Tests of information processing speed: what do people with multiple sclerosis think about them?

Prevalence of cognitive impairment (CI) in patients with multiple sclerosis (MS): A systematic review and meta-analysis

Background

One of the complications of multiple sclerosis (MS) is cognitive impairment (CI). The prevalence of CI is reported variously in previous studies. The goal of this systematic review and meta-analysis to estimate pooled prevalence of CI in patients with MS and also the prevalence of CI based on the type of applied test.

Methods

Two independent researchers systematically searched PubMed, Scopus, EMBASE, Web of Science, and google scholar as well as gray literature (conference abstracts, references of the references) which were published before up January 2022.

Results

We found 4089 articles by literature search, after deleting duplicates 3174 remained. Ninety articles remained for meta-analysis. The pooled prevalence of CI using all types of tests was 41% (95% CI: 38-44%) (I2=91.7%, p<0.001). The pooled prevalence of CI using BRB test was 39% (95%CI: 36-42%) (I2=89%, p<0.001). The pooled prevalence of CI using BICAMS was 44% (95%CI: 37-51%, I2=95.4%, p<0.001). The pooled prevalence of CI using MACFIMS was 44% (95% CI: 36-53%) (I2=89.3%, p<0.001).

Conclusions

The pooled prevalence of cognitive impairment in patients with MS is estimated as 41%, so CI it should be considered by clinicians.

Auditory Test of Processing Speed: Preliminary validation of a smartphone-based test of mental speed

BACKGROUND

The Symbol Digit Modalities Test (SDMT) is a gold-standard measure of cognitive efficiency and processing speed for people with multiple sclerosis (PwMS) but relies on vision and oculomotor function.

OBJECTIVES

To develop and validate a new processing speed test with minimal memory involvement and no eye function requirements.

METHODS

We created an Auditory Test of Processing Speed (ATOPS). A total of 122 PwMS, of whom 33 were severely disabled (median Expanded Disability Status Scale 8.0) and 37 healthy volunteers (HVs), were enrolled. We assessed sensitivity to discriminate MS participants from HVs, convergent validity between ATOPS and SDMT, sensitivity to discriminate between cognitively impaired (CI) and cognitively preserved (CP) MS participants, and correlations with MS pathology (overall brain lesion burden). Acceptability was examined with completion rates and participant ratings of ATOPS.

RESULTS

ATOPS discriminated PwMS from HVs (d = 0.739-0.856), correlated with SDMT (|r| = 0.528-0.587), discriminated between CI and CP PwMS (d = 0.623-0.776), and correlated with lesion burden (r = 0.332-0.436). All groups indicated high favorability of ATOPS and severely disabled MS patients could be assessed by ATOPS more frequently than by SDMT (100% vs. 72.4% completion).

CONCLUSIONS

ATOPS is a novel, accessible, and acceptable cognitive processing speed test that may be useful in clinical and/or research settings.

Slower tempo makes worse performance? The effect of musical tempo on cognitive processing speed

The effects of musical tempo on cognitive processing speed were investigated, and the mediating effect of arousal was empirically tested. In an experiment, participants were divided into fast tempo, slow tempo, and no-music groups and completed three cognitive processing speed tests measuring motor speed, visuospatial processing speed, and linguistic processing speed. The results indicated a significant effect of musical tempo on processing speed and task performance in all three tasks. The slow-tempo group exhibited slower processing speed and worse performance than the no-music group in all three tasks. The fast tempo group displayed no significant difference in processing speed or performance compared with the no-music group. In the linguistic processing task, those who listened to slow-tempo music had better accuracy than those in the other conditions. Arousal did not mediate the relationship between musical tempo and cognitive processing speed.

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.

MSCopilot: New smartphone-based digital biomarkers correlate with Expanded Disability Status Scale scores in people with Multiple Sclerosis

BACKGROUND

A previous clinical study showed the high specificity, sensitivity and reliability of MSCopilot, a software medical device designed by Ad Scientiam for the self-assessment of people with Multiple Sclerosis (PwMS), compared to the traditional Multiple Sclerosis Functional Composite (MSFC). We conducted further analyses to assess MSCopilot's performance with respect to the Expanded Disability Status Scale (EDSS).

