Clinical neurovascular coupling through cerebrovascular reserve and cognitive function.

Neurovascular coupling ensures that cerebral blood flow (CBF) is proportionally matched to neural activity. In patients with chronic cerebral hypoperfusion, this may be clinically assessed through multiple regression analysis with cognitive function and the cerebrovascular reserve (CVR) as key factors. Cognitive function (based on neuropsychological testing using the Neurobehavioral Cognitive Status Examination [COGNISTAT]) and cerebrovascular risk factors, including CBF, CVR (as evaluated using N-isopropyl-p-¹²³I-iodoamphetamine single-photon emission computed tomography with acetazolamide challenge), and periventricular hyperintensity (PVH) grade, were investigated in 65 patients with steno-occlusive disease of a main cerebral artery. Multiple regression analysis was performed between COGNISTAT scores and other factors in 41 patients with a vascular mild cognitive impairment pattern on COGNISTAT and a proportionally variable CVR range. Additionally, we examined subgroups based on HbA1c, PVH grade, and lipid values, as well as 10 patients who underwent anastomosis surgery. The multiple regression analysis of COGNISTAT scores and CVR showed statistically significant relationships in the 41 patients and all subgroups (adjusted R² > 0.45). The high HbA1c and high PVH grade groups exhibited lower standardized partial regression coefficients (SPRCs) for CVR compared with the lower groups (0.187, 0.203 vs. 0.230, 0.254, respectively). After anastomosis surgery, both COGNISTAT scores and CVR significantly improved while their relationship was maintained (SPRC = 0.224, p = 0.0092, adjusted R² = 0.457). A significant regression relationship was found between cognitive function and CVR, indicating a potential causal relationship based on clinical neurovascular coupling function that may vary depending on HbA1c level and PVH grade.