Cognitive dysfunction in patients with clinically isolated syndromes or newly diagnosed multiple sclerosis

Self-reported cognitive function mediates the relationship between employment status and cognitive functioning in persons with multiple sclerosis

BACKGROUND

Cognitive impairment (CI) is common in people with MS (PwMS). Evidence is lacking for the self-reported CI's mediation effect on employment status and objective cognitive performance. Self-reported CI was found to be unreliable and seemed to be more associated with depression rather than formal cognitive performance. We hypothesized that the link between subjective and objective assessments of cognitive functions, mood, and employment status may be more complex in PwMS than previously reported.

OBJECTIVE

The aims of this study are the following: (Romero-Pinel et al., 2022) to determine whether employment status could affect performance in cognitive function testing and (Rao et al., 1991) whether their relationship may be mediated by self-reported CI; and (Deluca et al., 2013) to determine whether self-reported depression interacts with self-reported CI in influencing performance in various cognitive domains in PwMS.

METHODOLOGY

A retrospective study was performed involving PwMS who completed the self-report Multiple Sclerosis Neuropsychological Questionnaire (MSNQ), Hospital Anxiety and Depression Scale-depression scale (HADS-D), Minimal Assessment of Cognitive Function in MS (MACFIMS) and had data regarding employment status. Included PwMS were classified as employed or unemployed. A structural equation modeling (SEM) approach was taken due to the advantage of examining multiple cognitive outcomes simultaneously while accounting for shared associations. First, a latent factor of memory and executive functioning modeled the error-free associations between both factors and a processing speed task (SDMT). Next, the model tested for the indirect effect of self-reported cognition (MSNQ) on employment status differences in each outcome (memory, speed, and executive functioning). Finally, we tested interactions between MSNQ and HADS-D on each of the outcomes.

RESULTS

We included 590 PwMS: 72.5% female, mean age 44.2 years (SD = 10.5), mean disease duration 8.6 years (SD 9.0). The majority (n = 455, 77.1%) had relapsing MS; 357 (60.5%) were employed. About half (n = 301, 51%) did not report CI on the MSNQ; of those, 213 (70.8%) were employed. The mean MSNQ for employed PwMS was 24.5 (SD = 10.7) and 29.8 (SD = 11.2) for unemployed PwMS. Employed PwMS had significantly better memory (β = .16, p < .05), executive functioning (β = .25, p < .05), and processing speed (β = .22, p < .05). MSNQ partially indirectly mediated the effect of employment status on memory (Δβ = .03, p < .05) and executive functioning (Δβ = .03, p < .05) and processing speed (Δβ = .04, p < .05), indicating that self-report CI partially explains the influence of employment status on these cognitive domains. The association between MSNQ with both memory and executive functioning was moderated by depression, meaning that in PwMS with high HADS-D scores, MSNQ was more strongly related to worse memory and executive functioning. The final model was an acceptable fit to the data (χ2(87) = 465.07, p < .05; CFI = .90, RMSEA = .08, 90% CI [.06, .09], SRMR = .05) explaining 41.20%, 38.50% and 33.40% of the variability in memory, executive functioning, and processing speed, respectively.

CONCLUSION

Self-reported CI partially explains the associations between employment status and objective cognitive assessment in PwMS. Depression may moderate the relationship between self-reported cognitive assessment and objective cognitive performance. Thus, employment status and mood may guide the interpretation of self-reported CI.

Association Between Disease-Modifying Therapy and Information Processing Speed in Multiple Sclerosis

BACKGROUND

Cognitive impairment (CI) is common in multiple sclerosis (MS). Processing speed (PS) is often affected, making it an ideal target for monitoring CI. This study aims to evaluate the association between disease-modifying therapy (DMT) use and intensity and longitudinal changes in Processing Speed Test (PST) scores for individuals with MS.

METHODS

A retrospective analysis of individual PST scores at a single MS center was conducted. Individuals with 2 or more PST assessments were included. Scores on the PST were compared longitudinally between those who had been on a DMT for 2 or more years and those who had been off a DMT for 2 or more years and between those on high-efficacy DMTs and those on low-/moderate-efficacy DMTs. A linear regression model was approximated to evaluate the rate of cognitive change over time. A propensity score adjustment was conducted using a multivariable logistic regression.

RESULTS

The cohort was 642 individuals, 539 on DMT and 103 off DMT. Median age and disease duration was 49.7 (IQR 42.4-57.9) and 16.6 years (IQR 9.3-23.0) in the DMT group, and 58.9 (IQR 52.2-65.3) and 20.0 years (IQR 14.1-31.4) in the non-DMT group. Both cohorts were predominantly female (75% DMT, 79.6% non-DMT), with a mean of 4 assessments (IQR 3-5), and an average monitoring duration of 1.9 years (1.2-2.4) in the DMT group, and 1.8 years (1.4-2.4) in the non-DMT group. After adjusting for multiple factors, DMT status and intensity were not found to be significant predictors of longitudinal PST change.

CONCLUSIONS

Neither DMT status nor intensity was a significant predictor of cognitive processing speed over a period of approximately 2 years. Future prospective studies are needed to further support these findings.

Associations Between Cognitive Impairment and Neuroimaging in Patients with Multiple Sclerosis

OBJECTIVE

Multiple sclerosis (MS) is a debilitating inflammatory and neurodegenerative disease which commonly involves cognitive dysfunction. Magnetic resonance imaging (MRI) studies have shown that patients with MS (pwMS) have diffuse patterns of brain atrophy, however, the relationship between the presentation of cognitive dysfunction and brain tissue loss remains understudied. Given the integral function of thalamus as a central nervous system relay center and its involvement in various brain circuits, thalamic atrophy may play a key role in the development and progression of cognitive dysfunction. The purpose of this study is to examine the relationship between cognitive impairment in pwMS and thalamic atrophy.

METHODS

A total of 121 pwMS who had neuropsychological testing and quantitative MRI within 1 year of each were retrospectively identified. Grouped LASSO linear regression with 10-fold cross validation was used to estimate each neuropsychological test score with thalamic volume as the focal predictor and all other demographic and MRI metrics as covariates.

RESULTS

Rates of impairment ranged from 19% to 44%. Results showed notable associations between thalamic volume and Symbol Digit Modalities Test (β = 0.11), Brief Visuospatial Memory Test, delayed (β = 0.12), California Verbal Learning Test, delayed and total (β = 0.24 and β = 0.15 respectively), and Trail Making Test Part A (β = -0.01), after adjusting for covariates.

CONCLUSIONS

These findings demonstrate an independent association between thalamic volumes and processing speed and memory performance, after accounting for demographic, clinical, and other MRI variables, among pwMS.

The 7-year follow-up of the Hungarian BICAMS validation cohort implies that cognitive performance may improve in multiple sclerosis patients

BACKGROUND

Cognitive impairment (CI) is a frequent symptom of multiple sclerosis (MS) and has a great impact on the patients' quality of life, so screening is essential. The brief international cognitive assessment for multiple sclerosis (BICAMS) was developed for this purpose. However, longitudinal data is lacking with the use of the battery.

OBJECTIVE

This study is to assess the performance of patients after 5 and 7 years of the original BICAMS validation study and to identify any influencing factors.

METHODS

BICAMS was used to measure cognitive function of 52 relapsing-remitting MS patients (RRMS) from the original validation study after 5 years (n = 43) and again, after 7 years (n = 42). Patients filled out the fatigue impact scale (FIS) and multiple sclerosis quality of life-54 (MSQoL-54) questionnaire, and we evaluated expanded disability status scale (EDSS).