METHODS

The data of 116 PwMS were analysed. We studied the correlations between MSCopilot scores and the EDSS, and their ability to distinguish PwMS with high and low EDSS through a study of the distribution of the digital test scores as well as logistic regression models. The same analyses were performed using the MSFC tests.

RESULTS

MSCopilot composite scores were as highly correlated to the EDSS (|r| = 0.65, p < 0.01) as their MSFC counterparts, confirming the known correlation of the MSFC with the EDSS. In a linear regression framework, the Walking digital tests have good explanatory power, especially for PwMS with EDSS > 3.5 (R²_adj=0.47). The mean values of each MSCopilot subscore were significantly different between patients with an EDSS > 3.5 and others (p < 0.05), which could not be proved for the MSFC Cognition tests. MSCopilot4 was the best model to predict an EDSS score > 3.5 (AUC = 0.92).

CONCLUSION

These analyses confirm the reliability of MSCopilot and show interesting correlations with the EDSS (similar results obtained with the MSFC). MSCopilot was able to highlight nuances in the different stages of MS the MSFC could not capture.

Cognitive fatigability in multiple sclerosis: How does performance decline over time on the Paced Auditory Serial Addition Test?

BACKGROUND

Cognitive fatigability (CF) can be defined as an inability to maintain an optimal level of performance throughout a sustained cognitive task. It remains unclear, however, whether there is a specific moment during a cognitive task, such as the Paced Auditory Serial Addition Test (PASAT), when performance begins to break down. Thus, the present study aimed to evaluate how performance declines over time on the PASAT in people with multiple sclerosis (PwMS) compared to healthy controls.

METHODS

178 PwMS and 186 control participants were administered the 3" and 2" PASAT as part of a larger battery of neuropsychological tests. To examine how CF differed between the groups, repeated measures ANOVAs were used to evaluate the cumulative error rates made by each group throughout the task. In addition, how the error rate developed across the task on each trial was examined to evaluate in more detail the difference between groups with respect to how performance declined from the beginning to the end of the task. Lastly, exploratory two-way independent sample ANOVAs examined whether there was an influence of stimulus complexity (single vs. double-digit answers) on task performance.

RESULTS

Compared to healthy controls, PwMS produced a greater number of errors overall on the PASAT and demonstrated more vulnerability to CF than healthy controls, as reflected by a greater number of errors made towards the end of the task. This difference was more noticeable on the 3" PASAT, given the difficulty both groups experienced on the 2" form. On the 3" PASAT, by Trial 37, PwMS had made significantly more cumulative errors than controls, however the rate of error generation was largely consistent and linear from the beginning to the end. Some of the group differences observed may be partially attributable to stimulus complexity influencing task performance.

CONCLUSIONS

The 3" PASAT is more sensitive to group differences in CF and error generation than the 2" PASAT. With respect to CF, the greater vulnerability observed in the MS group is not due to a breakdown in performance or an increase in the rate of error generation at any specific point during the task; rather there is a linear decline in performance from the start. These results suggest that PwMS struggle to maintain optimal performance during sustained cognitive effort from the very beginning and demonstrate a steeper, but steady, rate of decline over time.

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.

A Longitudinal Evaluation of Cognitive Fatigue on a Task of Sustained Attention in Early Relapsing-Remitting Multiple Sclerosis

Background

Cognitive fatigue can be objectively measured on tasks of sustained attention and can be defined as decreased performance as a result of sustained cognitive effort. Individuals with multiple sclerosis (MS) early in their disease are vulnerable to cognitive fatigue, although this has yet to be evaluated longitudinally. We aimed to evaluate cognitive fatigue over a 3-year interval in individuals with early-phase relapsing-remitting MS (RRMS). The sensitivity of the Paced Auditory Serial Addition Test (PASAT) at detecting cognitive fatigue was evaluated, as was the impact of scoring method.

Methods

32 people with MS and 32 controls completed the 3- and 2-second PASAT (PASAT-3″ and -2″) as a measure of sustained attention at baseline and 3-year follow-up.

