Alteration in Brain Functional Connectivity in Patients with Post-Stroke Cognitive Impairment During Memory Task: A fNIRS Study

Background: Post-stroke cognitive impairment (PSCI) refers to various types of cognitive deterioration after stroke, from mild cognitive impairment (MCI) to dementia. The cortical plastic changes in patients with MCI after stroke have not been entirely illustrated. Objective. This study aimed to reveal the physiological mechanism in patients with cognitive impairment after stroke using the functional connectivity (FC) method.Methods: FC was assessed by dynamic Bayesian inference of the oxygenated hemoglobin concentration signals measured through fNIRS. This signal was recorded from bilateral prefrontal cortex (PFC) and motor Abbreviations FCfunctional connectivity; PFC:prefrontal cortex; MS:motor sense; LMS:left motor sense; RMS:right motor sense; CDT:clock drawing test; DST:digit span test; CBT: corsi block-tapping test; HbO: oxyhemoglobin; Hb:deoxyhemoglobinsense cortex (MS) of participants in different groups.Results: Short-term memory and visuo-spatial abilities were assessed using clock drawing test (CDT), digit span test (DST) and Corsi Block-tapping (CBT) tests. and Mini-Mental State Examination (MMSE) scores were positively correlated with CDT and DST scores, but not with CBT scores. Within each group, the brain FC between left motor sense cortex (LMS) and right motor sense cortex (RMS) was the highest, and that between MSs (LMS and RMS) and PFC was the lowest. Compared with Healthy control (HC) and Stroke (STR) groups FC between MSs significantly decreased, and the difference was decreased in PSCI group. The PSCI group showed significantly lower FC between prefrontal lobes. FC levels were closely related to cognitive performance (MMSE scores).Conclusions: Decreased FC level may be a marker of impaired cognitive function in PSCI. The fNIRS-based FC network provides a non-invasive method to recognize PSCI. FC changes may help to further understand the neural mechanisms of PSCI. (the registration number:MR-43-22-003125.)