RESULTS

There was an improvement in the BVMT-R and the CVLT-II assessments at both the 5-year (p<0.001 and p=0.025) and the 7-year retest (p<0.001 and p=0.002). The prevalence of CI significantly decreased at the 5-year mark (p=0.021) but remained stable after that. There was no deterioration in MSQoL scores during the study. The basic cognitive performance is the most important influencing factor, but the duration of the disease, the EDSS score, and the escalation of the therapy also affect the cognitive scores.

CONCLUSION

This is the longest longitudinal study utilizing the BICAMS battery, reinforcing its feasibility as a clinical screening tool. It seems that cognitive performance may improve in the long term and early initiation of effective therapy may influence this outcome.

Functional and structural brain MRI changes associated with cognitive worsening in multiple sclerosis: a 3-year longitudinal study

BACKGROUND

Heterogeneous processes may contribute to cognitive impairment in multiple sclerosis (MS).

OBJECTIVE

To apply a longitudinal multiparametric MRI approach to identify mechanisms associated with cognitive worsening in MS patients.

METHODS

3 T brain functional and structural MRI scans were acquired at baseline and after a median follow-up of 3.4 years in 35 MS patients and 22 healthy controls (HC). Associations between cognitive worsening (reliable change index score < - 1.25 at the Rao's battery) and longitudinal changes in regional T2-hyperintense white matter (WM) lesions, diffusion tensor microstructural WM damage, gray matter (GM) atrophy and resting state (RS) functional connectivity (FC) were explored.

RESULTS

At follow-up, HC showed no clusters of significant microstructural WM damage progression, GM atrophy or changes in RS FC. At follow-up, 10 MS patients (29%) showed cognitive worsening. Compared to cognitively stable, cognitively worsened MS patients showed more severe GM atrophy of the right anterior cingulate cortex and bilateral supplementary motor area (p < 0.001). Cognitively worsened vs cognitively stable MS patients showed also decreased RS FC in the right hippocampus of the right working memory network and in the right insula of the default mode network. Increased RS FC in the left insula of the executive control network was found in the opposite comparison (p < 0.001). No significant regional accumulation of focal WM lesions nor microstructural WM abnormalities occurred in both patients' groups.

CONCLUSIONS

GM atrophy progression in cognitively relevant brain regions combined with functional impoverishment in networks involved in cognitive functions may represent the substrates underlying cognitive worsening in MS.

Women in the field of multiple sclerosis: How they contributed to paradigm shifts

History is full of women who made enormous contributions to science. While there is little to no imbalance at the early career stage, a decreasing proportion of women is found as seniority increases. In the multiple sclerosis (MS) field, 44% of first authors and only 35% of senior authors were female. So, in this review, we highlight ground-breaking research done by women in the field of MS, focusing mostly on their work as principal investigators. MS is an autoimmune disorder of the central nervous system (CNS), with evident paradigm shifts in the understating of its pathophysiology. It is known that the immune system becomes overactivated and attacks myelin sheath surrounding axons. The resulting demyelination disrupts the communication signals to and from the CNS, which causes unpredictable symptoms, depending on the neurons that are affected. Classically, MS was reported to cause mostly physical and motor disabilities. However, it is now recognized that cognitive impairment affects more than 50% of the MS patients. Another shifting paradigm was the involvement of gray matter in MS pathology, formerly considered to be a white matter disease. Additionally, the identification of different T cell immune subsets and the mechanisms underlying the involvement of B cells and peripheral macrophages provided a better understanding of the immunopathophysiological processes present in MS. Relevantly, the gut-brain axis, recognized as a bi-directional communication system between the CNS and the gut, was found to be crucial in MS. Indeed, gut microbiota influences not only different susceptibilities to MS pathology, but it can also be modulated in order to positively act in MS course. Also, after the identification of the first microRNA in 1993, the role of microRNAs has been investigated in MS, either as potential biomarkers or therapeutic agents. Finally, concerning MS therapeutical approaches, remyelination-based studies have arisen on the spotlight aiming to repair myelin loss/neuronal connectivity. Altogether, here we emphasize the new insights of remarkable women that have voiced the impact of cognitive impairment, white and gray matter pathology, immune response, and that of the CNS-peripheral interplay on MS diagnosis, progression, and/or therapy efficacy, leading to huge breakthroughs in the MS field.

Trail Making Test Could Predict Impairment in Cognitive Domains in Patients with Multiple Sclerosis: A Study of Diagnostic Accuracy

OBJECTIVE

Cognitive impairment (CI) and executive dysfunction (ED) are prevalent in patients with multiple sclerosis (PwMS). The Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) is the gold standard neuropsychological battery (NPB) for detecting CI. Delis-Kaplan Executive Function System (DKEFS) NPB evaluates ED. We aimed to find practical test(s) from DKEFS with acceptable diagnostic utility for early detection of impairment in cognitive and executive domains.

METHODS

Cognitive and executive tasks, physical disability, and depression scores of 30 PwMS were assessed (17 women, age: 38.1). Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), and Controlled Oral Word Association Test (COWAT) from MACFIMS and Trail Making Test (TMT), Design Fluency Test (DFT), and Verbal Fluency Test (VFT) from DKEFS were selected. The association between patients' characteristics and performance in tests, and diagnostic accuracy of DKEFS tests in detecting impairment in cognitive tasks were evaluated, using Pearson correlation and receiver operator characteristic curve analyses, respectively.

RESULTS

A significant correlation was found between disease duration and SDMT and TMT subtests. Expanded Disability Status Scale was significantly related to SDMT, VFT-switching, and TMT subtests. Beck Depression Inventory was significantly related to DFT. TMT-switching detected abnormalities in SDMT and PASAT with 100% sensitivity, 93.3% (for SDMT), and 85.7% specificity (for PASAT). TMT-letter showed 100% sensitivity and 90% specificity in identifying abnormalities in COWAT.

CONCLUSIONS

TMT, particularly the switching condition, is a practical paper-based test that could predict impairment in cognitive tasks. Clinicians may use TMT as a screening tool among PwMS.

High levels of kappa free light chain synthesis predict cognitive decline in relapsing-remitting multiple sclerosis

Background

Evolving evidence suggests that measurement of cerebrospinal fluid (CSF) kappa free light chain (KFLC) synthesis has high diagnostic sensitivity and specificity for multiple sclerosis (MS), but its prognostic ability is less investigated. The usefulness of KFLC in predicting cognitive impairment (CI) is still unknown.

Methods

In a monocentric longitudinal retrospecitve cohort study, KFLC-index ([CSF KFLC/serum KFLC]/[CSF albumin/serum albumin]) measured by latex-enhanced immunonephelometry was prospectively determined as part of the diagnostic workup in patients with early relapsing-remitting MS (RRMS, n=77). The ability of KFLC-index to predict information processing speed (IPS) worsening as assessed with the symbol digit modalities test (SDMT) was investigated in univariable and multivariable models.

Results

In patients with KFLC-index>100 (n=31), 11 subjects (35.5%) showed reduced SDMT scores by ≥8 points at follow-up (mean follow-up time 7.3 ± 2.6 years), compared with their baseline scores (p=0.01). Baseline KFLC-index>100 was strongly associated with a higher hazard of SDMT score reduction at follow-up (adjusted hazard ratio 10.5, 95% confidence interval 2.2-50.8, p=0.003; median time to SDMT reduction 7 years).

