Reliability and equivalence of alternate forms for the Symbol Digit Modalities Test: implications for multiple sclerosis clinical trials

Neuropsychological Manifestations of Multiple Sclerosis

This review article summarizes the literature on the cognitive impairment seen amongst people with multiple sclerosis (MS) and how that impairment can impact not only their lives but also how their care needs to be managed. Recommendations regarding screening and monitoring of cognitive issues are reviewed, as well as how common comorbidities can further impact cognition. The current literature with respect to treatment options is also summarized. Finally, the article reviews the literature on some special populations living with MS.

The time to include cognition in the multiple sclerosis concept of progression independent from relapse activity is now

Progression independent of relapse activity (PIRA) has been recently proposed in multiple sclerosis (MS) as a model identifying a continuous silent progression of disability without the manifestation of new clinical and magnetic resonance imaging (MRI) events that contribute to MS worsening. Despite evidence suggesting that clinical MS manifestations often affect cognitive functioning and the importance of neuropsychological monitoring over time, attention to silent cognitive progression is lacking, and the PIRA concept does not include a measure of cognitive function. In this personal viewpoint, we highlight the need to include cognition in the PIRA model to have a more comprehensive understanding of clinical progression in patients with MS.

Cognition in patients with myelin oligodendrocyte glycoprotein antibody-associated disease: a prospective, longitudinal, multicentre study of 113 patients (CogniMOG-Study)

BACKGROUND

Data on cognition in patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are limited to studies with small sample sizes. Therefore, we aimed to analyse the extent, characteristics and the longitudinal course of potential cognitive deficits in patients with MOGAD.

METHODS

The CogniMOG-Study is a prospective, longitudinal and multicentre observational study of 113 patients with MOGAD. Individual cognitive performance was assessed using the Paced Auditory Serial Addition Task (PASAT), the Symbol Digit Modalities Test (SDMT) and the Multiple Sclerosis Inventory Cognition (MuSIC), which are standardised against normative data from healthy controls. Cognitive performance was assessed at baseline and at 1-year and 2-year follow-up assessments. Multiple linear regression was used to analyse demographic and clinical predictors of cognitive deficits identified in previous correlation analyses.

RESULTS

At baseline, the study sample of MOGAD patients showed impaired standardised performance on MuSIC semantic fluency (mean=-0.29, 95% CI (-0.47 to -0.12)) and MuSIC congruent speed (mean=-0.73, 95% CI (-1.23 to -0.23)). Around 1 in 10 patients showed deficits in two or more cognitive measures (11%). No decline in cognition was observed during the 1-year and 2-year follow-up period. Cerebral lesions were found to be negatively predictive for SDMT (B=-8.85, 95% CI (-13.57 to -4.14)) and MuSIC semantic fluency (B=-4.17, 95% CI (-6.10 to -2.25)) test performance.

CONCLUSIONS

Based on these data, we conclude that MOGAD patients show reduced visuomotor processing speed and semantic fluency to the extent that the disease burden includes cerebral lesions.

Test-retest reliability, practice effects and estimates of change: A study on the Mindmore digital cognitive assessment tool

The present study aimed to establish test-retest reliability and investigate practice effects of the Mindmore cognitive assessment tool, a digital adaptation of traditional pencil and paper tests designed for self-administration. Additionally, normative change scores for the most frequently used tests were derived. A total of 149 healthy Swedish adults (aged 20-79) completed the test battery twice, 1 month apart. The battery assessed attention and processing speed, memory, language, visuospatial functions, and executive functions. Test-retest reliability, measured by ICC and Spearman coefficients, and practice effects were estimated for 22 main-scores and 33 sub-scores. Regression models were used to assess change in performance while controlling for demographics, computer equipment, testing location (online or in-laboratory) and baseline performance for 12 main-scores and nine sub-scores. Test-retest reliability was good for 11 main-scores (≥0.70), satisfactory for five (0.60-0.69), and minimal for six (<0.60) albeit three having satisfactory sub-scores. Practice effects were observed for tests with a major speed component, but not for reaction time, sustained attention, verbal memory and naming (alternate forms), nor visuospatial functions. Trackpad negatively influenced change for one test. Demographics and testing location did not significantly affect the change scores. Our study provides support for test-retest reliability and practice effects of the Mindmore cognitive assessment tool which were comparable to those of traditional tests. These findings, together with the normative change scores, can aid researchers and clinicians in interpreting test results and distinguishing between normal variations in performance and changes indicative of clinical impairment.

Delayed oculomotor response associates with optic neuritis in youth with demyelinating disorders

INTRODUCTION

Impairment in visual and cognitive functions occur in youth with demyelinating disorders such as multiple sclerosis, neuromyelitis optica spectrum disorder, and myelin oligodendrocyte glycoprotein antibody-associated disease. Quantitative behavioral assessment using eye-tracking and pupillometry can provide functional metrics for important prognostic and clinically relevant information at the bedside.

METHODS

Children and adolescents diagnosed with demyelinating disorders and healthy, age-matched controls completed an interleaved pro- and anti-saccade task using video-based eye-tracking and underwent spectral-domain optical coherence tomography examination for evaluation of retinal nerve fiber layer and ganglion cell inner plexiform layer thickness. Low-contrast visual acuity and Symbol Digit Modalities Test were performed for visual and cognitive functional assessments. We assessed saccade and pupil parameters including saccade reaction time, direction error rate, pupil response latency, peak constriction time, and peak constriction and dilation velocities. Generalized Estimating Equations were used to examine the association of eye-tracking parameters with optic neuritis history, structural metrics, and visual and cognitive scores.

RESULTS

The study included 36 demyelinating disorders patients, aged 8-18 yrs. (75% F; median = 15.22 yrs., SD = 2.8) and 34 age-matched controls (65% F; median = 15.26 yrs., SD = 2.3). Surprisingly, pro- and anti-saccade performance was comparable between patients and controls, whereas pupil control was altered in patients. Oculomotor latency measures were strongly associated with the number of optic neuritis episodes, including saccade reaction time, pupil response latency, and peak constriction time. Peak constriction time was associated with both retinal nerve fiber layer and ganglion cell inner plexiform layer thickness. Pupil response latency and peak constriction time were associated with visual acuity. Pupil velocity for both constriction and dilation was associated with Symbol Digit Modalities Test scores.

CONCLUSION

The strong associations between oculomotor measures with history of optic neuritis, structural, visual, and cognitive assessments in these cohorts demonstrates that quantitative eye-tracking can be useful for probing demyelinating injury of the brain and optic nerve. Future studies should evaluate their utility in discriminating between demyelinating disorders and tracking disease progression.

Feasibility of remotely delivered and supported aerobic walking exercise training for cognitive processing speed impairment in fully-ambulatory persons with multiple sclerosis

PURPOSE

The current pilot, single-blind, randomized controlled trial (RCT) examined the feasibility of remotely-delivered and supported aerobic walking exercise training compared with an active control condition on cognitive processing speed (CPS) in 19 fully-ambulatory persons with multiple sclerosis (pwMS) who were pre-screened for impaired CPS.

METHODS

Feasibility was assessed in the domains of process (e.g., recruitment), resource (e.g., monetary costs), management (e.g., time requirements), and scientific outcomes (i.e., treatment effect). Fully-ambulatory, but CPS-impaired pwMS were randomly assigned into either 16-weeks of home-based aerobic walking exercise or home-based stretching and range-of-motion activities. Both conditions involved delivery of informational newsletters and one-on-one, online video chats with a behavior coach. Participants across both conditions tracked their activity using highly accurate wearable motion sensors. Treatment-blinded assessors administered the Symbol Digit Modalities Test (SDMT) remotely before and after the 16-week study period.

RESULTS

The study was cost-effective, accessible, and acceptable. The intervention further was safe. Adherence and compliance rates across both conditions exceeded 80%. There was an overall moderate effect for change in SDMT score between the conditions (d = 0.42). The intervention was associated with a 4.8-point improvement in SDMT scores (d = 0.70; 10% increase) compared with a 1-point improvement for the control condition (d = 0.09; 2% increase).

CONCLUSIONS

This remotely-delivered and supported aerobic walking exercise training intervention was safe and feasible for fully-ambulatory, CPS-impaired pwMS. The pattern of results, including the promising effects on CPS, support the design and implementation of an appropriately-powered RCT on this approach for managing CPS impairment in a large MS sample.

