The Role of Information Processing Speed in Clinical and Social Support Variables of Patients with Multiple Sclerosis

Executive functions in relapsing-remitting multiple sclerosis

Some studies suggest that patients with relapsing-remitting multiple sclerosis have problems in the functioning of working memory, and more specifically in executive functions, but the available results are still inconsistent. The aim of the present study was to examine executive functioning in multiple sclerosis using classical and representative tasks for divided attention, updating, attentional shifting, and inhibition. The sample was composed of 48 participants aged between 18 and 59 years (24 persons living with multiple sclerosis and 24 healthy participants matched in age and education level). The executive functions of divided attention, updating, attentional shifting, and inhibition were analyzed through the Dual-Task Paradigm, the N-Back task, the Trail Making Test (TMT), and the Stroop test, respectively. The analyses of the data showed that the functioning of working memory was impaired in multiple sclerosis in the executive functions of divided attention and updating when the group of persons living with MS and the control group were compared. In addition, the performance in the four executive functions analyzed did not show the same profile across the persons living with MS in the sample, as no deficit in attentional shifting or inhibition was observed. It can be concluded that the presence of deficits was observed only in the executive functions of divided attention and updating under the condition of greater cognitive demand. The clinical implications of these results are underlined due to their impact on daily life.

Cognition and Cognitive Fatigability: Association with Employment Status in Multiple Sclerosis

BACKGROUND

Slowed processing speed impacts employment status in people with multiple sclerosis (PwMS). Studies on the Multiple Sclerosis Functional Composite (MSFC), which includes the Paced Auditory Serial Addition Test (PASAT), have demonstrated that the combined score predicts employment status. Whether PASAT performance alone is associated with employment status is less clear. In addition, no studies have yet evaluated whether cognitive fatigability (CF), as measured with the PASAT, is associated with employment status. The aim of the current study was to examine the association between PASAT performance, CF, and employment status in PwMS.

METHODS

Hundred and eighty-six PwMS completed the PASAT as part of a larger neuropsychological battery. ANOVAs and chi-squares analyzed group differences between employed and unemployed participants with respect to demographics, PASAT performance scores, and CF. Linear regression determined whether PASAT performance and/or CF scores were associated with employment status.

RESULTS

After controlling for demographic influences, group differences were noted between employed vs. unemployed individuals on PASAT performance scores only. Employment status was associated with PASAT performance scores but not CF.

CONCLUSIONS

The current study confirmed that PASAT performance is associated with employment status in MS. Given that CF was not associated, it seems difficulties with information processing speed (IPS) and working memory have more impact on a PwMS's ability to remain employed rather than within-task performance decline.

Importance of Identifying Cognitive Impairment in Multiple Sclerosis

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

Processing speed test: Results from a Japanese normative sample of healthy participants compared with a US normative sample

BACKGROUND

The Processing Speed Test (PST), a validated iPad®-based cognitive screening test for MS, has been applied to the cognitive assessment of Japanese MS patients using US normative data.

METHODS

To develop PST normative data from Japanese healthy volunteers and compare the PST score distribution between Japanese and US healthy volunteers, 254 healthy Japanese-speaking volunteers were enrolled and stratified by age (20-65 years). Potential participants with a Mini-Mental State Examination score < 27 were excluded. PST raw scores (total correct) were from the Japan cohort and compared with age-restricted US normative data and propensity score-matched data created by matching sex, age, and educational level from a published study of 428 healthy participants. PST score distributions and standardized z-scores were compared using t-test and Kolmogorov-Smirnov test statistics.

RESULTS

The mean age of the Japan cohort was 44.1 years. The PST scores of Japanese volunteers were significantly different from those of the age-restricted (mean ± SD 61.8 ± 10.1 vs 53.7 ± 10.8; p < 0.001) and the propensity score-matched US cohort (62.1 ± 10.1 vs 53.3 ± 10.6; p < 0.001).

CONCLUSION

Regression analyses centered on US normative data could underestimate disease severity in Japanese MS patients, suggesting that separate normative data should be considered for each population sample.

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.

Do cardiovascular disease comorbidities affect the cognitive function of Multiple Sclerosis patients?