Conclusion

Intrathecal KFLC synthesis has become an attractive diagnostic tool for MS. We show for the first time that in a real-world setting of early RRMS, KFLC-index predicted cognitive decline. Whether this predictive ability of KFLC-index also concerns other cognitive domains than IPS, warrants further investigations.

Factors associated with material deprivation in persons with multiple sclerosis in Switzerland: Cross-sectional data from the Swiss Multiple Sclerosis Registry

BACKGROUND

Multiple sclerosis (MS) impacts education, future career pathways and working capability and therefore may negatively impact the financial situation of persons with MS (pwMS) in Switzerland. We therefore investigated the financial situation and its influencing sociodemographic and disease-specific factors of pwMS compared to the general Swiss population with focus on material deprivation (MD).

METHODS

Data on the financial situation of pwMS were collected via a specific questionnaire added to the regular, semi-annual follow-up assessments of the Swiss Multiple Sclerosis Registry. Questions were taken in an unmodified format from the standardized "Statistics on Income and Living Conditions" (SILC) questionnaire 2019 of the Federal Statistical Office of Switzerland which evaluates the financial situation of the general Swiss population, enabling a direct comparison of pwMS with the general Swiss population.

RESULTS

PwMS were 1.5 times more frequently affected by MD than the general Swiss population (6.3% of pwMS versus 4.2% of the general Swiss population) which was confirmed in a multivariable logistic regression analysis of pooled SILC and Swiss Multiple Sclerosis Registry (SMSR) data. High symptom burden, having only mandatory schooling, well as having a pending disability insurance application (as opposed to no application or receiving benefits) were associated with a higher odds of MD whereas higher education, older age, having a Swiss citizenship, living with a spouse or a partner or being currently employed were independently associated with a lower odds of MD.

CONCLUSION

MS has a negative impact on the financial situation and is associated with MD. PwMS with a high symptom burden at the transition from work force to receiving disability benefits appeared to be vulnerable for MD. Higher education, older age, having a Swiss citizenship, living with a spouse or a partner or being currently employed were independently associated with a lower odds of MD.

The symbol digit modalities test and the paced auditory serial addition test involve more than processing speed

BACKGROUND

Slowed processing speed is the most frequently reported cognitive deficit for people with multiple sclerosis (MS). However, measures used to assess processing speed may also recruit other cognitive abilities. The present objective was to determine the contributions of different cognitive functions to performance on two commonly used processing speed measures: the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test (PASAT).

METHODS

Adults with relapsing-remitting MS (n = 70) and controls (n = 72) completed the SDMT, PASAT, and multiple measures assessing processing speed, working memory, and learning. Hierarchical regression analyses were used to examine the contributions of MS, processing speed, working memory, learning, and all possible interactions among factors to SDMT and PASAT scores.

RESULTS

Processing speed and working memory generally contributed to performance on the SDMT and PASAT, with learning additionally contributing to SDMT performance. However, significant interactions revealed processing speed did not influence PASAT performance for individuals with high working memory ability whereas processing speed became increasingly more important as working memory declined to average and low levels. Further, processing speed was associated with SDMT performance for patients with MS but not controls.

CONCLUSIONS

These findings support a multifactorial interpretation of the SDMT and PASAT, which facilitates their usefulness as screening measures for cognitive decline but prevents them from identifying which specific cognitive functions are affected.

The longitudinal relationship between fatigue, depression, anxiety, disability, and adherence with cognitive status in patients with early multiple sclerosis treated with interferon beta-1a

Background

Cognitive dysfunction is common in multiple sclerosis and may worsen with reduced treatment adherence. We examined longitudinal relationships between anxiety, depression, fatigue, disability and adherence with cognitive status in patients with relapsing-remitting multiple sclerosis (MS) treated with interferon beta-1a in four countries.

Methods

The Confidence study is a prospective study in 165 people with MS with four visits (baseline/12/24/36 months). Physical and psychological symptoms were assessed using standardized questionnaires. Adherence was calculated as the number of injections divided by number of expected injections. Cognitive status was assessed by the Brief Repeatable Battery of Neuropsychological Tests and converted to a global Z-score.

Results

At baseline, mean age was 35.7 ± 11 years and 66% were female (n = 109). Adherence to treatment was very high throughout the study (>99%). A depression score ≥ 8 was significantly associated with a higher risk of low cognitive status compared with a lower score (0–7): relative risk 1.79 (1.14–2.83) adjusted for education and time since diagnosis. The P-value-for-time was not significant (P = 0.304) meaning that associations existed since baseline and remained stable during follow-up.

Conclusion

Our findings provide evidence for a longitudinal association between depression and low cognitive status in patients treated with interferon beta-1a in routine medical practice.

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Long-term effects of adherence to treatment and MS symptoms with cognition are largely unknown.

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Depression was longitudinally associated with a higher risk of low cognitive status in a real-world population.

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Clinical consideration and additional investigation in the treatment of depression for cognitive benefits should be considered.

Validation of cognitive screening questionnaire for neurological disorders (CSQND) for screening of cognitive complaints among patients with multiple sclerosis

Background

The prevalence of cognitive impairment (CI) can reach up to 65% among multiple sclerosis (MS) patients. Self-administered screening questionnaires can offer a valuable solution for screening MS patients for cognitive complaints. The cognitive screening questionnaire for neurological disorders (CSQND) is an Arabic self-administered questionnaire that has been developed to screen patients with various neurological disorders attending neurology clinics. The aim of this study was to assess cognitive complaints and to validate the CSQND as a screening tool among Egyptian MS patients.

Results

Four-hundred MS patients and 400 controls were included in this study. All 400 patients and 400 controls were subjected to the CSQND, only 50 out of the 400 patients and 50 out of the 400 controls retook the CSQND 1 week later to establish test–retest reliability. Fifty patients and 50 controls were assessed by the symbol digit modalities test (SDMT) to establish concurrent validity. Thirty-four percent of patients complained of memory problems, 51% complained of concentration difficulties, 34% complained of language difficulties and 22.5% complained of space and time disorientation. Multiple sclerosis patients had significantly more cognitive complaints (12.4 ± 12.6) compared to controls (6.2 ± 6.8) when screened using the CSQND (P < 0.000001). Total scores of CSQND were positively significantly correlated to age at onset, total disease duration, EDSS scores and total number of relapses, (r = 0.14; 0.275; 0.3; 0.167, respectively), P < 0.05 for all. Agreement was found between CSQND results and the SDMT results, where the line of equality lied within the 95% confidence interval of the mean. A significant positive correlation was found between the CSQND results at the first application and upon retesting both in patients (R = 0.9, P = 0.0001) and controls (R = 0.85, P = 0.0001).

Conclusions

The CSQND was found to be a simple, valid, and reliable self-administered questionnaire to screen for cognitive complaints in MS patients.

Health-related quality of life of patients with multiple sclerosis: Analysis of ten years of national data

BACKGROUND

Multiple sclerosis (MS) is a progressive autoimmune disease of the central nervous system. Both the physical and mental burden of MS affect patients' health-related quality of life (HRQoL). However, there is limited research at the national level evaluating the humanistic burden among MS patients.

OBJECTIVES

This study evaluated the HRQoL and functional limitations among MS patients using ten years of national survey data.