Results

Performance on the PASAT remained stable across time, with improvement noted on the PASAT-2″ likely due to practice and the small sample size. Cognitive fatigue was noted at both times, although sensitivity varied based on scoring method. No evidence of worsening cognitive fatigue was noted over time. The MS group performed worse only when cognitive fatigue was the outcome variable.

Conclusions

Although individuals with MS continue to be vulnerable to cognitive fatigue at follow-up, severity does not seem to increase with time. Cognitive fatigue may be a more sensitive marker of cognitive impairment than overall task performance in those with early-phase RRMS, which has important implications given that clinically only task performance is typically assessed.

Canadian Normative Data for Minimal Assessment of Cognitive Function in Multiple Sclerosis

OBJECTIVE

The Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) is a consensus-based collection of neuropsychological tests that evaluate cognitive functioning in individuals with multiple sclerosis (MS). The tests are typically scored using each respective published test manual, leaving the examiner to make interpretations from norms derived from different American populations. Given demographic differences, this may lead to misinterpretation of findings in Canadians. Our goal was to establish both discrete and regression-based normative data for the MACFIMS based on a largely co-normed Canadian population to allow for improved psychometric interpretation.

METHODS

MACFIMS data sets were aggregated from across three different Canadian cities (Ottawa, Toronto, and London), yielding a total of 330 healthy control participants from four different studies evaluating cognition in individuals with MS. Given the variety of contributing studies, there was variability in terms of the number of participants completing each measure.

RESULTS

Both age-based discrete normative data and demographically adjusted (sex, age, and education) regression-based formulae were established. The demographic variables varied in their contribution to each MACFIMS test in the regression models, predicting 0 to 18% of the variance.

CONCLUSIONS

Provision of these regression-based formulae will allow for more accurate interpretation of Canadian-derived MACFIMS scores by allowing clinicians to correct for all relevant demographic variables simultaneously, leading to improved clinical decision making for individuals with multiple sclerosis.

Outcome Measures in Clinical Trials for Multiple Sclerosis

Due to the heterogeneous nature of the disease, it is a challenge to capture disease activity of multiple sclerosis (MS) in a reliable and valid way. Therefore, it can be difficult to assess the true efficacy of interventions in clinical trials. In phase III trials in MS, the traditionally used primary clinical outcome measures are the Expanded Disability Status Scale and the relapse rate. Secondary outcome measures in these trials are the number or volume of T2 hyperintense lesions and gadolinium-enhancing T1 lesions on magnetic resonance imaging (MRI) of the brain. These secondary outcome measures are often primary outcome measures in phase II trials in MS. Despite several limitations, the traditional clinical measures are still the mainstay for assessing treatment efficacy. Newer and potentially valuable outcome measures increasingly used or explored in MS trials are, clinically, the MS Functional Composite and patient-reported outcome measures, and on MRI, brain atrophy and the formation of persisting black holes. Several limitations of these measures have been addressed and further improvements will probably be proposed. Major improvements are the coverage of additional functional domains such as cognitive functioning and assessment of the ability to carry out activities of daily living. The development of multidimensional measures is promising because these measures have the potential to cover the full extent of MS activity and progression. In this review, we provide an overview of the historical background and recent developments of outcome measures in MS trials. We discuss the advantages and limitations of various measures, including newer assessments such as optical coherence tomography, biomarkers in body fluids and the concept of 'no evidence of disease activity'.

Distraction adds to the cognitive burden in multiple sclerosis

Background:

Cognitive dysfunction in multiple sclerosis (MS) causes numerous limitations in activities of daily living.

Objectives:

To develop an improved method of cognitive assessment in people with MS using novel real-world distracters.

Methods:

A sample of 99 people with MS and 55 demographically matched healthy controls underwent testing with the Minimal Assessment of Cognitive Functioning in Multiple Sclerosis (MACFIMS) and a modified version of the computerized Symbol Digit Modalities Test (c-SDMT). Half of the subjects completed the c-SDMT with built-in real-world distracters and half without.