INTRODUCTION

Cognitive impairment is a core symptom of multiple sclerosis, leading to disability in 40-70% of patients. The most common cognitive domains affected by MS are information processing speed, complex attention, executive functions and less frequently, episodic declarative memory. Cardiovascular disease comorbidities have been shown to increase the decline rate in many neurological conditions. Our study aims to examine the possible impact of CVD risk factors in the cognitive decline rate of PwMS.

METHODS

Over the course of a year, 248 PwMS with and without Cardiovascular comorbidity were cognitively evaluated using the written version of SDMT and the MoCA.

RESULTS

Compared to control, MS patients with comorbid CVD had greater general cognitive decline and decreased processing speed. Patients with comorbid diabetes and dyslipidemia had the highest impairment, followed by those with hypertension, compared to the control group and those patients with a high BMI.

CONCLUSION

The presence of cardiovascular comorbidities and especially dyslipidemia increases the rate of cognitive decline in MS patients. In such cases, patients should be evaluated every 6 months instead of a year and the use of the SDMT is advised since it's time efficient,it requires minimal training and correlates with MRI findings.

A promising cognitive screener in multiple sclerosis: The NIH toolbox cognition battery concords with gold standard neuropsychological measures

BACKGROUND

Routine cognitive screening is a priority in MS clinical care. The National Institutes of Health Toolbox (NIHTB) Cognition Battery is a 30-min instrument validated in neurological populations excluding MS.

OBJECTIVES

To assess construct validity of NIHTB tests and compare classification of cognitive impairment with gold-standard tests. To evaluate relationships between fluid cognition and clinical measures.

METHODS

Eighty-seven individuals, aged 30-59 years, completed the NIHTB, Minimal Assessment of Cognitive Function in MS (MACFIMS), Wechsler Adult Intelligence Scale-IV subtests, and measures of disease severity, depression, and fatigue.

RESULTS

The NIHTB showed adequate convergent validity for processing speed, working memory, and episodic memory. Although fluid cognition scores from the NIHTB and MACFIMS classified a similar proportion of participants as cognitively impaired, the two batteries differed in which individuals were classified as impaired versus preserved. NIHTB fluid cognition was inversely correlated with disease severity but not related to depression or fatigue.

CONCLUSIONS

The NIHTB concords with gold-standard measures, and classifies cognitive impairment at similar rates to the MACFIMS. Adjusted NIHTB fluid cognition was negatively associated with disease severity suggesting clinical utility. Psychometric validation of the NIHTB in clinical practice will elucidate its promise as a cognitive screener in MS.

Correlates of patient-reported cognitive performance with regard to disability

The patient-reported form of the Multiple Sclerosis Neuropsychological Questionnaire (MSNQ) assesses perceived problems attributable to cognitive and neuropsychiatric symptoms. It is inconsistently related to objective cognitive performance in multiple sclerosis (MS), while strongly correlated with depression. We assessed whether the relationship between subjective and objective cognitive screening tools is moderated by disability. Furthermore, we investigated the MSNQ as a screening tool for both cognitive impairment and depression. 275 MS patients completed the patient-reported MSNQ, two‐question screening tool for depression and Symbol Digit Modalities Test (SDMT) and were divided into Expanded Disability Status Scale (EDSS) subgroups: Low 0.0–3.0, Medium 3.5–6.0, High 6.5–9.0. MSNQ scores correlated significantly with depression but not SDMT in all subgroups. After correcting for age, sex, education, EDSS and depression, MSNQ significantly predicted SDMT in the total group, but not the subgroups. MSNQ significantly predicted a positive depression and/or cognitive impairment screen in the total group and all subgroups. The relationship between subjective and objective cognitive screening tools is not influenced by physical disability. MSNQ scores are substantially influenced by depression, and reflect cognitive function to some degree. Patient-reported cognitive measures can be useful to identify patients requiring further (neuro)psychological assessment.

