Editors' Note: Simple MRI Score Aids Prediction of Dementia in Cerebral Small Vessel Disease

Abstract

In the article “Simple MRI score aids prediction of dementia in cerebral small vessel disease,” Dr. Amin Al Olama et al. found that a small vessel disease (SVD) score obtained from routine MRI scans improved prediction of dementia compared with clinical risk factors alone in a pooled analysis of 3 prospective longitudinal cohort studies. In response, Drs. Nation and Kapoor posit that the associations between total MRI load of SVD and cognition reflect the global effect of SVD on the brain and note that this score could also aid Alzheimer Disease (AD) research, given the considerable prevalence of SVD in AD. In another response, Dr. Yuan identifies some potential issues with the SVD score used in the study, chiefly the exclusion of enlarged perivascular spaces, which are yet to be well studied in relation to longitudinal outcomes, and considerable methodological heterogeneities among the 3 studies. Dr. Yuan also notes that network disruption by the global disease, that is SVD, may play a key role in driving cognitive decline and dementia. These comments highlight the importance of further systematic study of various markers of SVD burden in relation to cognitive decline to better understand the contributions of such markers in various dementia phenotypes. As this understanding evolves, we may anticipate that changes in such markers may become important outcome measures in future trials of vascular or mixed cognitive impairment. In the article “Simple MRI score aids prediction of dementia in cerebral small vessel disease,” Dr. Amin Al Olama et al. found that a small vessel disease (SVD) score obtained from routine MRI scans improved prediction of dementia compared with clinical risk factors alone in a pooled analysis of 3 prospective longitudinal cohort studies. In response, Drs. Nation and Kapoor posit that the associations between total MRI load of SVD and cognition reflect the global effect of SVD on the brain and note that this score could also aid Alzheimer Disease (AD) research, given the considerable prevalence of SVD in AD. In another response, Dr. Yuan identifies some potential issues with the SVD score used in the study, chiefly the exclusion of enlarged perivascular spaces, which are yet to be well studied in relation to longitudinal outcomes, and considerable methodological heterogeneities among the 3 studies. Dr. Yuan also notes that network disruption by the global disease, that is SVD, may play a key role in driving cognitive decline and dementia. These comments highlight the importance of further systematic study of various markers of SVD burden in relation to cognitive decline to better understand the contributions of such markers in various dementia phenotypes. As this understanding evolves, we may anticipate that changes in such markers may become important outcome measures in future trials of vascular or mixed cognitive impairment.