METHODS

Guided by the conceptual framework of the Wilson and Cleary model, this study compared HRQoL between adults diagnosed with MS (Clinical Classification Code= "080″) and non-MS adults using the 2006-2015 Medical Expenditure Panel Survey (MEPS) data. The humanistic burden included HRQoL and functional limitations. The HRQoL was evaluated using physical component summary (PCS) and mental component summary (MCS) based on the Short Form Health Survey (SF-12). The study applied the multivariable Generalized Linear Models (GLM) to estimate the marginal differences in PCS and MCS based on the SF-12. In addition, seeking help for activities of daily living (ADL) and instrumental activities of daily living (IADL) were modeled with multivariable logistic regression.

RESULTS

According to the MEPS, the estimated annual prevalence of MS was 0.52 million (95% Confidence Interval [CI]: 0.42-0.60). MS patients were mainly female (71.90%), middle aged (50-64 years, 40.21%), non-Hispanic whites (78.29%), and enrolled in private insurance plans (68.93%). The average PCS scores in MS and non-MS groups were 35.70 and 49.48, respectively. The average MCS scores were 45.58 and 51.25 for MS and non-MS groups, respectively. In addition, 18.26% of MS patients sought help for ADL, and 27.08% sought help for IADL. After adjusting for individual, biological, and environmental characteristics, the multivariable GLM with Poisson distribution indicated that the marginal difference of PCS score was 11.10 (95% CI: 9.50-12.61) units lower, and the MCS score was 4.89 (95% CI: 3.44-6.30) units lower among MS patients. In addition, MS patients were 17.32 (95% CI: 11.61-25.84) and 14.43 (95% CI: 10.09-20.65) times more likely to request assistance for ADL and IADL, respectively.

CONCLUSIONS

MS was associated with lower physical and mental HRQoL than their non-MS counterparts and MS patients were more likely to request help for ADL and IADL. More work is needed to evaluate the effect of treatment strategies on improving the HRQoL and functional limitations in MS.

Improved prediction of early cognitive impairment in multiple sclerosis combining blood and imaging biomarkers

Disability in multiple sclerosis is generally classified by sensory and motor symptoms, yet cognitive impairment has been identified as a frequent manifestation already in the early disease stages. Imaging- and more recently blood-based biomarkers have become increasingly important for understanding cognitive decline associated with multiple sclerosis. Thus, we sought to determine the prognostic utility of serum neurofilament light chain levels alone and in combination with MRI markers by examining their ability to predict cognitive impairment in early multiple sclerosis. A comprehensive and detailed assessment of 152 early multiple sclerosis patients (Expanded Disability Status Scale: 1.3 ± 1.2, mean age: 33.0 ± 10.0 years) was performed, which included serum neurofilament light chain measurement, MRI markers (i.e. T₂-hyperintense lesion volume and grey matter volume) acquisition and completion of a set of cognitive tests (Symbol Digits Modalities Test, Paced Auditory Serial Addition Test, Verbal Learning and Memory Test) and mood questionnaires (Hospital Anxiety and Depression scale, Fatigue Scale for Motor and Cognitive Functions). Support vector regression, a branch of unsupervised machine learning, was applied to test serum neurofilament light chain and combination models of biomarkers for the prediction of neuropsychological test performance. The support vector regression results were validated in a replication cohort of 101 early multiple sclerosis patients (Expanded Disability Status Scale: 1.1 ± 1.2, mean age: 34.4 ± 10.6 years). Higher serum neurofilament light chain levels were associated with worse Symbol Digits Modalities Test scores after adjusting for age, sex Expanded Disability Status Scale, disease duration and disease-modifying therapy (B = −0.561; SE = 0.192; P = 0.004; 95% CI = −0.940 to −0.182). Besides this association, serum neurofilament light chain levels were not linked to any other cognitive or mood measures (all P-values > 0.05). The tripartite combination of serum neurofilament light chain levels, lesion volume and grey matter volume showed a cross-validated accuracy of 88.7% (90.8% in the replication cohort) in predicting Symbol Digits Modalities Test performance in the support vector regression approach, and outperformed each single biomarker (accuracy range: 68.6–75.6% and 68.9–77.8% in the replication cohort), as well as the dual biomarker combinations (accuracy range: 71.8–82.3% and 72.6–85.6% in the replication cohort). Taken together, early neuro-axonal loss reflects worse information processing speed, the key deficit underlying cognitive dysfunction in multiple sclerosis. Our findings demonstrate that combining blood and imaging measures improves the accuracy of predicting cognitive impairment, highlighting the clinical utility of cross-modal biomarkers in multiple sclerosis.

Predominant domains and associated demographic and clinical characteristics in multiple sclerosis-related cognitive impairment in mildly disabled patients

Background

Cognitive impairment (CI) is a common finding in multiple sclerosis (MS); however, there is a limited information about its prevalence in mildly disabled cases. We aimed to determine the most affected domains, and also the relation between the demographic factors and cognitive outcomes in mildly disabled relapsing–remitting MS (RRMS).

Results

Ninety-one mildly disabled RRMS patients with expanded disability status scale (EDSS) < 4 and literacy level above 9 years, were recruited. Based on Minimal Assessment of Cognitive Function in MS (MACFIMS) battery, CI was observed in 19.8% of the patients while 40.60% of the patients had at least one failure in cognitive tests. The most common impaired cognitive domain was information processing speed and working memory (27.5%). There was no significant difference between men and women in terms of CI in our sample (p-values > 0.05). Disease duration (p = 0.01), EDSS (p = 0.01), and education (p < 0.01) were significantly different between CI and non-CI patients, while age (p = 0.72), sex (p = 0.50), diagnostic gap (p = 0.89), and frequency of relapses (p = 0.22), did not differ considerably.

Conclusions

RRMS patients experience some degrees of CI that may present even before the onset of remarkable physical disability; nevertheless, a higher EDSS score and longer disease duration increases the risk of CI. These findings suggest routine cognitive assessment of MS patients.

miR-150-5p and let-7b-5p in Blood Myeloid Extracellular Vesicles Track Cognitive Symptoms in Patients with Multiple Sclerosis

Cognitive deficits strongly affect the quality of life of patients with multiple sclerosis (MS). However, no cognitive MS biomarkers are currently available. Extracellular vesicles (EVs) contain markers of parental cells and are able to pass from the brain into blood, representing a source of disease biomarkers. The aim of this study was to investigate whether small non-coding microRNAs (miRNAs) targeting synaptic genes and packaged in plasma EVs may reflect cognitive deficits in MS patients. Total EVs were precipitated by Exoquick from the plasma of twenty-six cognitively preserved (CP) and twenty-three cognitively impaired (CI) MS patients belonging to two independent cohorts. Myeloid EVs were extracted by affinity capture from total EVs using Isolectin B4 (IB4). Fourteen miRNAs targeting synaptic genes were selected and measured by RT-PCR in both total and myeloid EVs. Myeloid EVs from CI patients expressed higher levels of miR-150-5p and lower levels of let-7b-5p compared to CP patients. Stratification for progressive MS (PMS) and relapsing-remitting MS (RRMS) and correlation with clinical parameters suggested that these alterations might be attributable to cognitive deficits rather than disease progression. This study identifies miR-150-5p and let-7b-5p packaged in blood myeloid EVs as possible biomarkers for cognitive deficits in MS.

Multimodal Evoked Potentials as Potential Biomarkers of Disease Activity in Patients With Clinically Isolated Syndrome

Objective

There is an ongoing search for markers useful in monitoring and predicting disease activity at the early stage of multiple sclerosis (MS). The goals of this study were to prospectively evaluate the changes in parameters of multimodal evoked potentials (EP) and cognition within a 3-year follow-up period in patients with clinically isolated syndrome (CIS), and to assess the prognostic value of baseline findings with regard to the disease outcomes.

