AUTHOR=Rademacher Annette , Joisten Niklas , Proschinger Sebastian , Bloch Wilhelm , Gonzenbach Roman , Kool Jan , Langdon Dawn , Bansi Jens , Zimmer Philipp 

TITLE=Cognitive Impairment Impacts Exercise Effects on Cognition in Multiple Sclerosis

JOURNAL=Frontiers in Neurology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2020.619500

DOI=10.3389/fneur.2020.619500

ISSN=1664-2295

ABSTRACT=<p><bold>Purpose:</bold> Exercise training reveals high potential to beneficially impact cognitive performance in persons with multiple sclerosis (pwMS). Research indicates that high-intensity interval training (HIIT) has potentially higher effects on physical fitness and cognition compared to moderate continuous exercise. This study (i) compares the effects of a 3-week HIIT and moderate continuous exercise training on cognitive performance and cardiorespiratory fitness of pwMS in an overall analysis and (ii) investigates potential effects based on baseline cognitive status in a subgroup analysis.</p><p><bold>Methods:</bold> Seventy-five pwMS were randomly assigned to an intervention (HIIT: 5 × 1.5-min intervals at 95–100% HR<sub>max</sub>, 3 ×/week) or active control group (CG: 24 min continuous exercise at 65% HR<sub>max</sub>, 3 ×/week). Cognitive performance was assessed pre- and post-intervention with the Brief International Cognitive Assessment for MS (BICAMS). (I) To examine potential within (time) and interaction (time × group) effects in the overall analysis, separate analyses of covariance (ANCOVA) were conducted. (II) For the subgroup analysis, participants were divided into two groups [intact cognition or impaired cognition (&gt;1.5 standard deviation (SD) compared to healthy, age-matched norm data in at least one of the three tests of the BICAMS]. Potential impacts of cognitive status and intervention were investigated with multivariate analyses of variance (MANOVA).</p><p><bold>Results:</bold> Overall analysis revealed significant time effects for processing speed, verbal learning, rel. VO2peak, and rel. power output. A time<sup>*</sup>group interaction effect was observed for rel. power output. Subgroup analysis indicated a significant main effect for cognition (impaired cognition vs. intact cognition). Subsequent <italic>post-hoc</italic> analysis showed significant larger effects on verbal learning in pwMS with impaired cognition.</p><p><bold>Conclusion:</bold> Current results need to be confirmed in a powered randomized controlled trial with cognitive performance as primary endpoint and eligibility based on cognitive performance that is assessed prior to study inclusion.</p>