Glymphatic system impairment in Alzheimer's disease: associations with perivascular space volume and cognitive function.

• Patients with Alzheimer's disease dementia displayed a lower diffusion tensor image analysis along the perivascular space (DTI-ALPS) index, possibly indicating glymphatic impairment. • A lower DTI-ALPS index was associated with the enlargement of perivascular space and cognitive impairment. • DTI-ALPS index could be a promising biomarker of the glymphatic system in Alzheimer's disease dementia.