Effects of diminished positive mood and depressed mood upon verbal learning and memory among people with multiple sclerosis

Objective: Cognitive impairment affects as many as 65% of people with multiple sclerosis (PWMS), and memory impairment confers greater severity of disability and functional impairment. Depression is also common among PWMS, and lifetime prevalence rates are as high as 50%. Research has yet to clearly define the relationship between memory dysfunction and depression among PWMS, and may reflect incomplete assessment of depressive symptoms. The present study examined different aspects of depressive symptoms including anhedonia (i.e., diminished positive mood) and their relationships with verbal learning and memory among PWMS.Method: Participants were 48 healthy individuals and 96 PWMS. They were primarily Caucasian (90.3%) and female (75.0%). Participants completed the California Verbal Learning Test-2 (CVLT-2) to assess verbal learning and memory and the Chicago Multiscale Depression inventory to assess depressed mood (CMDI-Mood) and diminished positive mood (CMDI-DPM).Results: Linear regression revealed that the main effect of CMDI-DPM and the interaction of CMDI-DPM and CMDI-Mood significantly explained variance across learning, recall, and recognition CVLT-2 indices. Follow-up analyses indicated that CMDI-DPM was only significant in the absence of high CMDI-Mood scores. CMDI-Mood explained variance in only CVLT-2 Trial B.Conclusions: Depressed mood had little direct effect upon memory performance in PWMS. In the absence of severe depressed mood, higher levels of positive mood corresponded to better memory performance. However, the impact of diminished positive mood was rendered null among those endorsing high levels of depressed mood. These data may imply that anhedonia corresponds with poorer memory function among PWMS, and suggests that investigators and clinicians should assess multiple mood dimensions among PWMS.

Effect of Ozanimod on Symbol Digit Modalities Test Performance in Relapsing MS

BACKGROUND

Cognitive dysfunction, including slowed cognitive processing speed (CPS), is one of the most disabling symptoms of multiple sclerosis (MS). The Symbol Digit Modalities Test (SDMT) is a preferred measure of CPS for MS trials and routine screening. Based on encouraging SDMT results in the phase 3 SUNBEAM trial, these post hoc, exploratory analyses were conducted to further compare effects of the sphingosine 1-phosphate receptor modulator ozanimod versus intramuscular interferon β-1a on CPS in participants with relapsing multiple sclerosis (RMS).

METHODS

In the phase 3, double-blind, double-dummy, SUNBEAM study, adults (aged 18‒55 years) with RMS (N=1,346) were randomized to once-daily oral ozanimod 0.92 or 0.46 mg, or weekly intramuscular interferon β-1a 30 µg. The study continued until the last participant was treated for 12 months. CPS was measured as part of a secondary endpoint using the SDMT. Exploratory, post hoc analyses evaluated SDMT change and percentages of participants with clinically meaningful (≥4-point) SDMT improvement or worsening at months 6 and 12, and relationship between SDMT and brain volume on magnetic resonance imaging.

RESULTS

Ozanimod improved SDMT scores compared with interferon β-1a at months 6 and 12. At month 12, least squares mean difference in SDMT z-scores for ozanimod 0.92 mg versus interferon β-1a was 0.102 (95% CI, 0.031‒0.174, nominal p = 0.0051; standardized mean difference = 0.1376). A greater percentage of ozanimod 0.92 mg‒treated participants had clinically meaningful improvements in SDMT scores versus interferon β-1a at month 6 (30.0% versus 22.2%) and month 12 (35.6% versus 27.9%). Of those with SDMT improvement at month 6, 66.4% of those treated with ozanimod 0.92 mg and 55.9% of those treated with interferon β-1a had sustained improvement at month 12. Brain volume loss was similar for those with SDMT improvement versus worsening at month 12.

CONCLUSIONS

In these exploratory analyses, ozanimod had modestly beneficial effects on CPS in RMS participants. The effects of ozanimod on SDMT are being further evaluated in an ongoing 3-year clinical trial. SUNBEAM is registered on clinicaltrials.gov (NCT02294058) and the European Clinical Trials Database (EudraCT 2014-002320-27).

Training the brain: could it improve multiple sclerosis treatment?

Multiple sclerosis (MS) is a neurological disease characterized by neuroinflammation, demyelination and axonal degeneration along with loss of function in the central nervous system. For many years, research in MS has focused on the efficacy of pharmacological treatments. However, during the last years, many publications have been dedicated to the study of the efficacy of non-pharmacological strategies, such as physical exercise and cognitive training. Beneficial effects of the combination of both strategies on cognitive function have been described in both ageing adults and patients with neurodegenerative diseases, such as MS. The analysis of combining both physical and cognitive stimulation can be summarized by the environmental enrichment (EE) experiments, which are more suitable for animal models. EE refers to housing conditions consisting of exercise and cognitive and social stimulation. In this review, we will summarize the available studies that describe the influence of EE in both MS patients and MS animal models.

