Glymphatic dysfunction and cognitive impairment in tuberculous meningitis: insights from diffusion tensor imaging along the perivascular space (DTI-ALPS).

Background: Tuberculous meningitis (TBM), a severe central nervous system infection, carries significant mortality and long-term neurological morbidity. While cognitive impairment is a common consequences of TBM, the contribution of glymphatic system dysfunction to this process remains poorly characterized. Objective: To investigate glymphatic function in TBM patients using the diffusion tensor imaging (DTI)-derived along the perivascular space (ALPS) index and evaluate its utility in detecting and predicting mild cognitive impairment (MCI). Methods: This cross-sectional study enrolled 62 TBM patients and 61 matched healthy controls (HCs). ALPS indices (left/right/whole-brain) were computed from DTI data. Cognitive function was assessed using MMSE, MoCA, TMT-A/B, CDT, VFT, DST, and SDMT. Group comparisons, partial correlation analyses, and ROC curve assessments were performed to examine relationships between glymphatic function and cognitive performance. Results: TBM patients demonstrated significantly reduced ALPS indices (all Conclusion: The DTI-ALPS index effectively captures glymphatic dysfunction in TBM and correlates with domain-specific cognitive deficits. As a non-invasive biomarker, it shows promise for early identification of TBM patients at risk for MCI, potentially facilitating timely intervention to mitigate cognitive decline.