Early Strokes Are Associated with More Global Cognitive Deficits in Adults with Sickle Cell Disease

This study sought to link neurocognitive profiles in sickle cell disease (SCD) patients with clinical characteristics. We conducted a prospective cohort study of adults with SCD who underwent comprehensive neuropsychological assessment at the UMGGR clinic at Henri Mondor Hospital, Créteil (France). A cluster analysis was performed based on neuropsychological testing scores. The association between clusters and clinical profiles was assessed. Between 2017 and 2021, 79 patients with a mean age of 36 [range 19-65] years were included. On principal component analysis, a 5-factor model presented the best fit (Bartlett's sphericity test [χ2 (171) = 1345; p < 0.001]), explaining 72% of the variance. The factors represent distinct cognitive domains and anatomical regions. On hierarchical classification, three clusters emerged. Cluster 1 (n = 24) presented deficits in all five factors compared to Cluster 3 (n = 33). Cluster 2 (n = 22) had deficits in all factors, but to a lesser extent than Cluster 1. MoCA scores mirrored the severity of these cognitive deficits. Age, genotype and stroke prevalence did not differ significantly between clusters. However, the time of first stroke occurrence differed significantly between Cluster 1 and 2-3: 78% of strokes occurred during childhood, whereas 80% and 83% occurred during adulthood in Clusters 2 and 3, respectively. Educational attainment was also reduced in Cluster 1. SCD patients with childhood stroke seem to be at increased risk of a global cognitive deficit profile. In addition to existing methods of primary and secondary stroke prevention, early neurorehabilitation should be prioritized in order to reduce the long-term cognitive morbidity of SCD.

Cognition in patients with neuromyelitis optica spectrum disorders: A prospective multicentre study of 217 patients (CogniNMO-Study)

BACKGROUND

There is limited and inconsistent information on the prevalence of cognitive impairment in neuromyelitis optica spectrum disorders (NMOSD).

OBJECTIVE

To assess cognitive performance and changes over time in NMOSD.

METHODS

This study included data from 217 aquaporin-4-IgG-seropositive (80%) and double-seronegative NMOSD patients. Cognitive functions measured by Symbol Digit Modalities Test (SDMT), Paced Auditory Serial-Addition Task (PASAT), and/or Multiple Sclerosis Inventory Cognition (MuSIC) were standardized against normative data (N = 157). Intraindividual cognitive performance at 1- and 2-year follow-up was analyzed. Cognitive test scores were correlated with demographic and clinical variables and assessed with a multiple linear regression model.

RESULTS

NMOSD patients were impaired in SDMT (p = 0.007), MuSIC semantic fluency (p < 0.001), and MuSIC congruent speed (p < 0.001). No significant cognitive deterioration was found at follow-up. SDMT scores were related to motor and visual disability (p_Bon < 0.05). No differences were found between aquaporin-4-IgG-seropositive and double-seronegative NMOSD.

CONCLUSIONS

A subset of NMOSD patients shows impairment in visual processing speed and in semantic fluency regardless of serostatus, without noticeable changes during a 2-year observation period. Neuropsychological measurements should be adapted to physical and visual disabilities.

Effects of Repeated Administration and Comparability of Alternate Forms for the Global Neuropsychological Assessment (GNA)

The Global Neuropsychological Assessment (GNA) is an extremely brief battery of cognitive tasks assessing episodic memory, processing speed, working memory, verbal fluency, executive function, and mood. It can be given in under 15 minutes, has five alternate forms, and does not require an examinee to be literate. The purpose of this study was to quantify practice effects over repeated administrations and assess comparability of the GNA's five alternate forms, preparing the battery for repeated administration in research and clinical settings. Forty participants each completed all five GNA forms at weekly intervals following a Latin square design (i.e., each form was administered at every position in the sequence an equal number of times). In a cognitively intact population, practice effects of 0.56 to 1.06 SD were observed across GNA measures when comparing the first and fifth administration. Most GNA tests showed nonsignificant interform differences with cross-form means differing by 0.35 SD or less, with the exception of modest but statistically significant interform differences for the GNA Story Memory subtest across all five forms. However, post hoc analysis identified clusters of two and three Story Memory alternate forms that were equivalent.

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.

Reducing fatigue following acquired brain injury: A feasibility study of high intensity interval training for young adults

The aim was to evaluate feasibility of high-intensity interval training (HIIT) in fatigued adults (20-40 years old) with acquired brain injury (ABI). A prospective pre-post single-arm intervention trial was conducted, including 6-8 months follow-up assessment and interview. Intervention was 18 sessions of intermittent exercise on a cycle ergometer over six weeks. Six out of ten participants without motor impairments completed the intervention (all females, mean age = 30.2 years, months post-injury = 22). On average, participants attended 88% of sessions and achieved high intensity (93% of max heart rate). VO_2max improved by 0.53 l/min (SD = 0.29), and participants continued exercising post-intervention. All participants were satisfied with HIIT, were more inclined to exercise, and reported positive effects of exercising for self-management of fatigue. Three sessions a week were demanding to some participants. Findings support feasibility of HIIT as a promising intervention for young adults with post-ABI fatigue.

Validation of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) in the Russian Population

OBJECTIVE

Cognitive dysfunction is common in multiple sclerosis (MS). The Brief International Cognitive Assessment for MS (BICAMS) battery of tests has been suggested as a measure for the evaluation of the cognitive status of MS patients. This study aims to validate the BICAMS battery in the Russian population of MS patients.

METHODS

Age- and sex-matched MS patients (n = 98) and healthy individuals (n = 86) were included in the study. Symbol Digit Modalities Test (SDMT), California Verbal Learning Test, 2nd edition (CVLT-II) and the Brief Visuospatial Memory Test - Revised (BVMT-R) were administered to all participants. The battery was readministered 1 month later to 44 MS patients to investigate the test-retest reliability.

RESULTS

MS patients exhibited a significantly lower performance in testing with BICAMS than the control group in all three neuropsychological tests. Test-retest reliability was good for SDMT and CVLT-II (r = .82 and r = .85, respectively) and adequate for BVMT-R (r = .70). Based on the proposed criterion for impairment as z score below 1.5 SD the mean of the control group, we found that 34/98 (35%) of MS patients were found impaired at least in one cognitive domain. Patients with Expanded Disability Status Scale score ≥3.5 performed significantly worse than controls (SDMT, p < .0001; CVLT-II, p = .03; BVMT-R, p = .0004), while those with ≤3.0 scores did not.

CONCLUSION

This study demonstrates that the BICAMS battery is a valid instrument to identify cognitive impairment in MS patients and it can be recommended for routine use in the Russian Federation.

Cognitive fatigability assessment test (cFAST): Development of a new instrument to assess cognitive fatigability and pilot study on its association to perceived fatigue in multiple sclerosis

Background

Fatigue is a common symptom of many diseases, including multiple sclerosis. It manifests as a cognitive or physical condition. Fatigue is poorly understood, and effective therapies are missing. Furthermore, there is a lack of methods to measure fatigue objectively. Fatigability, the measurable decline in performance during a task, has been suggested as a complementary method to quantify fatigue.

Objective

To develop a new and objective measurement of cognitive fatigability and investigate its association with perceived fatigue.

Methods

We introduced the cognitive fatigability assessment test (cFAST), a novel smartphone-based test to quantify cognitive fatigability. Forty-two people with multiple sclerosis (23 fatigued and 19 non-fatigued, defined by the Fatigue Scale for Motor and Cognitive Functions) took part in our validation study. Patients completed cFAST twice. We used t-tests, Monte Carlo sampling, and area under the receiver operating characteristic curves to evaluate our approach using two sets of proposed metrics.

Results

When classifying fatigue, our fatigability metric Δresponse time has a mean area under the receiver operating characteristic curve of 0.74 (95% CI 0.64–0.84), making it the best performing metric for this task. Furthermore, Δresponse time shows a statistically significant difference between the fatigued and non-fatigued groups (t = 2.27, P = .03). Particularly, cognitively-fatigued patients decline in performance, while non-fatigued patients do not.

