Clinical Relevance of Enlarged Perivascular Spaces in Neurodegenerative Disease

Background: Enlarged perivascular space (ePVS) is recently reported to be associated with cerebral small vessel disease (SVD) and Alzheimer’s disease (AD). The topographical location of ePVS may relate to the underlying pathology; basal ganglia (BG)-ePVS has been associated with cerebral vascular diseases and centrum semi-ovale (CSO)-ePVS associated with cerebral amyloid angiopathy (CAA). However, the effects of ePVS on various neurological conditions remain still controversial. To investigate the clinical relevance of ePVS in neurodegenerative diseases, we tested relationships between ePVS and cognition, markers of SVD, vascular risk factors, or amyloid pathology.Methods: We retrospectively reviewed 292 patients (133 AD dementia, 106 mild cognitive impairment, 39 other neurodegenerative diseases, 14 subjective cognitive decline) who underwent both amyloid positron emission tomography and brain magnetic resonance imaging. Vascular risk factors and cognitive tests results were collected. The ePVS in the BG and CSO, SVD markers and the volume of white matter hyperintensities were measured.Results: There were no significant differences in the severity and distribution of ePVS among clinical syndromes. Both BG- and CSO-ePVS were not related to cognitive function. Patients with lacunes were more likely to have high-degree BG-ePVS. High degree CSO-ePVS had an odds ratio (OR) for amyloid positive of 2.351, while BG-ePVS was a negative predictor for amyloid pathology (OR, 0.336).Conclusions: Our findings support that ePVS has different underlying pathologies according to the cerebral topography. BG-ePVS would be attributed to hypertensive angiopathy considering the relation with SVD markers, whereas and CSO-ePVS would be attributed to CAA considering the association with amyloid pathology.