features, and asymmetry index (AI). RESULTS: Compared with HC, both the left and right involved patients showed reduced scores for total MoCA score. Comparisons of CBF with HC revealed that significant ischemic areas in patients were primarily localized to the perfusion territory of the middle cerebral artery in the affected hemisphere (p < 0.05, family-wise error [FWE] corrected). Despite morphometry abnormality being locally confined, AI exhibits more widespread alterations across a wider range of brain regions (both p < 0.05, FWE corrected). Both hypoperfusion and structural impairment were significantly associated with reduced MoCA score in left-involved patients, whereas only hypoperfusion showed a significant association in those with right-hemisphere involvement (p < 0.05, FWE corrected). Furthermore, the effect of ischemia on cognition was mediated by structural impairment and compensatory CBF simultaneously. CONCLUSION: These findings highlight that hypoperfusion and structural impairment are already concerning and jointly associated with cognitive impairment in MS/TIA patients with ICAS, emphasizing the need for early detection and intervention.