Conclusions

We introduce cFAST, a new instrument to quantify cognitive fatigability. Our pilot study provides evidence that cognitive fatigability assessment test produces a quantifiable drop in cognitive performance in a short period. Furthermore, our results indicate that cFAST may have the potential to serve as a surrogate for subjective cognitive fatigue. cFAST is significantly shorter than the existing fatigability assessments and does not require specialized equipment. Thus, it could enable frequent and remote monitoring, which could substantially aid clinicians in better understanding and treating fatigue.

Practice Effects of Mobile Tests of Cognition, Dexterity, and Mobility on Patients With Multiple Sclerosis: Data Analysis of a Smartphone-Based Observational Study

Background

Smartphones and their built-in sensors allow for measuring functions in disease-related domains through mobile tests. This could improve disease characterization and monitoring, and could potentially support treatment decisions for multiple sclerosis (MS), a multifaceted chronic neurological disease with highly variable clinical manifestations. Practice effects can complicate the interpretation of both improvement over time by potentially exaggerating treatment effects and stability by masking deterioration.

Objective

The aim of this study is to identify short-term learning and long-term practice effects in 6 active tests for cognition, dexterity, and mobility in user-scheduled, high-frequency smartphone-based testing.

Methods

We analyzed data from 264 people with self-declared MS with a minimum of 5 weeks of follow-up and at least 5 repetitions per test in the Floodlight Open study, a self-enrollment study accessible by smartphone owners from 16 countries. The collected data are openly available to scientists. Using regression and bounded growth mixed models, we characterized practice effects for the following tests: electronic Symbol Digit Modalities Test (e-SDMT) for cognition; Finger Pinching and Draw a Shape for dexterity; and Two Minute Walk, U-Turn, and Static Balance for mobility.

Results

Strong practice effects were found for e-SDMT (n=4824 trials), Finger Pinching (n=19,650), and Draw a Shape (n=19,019) with modeled boundary improvements of 40.8% (39.9%-41.6%), 86.2% (83.6%-88.7%), and 23.1% (20.9%-25.2%) over baseline, respectively. Half of the practice effect was reached after 11 repetitions for e-SDMT, 28 repetitions for Finger Pinching, and 17 repetitions for Draw a Shape; 90% was reached after 35, 94, and 56 repetitions, respectively. Although baseline performance levels were highly variable across participants, no significant differences between the short-term learning effects in low performers (5th and 25th percentile), median performers, and high performers (75th and 95th percentile) were found for e-SDMT up to the fifth trial (β=1.50-2.00). Only small differences were observed for Finger Pinching (β=1.25-2.5). For U-Turn (n=15,051) and Static Balance (n=16,797), only short-term learning effects could be observed, which ceased after a maximum of 5 trials. For Two Minute Walk (n=14,393), neither short-term learning nor long-term practice effects were observed.

Conclusions

Smartphone-based tests are promising for monitoring the disease trajectories of MS and other chronic neurological diseases. Our findings suggest that strong long-term practice effects in cognitive and dexterity functions have to be accounted for to identify disease-related changes in these domains, especially in the context of personalized health and in studies without a comparator arm. In contrast, changes in mobility may be more easily interpreted because of the absence of long-term practice effects, even though short-term learning effects might have to be considered.

A much needed metric: Defining reliable and statistically meaningful change of the oral version Symbol Digit Modalities Test (SDMT)

BACKGROUND

The Symbol Digit Modalities Test (SDMT) has been recommended for use in clinical trials and outcome studies to monitor cognitive change. However, defining what is a meaningful change has been elusive for several years.

OBJECTIVE

The present investigation aimed to develop methods for assessing individual-level statistically significant change on the SDMT - reliable change indices (RCIs) and standardized regression-based (SRB) equations.

METHODS

A total of 219 healthy individuals completed the oral version SDMT at baseline, 6-month and 1-year follow-up.

RESULTS

The SDMT demonstrated high reliability across all time points (r's = 0.83 to 0.86). Reliable change scores of 7, 8, and 10 points for the 6-month intervals represented statistically meaningful change at the 0.70, 0.80, and 0.90 confidence intervals, respectively. Over 1-year, a difference of 8, 10, and 12 was statistically meaningful at the 0.70, 0.80, and 0.90 confidence intervals, respectively. SRB equations are also provided taking into account additional factors found to be predictive of SDMT scores over time.

CONCLUSION

Clinicians frequently denote a decline of 4 points on the SDMT as meaningful. Results in this large normative sample show that higher cut-points are needed to demonstrate statistically significant decline at the individual level. RCIs are provided for 6 month and one year assessment, which is typical in clinical practice and trials. SRB equations are also provided for use when applicable and may provide a more precise assessment of meaningful change.

Interpreting change on the Symbol Digit Modalities Test in people with relapsing multiple sclerosis using the reliable change methodology

BACKGROUND

The Symbol Digit Modalities Test (SDMT) is increasingly utilized in clinical trials. A SDMT score change of 4 points is considered clinically important, based on association with employment anchors. Optimal thresholds for statistically reliable SDMT changes, accounting for test reliability and measurement error, are yet to be applied to individual cases.

OBJECTIVE

The aim of this study was to derive a statistically reliable marker of individual change on the SDMT.

METHODS

This prospective, case-control study enrolled 166 patients with multiple sclerosis (MS). SDMT scores at baseline, relapse, and 3-month follow-up were compared between relapsing and stable patient groups. Using data from the stable group and three previously published studies, candidate thresholds for reliable decline were calculated and validated against other tests and a clinically meaningful anchor-cognitive relapse.

RESULTS

Candidate thresholds for reliable decline at the 80% confidence level varied between 6 and 11 points. An SDMT change of 8 or more raw score points was deemed to offer the best balance of discriminatory power and external validity for estimating cognitive decline.

CONCLUSION

This study illustrates the feasibility and usefulness of reliable change methodology for identifying statistically meaningful cognitive decline that could be implemented to identify change in individual patients, for both clinical management and clinical trial outcomes.

Regional brain atrophy is related to social cognition impairment in multiple sclerosis

BACKGROUND

Multiple sclerosis exhibits specific neuropathological phenomena driving to both global and regional brain atrophy. At the clinical level, the disease is related to functional decline in cognitive domains as the working memory, processing speed, and verbal fluency. However, the compromise of social-cognitive abilities has concentrated some interest in recent years despite the available evidence suggesting the risk of disorganization in social life. Recent studies have used the MiniSEA test to assess the compromise of social cognition and have found relevant relationships with memory and executive functions, as well as with the level of global and regional brain atrophy.

OBJECTIVE

The present article aimed to identify structural changes related to socio-cognitive performance in a sample of patients with relapsing-remitting multiple sclerosis.

METHODS

68 relapsing-remitting multiple sclerosis Chilean patients and 50 healthy control subjects underwent MRI scans and neuropsychological evaluation including social-cognition tasks. Total brain, white matter, and gray matter volumes were estimated. Also, voxel-based morphometry was applied to evaluate regional structural changes.

RESULTS

Patients exhibited lower scores in all neuropsychological tests. Social cognition exhibited a significant decrease in this group mostly related to the declining social perception. Normalized brain volume and white matter volume were significantly decreased when compared to healthy subjects. The regional brain atrophy analysis showed that changes in the insular cortex and medial frontal cortices are significantly related to the variability of social-cognitive performance among patients.

CONCLUSIONS

In the present study, social cognition was only correlated with the deterioration of verbal fluency, despite the fact that previous studies have reported its link with memory and executive functions. The identification of specific structural correlates supports the comprehension of this phenomenon as an independent source of cognitive disability in these patients.

