Cognitive worsening over time independent of relapse and MRI activity
Sarah A Morrow, Heather Rosehart, Laura M Hancock, Marina EverestBackground
Progression independent of relapse and/or MRI activity (PIRA/PIRMA) is now understood to drive progression in persons with MS (PwMS). Worsening of cognition over time, cognitive PIRA or PIRMA, is understudied.
Objective
Examine change in cognition over 2 years in PwMS without relapse and/or MRI activity.
Methods
This study was a retrospective analysis of a prospective cohort assessing subjects at baseline and 2 years later; Symbol Digit Modalities Test (SDMT) and MRI were performed at both visits. PwMS aged ≥ 18 years were recruited consecutively, from November 2020 to August 2022. We identified subjects who did not experienced a relapse and/or new lesions on MRI yet demonstrated worsened on SDMT over time (cognitive PIRA and/or PIRMA).
Results
One hundred subjects completed the baseline visit, 95 subjects completed year 2. Four subjects had relapses. 29 (31.9%) had any decrease on SDMT: 17 (18.7%) decrease of ≥ four points; 6 (6.6%) a decrease of ≥ eight points. An additional 11 subjects had new lesions on MRI. In this remaining cohort, 25 (31.3%) had a decrease on SDMT: 14 (17.5%) ≥ four points; 4 (5.0%) ≥ eight points.
Conclusion
Cognitive PIRA/PIRMA is common in PwMS. More studies are needed to better understand this phenomenon.