title: Early cerebral small vessel disease and brain volume, cognition, and gait.
abstract: OBJECTIVE
  Decline in cognitive function begins by the 40s, and may be related to future dementia risk. We used data from a community-representative study to determine whether there are age-related differences in simple cognitive and gait tests by the 40s, and whether these differences were associated with covert cerebrovascular disease on magnetic resonance imaging (MRI).
  
  
  METHODS
  Between 2010 and 2012, 803 participants aged 40 to 75 years in the Prospective Urban Rural Epidemiological (PURE) study, recruited from prespecified postal code regions centered on 4 Canadian cities, underwent brain MRI and simple tests of cognition and gait as part of a substudy (PURE-MIND).
  
  
  RESULTS
  Mean age was 58 ± 8 years. Linear decreases in performance on the Montreal Cognitive Assessment, Digit Symbol Substitution Test (DSST), and Timed Up and Go test of gait were seen with each age decade from the 40s to the 70s. Silent brain infarcts were observed in 3% of 40- to 49-year-olds, with increasing prevalence up to 18.9% in 70-year-olds. Silent brain infarcts were associated with slower timed gait and lower volume of supratentorial white matter. Higher volume of supratentorial MRI white matter hyperintensity was associated with slower timed gait and worse performance on DSST, and lower volumes of the supratentorial cortex and white matter, and cerebellum.
  
  
  CONCLUSIONS
  Covert cerebrovascular disease and its consequences on cognitive and gait performance and brain atrophy are manifest in some clinically asymptomatic persons as early as the 5th decade of life.
authors.affiliation: Hotchkiss Brain Institute; Department of Clinical Neurosciences; Department of Radiology; Seaman Family Centre, University of Calgary, Calgary, Alberta.
authors.forename: Eric E
authors.initials: EE
authors.lastname: Smith
authors.forename: Martin
authors.initials: M
authors.lastname: O'Donnell
authors.forename: Gilles
authors.initials: G
authors.lastname: Dagenais
authors.forename: Scott A
authors.initials: SA
authors.lastname: Lear
authors.forename: Andreas
authors.initials: A
authors.lastname: Wielgosz
authors.forename: Mukul
authors.initials: M
authors.lastname: Sharma
authors.forename: Paul
authors.initials: P
authors.lastname: Poirier
authors.forename: Grant
authors.initials: G
authors.lastname: Stotts
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Black
authors.forename: Stephen
authors.initials: S
authors.lastname: Strother
authors.forename: Michael D
authors.initials: MD
authors.lastname: Noseworthy
authors.forename: Oscar
authors.initials: O
authors.lastname: Benavente
authors.forename: Jayesh
authors.initials: J
authors.lastname: Modi
authors.forename: Mayank
authors.initials: M
authors.lastname: Goyal
authors.forename: Saima
authors.initials: S
authors.lastname: Batool
authors.forename: Karla
authors.initials: K
authors.lastname: Sanchez
authors.forename: Vanessa
authors.initials: V
authors.lastname: Hill
authors.forename: Cheryl R
authors.initials: CR
authors.lastname: McCreary
authors.forename: Richard
authors.initials: R
authors.lastname: Frayne
authors.forename: Shofiqul
authors.initials: S
authors.lastname: Islam
authors.forename: Jane
authors.initials: J
authors.lastname: DeJesus
authors.forename: Sumathy
authors.initials: S
authors.lastname: Rangarajan
authors.forename: Koon
authors.initials: K
authors.lastname: Teo
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
mesh_terms: D000328:Adult; D000368:Aged; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000473:pathology*; D002170:Canada / Q000453:epidemiology; D059345:Cerebral Small Vessel Diseases / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D003071:Cognition / Q000502:physiology*; D042241:Early Diagnosis; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011159:Population Surveillance / Q000379:methods; D011446:Prospective Studies