Reliability of a cognitive endpoint for use in a multiple sclerosis pharmaceutical trial

Assessing everyday functional activity in cognitively impaired people with multiple sclerosis: The use of Actual RealityTM

BACKGROUND

There is considerable evidence that persons with multiple sclerosis (PwMS) who experience cognitive impairments (CIs) are at risk of having significant limitations in activities of daily living (ADLs). However, ADL assessment often consists of proxies or self-report of ADLs. This study examined whether the performance of instrumental ADLs (I-ADL) is impaired in PwMS with and without CI.

METHODS

Participants included 72 PwMS and 48 matched healthy controls (HCs). PwMS were divided into MS-CI (n = 25) and MS-not-impaired (n = 47) groups based on the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) scores. All participants performed the Actual RealityTM (AR) test, measuring I-ADL using authentic websites.

RESULTS

The MS-CI performed significantly worse on AR compared with HC and MS-not-impaired. In addition, the MS-not-impaired performed significantly worse than HC on AR. AR differentiates well between PwMS with and without CI.

CONCLUSIONS

While CI in MS results in significant limitations in the performance of I-ADL, PwMS who do not show evidence of CI can have limitations in I-ADL. AR assessment is a valid and reliable tool sensitive to CI. It should be used in addition to traditional cognitive assessments to detect early functional deterioration through the course of MS.

Cognitive impairment in multiple sclerosis: "classic" knowledge and recent acquisitions

Multiple sclerosis (MS) is a central nervous system (CNS) disease characterized by inflammation, axonal demyelination, and neurodegeneration, which can have a strong impact on all aspects of the life of the patient. Multiple sclerosis causes motor, sensory, cerebellar, and autonomic dysfunctions, as well as cognitive and psychoemotional impairment. The most frequently compromised cognitive domains are complex attention/information processing, memory, executive and visuospatial functions. Recently, alterations have also been evidenced in complex cognitive functions, such as social cognition, moral judgment, and decision-making. Cognitive impairment is characterized by high variability and can affect work skills, social interactions, coping strategies and more generally the quality of life of patients and their families. With the use of sensitive and easy-to-administer test batteries, an increasingly accurate and early diagnosis is feasible: this allows to determine the effectiveness of possible preventive measures, to predict the future progression of the disease and to improve the quality of life of patients. There is currently limited evidence regarding the efficacy, on cognitive impairment, of disease-modifying therapies. The most promising approach, which has received strong empirical support, is cognitive rehabilitation.

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.

Sensory-Motor and Affective-Fatigue Factors are Associated with Symbol Digit Performance in Multiple Sclerosis

OBJECTIVES

The oral Symbol Digit Modalities Test (SDMT) has become the standard for the brief screening of cognitive impairment in persons with multiple sclerosis (PwMS). It has been shown to be sensitive to sensory-motor factors involving rudimentary oral motor speed and visual acuity, as well as multiple sclerosis (MS) affective-fatigue factors including depression, fatigue, and anxiety. The present study was designed to provide a greater understanding of these noncognitive factors that might contribute to the oral SDMT by examining all these variables in the same sample.

METHODS

We examined 50 PwMS and 49 healthy controls (HCs). All participants were administered the oral SDMT, two sensory-motor tasks (visual acuity and oral motor speed), and three affective-fatigue measures (depression, fatigue, and anxiety).

RESULTS

Partially consistent with hypotheses, we found that sensory-motor skills, but not affective-fatigue factors, accounted for some of the group differences between the MS and HC groups on the oral SDMT, reducing the MS/HC group variance predicted from 10% to 4%. Also, PwMS with below average sensory-motor abilities had oral SDMT scores that were lower than PwMS with intact sensory-motor skills (p < .05). Finally, 71% of PwMS in the below-average sensory-motor group were impaired on the oral SDMT compared with 14% of the intact group (p = .006).

CONCLUSIONS

When the oral SDMT is used as the sole screening tool for cognitive impairment in MS, clinicians should know that limitations in visual acuity and rudimentary oral motor speed should be considered as possibly being associated with performance on it in MS.

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.

The adapted symbol digit modalities test: Examining the impact of response modality

BACKGROUND

Information processing speed is often impaired in neurological disorders, as well as with healthy aging. Thus, being able to accurately assess information processing speed is of high importance. One of the most commonly used tests to examine information processing speed is the Symbol Digit Modalities Test (SDMT), which has been shown to have good psychometric properties.