Methods

In 29 patients (20 women, nine men, mean age 31.1) multimodal (visual, brainstem auditory, somatosensory, event-related) EP and neuropsychological tests (NT) were performed at baseline (T0) and after 1 (T1) and 3 (T3) years. Their results were compared longitudinally between baseline, T1, and T3. Baseline results confirmed conversion of CIS into multiple sclerosis (MS) and disability level at T1 and T3 using multiple comparisons and a logistic regression model.

Results

Apart from mean N13/P16 SEP (somatosensory evoked potentials) amplitude (lower at T1 and T3 than at baseline (T0 1.02 ± 0.37 μV, T1 0.90 ± 0.26 μV, T3 0.74 ± 0.32 μV, p < 0.05 for both comparisons), no significant changes of EP or NT parameters were found in longitudinal assessment. Baseline P300 Pz latency was longer for the patients with MS than for those with CIS at T1 (352.69 vs. 325.56 ms). No predictive value was shown for any of the analyzed baseline variables with regard to conversion from CIS into MS.

Significance

Baseline ERP abnormalities were associated with their short-term conversion into MS. ERP are worth considering in multimodal EP evaluation at the early stage of MS.

Multiple sclerosis care units in Latin America: Consensus recommendations about its objectives and functioning implementation

OBJECTIVE

Currently, there are several reasons to promote worldwide the concept of multiple sclerosis care units (MSCU) for a better management of affected patients. Ideally, the MSCU should have some human and technical resources that distinguish and improve the care of affected patients; however, local, and regional aspects should be considered when recommending how these units should operate. The objective of these consensus recommendations was to review how MSCU should work in Latin America to improve long-term outcomes in MS patients.

METHODS

A panel of neurology experts from Latin America dedicated to the diagnosis and care of MS patients gathered virtually during 2019 and 2020 to carry out a consensus recommendation about objectives and functioning implementation of MSCU in Latin America. To achieve consensus, the methodology of "formal consensus-RAND/UCLA method" was used.

RESULTS

Recommendations focused on the objectives, human and technical resources, and the general functioning that MSCU should have in Latin America.

CONCLUSIONS

The recommendations of these consensus guidelines attempt to optimize the health care and management of MS patients by setting how MSCU should work in our region.

Factors determining the treatment ineffectiveness in multiple sclerosis

BACKGROUND

In patients with multiple sclerosis (MS), the suboptimal response should be well evaluated at every step of treatment.

REVIEW SUMMARY

Determining patients with moderate or high activity and suboptimal response to treatment (clinical variables, MRI activity, perception of the patient and physician, side effects, serious risks, etc.) and timely intervention in the treatment are very important in achieving the desired effectiveness in the long term. Within the early stages, there is a limited time interval for effective treatment of MS patients. During this time, intervention is critical to achieve long-term positive results. After diagnosis, an early and individualized specific treatment for MS, depending on the severity of the disease, can prevent radiological and physical disability in the medium/long term.

CONCLUSIONS

With the emergence of a number of new treatments each with their own benefits and risks, a change in the nature of interactions between patients and MS physicians has been anticipated and will be required in the patient-related clinical decision-making process in the developing MS landscape.

Beneficial effects of a nano formulation of pomegranate seed oil, GranaGard, on the cognitive function of multiple sclerosis patients

BACKGROUND

Though often neglected, cognitive impairment is a common feature of multiple sclerosis in 43-70% of patients. None of the novel MS treatment seems to substantially affect or restore cognitive disability in MS. GranaGard (Granalix Bio Technologies LTD) is a food supplement shown to prevent neuronal death in several animal models of neurological diseases. Capsules of GranaGard comprise a self-emulsion nano formulation of pomegranate seed oil (PSO). This oil contains 80-90% of Punicic Acid (PA), one of the strongest natural antioxidants. In animal experiments, administration of GranaGard results in conjugation with linoleic acid (CLA), the main metabolite of PA, which is a well-known neuroprotective agent.

AIMS

To investigate whether GranaGard administration has an effect on the cognitive state of MS patients.

METHODS

This is a single center, randomized double blind clinical trial that started in May 2018. The study included 30 MS patients; half of them (Group-A) were given GranaGard for the first three months and then placebo pills containing soybean oil for additional three months. Patients in Group-B received placebo for the first three months, and GranaGard for the following three months. GranaGard was administrated in addition to their immunomodulatory MS-treatments. Subsequently, all patients received GranaGard for additional six months. Patients were required to visit the neurologist at baseline (inclusion, visit 1) and at 3 months after treatment-initiation at each cycle of the trial (visits 2 and 3). During the follow up visits, clinical and cognitive examinations were performed, including Expanded Disability Status Scale (EDSS), Multiple Sclerosis Functional Composite (MSFC: 25 ft walking test, 9 PEG hole test & PASAT). Cognitive tests included The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) battery: 1) Symbol Digit Modalities Test (SDMT); 2) California Verbal Learning Test - Second Edition (CVLT-II); 3) and Brief Visuospatial Memory Test - Revised (BVMT-R). Cognitive outcomes were normalized to the healthy population and expressed as z-scores, depended on age, gender and education. Short quality of life and fatigue questionnaires (SF-12, MFIS-5) were also provided by the participants.

RESULTS

No serious adverse effects, related to the product, were observed during the study period. All patients receiving GranaGard reported a ''positive'' effect in their ADL while using the product. While there were no significant differences in the clinical parameters of disability (EDSS scores) between the treatment groups, there was a trend of beneficial effect of GranaGard, on the verbal testing during the first 3-month period of treatment. The z score for CVLT-II, significantly increased (from 0.891 to 1.415, p = 0.012, Wilcoxon rank test) at 3-months in the group of patients who were treated with GranaGard, as compared to baseline. A similar (but not statistically significant) trend was seen also in the BVMTr testing during the same 3 months-period, whereas there was no change in the SDMT. The overall average z-score of all three cognitive functions was significantly improved in the three months of Granagard treatment (-0.0077 at 3 months vs 0.462 at baseline, p = 0.034, Wilcoxon rank test). During the same 3-months period there were no significant changes in the placebo-treated group. For the patients receiving GranaGard in the initial 3 months, the value of z score of CVLT-II remained high (z = 1.415) also at the following three months (while they received placebo), suggesting a longer lasting effect for at least 3 months after discontinuation of the drug.

CONCLUSION

This is the first study in which GranaGard, a brain targeted nano-formulation of PSO, was tested in humans. Our results in this small pilot, controlled trial provide indications that GranaGard administration to MS patients might improve/stabilize cognitive disability. Larger studies with longer duration, are needed to confirm these initial observations.

Neurodegeneration in Multiple Sclerosis: Symptoms of Silent Progression, Biomarkers and Neuroprotective Therapy-Kynurenines Are Important Players

Neurodegeneration is one of the driving forces behind the pathogenesis of multiple sclerosis (MS). Progression without activity, pathopsychological disturbances (cognitive impairment, depression, fatigue) and even optic neuropathy seems to be mainly routed in this mechanism. In this article, we aim to give a comprehensive review of the clinical aspects and symptomology, radiological and molecular markers and potential therapeutic targets of neurodegeneration in connection with MS. As the kynurenine pathway (KP) was evidenced to play an important role in the pathogenesis of other neurodegenerative conditions (even implied to have a causative role in some of these diseases) and more and more recent evidence suggest the same central role in the neurodegenerative processes of MS as well, we pay special attention to the KP. Metabolites of the pathway are researched as biomarkers of the disease and new, promising data arising from clinical evaluations show the possible therapeutic capability of KP metabolites as neuroprotective drugs in MS. Our conclusion is that the kynurenine pathway is a highly important route of research both for diagnostic and for therapeutic values and is expected to yield concrete results for everyday medicine in the future.