Regional Cerebellar Volume Loss Predicts Future Disability in Multiple Sclerosis Patients

Cerebellar symptoms in multiple sclerosis (MS) are well described; however, the exact contribution of cerebellar damage to MS disability has not been fully explored. Longer-term observational periods are necessary to better understand the dynamics of pathological changes within the cerebellum and their clinical consequences. Cerebellar lobe and single lobule volumes were automatically segmented on 664 3D-T1-weighted MPRAGE scans (acquired at a single 1.5 T scanner) of 163 MS patients (111 women; mean age: 47.1 years; 125 relapsing–remitting (RR) and 38 secondary progressive (SP) MS, median EDSS: 3.0) imaged annually over 4 years. Clinical scores (EDSS, 9HPT, 25FWT, PASAT, SDMT) were determined per patient per year with a maximum clinical follow-up of 11 years. Linear mixed-effect models were applied to assess the association between cerebellar volumes and clinical scores and whether cerebellar atrophy measures may predict future disability progression. SPMS patients exhibited faster posterior superior lobe volume loss over time compared to RRMS, which was related to increase of EDSS over time. In RRMS, cerebellar volumes were significant predictors of motor scores (e.g. average EDSS, T25FWT and 9HPT) and SDMT. Atrophy of motor-associated lobules (IV-VI + VIII) was a significant predictor of future deterioration of the 9HPT of the non-dominant hand. In SPMS, the atrophy rate of the posterior superior lobe (VI + Crus I) was a significant predictor of future PASAT performance deterioration. Regional cerebellar volume reduction is associated with motor and cognitive disability in MS and may serve as a predictor for future disease progression, especially of dexterity and impaired processing speed.

Association between symbol digit modalities test and regional cortex thickness in young adults with relapsing-remitting multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system, predominating within young adults. Cognitive disorders are common in MS and have are associated with several Magnetic Resonance Imaging (MRI) markers, especially brain atrophy. Many have found the symbol digit modalities test (SDMT) to be the most sensitive individual cognitive measure relevant to MS. However, the relationship between SDMT and regional brain cortex thickness in young adults with relapsing-remitting multiple sclerosis (YA-RRMS) has been little explored. The purpose of this study was to investigate the association between the SDMT and regional cortex thickness in YA-RRMS by FreeSurfer, which is an automatic brain structure segmentation method.

METHOD

Twenty-eight YA-RRMS patients (18-35 years old) were enrolled in the present study. Informed consent and information including gender, age, disease duration, number of relapses, annual relapse rate was collected from all patients. Clinical cognitive evaluations (SDMT and auditory verbal learning test (AVLT)) and daily performance: activities of daily living (ADL) were assessed in the present study. MRI scans were performed at the Institute of Neurosurgery of Tiantan Hospital. Twenty-eight matched healthy controls (HC) MRI data were obtained from Tiantan Hospital database. Data on thirty-four points of bilateral cortical structure thickness using statistically defined brain regions-of-interest from FreeSurfer were obtained from all participants.

RESULTS

Patients with RRMS exhibited extensively thinner cerebellar cortex compared with HC. SDMT scores were significantly correlated with AVLT subentries (IM, immediate memory; DRM, delayed recall memory; LTRM, long-term recognition memory) in YA-RRMS patients (P < 0.05). SDMT was strongly correlated with regional cortex thickness differences of the right temporal pole (r = 0.68) and bilateral parahippocampal areas (right r = 0.62; left r = 0.60), and moderately correlated with regional cortex thickness differences including the left superior temporal and right insula (r = 0.57 and 0.56, respectively) in YA-RRMS patients.

CONCLUSION

The present study has shown the SDMT is strongly correlated with selected cortex regions including the bilateral parahippocampal area and the right temporal pole which are involved in geometric structures processing.

A Randomized Computer-Assisted Rehabilitation Trial of Attention in Pediatric Multiple Sclerosis: A Post Hoc Analysis

Cognitive impairment (CI) is a remarkable feature in pediatric-onset multiple sclerosis (POMS). The Symbol Digit Modalities Test (SDMT) is increasingly used to explore CI in MS. Recently, a four-point worsening on the SDMT score has been demonstrated to correlate with a clinically meaningful cognitive worsening in adult MS. We conducted a post hoc analysis of a randomized computer-assisted rehabilitation trial for attention impairment in POMS to test the clinical meaningfulness of the changes in SDMT scores at the end of the trial (delta SDMT). A four-point SDMT cut-off was applied. POMS patients exposed to specific computer training (ST) and non-specific training (nST) were compared. Data of 16 POMS (9 females, age 15.75 ± 1.74 years) patients were analyzed. At the end of the trial, 25% of patients reported no clinically significant changes (−3 to 3), 12.5% a clinically significant worsening (≤−4) and 62.5% a clinically significant improvement (≥4) in the delta SDMT. The proportion of patients reporting a clinically meaningful improvement was significantly (p = 0.008) higher (100%) in patients exposed to ST in comparison to those (25%) exposed to nST. The use of the four-point SDMT cut-off may be useful to assess the clinical meaningfulness of results from cognitive rehabilitation trials.

Alterations in functional connectivity are associated with white matter lesions and information processing efficiency in multiple sclerosis

Functional connectivity (FC) is typically altered in individuals with Multiple Sclerosis (MS). However, in relapsing-remitting multiple sclerosis (RRMS) patients, the relationship between brain FC, tissue integrity and cognitive impairment is still unclear as contradictory findings have been documented. In this exploratory study we compared both the whole brain connectome and resting state networks (RSNs) FC of twenty-one RRMS and seventeen healthy controls (HCs), using combined network based statistics and independent component analyses. The total white matter (WM) lesion volume and information processing efficiency were also correlated with FC in the RRMS group. Both whole brain connectome and individual RSNs FC were diminished in patients with RRMS compared to HC. Additionally, the reduction in FC was found to be a function of the total WM lesion volume, with greatest impact in those harboring the largest lesion volume. Finally, a positive correlation between FC and information processing efficiency was observed in RRMS. This complimentary whole brain and RSNs FC approach can contribute to clarify literature inconsistencies regarding FC alterations and provide new insights on the white matter structural damage in explaining functional abnormalities in RRMS.

Computerized Symbol Digit Modalities Test in a Swiss Pediatric Cohort - Part 2: Clinical Implementation

Background

Information processing speed (IPS) is a marker for cognitive function. It is associated with neural maturation and increases during development. Traditionally, IPS is measured using paper and pencil tasks requiring fine motor skills. Such skills are often impaired in patients with neurological conditions. Therefore, an alternative that does not need motor dexterity is desirable. One option is the computerized symbol digit modalities test (c-SDMT), which requires the patient to verbally associate numbers with symbols.

Methods

Eighty-six participants (8–16 years old; 45 male; 48 inpatients) were examined, 38 healthy and 48 hospitalized for a non-neurological disease. All participants performed the written SDMT, c-SDMT, and the Test of Non-verbal Intelligence Fourth Edition (TONI-4). Statistical analyses included a multivariate analysis of covariance (MANCOVA) for the effects of intelligence (IQ) and hospitalization on the performance of the SDMT and c-SDMT. A repeated measures analysis of variance (repeated measures ANOVA) was used to compare performance across c-SDMT trials between inpatients and outpatients.

Results

The MANCOVA showed that hospitalization had a significant effect on IPS when measured with the SDMT (p = 0.04) but not with the c-SDMT (p = 0.68), while IQ (p = 0.92) had no effect on IPS. Age (p < 0.001) was the best predictor of performance of both tests. The repeated measures ANOVA revealed no significant difference in within-test performance (p = 0.06) between outpatient and inpatient participants in the c-SDMT.

Conclusion

Performance of the c-SDMT is not confounded by hospitalization and gives within-test information. As a valid and reliable measure of IPS for children and adolescents, it is suitable for use in both inpatient and outpatient populations.

Computerized Symbol Digit Modalities Test in a Swiss Pediatric Cohort Part 1: Validation

OBJECTIVE

The objective of this study was to validate the computerized Symbol Digit Modalities Test (c-SDMT) in a Swiss pediatric cohort, in comparing the Swiss sample to the Canadian norms. Secondly, we evaluated sex effects, age-effects, and test-retest reliability of the c-SDMT in comparison to values obtained for the paper and pencil version of the Symbol Digit Modalities Test (SDMT).

METHODS

This longitudinal observational study was conducted in a single-center setting at the University Children's Hospital of Bern. Our cohort consisted of 86 children (45 male and 41 female) aged from 8 to 16 years. The cohort included both healthy participants (n = 38) and patients (n = 48) hospitalized for a non-neurological disease. Forty eight participants were assessed during two testing sessions with the SDMT and the c-SDMT.

RESULTS

Test-retest reliability was high in both tests (SDMT: ICC = 0.89, c-SDMT: ICC = 0.90). A reliable change index was calculated for the SDMT (RCIp = -3.18, 14.01) and the c-SDMT (RCIp = -5.45, 1.46) corrected for practice effects. While a significant age effect on information processing speed was observed, no such effect was found for sex. When data on the c-SDMT performance of the Swiss cohort was compared with that from a Canadian cohort, no significant difference was found for the mean time per trial in any age group. Norm values for age groups between 8 and 16 years in the Swiss cohort were established.

