Early Glymphatic Flow Dysfunction in Relapsing‐Remitting Multiple Sclerosis: A Meta‐Analysis Using DTI‐ALPS

Objective To conduct a comprehensive meta‐analysis on glymphatic system dysfunction in relapsing‐remitting multiple sclerosis (RRMS) using the diffusion tensor imaging along the perivascular space (DTI‐ALPS) index compared with healthy controls (HCs). Methods This review followed PRISMA guidelines and systematically searched PubMed, Web of Science, Scopus, and Embase up to July 14, 2025. Inclusion criteria focused on studies utilizing DTI‐ALPS to compare glymphatic function in RRMS patients with HCs. The standardized mean difference (SMD) was calculated using a random‐effects model. Subgroup analyses and meta‐regression were performed to investigate potential sources of heterogeneity. Results Data were extracted from seven eligible studies, comprising a total of 405 RRMS patients (36% male) and 303 HCs. A statistically significant and robust reduction in the DTI‐ALPS index was observed in patients with RRMS (SMD = −0.58, 95% CI: −0.78 to −0.38; p < 0.001), indicating impaired glymphatic function. The analysis revealed moderate heterogeneity among studies ( I 2 = 37.17%). Meta‐regression revealed that age and disease duration fully explained the heterogeneity. No publication bias or risk of bias was detected. Conclusion The DTI‐ALPS index revealed glymphatic dysfunction in RRMS, highlighting the importance of investigating glymphatic impairment in MS.