OBJECTIVES

The current study aims to examine differences between two response modalities, written and oral, on the performance of an adapted version of the Symbol Digit Modalities Test.

METHODS

Ninety-nine individuals completed two alternate forms of the adapted version of the SDMT (aSDMT). Participants were instructed to complete the five lines of the task as quickly and accurately as possible. On one form participants were instructed to provide their response in writing and on the other one, orally. Form and response modality (oral vs. written) were counterbalanced to control for practice effects.

RESULTS

On average, there was a significant difference between response modalities, such that participants needed more time to respond when the response modality was written. For both response modalities, time to complete each line of stimuli decreased as the task progressed. While changes in response time on the first four lines of stimuli on the oral version were not found, there was a substantial improvement in response time on the fifth line. In contrast, on the written version a gradual learning effect was observed, in which response time was the slowest on the first two lines, an intermediate response time was noted on line 3, and the fastest response time was achieved on lines four and five.

CONCLUSION

The current study demonstrates that response modality, oral versus written, can significantly impact performance efficiency (the length of time it takes to complete a task), but not accuracy (total correct responses), on a new adaptation of the SDMT, the aSDMT.

Reliability and validity of Arabic version of the brief international cognitive assessment for multiple sclerosis: Egyptian dialect

Background

Given the diversity of multiple sclerosis (MS) symptoms including cognitive impairment in certain domains, the need to develop a rapid and at the same time thorough tool for cognitive assessment is mandatory and represents an unmet need in the clinical and research fields of MS. The Brief International Cognitive Assessment for MS (BICAMS) is a good and practical tool to achieve this mission but is not present in the Arabic language for Arabic speaking countries yet.

Objectives

To assess the reliability and validity of Arabic version of the BICAMS (Egyptian dialect).

Methods

Ninety Egyptian MS patients and 85 matched healthy controls underwent neuropsychological testing using the BICAMS Arabic version (Egyptian dialect) battery including the Symbol Digit Modality Test (SDMT), California Verbal Learning Test 2nd edition (CVLT-II), and revised Brief Visuospatial Retention Test- (BVRT-R). Test–retest data were obtained from MS patients 2 weeks after the initial assessment. Mean differences between both groups were assessed controlling for age, gender, and educational level.

Results

The MS patients scored significantly lower on the SDMT, CVLT-II, and BVMT-R tests compared to healthy controls (p<0.001). For MS patients’ group, intra-observer (test–retest) reliability was satisfactory for SDMT, CVLT-II total, and BVRT-R total with r values of 0.85, 0.61, and 0.68, respectively.

Conclusion

BICAMS Arabic version is a reliable and valid tool for cognitive assessment of Arabic speaking MS patients in different clinical and research settings.

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.

Time-Based Prospective Memory Is Associated with Functional Performance in Persons with MS

OBJECTIVE

Persons with multiple sclerosis (MS) often report prospective memory (PM) failures that directly impact their everyday life. However, it is not known whether PM deficits confer an increased risk of poorer everyday functioning. The aims of this study were to: (1) compare time- (Time-PM) and event-based PM (Event-PM) performance between persons with MS and healthy controls (HCs), (2) examine the neuropsychological correlates of PM in MS, and (3) examine the relationship between PM and everyday functioning in MS.

METHOD

A between-subjects design was used to examine 30 adults with MS and 30 community-dwelling HC. Participants were administered the Memory for Intentions Screening Test (MIST) to assess PM skills, the Actual Reality™ (AR) to assess everyday functioning, and a battery of cognitive tests.

RESULTS

The MS group performed significantly worse on Time-PM compared to HC but not on Event-PM tasks. While both Time-PM and Event-PM subscales were correlated with retrospective learning and memory, the MIST Time-PM subscale was correlated with executive functions. Significant correlations were observed between AR and the MIST Time-PM, but not Event-PM, subscales.

CONCLUSIONS

The results highlight the role of executive functions on Time-PM. Furthermore, significant relationships with AR extend the ecological validity of the MIST to MS populations.

Computerized neuropsychological assessment devices in multiple sclerosis: A systematic review

Background:

The proliferation of computerized neuropsychological assessment devices (CNADs) for screening and monitoring cognitive impairment is increasing exponentially. Previous reviews of computerized tests for multiple sclerosis (MS) were primarily qualitative and did not rigorously compare CNADs on psychometric properties.

Objective:

We aimed to systematically review the literature on the use of CNADs in MS and identify test batteries and single tests with good evidence for reliability and validity.

