Photo for PURE-MIND


Official Title

Prospective Urban Rural Epidemiologic (PURE) MIND sub-study




Large epidemiological studies in Europe, United States and Japan have reported the epidemiology of covert infarction and WML.13-19. However, key limitations of these studies include:

  • An absence of complete information on multi-level clinical determinants including individual (e.g. diet) and community-level factors
  • Limited information on genetic risk factors for silent brain infarction and WML, despite data showing high heritability for WML20-22 and a suggestion of gene-environment interactions
  • Inadequate sampling of middle-aged populations
  • Use of semi-quantitative visual rating scales of WML in many cases,24-26 rather than direct volumetric measurements
  • Confinement to high-income countries with very limited ethnic and cultural diversity
  • The use of differing methodologies (including measurement scales), MRI protocols and definitions, making between-study comparisons challenging and likely inaccurate
  • The inability to achieve high rates of neuroimaging follow-up.

To date, no study has been undertaken in Canada. We propose the first population-based study in Canada that will overcome the limitations of previous studies.

Study Design

Cohort study

Primary Endpoint

The overall objective of this study is to determine the prevalence, natural history, determinants and clinical consequence of covert cerebral ischemia in a defined population of community-dwelling participants in Canada, India, Poland, and China. We propose to carry out this sub-study within the ongoing Prospective Urban Rural Epidemiologic (PURE) study, a multinational longitudinal cohort study examining novel individual, household, community and societal determinants of cardiovascular disease.

Number of Patients


Number of Sites


Number of Countries


Study Period


Principal Investigator

Dr. Martin O’Donnell and Dr. Eric Smith

Program Manager

Sumathy Rangarajan

Research Coordinator

Maha Mushtaha

Key Publications

Smith EE, O’Donnell M, Dagenais G, Lear SA, Wielgosz A, Sharma M, Poirier P, Stotts G, Black SE, Strother S, Noseworthy MD, Benavente O, Modi J, Goyal M, Batool S, Sanchez K, Hill V, McCreary CR, Frayne R, Islam S, DeJesus J, Rangarajan S, Teo K, Yusuf S; PURE Investigators. Early cerebral small vessel disease and brain volume, cognition, and gait. Ann Neurol 2015; 77(2): 251-61.