Benchmarks of meaningful improvement on neurocognitive tests in multiple sclerosis

Importance of Identifying Cognitive Impairment in Multiple Sclerosis

This article aims to highlight the impact of cognitive impairment on outcomes and quality of life for people with multiple sclerosis (MS) and to review current evidence for the efficacy of disease-modifying therapies (DMTs) and other interventions. In addition, we provide clinical practice insights regarding screening and management of cognitive impairment in people with MS. Evidence suggests that cognitive deterioration often accompanies magnetic resonance imaging changes. Neocortical volume and deep grey matter atrophy correlate with cognitive impairment. Similarly, cognitive decline is predictive of a higher lesion burden. Cognitive impairment is an important clinical measure of disability and negatively impacts quality of life. Phase 3 studies suggest that DMTs such as natalizumab, ozanimod and fingolimod may provide long-lasting, clinically meaningful effects on cognition in people with MS. Further data are needed to support the use of adjunct cognitive behavioural and exercise interventions for people with MS who have cognitive impairment. More data are needed to define appropriate management strategies for cognitive impairment in people with MS. Baseline and periodic screening for cognitive impairment and inclusion of cognitive impairment as a clinical trial endpoint will help to inform efforts to manage this important aspect of MS.

Cognitive trajectories in relapsing-remitting multiple sclerosis: Evidence of multiple evolutionary trends

BACKGROUND

Cognitive impairment (CI) frequently occurs in multiple sclerosis (MS) and is assumed to increase over time. However, recent studies have suggested that the evolution of cognitive status in patients with MS may be more heterogeneous than expected. Predicting CI remains also challenging, and longitudinal studies exploring the baseline determinants of cognitive performances are limited. No studies have explored the predictive value of patient-reported outcome measures (PROMs) regarding future CI.

OBJECTIVE

To explore the evolutionary patterns of cognitive status in a cohort of RRMS patients initiating a new disease modifying treatment (DMT), and to determine whether PROMs may have a predictive value for future CI.

METHODS

The present prospective study is a 12-month follow-up of a cohort of 59 RRMS patients who underwent yearly a comprehensive, multiparametric assessment combining clinical (with EDSS assessment), neuropsychological (BVMT-R, SDMT, CVLT-II), MRI-derived metrics and a set of self-reported questionnaires. Lesion and brain volumes were analyzed and processed by the automated MSmetrix® software (Icometrix®, Leuven, Belgium). Spearman's correlation coefficient was used to evaluate the association of collected variables. A longitudinal logistic regression analysis was performed to find baseline correlates of CI at 12 months (T1).

RESULTS

A total of 33 patients (56%) were defined as cognitively impaired at baseline, and 20 (38%) were defined as impaired at follow-up after 12 months. The mean raw scores and Z-scores of all the cognitive tests were significantly improved at T1 (p < 0.05). There was a statistically significant improvement in most PROM scores at T1 (p < 0.05) in comparison with baseline scores. Among the variables assessed, lower education and physical disability level at baseline correlated with impaired SDMT (OR: 1.68, p = 0.01; OR: 3.10, p = 0.02, respectively) and impaired BVMT-R (OR: 4.08, p=<0.001; OR: 4.82, p = 0.001, respectively) at T1. Neither baseline PROMs nor MRI volumetric parameters were predictive of cognitive performances at T1.

CONCLUSIONS

These findings provide additional evidence that evolution of CI in MS may be a dynamic phenomenon and will not usually follow an inevitable, declining trajectory, and do not support the utility of PROMs in predicting CI in RRMS. The present study is still ongoing to determine whether our findings are confirmed at 2 and 3 years of follow-up.

Assessing cognitive changes in multiple sclerosis: criteria for a reliable decision

INTRODUCTION

Quantifying a significant cognitive change on a neuropsychological battery is essential to assess patients' decline or recovery and offer appropriate care. The reliability of change indices is particularly important in multiple sclerosis (MS), as the course of cognitive impairment is quite unpredictable, due at least in part to substantial interindividual variability. The main objective of this study was to compare six different methods for assessing cognitive change in an MS sample: the SD method, two reliable change indices, two standardized regression-based methods (SRB), and the generalized regression-based method (GSRB).

METHOD

One hundred and twenty-three patients with clinically definite MS and 89 healthy controls underwent a battery of standardized neuropsychological tests assessing cognitive functions that are frequently affected in this disease (i.e., verbal episodic memory, working memory, processing speed and verbal fluency).

RESULTS

We observed fairly similar proportions of improvement, decline or stability in the control group whatever the method. By contrast, in the MS sample, regression-based methods with one predictor (i.e., score at T1) and four predictors (i.e., score at T1 and demographic factors: age, sex, education level) detected a significant worsening more often than the reliable change indices while the GSRB method was more consistent with the RCI methods in tasks associated with ceiling effects.