CONCLUSION

Norms for the c-SDMT between the Swiss and the Canadian cohort were comparable. The c-SDMT is a valid alternative to the SDMT. It is a feasible and easy to administer bedside tool due to high reliability and the lack of motor demands.

The role of hippocampal theta oscillations in working memory impairment in multiple sclerosis

Working memory (WM) problems are frequently present in people with multiple sclerosis (MS). Even though hippocampal damage has been repeatedly shown to play an important role, the underlying neurophysiological mechanisms remain unclear. This study aimed to investigate the neurophysiological underpinnings of WM impairment in MS using magnetoencephalography (MEG) data from a visual-verbal 2-back task. We analysed MEG recordings of 79 MS patients and 38 healthy subjects through event-related fields and theta (4-8 Hz) and alpha (8-13 Hz) oscillatory processes. Data was source reconstructed and parcellated based on previous findings in the healthy subject sample. MS patients showed a smaller maximum theta power increase in the right hippocampus between 0 and 400 ms than healthy subjects (p = .014). This theta power increase value correlated negatively with reaction time on the task in MS (r = -.32, p = .029). Evidence was provided that this relationship could not be explained by a 'common cause' confounding relationship with MS-related neuronal damage. This study provides the first neurophysiological evidence of the influence of hippocampal dysfunction on WM performance in MS.

Remote administration of the symbol digit modalities test to individuals with multiple sclerosis is reliable: A short report

Background

The Symbol Digit Modalities Test (SDMT) is the gold standard for cognitive screening in multiple sclerosis (MS).

Objective

Due to the recent COVID-19 pandemic and the increased need for virtual clinical visits, we examined the reliability of remote administration of the SDMT vs. standard in-person administration to individuals with MS.

Methods

Pearson’s correlation analysis was performed between SDMT scores on the in-person and remote administrations.

Results

For n = 132 participants, remote and in-person SDMT scores were strongly correlated (r = .80, p = .000).

Conclusion

Remote administration of the SDMT is a reliable cognitive screening approach in MS.

Exercise training and cognition in multiple sclerosis: The GET Smart trial protocol

BACKGROUND AND OBJECTIVES

Multiple sclerosis (MS) causes cognitive impairment in approximately 50% of cases. Disease modifying medications and cognitive rehabilitation produce only small positive effects on cognition in MS. Converging animal and human research suggests that aerobic exercise may improve cognition in people with MS, but definitive trials are lacking. We describe the design of the GET Smart study, a randomized controlled trial comparing the effects of aerobic exercise versus stretching and toning on cognition in MS.

METHODS

The study is a single-blind, parallel group randomized (1:1) controlled trial that compares aerobic exercise training with an active control group consisting of stretching and toning exercises for improving cognition. Participants are nondepressed, ambulatory, non-exercising adults with MS aged 18-54 years who have below average cognitive processing speed. Both treatments were designed to generate equivalent outcome expectancies and entailed supervised, progressive exercise programs, 3 times per week for up to 40 min over a 6 month period.

PROJECTED PATIENT OUTCOMES

The primary hypothesis is that the aerobic training group will demonstrate significantly greater cognitive processing speed compared with the control group at the end of the treatment phase (6 months) as measured by a composite of the Paced Auditory Serial Additon Test and the oral Symbol-Digit Modalities Test using intent-to treat analyses. Secondary outcomes are neuropsychological functioning and cardiorespiratory fitness as well as participant reported outcomes such as depression, sleep, and fatigue. Study findings will inform future research, patient education, clinical care and policymaking.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT02106052.

Smartphone-based symbol-digit modalities test reliably captures brain damage in multiple sclerosis

As the burden of neurodegenerative diseases increases, time-limited clinic encounters do not allow quantification of complex neurological functions. Patient-collected digital biomarkers may remedy this, if they provide reliable information. However, psychometric properties of digital tools remain largely un-assessed. We developed a smartphone adaptation of the cognitive test, the Symbol-Digit Modalities Test (SDMT) by randomizing the test’s symbol-number codes and testing sequences. The smartphone SDMT showed comparable psychometric properties in 154 multiple sclerosis (MS) patients and 39 healthy volunteers (HV). E.g., smartphone SDMT achieved slightly higher correlations with cognitive subscores of neurological examinations and with brain injury measured by MRI (R² = 0.75, Rho = 0.83, p < 0.0001) than traditional SDMT. Mathematical adjustment for motoric disability of the dominant hand, measured by another smartphone test, compensates for the disadvantage of touch-based test. Averaging granular home measurements of the digital biomarker also increases accuracy of identifying true neurological decline.

Symbol Digit Modalities Test: Greek Normative Data for the Oral and Written Version and Discriminative Validity in Patients with Multiple Sclerosis

OBJECTIVES

The purpose of this study was to generate normative data on the Symbol Digits Modalities Test (SDMT) for the written and oral versions in the Greek adult population. We also investigated the test's validity in discriminating the performance of healthy adults from two groups of adults diagnosed with relapsing remitting (RRMS) and secondary progressive (SPMS) multiple sclerosis.

METHOD

The sample consisted of 609 healthy men and women between the ages of 18 and 65. All participants were monolingual native Greek adult speakers. Each healthy participant was administered either the written (n = 460) or oral (n = 149) versions of the SDMT. Discriminant validity was examined by comparing 35 healthy participants who had completed the oral version of the SDMT to 35 age - and education-matched RRMS and SPMS patients.

RESULTS

Linear regression models explained between 36% and 55% of the variance in the SDMT oral and written version scores. Age was the strongest predictor of difference in SDMT written and oral version performance, followed by education that also accounted for a further proportion of the SDMT variance. On the contrary, gender was found not to contribute significantly to the variance in the SDMT for either the written or the oral versions. As a result, age- and education-adjusted norms were generated. Regarding the tests discriminative validity, we found that both MS patient groups scored significantly lower than the healthy group.

CONCLUSIONS

This is the first study to provide comprehensive normative data for the SDMT in the adult population in Greece, impacting the future practice of neuropsychological assessment in this country.

Siponimod and Cognition in Secondary Progressive Multiple Sclerosis: EXPAND Secondary Analyses

OBJECTIVE

To investigate the effects of siponimod on cognitive processing speed in patients with secondary progressive (SP) multiple sclerosis (MS), by means of a predefined exploratory and post hoc analysis of the Exploring the Efficacy and Safety of Siponimod in Patients With Secondary Progressive Multiple Sclerosis (EXPAND) study, a randomized controlled trial comparing siponimod and placebo.

METHODS

EXPAND was a double-blind, placebo-controlled phase 3 trial involving 1,651 patients with SPMS randomized (2:1) to either siponimod 2 mg/d or placebo. Cognitive function was assessed with the Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), and Brief Visuospatial Memory Test-Revised (BVMT-R) administered at baseline, 6-month intervals, and end of treatment.

RESULTS

Between-group differences in mean change from baseline in SDMT scores were significantly better in siponimod- vs placebo-treated patients at month 12 (difference 1.08 [95% confidence interval 0.23-1.94]; p = 0.0132), month 18 (1.23 [0.25-2.21); p = 0.0135), and month 24 (2.30 [1.11-3.50]; p = 0.0002). Siponimod-treated patients were at significantly lower risk for having a 4-point sustained decrease in SDMT score (hazard ratio [HR] 0.79 [0.65-0.96]; p = 0.0157), while their chance for having a 4-point sustained increase in SDMT score was higher (HR 1.28 [1.05-1.55]; p = 0.0131). PASAT and BVMT-R scores did not differ significantly between the 2 treatment groups (all p > 0.28).

CONCLUSION

Siponimod had a significant benefit on SDMT in patients with SPMS. Siponimod-treated patients were at significantly lower risk for having a ≥4-point decrease in SDMT score and had a significantly higher chance for having a ≥4-point increase in SDMT score, a magnitude of change accepted as clinically meaningful.

CLINICALTRIALSGOV IDENTIFIER

NCT01665144.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that, for patients with SPMS, siponimod had a significant benefit on cognitive processing speed.