Method:

A search of four major online databases was conducted for publications related to computerized testing and MS. Test–retest reliability and validity coefficients and effect sizes were recorded for each CNAD test, along with administration characteristics.

Results:

We identified 11 batteries and 33 individual tests from 120 peer-reviewed articles meeting the inclusion criteria. CNADs with the strongest psychometric support include the CogState Brief Battery, Cognitive Drug Research Battery, NeuroTrax, CNS-Vital Signs, and computer-based administrations of the Symbol Digit Modalities Test.

Conclusion:

We identified several CNADs that are valid to screen for MS-related cognitive impairment, or to supplement full, conventional neuropsychological assessment. The necessity of testing with a technician, and in a controlled clinic/laboratory environment, remains uncertain.

Self-regulation of brain activity and its effect on cognitive function in patients with multiple sclerosis - First insights from an interventional study using neurofeedback

OBJECTIVE

To investigate the effects of EEG-based neurofeedback training, in which one can learn to self-regulate one's own brain activity, on cognitive function in patients with multiple sclerosis (pwMS).

METHODS

Fourteen pwMS performed ten neurofeedback training sessions within 3-4 weeks at home using a tele-rehabilitation system. The aim of the neurofeedback training was to increase voluntarily the sensorimotor rhythm (SMR, 12-15 Hz) in the EEG over central brain areas by receiving visual real-time feedback thereof. Cognitive function was assessed before and after all neurofeedback training sessions using a comprehensive standardized neuropsychological test battery.

RESULTS

Half of the pwMS (N = 7) showed cognitive improvements in long-term memory and executive functions after neurofeedback training. These patients successfully learned to self-regulate their own brain activity by means of neurofeedback training. The other half of pwMS (N = 7) did neither show any cognitive changes when comparing the pre- and post-assessment nor were they able to modulate their own brain activity in the desired direction during neurofeedback training.

CONCLUSIONS

Data from this interventional study provide first preliminary evidence that successful self-regulation of one's own brain activity may be associated with cognitive improvements in pwMS.

SIGNIFICANCE

These promising results should stimulate further studies. Neurofeedback might be a promising and alternative tool for future cognitive rehabilitation.

A clinical screening tool for objective and subjective cognitive disorders in multiple sclerosis

BACKGROUND

Cognitive dysfunction is common in multiple sclerosis (MS). Deficits can affect attention, concentration, planning, and memory. They can have severe functional consequences in many domains. Cognitive complaints are frequently associated with other confounding factors (fatigue, anxiety, depression, or treatment side effects). In most cases, cognitive assessment is proposed after a spontaneous complaint, but determining the extent of discomfort perceived by the patient, the influence of coexisting factors, or the optimal timing for a more complete neuropsychological assessment is difficult.

OBJECTIVE

The objective of this work was to evaluate the feasibility and relevance of a fast global assessment of both objective and subjective cognitive dysfunction in MS.

METHODS

MS patients underwent a brief cognitive assessment including 7 visual analogue scales (VASs) asking about the patient's subjective level of discomfort in various domains, a memory test (Barbizet's lion story), a commonly used test of information processing speed (Symbol Digit Modalities Test [SDMT]) and self-reporting questionnaires for fatigue and mood (Fatigue Severity Scale [FSS] and Hospital Anxiety and Depression Scale [HADS]). Spearman correlation coefficients among scores were estimated.

RESULTS

The mean age of the 73 patients included was 48.3 (SD 11.1) years; 78% were females and 52.8% had the remittent-recurrent MS form, 8.3% the primary progressive form, and 38.9% the secondary progressive form. In less than 20min, this brief cognitive assessment was able to identify symptoms and quantify discomfort level. Symptoms of fatigue and anxiety frequently coexisted with cognitive complaints. We found modest correlations between scores on the VAS fatigue and the FSS and between scores on the VAS mood and the HADS. Analytical evaluation revealed that most patients had similar SDMT and recall profiles; however, a small proportion showed a dissociation between these 2 tests, which validated the inclusion of both tests in the assessment. Accounting for coexisting factors (e.g., anxiety and fatigue) and their functional repercussions is essential for prioritizing these problems within the context of multidisciplinary patient treatment.

CONCLUSION

Considering the possible multifactorial character of cognitive dysfunction in MS, it is essential to ask patients about their experiences and to take into account cognitive complaints in the follow-up of patients. The assessment tool we propose is simple and easy to use in a clinical setting and provides the information necessary for requesting (or not) a more complete neuropsychological assessment.

