Imaging Measures Reflect Cognitive Changes Over Time in Multiple Sclerosis Patients
Posted April 28, 2021
Katherine A. Koenig, Ph.D., The Cleveland Clinic
Many people with multiple sclerosis (MS) experience cognitive decline, which is associated with increased depression and decreased employment and can have a major impact on quality of life. A measure that could quantify the risk of cognitive decline would provide valuable information to patients and their physicians when evaluating treatment strategies and assessing future options in domains typically affected by cognitive decline. It would also provide a powerful evaluation strategy for new medications used to treat MS.
With support from a fiscal year 2015 Multiple Sclerosis Research Program Investigator-Initiated Research Award, Dr. Katherine Koenig, of The Cleveland Clinic, sought to develop a brain imaging measure capable of tracking or predicting cognitive decline in MS patients. Her project builds on promising neuroimaging measures identified in a cross-sectional study of MS and uses ultra-high field magnetic resonance imaging to longitudinally assess the relationship of imaging measures to changes in performance on neuropsychological testing. Specifically, this study assessed 80 participants with MS at baseline and after a one-year interval, with half of the sample returning for yearly neuropsychological testing at a third time point. The research team observed that the health of white matter in the brain, measured by water diffusion, was related to future cognitive measures. Those with healthier white matter at baseline were more likely to have stable cognitive performance over time, and those with a larger decline in white matter health were more likely to score lower on cognitive tests at follow-up. The research team also assessed the strength of functional connections between brain regions, finding that changes in connectivity of the prefrontal cortex were related to changes in the Selective Reminding Test, which assesses verbal episodic memory. However, functional connectivity was unable to significantly differentiate which participants were cognitively stable or declining. Finally, the research team found that total volumes of both the left and right hippocampus were related to changes in performance on the Brief Visuospatial Memory Test, which assesses the visual spatial episodic memory. The change in volume of a subfield of the hippocampus, the dentate gyrus (DG), was related to follow-up cognitive measures bilaterally, and changes in left DG volume could weakly differentiate between cognitively stable and declining participants.
Based on these findings, the researchers expect that these measures could serve as clinical predictors of cognitive decline in MS. Future work will focus on refinement, automation of methods, and validation on a larger scale to confirm the use of these measures as a tool to track cognitive changes and decline in MS populations.
Last updated Thursday, April 29, 2021