Effects of Transcranial Direct Current Stimulation on Information Processing Speed, Working Memory, Attention, and Social Cognition in Multiple Sclerosis

Multiple Sclerosis (MS) is a chronic inflammatory disease of the central nervous system. Cognitive impairment occurs in 40-65% of patients and could drastically affect their quality of life. Deficits could involve general cognition (e.g., attention and working memory) as well as social cognition. Transcranial direct current stimulation (tDCS), is a novel brain stimulation technique that has been assessed in the context of several neuropsychiatric symptoms, including those described in the context of MS. However, very rare trials have assessed tDCS effects on general cognition in MS, and none has tackled social cognition. The aim of this work was to assess tDCS effects on general and social cognition in MS. Eleven right-handed patients with MS received two blocks (bifrontal tDCS and sham, 2 mA, 20 min, anode/cathode over left/right prefrontal cortex) of 5 daily stimulations separated by a 3-week washout interval. Working memory and attention were, respectively, measured using N-Back Test (0-Back, 1-Back, and 2-Back) and Symbol Digit Modalities Test (SDMT) at the first and fifth day of each block and 1 week later. Social cognition was evaluated using Faux Pas Test and Eyes Test at baseline and 1 week after each block. Interestingly, accuracy of 1-Back test improved following sham but not active bifrontal tDCS. Therefore, active bifrontal tDCS could have impaired working memory via cathodal stimulation of the right prefrontal cortex. No significant tDCS effects were observed on social cognitive measures and SDMT. Admitting the small sample size and the learning (practice) effect that might arise from the repetitive administration of each task, the current results should be considered as preliminary and further investigations in larger patient samples are needed to gain a closer understanding of tDCS effects on cognition in MS.

Symbol Digit Modalities Test Variant in a Smartphone App for Persons With Multiple Sclerosis: Validation Study

Background

The decline of cognitive processing speed (CPS) is a common dysfunction in persons with multiple sclerosis (MS). The Symbol Digit Modalities Test (SDMT) is widely used to formally quantify CPS. We implemented a variant of the SDMT in MS sherpa, a smartphone app for persons with MS.

Objective

The aim of this study was to investigate the construct validity and test-retest reliability of the MS sherpa smartphone variant of the SDMT (sSDMT).

Methods

We performed a validation study with 25 persons with relapsing-remitting MS and 79 healthy control (HC) subjects. In the HC group, 21 subjects were matched to the persons with MS with regard to age, gender, and education and they followed the same assessment schedule as the persons with MS (the “HC matched” group) and 58 subjects had a less intense assessment schedule to determine reference values (the “HC normative” group). Intraclass correlation coefficients (ICCs) were determined between the paper-and-pencil SDMT and its smartphone variant (sSDMT) on 2 occasions, 4 weeks apart. Other ICCs were determined for test-retest reliability, which were derived from 10 smartphone tests per study participant, with 3 days in between each test. Seven study participants with MS were interviewed regarding their experiences with the sSDMT.

Results

The SDMT scores were on average 12.06% higher than the sSDMT scores, with a standard deviation of 10.68%. An ICC of 0.838 was found for the construct validity of the sSDMT in the combined analysis of persons with MS and HC subjects. Average ICCs for test-retest reliability of the sSDMT for persons with MS, the HC matched group, and the HC normative group were 0.874, 0.857, and 0.867, respectively. The practice effect was significant between the first and the second test of the persons with MS and the HC matched group and trivial for all other test-retests. The interviewed study participants expressed a positive attitude toward the sSDMT, but they also discussed the importance of adapting a smartphone cognition test in accordance with the needs of the individual persons with MS.

Conclusions

The high correlation between sSDMT and the conventional SDMT scores indicates a very good construct validity. Similarly, high correlations underpin a very good test-retest reliability of the sSDMT. We conclude that the sSDMT has the potential to be used as a tool to monitor CPS in persons with MS, both in clinical studies and in clinical practice.

Cognitive impairment in multiple sclerosis: clinical management, MRI, and therapeutic avenues

Multiple sclerosis is a chronic, demyelinating disease of the CNS. Cognitive impairment is a sometimes neglected, yet common, sign and symptom with a profound effect on instrumental activities of daily living. The prevalence of cognitive impairment in multiple sclerosis varies across the lifespan and might be difficult to distinguish from other causes in older age. MRI studies show that widespread changes to brain networks contribute to cognitive dysfunction, and grey matter atrophy is an early sign of potential future cognitive decline. Neuropsychological research suggests that cognitive processing speed and episodic memory are the most frequently affected cognitive domains. Narrowing evaluation to these core areas permits brief, routine assessment in the clinical setting. Owing to its brevity, reliability, and sensitivity, the Symbol Digit Modalities Test, or its computer-based analogues, can be used to monitor episodes of acute disease activity. The Symbol Digit Modalities Test can also be used in clinical trials, and data increasingly show that cognitive processing speed and memory are amenable to cognitive training interventions.

Gaining First Insights on Secondary Progressive Multiple Sclerosis Patients Treated With Siponimod in Clinical Routine: Protocol of the Noninterventional Study AMASIA

Background

A high proportion of patients with relapsing remitting multiple sclerosis convert to secondary progressive multiple sclerosis (SPMS) characterized by irreversibly progressing disability and cognitive decline. Siponimod (Mayzent), a selective sphingosine-1-phosphate receptor modulator, was recently approved by the European Medicines Agency for the treatment of adult SPMS patients with active disease, as evidenced by relapses or magnetic resonance imaging features of ongoing inflammatory activity. Approval by the Food and Drug Administration covers a broader range of indications, comprising clinically isolated syndrome, relapsing remitting multiple sclerosis, and active SPMS. However, treatment effects of siponimod have not been assessed in a structured setting in clinical routine so far.

Objective

The objectives of AMASIA (impAct of Mayzent [siponimod] on secondAry progressive multiple Sclerosis patients in a long-term non-Interventional study in GermAny), a prospective noninterventional study, are to assess the long-term effectiveness and safety of siponimod in clinical routine and to evaluate the impact of disease burden on quality of life and socioeconomic conditions. Here, we report the study design of AMASIA.

Methods

Treatment effects of siponimod will be evaluated in 1500 SPMS patients during a 3-year observational phase. According to the genetic polymorphism of CYP2C9, the initial dose will be titrated to the maintenance dose of 1 mg (CYP2C9*1*3 and *2*3) or 2 mg (all other polymorphisms of CYP2C9 except *3*3, which is contraindicated) taken orally once daily. Primary endpoint is the 6-month confirmed disability progression, as assessed by a functional composite endpoint comprising the Expanded Disability Status Scale and symbol digit modalities test to take appropriate account of cognitive changes and increase sensitivity. Further measures including multiple sclerosis activity data; assessments of functional domains; questionnaires addressing the patients’, physicians’, and relatives’ perspectives of disability progression; cognitive worsening; quality of life; and socioeconomic aspects will be documented using the multiple sclerosis documentation system MSDS3D.

Results

AMASIA is being conducted between February 2020 and February 2025 in up to 250 neurological centers in Germany.

Conclusions

AMASIA will complement the pivotal phase III–derived efficacy and safety profile of siponimod with real-world data and will further evaluate several individual treatment aspects such as quality of life and socioeconomic conditions of patients and caregivers. It might help to establish siponimod as a promising option for the treatment of SPMS patients in clinical routine.

International Registered Report Identifier (IRRID)

DERR1-10.2196/19598

A validation study for remote testing of cognitive function in multiple sclerosis

OBJECTIVES

Determine the validity and reliability of a remote, technician-guided cognitive assessment for multiple sclerosis (MS), incorporating the Symbol Digit Modalities Test (SDMT) and the California Verbal Learning Test, Second Edition (CVLT-II).

METHODS

In 100 patients, we compared conventional in-person testing to remote, web-assisted assessments, and in 36 patients, we assessed test-retest reliability using two equivalent, alternative forms.

RESULTS

In-person and remote-administered SDMT (r = 0.85) and CVLT-II (r = 0.71) results were very similar. Reliability was adequate and alternative forms of SDMT (r = 0.92) and CVLT-II (r = 0.81) produced similar results.

CONCLUSIONS

Findings indicate remote assessment can provide valid, reliable measures of cognitive function in MS.