Clinical outcome measures for progressive MS trials

Treatment options for progressive multiple sclerosis remain the main unmet need of the field. As the understanding of multiple sclerosis (MS) pathogenesis improves, new pathways and molecules will be tested for potential reparative, remyelinating, or neuroprotective effects. The clinical outcomes used will determine successful demonstration of beneficial treatment effects to regulatory agencies, clinicians, and persons with MS. This review focuses on clinical outcome measures including the Expanded Disability Status Scale, Multiple Sclerosis Functional Composite, and novel composite measures of disability. The paper also covers cognitive outcomes and screening tests for use in clinical trials. The growing importance of patient-reported outcomes and their suitability for clinical trials is also presented. The review aims to create consensus in regard to these topics and suggestions for future research.

Cognition During and After Multiple Sclerosis Relapse as Assessed With the Brief International Cognitive Assessment for Multiple Sclerosis

There is some evidence that cognition may be impaired during multiple sclerosis (MS) relapse. The aims of this study were to assess the cognitive status with the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) in MS patients during relapse, in stable patients, and in healthy controls; to evaluate cognitive changes up to 3 months after relapse; and to estimate the impact of different factors on cognition after relapse. BICAMS was performed in 60 relapsing, 30 stable patients and 30 controls. Relapsing MS patients were assessed during relapse and one and three months after relapse. SDMT score was lower in relapsing than in stable patients. The mean scores of all BICAMS tests were higher one month after relapse than during relapse (p < 0.001). SDMT score after relapse improved in younger patients, who had more severe relapse (p < 0.05). BVMT-R score improved more in men, in patients with biologically active interferon-beta, in patients treated with methylprednisolone and in patients who were rehabilitated (p < 0.05). CVLT-II score improved in women and in patients with shorter relapse (p < 0.05). A neuropsychological assessment, like the evaluation of physical disability, is important during relapse. BICAMS may be suitable for a quick and effective assessment of cognition during relapse.

Everyday memory measures in multiple sclerosis: a systematic review

Everyday memory is one of the most affected cognitive functions in multiple sclerosis (MS). Assessing everyday memory problems is crucial for monitoring the impact of memory deficits on individuals' day-to-day lives and evaluating the effectiveness of interventions that aim to improve cognitive functions. The aim of this systematic review was to identify the research literature on everyday memory measures used with people with MS, describe the types of measures used, and summarise their psychometric properties. Empirical studies of cognitive function in MS using standardised everyday memory measures were included. Online databases (MEDLINE, PsycINFO, PsycARTICLES, Embase) and Google Scholar were searched. Forty-four studies met the inclusion criteria. A total of 12 measures were identified, with varied uses and administration methods. The majority of papers did not report any psychometric properties for MS populations. The few papers that did, reported that the measures have good reliability and appear to have good face, concurrent, and ecological validity, but these need to be evaluated further. This review presents researchers and clinicians with an overview of the various everyday memory measures used in studies with people with MS, to help them choose the appropriate measure for their evaluations.

Natalizumab stabilizes physical, cognitive, MRI, and OCT markers of disease activity: A prospective, non-randomized pilot study

Natalizumab is an effective therapy for multiple sclerosis (MS). Its effectiveness has been demonstrated in several clinical and imaging studies. The objective of this study was to further demonstrate the efficacy of natalizumab using a comprehensive battery of clinical and imaging markers in the same cohort of patients followed longitudinally, hence capturing the multi-faceted nature of the MS disease process. A prospective, open-label, pilot study of 20 MS patients treated with natalizumab was conducted. High resolution MRI, Symbol-Digit Modalities Test (SDMT), and Optical Coherence Tomography (OCT) scans were obtained at baseline, 48, and 96 weeks. 15 patients completed the study. Natalizumab treatment decreased Expanded Disability Status Scale score (EDSS) and no change in SDMT, Brain Parenchymal Fraction (BPF), or any of the OCT markers of retinal degeneration was observed. Thalamic and whole brain volume as assessed by Percentage Brain Volume Change (PBVC) showed continuous deterioration. Higher baseline T2 lesion load correlated with increased rate of PBVC at 96-weeks (r = 0.566, R2 = 0.320, p = 0.035) and thalamic volume loss (r = -0.586, R2 = 0.344, p = 0.027). Most patients, 93%, achieved no evidence of disease activity (NEDA) at 2 years, likely due to early disease duration and lower initial baseline lesion load. This study further demonstrates stabilization of clinical and imaging markers of disease activity during natalizumab treatment.