Results:

The mean time on the c-SDMT was significantly greater in MS subjects than healthy controls for both distracter ( p = 0.001) and non-distracter ( p < 0.001) versions. Significantly more MS subjects were impaired on the c-SDMT with distracters than the traditional SDMT (47.1% vs 30.3%, p = 0.04). There were no differences in impairment between the c-SDMT with and without distracters (47.1% vs 37.5%, p = 0.34). The distracter version had a sensitivity of 81% and specificity of 88% in detecting global cognitive impairment.

Conclusions:

The incorporation of distracters improves the sensitivity of a validated computerized version of the SDMT relative to the non-distracter and traditional versions and offers a quick and easy means of detecting cognitive impairment in people with MS.

Functional clinical outcomes in multiple sclerosis: Current status and future prospects

For decades, the Expanded Disability Status Scale (EDSS) has been the principal measure of disability in clinical trials in patients with multiple sclerosis (MS) and in clinical practice. However, this test is dominated by effects on ambulation. Composite endpoints may provide a more sensitive measure of MS-related disability through the measurement of additional neurological functions. The MS Functional Composite (MSFC) includes a walking test (25-ft walk) plus tests of upper extremity dexterity (9-hole peg test) and cognitive function (Paced Auditory serial Addition test [PASAT]). Replacing PASAT with the Symbol Digit Modality test, a more sensitive test preferred by patients, may improve the clinical utility of the MSFC. In addition, disease-specific measures of QoL may be used alongside the MSFC (which does not include measurement of QoL). Clinical data suggest that disease-modifying therapies may delay or prevent relapse, and better composite measures will be valuable in the assessment of disease activity-free status in people with MS.

The relationship between specific cognitive domains, fear of falling, and falls in people with multiple sclerosis

The primary aim was to examine the relationship between seven definite aspects of cognition measured by a computerized cognitive testing tool on the history falls in people with mild to moderate MS (PwMS). Secondary aims focused on whether cognition performance is correlated to fear of falling, walking velocity, and a patient-rated measure of walking ability. One hundred and one PwMS were included in the study analysis. Fifty-two had a history of at least one fall during the past year. Outcome measures included a computerized cognitive test battery designed to evaluate multiple cognitive domains, gait speed, and self-reported questionnaires; 12-item MS walking scale (MSWS-12); and Falls Efficacy Scale International. Significant differences between fallers and nonfallers were exhibited in attention and verbal function, scoring 7.5% (P = 0.013) and 6.2% (P = 0.05), respectively, below the parallel scores of the nonfallers. Attention was the only cognitive component significantly correlated with the MSWS-12 self-reported questionnaire. Fear of falling was significantly correlated with 6 (out of 7) definite cognitive variables. The present findings support the concept that when evaluating and attempting to reduce fall risk, emphasis should be placed not only on traditional fall risk factors like muscle strength and motor function, but also on cognitive function.

Cognitive fatigue in individuals with multiple sclerosis undergoing immunoablative therapy and hematopoietic stem cell transplantation

BACKGROUND

Fatigue presents as a significant problem in multiple sclerosis (MS). Cognitive fatigue (CF) can be defined as a decrease in, or inability to maintain task performance throughout the duration of a continuous cognitive task. CF was evaluated using the Paced Auditory Serial Addition Test (PASAT) both pre- and post-immunoablation and hematopoietic stem cell transplantation (IA-HSCT) over a 3-year follow-up period. The magnitude of CF was examined and the impact of scoring methodology was evaluated.

METHODS

Twenty-three individuals with rapidly progressive MS and poor prognosis underwent high dose immunosuppression and subsequent HSCT. Individuals completed the 3″ and 2″ PASAT at baseline and every 6 months thereafter over a period of 36 months. As scoring methodology can impact its sensitivity to CF, the PASAT was scored according to three scoring methods.

RESULTS

CF was noted across all three scoring methods at baseline and at the majority of time points post-IA-HSCT on both the 3″ and 2″ PASAT. The magnitude of CF remained consistent both pre-and post-IA-HSCT.

CONCLUSIONS

While results suggest that the procedure itself does not ameliorate an individual's susceptibility to CF; neither does it seem to negatively impact levels of CF. As such, results support the notion that the IA-HSCT procedure, despite its aggressive nature, does not exacerbate CF in this particular sample.