Assessment of cognitive functions in patients with multiple sclerosis applying the normative values of the Rao's brief repeatable battery in the Portuguese population

Background

The Brief Repeatable Battery of Neuropsychological Tests (BRBN-T) is one of the most sensitive and used measures for detecting cognitive impairment in Multiple Sclerosis (MS).

Objective

The aim of this study was to adapt and validate this battery to the Portuguese population of MS patients.

Methods

The Portuguese version of the BRBN-T was applied to a stratified control national sample of 326 individuals considering sex, age, educational level and geographic location and also a clinical sample of 115 MS patients from several national hospitals. Through the exploration of its psychometrics properties, the Portuguese BRBN-T norms were produced.

Results

The normative data is presented as a regression-based formula to adjust test scores for gender, education and age, and the results reveal the BRBN-T has the ability to differentiate between MS patients and healthy participant’s cognitive performance.

Conclusion

This study demonstrated in our clinical population a good ability to detect cognitive impairment. Its clearly contributed to reinforcing the neuropsychological assessment in Portugal in patients with MS, by providing a new set of instruments, which can be used in the clinical practice, and in future studies. Moreover, it will allow a rigorous and precise support in relation to neuropsychological assessment for future longitudinal studies and clinical trials.

Cognitive impairment in multiple sclerosis: diagnosis and monitoring

INTRODUCTION

Cognitive impairment (CI) has a prevalence of 45-70% in people with multiple sclerosis (MS), producing a negative impact on their quality of life, personal life, and work. Early detection of CI has become an important aspect to be considered for an adequate follow-up, to optimize social adaptation and to implement specific cognitive rehabilitation strategies. The aim of this work is to propose a suitable cognitive evaluation of patients with MS based on available and efficient tools for diagnosis and monitoring purposes well supported by literature review and clinical experience.

METHODS

A multidisciplinary panel of professionals from the field of neurology, neuropsychology, and neuroimaging performed a literature review of the topic of cognitive impairment assessment. This was combined and completed with their clinical experience to produce a set of recommendations.

RESULTS

Some limitations to cognitive evaluation are described: shortage of time and resources during the neurology consultation, scarceness or absence of specialized professionals' availability, importance of tests adaptation, and doubts about its use to define therapeutic efficiency. We recommend a baseline and annual screening evaluation, and we suggest a baseline and periodic neuropsychological assessment. The latter ought to change to a recommendation with the presence of either positive screening test, or subjective to cognitive complaints, screening-test results and patient or family report mismatch, or in specific social/work situations.

CONCLUSIONS

Cognitive evaluation should be performed on all patients diagnosed with MS and throughout follow-up. It is necessary to support the creation of multidisciplinary MS teams to optimize the evaluation and follow-up of MS patients.

Neurocognitive impairment and social cognition in multiple sclerosis

PURPOSE/AIM OF THE STUDY

The impairment of neurocognitive functions occurs in all subtypes of multiple sclerosis, even from the earliest stages of the disease. Commonly reported manifestations of cognitive impairment include deficits in attention, conceptual reasoning, processing efficiency, information processing speed, memory (episodic and working), verbal fluency (language), and executive functions. Multiple sclerosis patients also suffer from social cognition impairment, which affects their social functioning. The objective of the current paper is to assess the effect of neurocognitive impairment and its potential correlation with social cognition performance and impairment in multiple sclerosis patients.

MATERIALS AND METHODS

An overview of the available-to-date literature on neurocognitive impairment and social cognition performance in multiple sclerosis patients by disease subtype was performed.

RESULTS

It is not clear if social cognition impairment occurs independently or secondarily to neurocognitive impairment. There are associations of variable strengths between neurocognitive and social cognition deficits and their neural basis is increasingly investigated.

CONCLUSIONS

The prompt detection of neurocognitive predictors of social cognition impairment that may be applicable to all multiple sclerosis subtypes and intervention are crucial to prevent further neural and social cognition decline in multiple sclerosis patients.

Identifying Early Neuropsychological Indicators of Cognitive Involvement in Multiple Sclerosis

Multiple sclerosis (MS) is a debilitating disease of the central nervous system that is most commonly seen in early to middle adulthood, although it can be diagnosed during childhood or later in life. While cognitive impairment can become more prevalent and severe as the disease progresses, signs of cognitive involvement can be apparent in the early stages of the disease. In this review, we discuss the prevalence and types of cognitive impairment seen in early MS, including the specific measures used to identify them, as well as the challenges in characterizing their frequency and progression. In addition to examining the progression of early cognitive involvement over time, we explore the clinical factors associated with early cognitive involvement, including demographics, level of physical disability, disease modifying therapy use, vocational status, and psychological and physical symptoms. Given the prevalence and functional impact these impairments can have for persons with MS, considerations for clinicians are provided, such as the role of early cognitive screenings and the importance of comprehensive neuropsychological assessments.

Does cognitive training improve attention/working memory in persons with MS? A pilot study using the Cogmed Working Memory Training program

BACKGROUND

Cognitive deficits, especially in attention, are common in persons with MS (PwMS) and are associated with clinically meaningful outcomes, such as work disability and lower quality of life (QOL). In this study, we aimed to determine whether Cogmed Working Memory Training (CWMT) improves attention/working memory in PwMS displaying impairment in these domains.

METHODS

This single blind, randomized controlled, pilot study compared the effects of CWMT, a five-week evidenced-based computer-assisted training program that is supported by weekly meetings with a coach, to standard medical care (treatment as usual). We recruited PwMS from one MS center (London (ON) Canada), aged 18-64, with an Expanded Disability Status Scale (EDSS) score of ≤ 7.0, and a visual acuity (corrected) of at least 20/70. Potential subjects had to demonstrate impaired attention on at least two of three measures (Paced Auditory Serial Addition Test [PASAT], Symbol Digit Modalities Test [SDMT], and/or DKEFS Color-Word Interference Test); these measures also served as the primary study outcomes. Subjects were randomized to either the CWMT or treatment as usual. Secondary cognitive outcomes included other measures of attention, memory, as well as a self-reported cognitive function measure. Self-reported measures of mood (depression and anxiety), pain, and QOL were also included as other secondary outcomes. Subjects received assessments at baseline, post-treatment, and 6-month follow-up, or an equivalent time period for the treatment as usual group. The two groups were compared at baseline on background measures using independent samples t-tests, Chi-Square tests, and Mann-Whitney U tests. To analyze primary and secondary outcomes, a non-parametric approach was used due the small sample size and that many of our outcomes did not meet assumptions for parametric analyses. Friedman's test was conducted followed by post hoc pairwise comparisons within each group using Wilcoxon Signed-Rank tests with Bonferroni corrected post hoc contrasts, which allowed us to examine for differences between time points.

RESULTS

Of 30 subjects, 15 were assigned to CWMT. Significant training effects were noted in 1 of 3 primary attentional outcomes (DKEFS Color-Word Interference Test), 2 of 3 secondary attentional outcomes (Letter-Number Sequencing, Digit Span), and 1 mood scale (Hospital Anxiety and Depression scale (HADS) - Depression Subscale), ps < .025. No significant changes were observed in the treatment as usual group.

