Association of CSF amyloid-β and tau with diffusion along the perivascular space in Alzheimer’s disease

Motivation: Glymphatic clearance of toxic proteins, quantified by the “DTI-along-the-perivascular-space” (ALPS) index, is impaired in Alzheimer’s disease (AD) Goal(s): We tested the association of the ALPS index to CSF Aβ and tau. Approach: We used imaging, CSF biomarker, and neuropsychological assessment data from 12 MCI, 21 AD, and 11 other dementia patients. We generated color FA maps and ALPS ROIs, before testing the interaction effects of ALPS × group on each CSF biomarker measure. Results: In our sample of AD and mild cognitive impairment patients (n=44), we found significant positive association of CSF tau and phosphorylated tau (but not amyloid-β) with the ALPS index. Impact: Our study establishes a novel link between brain glymphatic function and CSF phosphorylated tau in AD via the ALPS index.