Furthermore, it has been suggested that the glymphatic system represents a final common pathway for neurodegenerative diseases, for example impaired perivascular efflux of amyloid-β and tau in Alzheimer's disease and impaired perivascular efflux of α-synuclein in Parkinson's disease (Nedergaard and Goldman, 2020). Here, MAPT is linked to early-onset autosomal dominant Alzheimer disease.