CONCLUSION

This pilot study demonstrates that cognitive training with CWMT has the potential to improve attention/working memory in PwMS, as well as a potential positive effect on mood, in PwMS. Further exploration of this intervention in PwMS with attention/working memory impairment is warranted.

The Expanded Disability Status Scale Score and Demographic Indexes Are Correlated with the Severity of Cognitive Impairment in Multiple Sclerosis Patients

Background and Purpose

Cognitive impairment (CI) is a common symptom of multiple sclerosis (MS). Although demographic and clinical factors contribute to MS-dependent CI, previous findings have been inconsistent. This study aimed to identify the cognitive domains that are impaired in MS patients, and to determine the impacts of the Expanded Disability Status Scale (EDSS) score and other clinical and demographic factors on them domains.

Methods

This study enrolled 115 MS patients. Cognitive performance was assessed using the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) battery. CI severity was assessed based on the number of impaired tasks in the MACFIMS battery, with impairment in two or more tasks defined as CI cases. Correlation analysis was used to determine whether factors including current age, age at disease onset, EDSS score, disease duration, relapse rate, and education level affect the severity of CI.

Results

The scores on the Paced Auditory Serial Addition Test and Delis-Kaplan Executive Function System were the most and least affected, respectively. EDSS score (r=0.438, p<0.001), current age (r=0.393, p<0.001), and disease duration (r=0.486, p<0.001) were positively correlated with CI severity, whereas education level (r=−0.527, p<0.001) had a negative correlation with CI severity, and age at disease onset and relapse rate were not correlated with CI severity (r=0.150 and p=0.107, and r=0.052 and p=0.530, respectively). However, all variables (except EDSS score) significantly predicted CI severity in a multiple regression model (p<0.001, r=0.668).

Conclusions

Information processing speed and working memory were the most commonly affected cognitive domains in the present MS patients. CI severity had strong positive correlations with current age, EDSS score, and disease duration, and a negative correlation with education level. The relapse rate and age at disease onset were not correlated with CI severity.

Neurochemical Changes in the Brain and Neuropsychiatric Symptoms in Clinically Isolated Syndrome

To assess cognitive impairment and affective symptoms and their association with damage to normal-appearing white matter (NAWM) in patients with clinically isolated syndrome (CIS), we compared neuropsychological test scores between patients with CIS and healthy controls and examined correlations between these and proton magnetic resonance spectroscopy (¹H-MRS) outcomes in patients with CIS. Forty patients with CIS and 40 healthy participants were tested with a set of neuropsychological tests, which included the Beck Depression Inventory (BDI) and the Hospital Anxiety and Depression Scale (HADS). Single-voxel ¹H-MRS was performed on frontal and parietal NAWM of patients with CIS to assess ratios of N-acetyl-aspartate (NAA) to creatine (Cr), myo-inositol (mI), and choline (Cho), as well as mI/Cr and Cho/Cr ratios. Patients with CIS had lower cognitive performance and higher scores for the BDI and anxiety subscale of HADS than healthy controls. There were significant correlations between the following neuropsychological tests and metabolic ratios in the frontal NAWM: Stroop Color-Word Test and Cho/Cr, Symbol Digit Modalities Test and mI/Cr, as well as NAA/mI, Go/no-go reaction time, and NAA/Cho, as well as NAA/mI, Californian Verbal Learning Test, and NAA/Cr. BDI scores were related to frontal NAA/mI and parietal NAA/Cr and Cho/Cr ratios, whereas HADS-depression scores were associated with frontal NAA/Cr and NAA/mI and parietal NAA/Cr and Cho/Cr ratios. HADS-anxiety correlated with parietal NAA/Cr ratio. This study suggests that neurochemical changes in the NAWM assessed with single-voxel ¹H-MRS are associated with cognitive performance and affective symptoms in patients with CIS.

Focus on neglected features of cognitive rehabilitation in MS: Setting and mode of the treatment

Cognitive rehabilitation in multiple sclerosis (MS) aims at reducing patients’ cognitive impairments, improving their awareness and ability to take cognitive difficulties into account in their daily living. However, at this moment, more high-quality randomized trials are needed to draw conclusion about the effectiveness of cognitive interventions in MS. Although existing studies provide clear descriptions of intervention key ingredients (e.g. targeted cognitive domain as well as treatment frequency and duration) and the practical details needed to manage these key elements (e.g. restorative approaches, compensatory strategies, or environmental modifications), other crucial aspects received less attention in rehabilitation research. The aim of this topical review is to try to elucidate some critical issues that were only partly addressed and analyzed by the scientific literature: setting (center-based vs home-based) and mode (individual vs group) of the cognitive rehabilitation treatment.

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.

Anterior Insular Resting-State Functional Connectivity is Related to Cognitive Reserve in Multiple Sclerosis

BACKGROUND AND PURPOSE

Cognitive dysfunction is common in multiple sclerosis (MS). The dorsal anterior insula (dAI) is a key hub of the salience network (SN) orchestrating access to critical cognitive brain regions. The aim of this study was to assess whole-brain dAI intrinsic functional connectivity (iFC) using resting-state functional MRI (rs-fMRI) in people with MS and healthy controls (HC) and test the relationship between cognitive reserve (CR) and dAI iFC in people with MS.

METHODS

We studied 28 people with relapsing-remitting MS and 28 HC. CR index was quantified by combining premorbid IQ, leisure activities, and education level. For whole-brain iFC analyses, the bilateral dAI were used as seeds. Individual subject correlation maps were entered into general linear models for group comparison and to analyze the effect of CR index on dAI iFC, controlling for multiple comparisons. The correlation between CR index and iFC was assessed using a linear regression model.

RESULTS

rs-fMRI analyses revealed a negative relationship between CR index and iFC within the left dAI and a left occipital cluster in people with MS including regions of the cuneus, superior occipital gyrus, and parieto-occipital sulcus. The regression analysis showed that people with MS and a higher CR index had a statistically significantly reduced iFC within the left dAI and the cluster.

CONCLUSIONS

CR is relevant to functional connectivity within one of the main nodes of the SN, the dAI, and occipital regions in MS. These results have implications for how CR may modulate the susceptibility to cognitive dysfunction in MS.

Spatial navigation in early multiple sclerosis: a neglected cognitive marker of the disease?

BACKGROUND

Cognitive deficits are common in early multiple sclerosis (MS), however, spatial navigation changes and their associations with brain pathology remain poorly understood.

OBJECTIVE

To characterize the profile of spatial navigation changes in two main navigational strategies, egocentric (self-centred) and allocentric (world-centred), and their associations with demyelinating and neurodegenerative changes in early MS.

METHODS

Participants with early MS after the first clinical event (n = 51) and age-, gender- and education-matched controls (n = 42) underwent spatial navigation testing in a real-space human analogue of the Morris water maze task, comprehensive neuropsychological assessment, and MRI brain scan with voxel-based morphometry and volumetric analyses.

RESULTS

The early MS group had lower performance in the egocentric (p = 0.010), allocentric (p = 0.004) and allocentric-delayed (p = 0.038) navigation tasks controlling for age, gender and education. Based on the applied criteria, lower spatial navigation performance was present in 26-29 and 33-41% of the participants with early MS in the egocentric and the allocentric task, respectively. Larger lesion load volume in cortical, subcortical and cerebellar regions (ß ≥ 0.29; p ≤ 0.032) unlike brain atrophy was associated with less accurate allocentric navigation performance.

CONCLUSION

Lower spatial navigation performance is present in up to 41% of the participants with early MS. Demyelinating lesions in early MS may disrupt neural network forming the basis of allocentric navigation.