Validity of the Symbol Digit Modalities Test as a cognition performance outcome measure for multiple sclerosis

Cognitive and motor performance measures are commonly employed in multiple sclerosis (MS) research, particularly when the purpose is to determine the efficacy of treatment. The increasing focus of new therapies on slowing progression or reversing neurological disability makes the utilization of sensitive, reproducible, and valid measures essential. Processing speed is a basic elemental cognitive function that likely influences downstream processes such as memory. The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) includes representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS. Among the MSOAC goals is acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful to persons with MS. A critical step for these neuroperformance metrics is elucidation of clinically relevant benchmarks, well-defined degrees of disability, and gradients of change that are deemed clinically meaningful. This topical review provides an overview of research on one particular cognitive measure, the Symbol Digit Modalities Test (SDMT), recognized as being particularly sensitive to slowed processing of information that is commonly seen in MS. The research in MS clearly supports the reliability and validity of this test and recently has supported a responder definition of SDMT change approximating 4 points or 10% in magnitude.

Cognitive impairment predicts disability progression and cortical thinning in MS: An 8-year study

BACKGROUND

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system (CNS). Although cognitive impairment (CI) affects a large proportion of MS patients, only few data are available about its prognostic value associated with advanced magnetic resonance imaging (MRI) metrics.

OBJECTIVES

We aimed at investigating the relationship between the early CI and the disease progression over 8-year follow-up in MS patients.

METHODS

We conducted a retrospective 8-year longitudinal study involving 78 patients with relapsing-remitting MS, who completed neuropsychological examination and structural MRI at the time of diagnosis. Each patient was clinically evaluated every 6 months, and cortical thickness was quantified at baseline and at the end of the follow-up. Patients were classified as having normal cognition and mild or severe CI.

RESULTS

The results show that CI at the time of diagnosis is a good predictor of conversion to definite MS ( p < 0.001), disability progression ( p < 0.001), as well as of transition to secondary progressive phase ( p < 0.001) and of cortical thinning ( p < 0.001).

CONCLUSION

We confirmed and extended the evidence that early CI might be helpful in the identification of MS patients at high risk of disability progression and poor clinical outcome and should be considered as a marker of most aggressive pathology.

Assessing the criterion validity of four highly abbreviated measures from the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS)

OBJECTIVE

Cognitive dysfunction is prevalent in multiple sclerosis. As self-reported cognitive functioning is unreliable, brief objective screening measures are needed. Utilizing widely used full-length neuropsychological tests, this study aimed to establish the criterion validity of highly abbreviated versions of the Brief Visuospatial Memory Test - Revised (BVMT-R), Symbol Digit Modalities Test (SDMT), Delis-Kaplan Executive Function System (D-KEFS) Sorting Test, and Controlled Oral Word Association Test (COWAT) in order to begin developing an MS-specific screening battery.

METHOD

Participants from Holy Name Medical Center and the Kessler Foundation were administered one or more of these four measures. Using test-specific criterion to identify impairment at both -1.5 and -2.0 SD, receiver-operating-characteristic (ROC) analyses of BVMT-R Trial 1, Trial 2, and Trial 1 + 2 raw data (N = 286) were run to calculate the classification accuracy of the abbreviated version, as well as the sensitivity and specificity. The same methods were used for SDMT 30-s and 60-s (N = 321), D-KEFS Sorting Free Card Sort 1 (N = 120), and COWAT letters F and A (N = 298).

RESULTS

Using these definitions of impairment, each analysis yielded high classification accuracy (89.3 to 94.3%).

CONCLUSIONS

BVMT-R Trial 1, SDMT 30-s, D-KEFS Free Card Sort 1, and COWAT F possess good criterion validity in detecting impairment on their respective overall measure, capturing much of the same information as the full version. Along with the first two trials of the California Verbal Learning Test - Second Edition (CVLT-II), these five highly abbreviated measures may be used to develop a brief screening battery.