A novel in-home digital treatment to improve processing speed in people with multiple sclerosis: A pilot study

OBJECTIVE

To assess whether a videogame-like digital treatment is superior to a control in improving processing speed in adults with multiple sclerosis (MS).

METHODS

Adults with MS and baseline Symbol Digit Modalities Test (SDMT) z-scores between -2 and 0 were enrolled in a double-blind randomized controlled clinical trial. After completing a baseline in-clinic evaluation (Visit 1), they were randomized to complete an in-home, tablet-based videogame-like digital treatment (AKL-T03) or control word game (AKL-T09) for up to 25 minutes/day, 5 days/week, for 6 weeks. A repeat in-clinic evaluation occurred at 6 weeks (Visit 2), and again 8 weeks later to determine persistence of effects (Visit 3). The pre-specified primary outcome was change in SDMT score between Visits 1 and 2.

RESULTS

SDMT increased at Visit 2 for participants randomized to both AKL-T03 (p < 0.001) and AKL-T09 (p = 0.024). These respective mean improvements were +6.10 and +3.55 (comparison p = 0.21). At Visit 3, 70% of participants randomized to AKL-T03 maintained a clinically meaningful 4+-point increase in SDMT above their baseline, compared with 37% for AKL-T09 (p = 0.038).

CONCLUSION

This in-home digital intervention resulted in substantial and durable improvements in processing speed. A larger randomized controlled clinical trial is planned.

TRIAL REGISTRATION

This trial is registered on ClinicalTrials.gov under "NCT03569618," https://clinicaltrials.gov/ct2/show/NCT03569618.

A new look at an old test: Normative data of the symbol digit modalities test -Oral version

BACKGROUND

The Symbol Digit Modalities Tests (SDMT) is the most sensitive measure to multiple sclerosis (MS)-related cognitive dysfunction. However, existing normative data has been under scrutiny. Specifically, they are outdated, do not take into account gender, and are poorly stratified by education. More importantly, there exists no oral only version norms, which is typical administration among individuals with MS.

OBJECTIVE

The present investigation aimed to develop updated normative data of the oral version SDMT in which age, gender, and education were taken into consideration.

METHODS

A total of 675 healthy individuals, stratified by age, gender, and education completed the oral version SDMT.

RESULTS

Significant effects were found for age, gender, and education, consistent with previous contentions. Specifically, performance on the SDMT tends to decline with age, with the most noticeable decline beginning in the third decade of life and continuing into the sixth decade. Women, in general perform better than men, with an average of 5.1 more points. Finally, education effects were apparent among those aged 25-54.

CONCLUSION

Based on these findings, updated normative data are provided. Utilization of these updated norms will result in a much needed and more accurate assessment of processing speed for individuals with MS.

Trajectories of Symbol Digit Modalities Test performance in individuals with multiple sclerosis

Background:

Although cognitive problems have been identified in people with multiple sclerosis (PwMS), few studies have investigated the long-term change in cognitive functioning.

Objective:

To identify trajectories of change in cognitive functioning for PwMS.

Methods:

Participants enrolled in the quality-of-life subgroup from the Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Women’s Hospital (CLIMB) were eligible for our analysis. In 2006, participants in this group began to complete the Symbol Digit Modalities Test (SDMT) annually. Latent trajectory models were used to identify groups of participants with similar longitudinal change in SDMT scores. Linear and quadratic trajectory models were fit, and the models were compared. Latent trajectory models were also fit adjusting for baseline age and disease duration as well as using normalized SDMT scores. The groups identified across the approaches were compared.

Results:

We found that classes with higher-than-average baseline values improved, classes with average baseline values remained relatively constant, and classes with lower baseline values experienced cognitive worsening. Similar results were observed in the alternative latent trajectory models accounting for other variables.

Conclusion:

Our models show that subjects with higher SDMT scores at baseline showed improvement, while subjects with lower SDMT scores at baseline showed worsening. Baseline age and disease duration were also associated with SDMT performance.

iCAMS: Assessing the Reliability of a Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) Tablet Application

Background

This study aimed to develop a Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) tablet application, "iCAMS," and examine equivalency between the original paper-based and the tablet-based assessments.

Methods

This study enrolled 100 participants with physician-confirmed multiple sclerosis (MS). Interrater reliability, parallel forms reliability, and concurrent validity were evaluated by incorporating two test administrators in each session: one scoring participant responses with the original paper assessments and the other with iCAMS. Although the participant was exposed to the material only once, responses were recorded on both administration methods. In addition to the standard test procedures, each research assistant used a stopwatch to measure the amount of time required to administer and score each version of BICAMS.

Results

Pearson correlation coefficients (r) revealed strong and significant correlations for all three tests. Excellent agreement was observed between iCAMS and paper versions of the BICAMS tests, with all intraclass correlation coefficients exceeding 0.93. The scores from all the cognitive tests were not statistically significantly different, indicating no proportional bias. Including scoring, administration of the iCAMS application saved approximately 10 minutes over the paper version.

Conclusions

Preliminary findings suggest that the tablet application iCAMS is a reliable and fast method for administering BICAMS.

Do Secondary Progressive Multiple Sclerosis patients benefit from Computer- based cognitive neurorehabilitation? A randomized sham controlled trial

BACKGROUND

Cognitive impairment is common in multiple sclerosis (MS), but deficits tend to be more pronounced in progressive MS, negatively impacting daily functional capacity. Despite this, most cognitive rehabilitation (CR) interventions to date have focused on relapsing-remitting MS (RRMS). Moreover, information on the efficacy of CR in progressive MS is limited and controversial. The present study investigated the efficacy of a home based, computer assisted cognitive rehabilitation (HBCACR) intervention (RehaComTM software) exclusively in a Secondary Progressive Multiple Sclerosis (SPMS) sample.

METHODS

This was a randomized, multi site, sham controlled trial. Thirty six (36) individuals with SPMS, naïve to the RehaCom software, with cognitive deficits were randomized to the treatment (IG; n= 19) or control group condition (CG; n=17). Treatment with the RehaCom modules consisted of 24 domain and task specific, 45 minute session's over an 8-week period, three sessions per week, applied by each patient at home. The CG completed non specific computer based activities at home with the same frequency and duration. Primary cognitive outcome measures included the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) battery, and secondary outcome measures for depression (BDI-FS), fatigue (MFIS), and quality of life (EuroQol EQ-5D) visual analogue scale (VAS).

RESULTS

The two groups were well matched on demographic and clinical characteristics, cognitive reserve and severity of cognitive deficits at baseline assessment. At post treatment assessment the IG group showed significant improvements with large effect sizes; in verbal learning [z = -4.759, p <.0005, g = 2.898], visuospatial memory [z = -3.940, p <.0005, g = 1.699] and information processing speed [z= -4.792, p <.0005, g = 2.980], compared with the sham control group. We also found significant between group differences on physical [z=-3.308, p = .001, g= -.604], cognitive [z = -4.011, p <.0005, g = -1.654], psychosocial [z= 3.308, p = .010, g = -.940], and general fatigue impact [z= -2.623, p = .008, g = -.519], depression severity [z = -2.730, p = .006, g = -.519], and quality of life [z= -4.239, p <.0005, g = -1.885] in favor of the treated group.

CONCLUSION

These data provide the first evidence supporting the efficacy of computer based restorative cognitive rehabilitation applied at home exclusively in SPMS patients, suggesting that adaptive neuroplasticity may occur after functional cognitive training in progressive MS. Improved cognitive functioning in combination with mood augmentation appear to have ameliorated fatigue, which impacted daily functioning activity and culminated in improved health related quality of life.

Cognitive processing speed in pediatric-onset multiple sclerosis: Baseline characteristics of impairment and prediction of decline

BACKGROUND

Cognitive impairment occurs in approximately one-third of pediatric-onset multiple sclerosis (POMS) patients. The Symbol Digit Modalities Test (SDMT), a widely used cognitive screen in adults, has yet to be incorporated early into the standard care of POMS.

OBJECTIVE

To screen for cognitive impairment early in the course of POMS and analyze predictive factors.

