Non-invasive assessment of glymphatic dysfunction in middle cerebral artery stenosis based on DTI-ALPS and ro-ALPS.

BACKGROUND

Middle cerebral artery stenosis (MCA-S) impairs cerebral perfusion and vascular pulsatility, potentially disrupting cerebrospinal fluid dynamics. We evaluated perivascular diffusivity in MCA-S using diffusion tensor image analysis along the perivascular space (DTI-ALPS) index and the redirected ALPS (ro-ALPS) index, and assessed their clinical correlations.

METHODS

Thirty-seven patients with MCA-S and 41 matched healthy controls (HCs) underwent MRI and cognitive function testing. We compared the DTI-ALPS index and ro-ALPS indices between the two groups and performed correlation analyses with cognitive scores and clinical indicators, including high-density lipoprotein, homocysteine, and choroid plexus (CP) volume.

RESULTS

The results showed that both DTI-ALPS index and ro-ALPS index were significantly lower in the MCA-S group than in the HC group (both p < 0.001). In MCA-S patients, the DTI-ALPS index was negatively correlated with CP volume (r = -0.541, pFDR = 0.012), and the ro-ALPS index showed a negative correlation with CP volume (r = -0.568, pFDR < 0.001).

CONCLUSION

These findings suggest that perivascular clearance is impaired in patients with MCA-S, as reflected by lower ALPS indices. These ALPS indices, as imaging biomarkers, show significant associations with CP volume, suggesting their potential utility in monitoring disease progression.