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The Multiple Sclerosis Performance Test MSPT: An iPad-Based Disability Assessment Tool
Published on: June 30, 2014
Detecting isolated cognitive relapses in persons with MS
Sarah A Morrow1, Zachary L Weinstock2, Omid Mirmosayyeb2
1University Hospital, London Health Sciences Center, Department of Clinical Neurological Sciences, Western University, London, ON, Canada.
Background:
The existence of isolated cognitive relapses (ICRs) in persons with MS (PwMS) has been debated.
Objective:
To examine relapses with decline on Symbol Digit Modalities Test (SDMT) but no change on Expanded Disability Status Scale (EDSS).
Methods:
This 3-year prospective cohort study identified PwMS experiencing a relapse with decrease on SDMT. Participants with SDMT decline/stable EDSS were labeled "ICR," while those with a corresponding decrease on EDSS were classified "Relapse with Cognitive Decline (RCD)." Two definitions of SDMT decline were explored: (1) ⩾ 8 points, and (2) ⩾ 4 points. Logistic regression was used to analyze the relationship between ICR and RCD.
Results:
The full cohort had 592 participants: 83 experienced relapses; 22 (26.5%) had an SDMT decrease of ⩾ 8 points; 14 (63.6%) met ICR criteria. Logistic regression (X2(1) = 5.112, p = 0.024) using demographics and disease characteristics explained 28.4% of the variance in ICR versus RCD. Only the MS Neuropsychological Questionnaire was associated with ICR (odds ratio (OR): 8.6; 95% confidence interval (CI): 1.1-16.4) 40 relapsing participants with SDMT decrease of ⩾ 4 points were identified: 26 (65%) had a stable EDSS (ICR). Logistic regression did not find any variable predictive of ICR.
Conclusion:
This prospective study demonstrates evidence of ICR in PwMS.
