Dilated brain perivascular spaces and their role in Alzheimer disease

Abstract

AbstractBackgroundDilated small perivascular spaces (SPVS) have gained interest as MRI markers of cerebrovascular disease and possibly dementia.MethodWe leveraged existing data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) to extract information regarding participants’ demographics, vascular risks, cognitive profile, APOE4 genotype and PET imaging for beta amyloid (AV‐45) and phospho tau (AV‐1451). For cognition and dementia status, we used the total Montreal Cognitive Assessment (MOCA), Alzheimer's Disease Assessment Scale–Cognitive Subscale (ADAS‐Cog), and clinical dementia rating (CDR) scores. We used composite gray matter regions for PET measurements of amyloid and tau. We rated SPVS using a previously validated and reliable visual scale that assesses 14 brain regions for presence of SPVS. Each region was given a score of 0 (no SPVS), 1 (1‐3 SPVS), or 2(>3 SPVS). Regional scores were combined to create global SPVS scores. We built multivariate regression models using sex, age, education (in years), hypertension, prior stroke, white matter hypointensities (WMH) volume and APOE4 carrier status.ResultWe included 1,278 participants (mean age 75±8, 48%women, 89% non‐Hispanic white). SPVS were present in 85% of participants (median 6, range 0‐25). In multivariate analysis, SPVS score was associated with older age (B=0.05, P=0.01), history of stroke (B=6.9, P<0.001), WMH (B=0.33 per standard deviation, P=0.05) and marginally with hypertension (B=0.51, P=0.08). SPVS score, however, was associated with a higher MOCA score (B=0.06, P=0.03). There were no associations between SPVS with total ADAS score (B=‐0.02, P=0.71), CDR score (B= ‐0.03, P=0.07), amyloid (B=0.001, P=0.94) or tau (B=0.01, P=0.45).ConclusionBrain SPVS are associated with cerebrovascular disease and aging, but their additional value compared to other imaging markers of cerebrovascular disease as predictors of poorer cognition, dementia or Alzheimer disease is not supported by these data.