30.01.2024
Isolated cognitive impairment in people with multiple sclerosis: frequency, MRI patterns and its development over time, Bouman et.al., 2024
Summary
This study on multiple sclerosis (MS) patients found that isolated cognitive impairments, particularly in processing speed, are common and predictive of further cognitive decline. The research highlights the significance of cortical and deep grey matter atrophy in these impairments. Early detection and tailored interventions, especially for processing speed deficits, are crucial for mitigating further decline, underscoring the need for prompt and specific therapeutic strategies.
Published in
Journal of Neurology
Authors
P. M. Bouman, M.A. van Dam, L. E. Jonkman, M. D. Steenwijk, M. M. Schoonheim, J. J. G. Geurts, H. E. Hulst
Summary
This study on multiple sclerosis (MS) patients found that isolated cognitive impairments, particularly in processing speed, are common and predictive of further cognitive decline. The research highlights the significance of cortical and deep grey matter atrophy in these impairments. Early detection and tailored interventions, especially for processing speed deficits, are crucial for mitigating further decline, underscoring the need for prompt and specific therapeutic strategies.
Abstract
Objectives
To study the frequency of isolated (i.e., single-domain) cognitive impairments, domain specific MRI correlates, and its longitudinal development in people with multiple sclerosis (PwMS).
Methods:
348 PwMS (mean age 48 ± 11 years, 67% female, 244RR/52SP/38PP) underwent neuropsychological testing (extended BRB-N) at baseline and at five-year follow-up. At baseline, structural MRI was acquired. Isolated cognitive impairment was defined as a Z-score of at least 1.5 SD below normative data in one domain only (processing speed, memory, executive functioning/working memory, and attention). Multi-domain cognitive impairment was defined as being affected in ≥ 2 domains, and cognitively preserved otherwise. For PwMS with isolated cognitive impairment, MRI correlates were explored using linear regression. Development of isolated cognitive impairment over time was evaluated based on reliable change index.
Results:
We analyzed data from 128 clinically normal older adults, including 72 (56%) women and 56 (44%) men; median age at inclusion was 73 years (range 63–87). Thirty-four participants (27%) exhibited an initial high-Aβ burden on PET imaging. Faster HV atrophy was correlated with faster cognitive decline (R2 = 0.28, p < 0.0001). When comparing all biomarkers, HV slope was associated with cognitive decline independently of Aβ and tau measures, uniquely accounting for 10% of the variance. Altogether, 45% of the variance in cognitive decline was explained by combining the change measures in the different imaging biomarkers.
Conclusion:
Isolated cognitive impairment is frequently present in PwMS and can serve as a proxy for further decline, particularly when it concerns processing speed. Cortical and deep grey matter atrophy seem to play a pivotal role in isolated cognitive impairment. Timely detection and patient-tailored intervention, predominantly for IPS, may help to postpone further cognitive decline.