METHODS

Of the 955 POMS or clinically isolated syndrome (CIS) patients prospectively assessed from March 2014 to July 2018, 500 POMS and 116 CIS patients met inclusion criteria (disease onset before the age of 18, one or more SDMTs, and 8 years or older at the time of testing). Those with relapse were analyzed separately from those who were relapse-free.

RESULTS

At initial assessment, the mean (interquartile range (IQR)) age at symptom onset was 13.5 years (12.0, 15.9) and the mean (±SD) disease duration was 3.0 ± 2.9 years. Impaired processing speed occurred in 23.4% of POMS and in 16.4% of CIS. On serial testing (n = 383, mean follow-up: 1.8 years), 14.1% had clinically meaningful decline predicted by older age of multiple sclerosis (MS) onset and male gender. Disease relapse or steroid use led to transient worsening on the SDMT.

CONCLUSION

Early in the disease, some POMS and CIS patients are at risk for cognitive impairment and subsequent decline.

Brief international cognitive assessment for multiple sclerosis (BICAMS): A danish validation study of sensitivity in early stages of MS

BACKGROUND

Cognitive impairment is highly prevalent in multiple sclerosis (MS). Due to the lack of specialized neuropsychological resources in many MS clinics, a brief cognitive monitoring tool that can be administered by other MS clinic staff is needed. BICAMS (Brief International Cognitive As-sessment for Multiple Sclerosis) has been developed and recommended by MS experts to monitor MS-related cognitive impairment. International validations of the tool are warranted.

OBJECTIVE

The primary aim of the study was to establish a Danish translation of BICAMS as a feasible cognitive monitoring tool and to provide a Danish contribution to the international validation of BI-CAMS. A secondary aim was to determine if BICAMS correlated with self-reported cognition. The study population comprised people with MS (pwMS) with relatively early MS and newly diagnosed.

METHODS

65 pwMS were compared to healthy controls (HCs) matched on age, sex and education. PwMS and controls completed the BICAMS test battery which includes the Symbol Digit Modalities Test (SDMT, oral version), California Verbal Learning Test-II (CVLT-II) and the Brief Visuospatial Memory Test-Revised (BVMT-R). In addition, self-reported cognition, fatigue, depression and quality of life were assessed. To evaluate the reliability of the BICAMS test, all participants were retested 2-3 weeks later with alternate versions of the tests.

RESULTS

Mean age of the MS group was 37.2 years; 63% were female and all pwMS had a relapsing-remitting disease course. MS disease duration was relatively short; mean disease duration was 3.9 years and 32 of 65 pwMS (49%) were newly diagnosed with MS, i.e. diagnosed within the last 2 years. Mean EDSS was 1.8 with a span from 0-4. Comparison of the groups showed that the MS group performed significantly below the control group on the 3 BICAMS measures: SDMT (p<0.005), CVLT-II (p<0.05) and BVMT-R (p<0.05). When the results were controlled for influence from depression and fatigue by regression analysis, group differences were limited to the SDMT (p<0.05) and the BVMT-R (p<0.05) and these group differences were only found at the retest session. The BICAMS measures were reliable over time (r = 0.90 for SDMT, r = 0.82 for CVLT-II and r = 0.68 for BVMT-R). 32.3% of the MS population was cognitively impaired on at least one of the 3 BICAMS tests (defined as -1.5 SD compared to HCs). In the MS group 20% were impaired on the SDMT; 16.9% were impaired on the BVMT-R and 10.7% were impaired on the CVLT-II. There was no relationship between BICAMS test-scores and subjectively reported cognition, fatigue or depression.

CONCLUSION

The Danish translation of BICAMS was a reliable and feasible cognitive assessment tool. This finding was confirmed even in an MS population characterized by relatively early MS and high cognitive reserve. Frequency of cognitive dysfunction detected by BICAMS in this study was relatively low due to population characteristics.

Operators' views of mobile equipment ingress and egress safety

A large proportion of non-fatal slips, trips, and falls (STFs) at surface mining facilities are associated with mobile equipment. Ingress and egress from mobile equipment can pose a fall risk to mobile equipment operators. The objective of this study was to determine mobile equipment operators' views of STF risks from mobile equipment, and to ascertain what factors, tasks, and conditions they perceive as contributing to these risks. A thematic analysis of 23 individual interviews and 2 group interviews was conducted, with 10 overarching themes identified from the transcripts. Mobile equipment operators indicated that being unable to see their feet or the ladder rungs during descent and the presence of contaminants on the ladders caused by normal operation make egress more dangerous than ingress. The flexible rails and high heights of the lower rungs identified over 40 years ago as issues for mobile equipment operators still pose a perceived STF risk. Further, the requirements of routine maintenance tasks such as oil and filter changes, greasing, and cleaning windows pose fall risks due to inadequate access and the need to carry supplies up and down equipment ladders. In addition to the mobile equipment, hazardous ground conditions and insufficient lighting were found to be key issues around the mobile equipment and in parking areas. The findings of this work indicate that mobile equipment operators feel at risk for STFs due to the design and condition of their equipment, and would like to see ladders replaced with safer stairways as the primary ingress/egress system.

Management of multiple sclerosis symptoms through reductions in sedentary behaviour: protocol for a feasibility study

INTRODUCTION

People with multiple sclerosis (MS) are less physically active, and more sedentary than their peers despite evidence that activity helps to manage MS-related symptoms. Traditional approaches to increasing physical activity, such as exercise programmes, can be challenging for people with MS, especially those with walking disability. Focusing on decreasing prolonged sitting, and increasing light-intensity activities may be more feasible and result in more sustainable behaviour change in persons with MS. This paper describes the rationale and development of a sedentary behaviour intervention targeting persons with MS.

METHODS AND ANALYSIS

The feasibility and preliminary efficacy of a sedentary behaviour intervention will be tested using a prepost intervention design in 40 adults with MS. The 22-week programme includes a 15-week intervention and a 7-week follow-up. The intervention itself is divided into two stages: Sit-Less and Move-More. The Sit-Less stage is designed to encourage participants to break up prolonged sitting bouts, while the Move-More stage promotes increasing steps per day, in addition to interrupting sitting. The intervention is delivered through individual coaching sessions between an interventionist and a participant, and an accompanying newsletter based on social cognitive theory. A Fitbit is used to monitor activity throughout the programme. Process, resource and management metrics will be recorded (eg, retention, time required for communication during the trial). Sedentary and physical activities and MS-related symptoms are measured before and after the intervention and again during follow-up. Experiences with the programme are explored through an online survey and one-on-one interviews.

ETHICS AND DISSEMINATION

The Health Research Ethics Board at the University of Alberta granted permission to conduct this study. Results will be disseminated in scientific journals and conferences, and the MS Society of Alberta. Physical therapists and kinesiologists are important stakeholders and will be targeted during dissemination.

TRIAL REGISTRATION NUMBER

NCT03136744.

Neurosonological and cognitive screening for evaluation of systemic sclerosis patients

OBJECTIVE

Assessment of cerebrovascular hemodynamics, third ventricle diameter (as a proxy of brain atrophy) by transcranial sonography (TCS), and screening of cognitive performance by the Symbol Digit Modalities Test (SDMT) in systemic sclerosis (SSc) patients.

METHODS

A total of 38 SSc patients recruited from the outpatient clinic of the Rheumatology Department, Kasr Alainy Hospital, Cairo University, and 51, age- and sex-matched, healthy controls were included in the study. TCS was used to assess the mean flow velocity (MFV), pulsatility index (PI) of the anterior, middle, and posterior cerebral arteries bilaterally, and to measure the third ventricle diameter as a proxy of brain atrophy. Cognitive impairment was screened using the SDMT. p values < 0.05 were considered statistically significant.

RESULTS

There was no significant difference between SSc patients and controls regarding either PI or MFV of the anterior, middle, and posterior cerebral arteries; also, there was no difference regarding the third ventricle diameter; however, limited SSc patients showed a significant increase in the PI of PCA and MFV of ACA as compared with diffuse SSc patients (p = 0.005, 0.004). There was a significant difference between SSc patients and controls regarding the SDMT (p = 0.016).

CONCLUSION

There is an evidence of increased cerebral vascular tone and resistance in limited SSc patients compared with diffuse SSc subgroup, without evidence of cerebral atrophy, suggesting early cerebrovascular affection even in asymptomatic limited SSc patients. There was also an evidence of cognitive impairment in SSc patients.