Abstract Emerging evidence indicates that stroke may impair glymphatic function by disrupting cerebrospinal fluid (CSF) clearance. The coupling between global blood-oxygen-level-dependent signals and CSF flow has been proposed as a noninvasive biomarker of glymphatic activity. However, it remains unclear whether this coupling can be modulated through rehabilitation. This study investigated whether language therapy in patients with post-stroke aphasia enhances global blood-oxygen-level-dependent–CSF coupling, thereby reflecting potential restoration of fluid–brain interaction. This longitudinal observational study was conducted at a single center and included 20 patients with post-stroke aphasia and 35 age- and sex- balanced healthy controls. All participants underwent MRI scanning, including resting-state blood-oxygen-level-dependent and structural imaging. Among the post-stroke aphasia group, 14 patients completed both pre- and post-treatment assessments after undergoing a standardized 4-week speech-language therapy program. The Western Aphasia Battery was used to quantify language deficits and monitor treatment-related changes. Global blood-oxygen-level-dependent–CSF coupling was quantified using cross-correlation analysis across the whole brain and four predefined language-related resting-state networks. At baseline, patients exhibited significantly reduced global blood-oxygen-level-dependent–CSF coupling compared to healthy controls (P 0.05). Following therapy, coupling significantly increased within the language, salience, and dorsal attention networks, whereas coupling within the default mode network significantly decreased (all P 0.05). Notably, increased global blood-oxygen-level-dependent–CSF coupling in specific networks was significantly correlated with improvements in targeted language functions, such as object naming, responsive naming, and auditory word recognition (P 0.05). These findings suggest that language rehabilitation enhances neurophysiological coupling between brain activity and CSF flow, potentially reflecting restoration of fluid–brain interaction in post-stroke aphasia.
Zhang et al. (Sat,) studied this question.