title: Progression of MRI markers in cerebral  small vessel disease: Sample size  considerations for clinical trials.
abstract: Detecting treatment efficacy using cognitive change in trials of cerebral small vessel disease (SVD) has been challenging, making the use of surrogate markers such as magnetic resonance imaging (MRI) attractive. We determined the sensitivity of MRI to change in SVD and used this information to calculate sample size estimates for a clinical trial. Data from the prospective SCANS (St George’s Cognition and Neuroimaging in Stroke) study of patients with symptomatic lacunar stroke and confluent leukoaraiosis was used (n = 121). Ninety-nine subjects returned at one or more time points. Multimodal MRI and neuropsychologic testing was performed annually over 3 years. We evaluated the change in brain volume, T2 white matter hyperintensity (WMH) volume, lacunes, and white matter damage on diffusion tensor imaging (DTI). Over 3 years, change was detectable in all MRI markers but not in cognitive measures. WMH volume and DTI parameters were most sensitive to change and therefore had the smallest sample size estimates. MRI markers, particularly WMH volume and DTI parameters, are more sensitive to SVD progression over short time periods than cognition. These markers could significantly reduce the size of trials to screen treatments for efficacy in SVD, although further validation from longitudinal and intervention studies is required.
authors.forename: Philip
authors.initials: P
authors.lastname: Benjamin
authors.forename: Eva
authors.initials: E
authors.lastname: Zeestraten
authors.forename: Christian
authors.initials: C
authors.lastname: Lambert
authors.forename: Irina Chis
authors.initials: IC
authors.lastname: Ster
authors.forename: Owen A
authors.initials: OA
authors.lastname: Williams
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Lawrence
authors.forename: Bhavini
authors.initials: B
authors.lastname: Patel
authors.forename: Andrew D
authors.initials: AD
authors.lastname: MacKinnon
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Barrick
authors.forename: Hugh S
authors.initials: HS
authors.lastname: Markus
mesh_terms: D000368:Aged; D059345:Cerebral Small Vessel Diseases / Q000473:pathology* / Q000523:psychology; D002986:Clinical Trials as Topic / Q000379:methods*; D003072:Cognition Disorders / Q000523:psychology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests; D018401:Sample Size; D066127:White Matter / Q000473:pathology*