Impact of Pharmacotherapy on Cognitive Dysfunction in Patients with Multiple Sclerosis

Cognitive impairment is a common symptom of multiple sclerosis (MS), adversely impacting many spheres of daily functioning. Yet the effectiveness of pharmacological interventions for cognitive impairment in MS is unclear. Clinicians and patients alike would benefit from formal guidelines regarding effective management of cognitive symptoms. We reviewed the background on the measurement, pathophysiology and risk factors for cognitive dysfunction in MS, and then examined the published clinical trials of pharmacotherapy, including both disease-modifying treatments (DMTs) and symptom-management therapies (SMTs). Our review of DMTs revealed only a single well-designed, randomized, controlled trial where intramuscular interferon (IFN)-β1a, administered once weekly, was compared with placebo. The results showed significant benefits in terms of cognitive processing speed and memory. Less convincing but promising data have shown the potential benefits of IFN-β1b and natalizumab. The literature on SMTs is replete with placebo-controlled, single-centre studies, with a failure to replicate initially promising results. The results for SMTs such as acetylcholinesterase inhibitors and psychostimulants are mixed. Some encouraging data show promise but not to a threshold of indication for standard clinical use. Numerous methodological factors hamper research in this area. Acknowledging the lack of firm conclusions, we argue that all DMTs are likely to benefit cognition and that, if otherwise safe, SMTs with some empirical support may be attempted at the discretion of the treating clinician. We offer some guidance on the assessment and monitoring of cognitive function to inform off-license treatment of cognitive impairment in MS patients.

Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) and performance of everyday life tasks: Actual Reality

BACKGROUND

Recently, a brief cognitive assessment (Brief International Cognitive Assessment for Multiple Sclerosis: BICAMS) has been recommended for use with patients diagnosed with multiple sclerosis (MS) to screen for cognitive impairments. However, the relationship between the BICAMS and everyday life activity has not been examined. The aim of this study was to examine whether the BICAMS can predict performance of activities of daily living using Actual Reality(TM) (AR) in persons with MS.

METHOD

A between-subjects design was utilized to compare 41 individuals with MS and 32 healthy controls (HC) performing BICAMS and an AR task. Participants were asked to access the internet to purchase a flight ticket or cookies, and were administered the BICAMS and questionnaires to assess quality of life (QOL), affect symptomatology, and prior internet experience.

RESULTS

Participants with MS performed significantly worse than HC on the BICAMS and the AR. Additionally, better BICAMS performance was associated with more independent AR performance. Self-reports of QOL were not correlated with AR or BICAMS performance.

CONCLUSIONS

Individuals with MS have greater problems with actual everyday life tasks as compared to HC. The BICAMS is a promising cognitive screening tool to predict actual functional performance in participants with MS.

Thalamic-hippocampal-prefrontal disruption in relapsing-remitting multiple sclerosis

Background

Cortical, thalamic and hippocampal gray matter atrophy in relapsing–remitting MS (RRMS) is associated cognitive deficits. However, the role of interconnecting white matter pathways including the fornix, cingulum, and uncinate fasciculus (UF) is less well studied.

Objective

To assess MS damage to a hippocampal–thalamic–prefrontal network and the relative contributions of its components to specific cognitive domains.

Methods

We calculated diffusion tensor fractional anisotropy (FA) in the fornix, cingulum and UF as well as thalamic and hippocampal volumes in 27 RRMS patients and 20 healthy controls. A neuropsychological battery was administered and 4 core tests known to be sensitive to MS changes were used to assess cognitive impairment. To determine the relationships between structure and cognition, all tests were grouped into 4 domains: attention/executive function, processing speed, verbal memory, and spatial memory. Univariate correlations with structural measures and depressive symptoms identified potential contributors to cognitive performance and subsequent linear regression determined their relative effects on performance in each domain. For significant predictors, we also explored the effects of laterality and axial versus radial diffusivity.

Results

RRMS patients had worse performance on the Symbol Digit Modalities Test, but no significant impairment in the 4 cognitive domains. RRMS had reduced mean FA of all 3 pathways and reduced thalamic and hippocampal volumes compared to controls. In RRMS we found that thalamic volume and BDI predicted attention/executive function, UF FA predicted processing speed, thalamic volume predicted verbal memory, and UF FA and BDI predicted spatial memory.

Conclusions

Hippocampal–thalamic–prefrontal disruption affects cognitive performance in early RRMS with mild to minimal cognitive impairment, confirming both white and gray matter involvement in MS and demonstrating utility in assessing functional networks to monitor cognition.

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We detect limbic white matter and gray matter insult in early RRMS patients with mild to minimal cognitive impairment.

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Thalamic atrophy and uncinate fasciculus microstructural changes are associated with cognitive performance in early RRMS.

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Depressive symptomatology also independently predicts cognitive performance