CONCLUSIONS

The interpretation of a patient's cognitive changes depends on which method is used. The (G)SRB methods appear to be relevant indicators for assessing cognitive change in MS. The addition of demographic factors does not seem to play an important role in the prediction of significant worsening in the MS sample, regardless of cognitive domain. For clinicians, an easy-to-use free shiny app is provided.

Longitudinal assessment of neurocognitive function in people with relapsing multiple sclerosis initiating alemtuzumab in routine clinical practice: LEM-COG study results

BACKGROUND

Alemtuzumab is effective in reducing relapse rate and disability, but limited data exist on its effect on cognitive function in relapsing multiple sclerosis (RMS). The present study assessed neurocognitive function and safety associated with alemtuzumab treatment in RMS.

METHODS

This longitudinal, single-arm, prospective study included people with RMS (aged 25-55 years) who were treated with alemtuzumab in clinical practice in the United States of America and Canada. The first participant was enrolled in December 2016. The primary endpoint was the change from baseline to post-baseline (month [M] 12/24) in MS-COGnitive (MS-COG) composite score. Secondary endpoints included Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), Brief Visuospatial Memory Test-Revised (BVMT-R), Selective Reminding Test (SRT), Controlled Oral Word Association Test (COWAT), and Automated Neuropsychological Assessment Metrics (ANAM) scores. Depression and fatigue were assessed using Hamilton Rating Scale-Depression (HAM-D) and Fatigue Severity Scale (FSS)/Modified Fatigue Impact Scale (MFIS), respectively. Magnetic resonance imaging (MRI) parameters were assessed when available. Safety was assessed throughout the study. Descriptive statistics were used for the pre-specified statistical analyses. Since the study was terminated early (November 2019) because of operational and resource difficulties, post hoc analyses for statistical inference were performed among participants who had a baseline value and at least one complete post-baseline assessment for cognitive parameters, fatigue, or depression.

RESULTS

Of the 112 participants enrolled, 39 were considered as the primary analysis population at M12. At M12, a mean change of 0.25 (95% confidence interval [CI]: 0.04, 0.45; p = 0.0049; effect size [ES]: 0.39) was observed in the MS-COG composite score. Improvements were observed in processing speed (based on PASAT and SDMT; p < 0.0001; ES: 0.62), as well as in individual PASAT, SDMT and COWAT scores. An improvement was also noted in HAM-D (p = 0.0054; ES: -0.44), but not in fatigue scores. Among MRI parameters, decreases in burden of disease volume (BDV; ES: -0.12), new gadolinium-enhancing lesions (ES: -0.41) and newly active lesions (ES: -0.07) were observed at M12. About 92% of participants showed stable or improved cognitive status at M12. There were no new safety signals reported in the study. The most common adverse events (≥10% of participants) were headache, fatigue, nausea, insomnia, urinary tract infection, pain in extremity, chest discomfort, anxiety, dizziness, arthralgia, flushing, and rash. Hypothyroidism (3.7%) was the most frequent adverse event of special interest.

CONCLUSION

The findings from this study suggest that alemtuzumab has a positive impact on cognitive function with significant improvements in processing speed and depression in people with RMS over a period of 12 months. The safety profile of alemtuzumab was consistent with previous studies.

Repeated forms, testing intervals, and SDMT performance in a large multiple sclerosis dataset

BACKGROUND

The Symbol Digit Modalities Test (SDMT), the most reliable and sensitive measure of cognition in people with multiple sclerosis (PwMS), is increasingly used in clinical trials and care.

OBJECTIVES

We aimed to establish how SDMT performance is influenced by repeating forms and frequency of use in PwMS.

METHODS

A retrospective analysis was completed on a large database of PwMS (n = 740) with multiple SDMT administrations. Change in SDMT performance was analyzed, accounting for frequency of tests and utilization of alternate- versus same-form conditions.

RESULTS

SDMT administrations ranged from 2 to 14 per subject over a mean (SD) of 5.9 (4.5) years. Accounting for demographics, the mixed effects model revealed a significant main effect of SDMT exposures (1.8 point improvement per repetition, p = 0.001) and an interaction between time since previous SDMT and whether the same test form was administered in the previous administration (estimate=-1.1, p = 0.037). As well, SDMT decline is observed when testing intervals exceed two years (F = 9.69, p<0.001).

CONCLUSION

Improvements in SDMT performance with repeated exposure, likely reflecting practice effects, were greatest when repeating the same SDMT form over briefer intervals. We recommend the use of alternate forms or analogous versions of timed symbol-digit coding particularly where samples are saturated with many administrations.