The MSReactor computerized cognitive battery correlates with the processing speed test in relapsing-remitting multiple sclerosis

BACKGROUND

Monitoring and screening of cognitive function in the ambulatory setting requires simple, brief cognitive tests that are reproducible. MSReactor (MSR) is a web-based platform that screens psychomotor (processing) speed, attention and working memory using a game-like interface. The Processing Speed Test (PST) is a validated computerized version of the Symbol Digit Modalities test (SDMT) and component of the Multiple Sclerosis Performance Test (MSPT).

OBJECTIVE

To determine the baseline and 6-month predictive correlations between the MSReactor computerised cognitive battery and the PST.

METHODS

Prospectively enrolled relapsing-remitting multiple sclerosis (RRMS) patients completed the MSR and the PST during 6-monthly clinic visits. Pearson's product-moment coefficients with partial correlation adjustment were calculated between the PST and MSR reaction times for Simple reaction test (SRT), Choice reaction test (CRT) and One- back test (OBK).

RESULTS

379 RRMS patients from six tertiary MS centres in Australia were enrolled. The mean age was 40.4 years (SD 10.3) and median Expanded Disability Status Scale (EDSS) score was 1.5 (IQR 1.0 - 2.0). Most (66%) were on high efficacy disease-modifying treatment. Baseline PST scores correlated with the MSR reaction times: SRT (R=-0.40), CRT (R= -0.44) and OBK (R= -0.47), p <0.05. There was a moderate correlation between the first visit MSR and 6-month PST test for SRT (R= -0.37, p<0.001), CRT (R=-0.44, p < 0.001) and OBK (R= -0.43, p < 0.001) speed.

CONCLUSIONS

MSR-measured psychomotor speed, attention and working memory at baseline moderately correlates with baseline and 6-month PST; suggesting overlapping cognitive processes are being tested. Six-month test-retest reliability was acceptable for both tests.

Slowed Information Processing Speed at Four Years Poststroke: Evidence and Predictors from a Population-Based Follow-up Study

BACKGROUND AND PURPOSE

Slowed Information Processing Speed (IPS) is a commonly reported cognitive deficit following stroke, affecting up to 50% to 70 % of stroke survivors. IPS has a major influence on poststroke cognitive dysfunction, affecting quality of life and increasing dependence on others. Few studies have examined predictors of slow IPS after stroke, and there is a paucity of data in terms of long-term prevalence. This study examined baseline predictors associated with long-term slow IPS in a population-based stroke incidence cohort, 4 years after stroke onset.

METHODS

Adults with stroke (n = 133, m = 71.1 ± 13.5 years) completed the Symbol Digit Modalities Test (SDMT) at 4 years poststroke. Baseline predictors were obtained within 2 weeks of the acute event. Multivariate regression linear and logistic models were used to identify baseline predictors (reported as OR with 95%CI) and prevalence of impaired IPS at 4-years.

RESULTS

51% of people with stroke had low scores on the SDMT as indicated by a score of -1.0 SD to -2.5 SD (ranging from low to very low respectively). There were significant associations between slow IPS at 4-years after controlling for age and education level and the following baseline factors: older age (>75 years) (OR 3.03, 95% CI .9-9.3,P = .05), previous stroke (OR 2.74, 95% CI 1.0-7.4,P = .05), high cholesterol (OR 2.72, 95% CI 1.3-5.4,p = .01), hypertension (OR 1.82, 95% CI 0.9-3.6,p = .05), and presence of coronary artery disease (OR 3.35, 95% CI 1.6-9.6,P = .01), or arrhythmia (OR 4.40, 95% CI 1.5-12.4,P = .01).

CONCLUSIONS

Even after 4-years poststroke, slowed IPS is highly prevalent, with comorbid vascular risk factors significantly contributing to persistent impaired IPS. Early identification of adults who are at higher risk of deficits in IPS is vital to targeting the timely delivery of cognitive rehabilitation interventions, improving overall outcomes.