Impaired cognition is related to microstructural integrity in relapsing remitting multiple sclerosis

Background

Cognitive impairment is common in multiple sclerosis (MS). However, the relationship between cognitive deficits and microstructural abnormalities in Chinese MS patients remains unclear. We aimed to investigate the importance of microstructural abnormalities and the associations with cognitive impairment in Chinese MS patients.

Methods

Three‐dimensional T1‐weighted magnetic resonance imaging (MRI) scans were obtained from 36 relapsing remitting MS patients. Diffusion tensor imaging (DTI) scans were acquired for 29 (81%) patients. Cognitive impairment was assessed using a comprehensive neuropsychological battery. Patients were classified into cognitively impaired (CI) group and cognitively preserved (CP) group. Using volBrain and FSL software, we assessed white matter lesion burden, white matter (WM) and gray matter (GM) volumetric as well as microstructural diffusivity. MRI variables explaining cognitive impairment were analyzed.

Results

Fifteen (42%) patients were classified as CI. Verbal learning and memory was the most commonly impaired domain (n = 16, 44%). CI patients had lower mean skeleton fractional anisotropy (FA) value than CP patients (275.45 vs. 283.61 × 10⁻³, P = 0.023). The final predicting model including demographic variables and global skeleton mean diffusivity (MD) explained 43.6% of variance of the presence of cognitive impairment (β = 0.131, P = 0.041). CI patients showed a widespread change of microstructural integrity comparing to CP patients, which was rarely overlapping with lesion probability map. Microstructural abnormalities in corpus callosum were associated with performance in verbal learning and memory, processing speed and selective attention (P < 0.05).

Conclusion

Loss of microstructural integrity demonstrated by DTI helps explain cognitive dysfunction in Chinese MS patients.

Inhibition of the NLRP3-inflammasome prevents cognitive deficits in experimental autoimmune encephalomyelitis mice via the alteration of astrocyte phenotype

Multiple sclerosis (MS) is a chronic disease that is characterized by demyelination and axonal damage in the central nervous system. Cognitive deficits are recognized as one of the features of MS, and these deficits affect the patients’ quality of life. Increasing evidence from experimental autoimmune encephalomyelitis (EAE), the animal model of MS, has suggested that EAE mice exhibit hippocampal impairment and cognitive deficits. However, the underlying mechanisms are still unclear. The NLRP3 inflammasome is a key contributor to neuroinflammation and is involved in the development of MS and EAE. Activation of the NLRP3 inflammasome in microglia is fundamental for subsequent inflammatory events. Activated microglia can convert astrocytes to the neurotoxic A1 phenotype in a variety of neurological diseases. However, it remains unknown whether the NLRP3 inflammasome contributes to cognitive deficits and astrocyte phenotype alteration in EAE. In this study, we demonstrated that severe memory deficits occurred in the late phase of EAE, and cognitive deficits were ameliorated by treatment with MCC950, an inhibitor of the NLRP3 inflammasome. In addition, MCC950 alleviated hippocampal pathology and synapse loss. Astrocytes from EAE mice were converted to the neurotoxic A1 phenotype, and this conversion was prevented by MCC950 treatment. IL-18, which is the downstream of NLRP3 inflammasome, was sufficient to induce the conversion of astrocytes to the A1 phenotype through the NF-κB pathway. IL-18 induced A1 type reactive astrocytes impaired hippocampal neurons through the release of complement component 3 (C3). Altogether, our present data suggest that the NLRP3 inflammasome plays an important role in cognitive deficits in EAE, possibly via the alteration of astrocyte phenotypes. Our study provides a novel therapeutic strategy for hippocampal impairment in EAE and MS.

[Norepinephrine and intestinal microbiome in the early stages of demyelination: clinical-immunological parallels]

Biogenic amines are key mediators of neuroimmune interaction and may influence on multiple sclerosis (MS) pathogenesis and MS course. At the same time, the role of biogenic amines in immunoregulation of early stages of demyelination, in particular clinically isolated syndrome (CIS) and radiologically isolated syndrome (RIS) is still unclear. This literature review addresses a role of norepinephrine in the regulation of neuroimmune interactions in the early stages of the demyelination. Neuropsychological disorders, immunological characteristics, gut-brain axis as well as the role of norepinephrine in these interactions in patients with CIS, RIS and early MS are discussed.

Contributing factors to health-related quality of life in multiple sclerosis

BACKGROUND

Health-related quality of life (HRQoL) is lower in people with multiple sclerosis (PwMS) compared to the healthy population, psychological symptoms accompanying multiple sclerosis (MS) have a serious impact on the HRQoL of PwMS. Data regarding the subject, however, remain conflicting.

OBJECTIVES

To evaluate the patients' sociodemographic attributes, education, fatigue, depression, and cognitive impairment level of impact on the HRQoL for the whole cohort as well as comparing the sexes.

MATERIALS AND METHODS

Three hundred and twenty-two relapse-remitting MS patients filled out the Fatigue Impact Scale (FIS), Beck Depression Inventory (BDI), MS Quality of Life-54 (MSQoL-54) questionnaires, cognitive impairment were identified using Brief International Cognitive Assessment for MS (BICAMS) test. The patients' data were acquired from our clinic's MS registry or from patients' files.

RESULTS

Depression and fatigue were found to have the most ubiquitous and robust effect on the overall and any given subdivision of the HRQoL composite. Other factors had a slight effect on some of the subscales when the whole cohort was evaluated. When the genders were compared, differences were found on 10 domains.

CONCLUSION

Psychopathological symptoms have a more powerful influence on the HRQoL of MS patients than physical impairment, also these symptoms influence men's and women's HRQoL with different power. This invokes the need for complex and personalized care in the treatment of PwMS. Ours is the first study to show a difference between the sexes in this regard.

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.

Resolving the cognitive clinico-radiological paradox - Microstructural degeneration of fronto-striatal-thalamic loops in early active multiple sclerosis

BACKGROUND

Associations between cognitive impairment (CI) and both global and regional brain volumes can be weak in early multiple sclerosis (MS), a dilemma known as cognitive clinico-radiological paradox. We hypothesized that white-matter (WM) integrity within fronto-striatal-thalamic networks may be a sensitive marker for impaired performance in speed-dependent tasks, typical for early MS.

METHODS

Twenty-seven patients with early active relapsing-remitting MS (RRMS) received comprehensive neuropsychological assessment and underwent structural and diffusion-weighted brain magnetic resonance imaging (MRI). Global and regional brain volumes were obtained using FreeSurfer software. Fractional anisotropy (FA) was computed from diffusion tensor images to assess microstructural alterations within three anatomically predefined fronto-striatal-thalamic loops known to be relevant for speed-dependent attention and executive functions.

RESULTS

Overall cognitive performance (Spearman's ρ = .51) and performance in the domains processing speed (ρ = .44) and executive functions (ρ = .41) were correlated with patients' mean FA within the right dorsolateral-prefrontal loop. In addition, overall cognitive performance correlated with mean FA within the right lateral orbitofrontal loop (ρ = .39) - but only before controlling for WM lesion count. In contrast, regional volumes of grey-matter structures within these fronto-striatal-thalamic loops (including the thalamus) were not significantly related to CI. The total brain volume was associated with performance in the domain verbal memory (ρ = .43) only.

CONCLUSIONS

Microstructural degeneration within specific fronto-striatal-thalamic WM networks, previously characterized as crucial for task-monitoring, better accounts for speed-dependent CI in patients with early active RRMS than global or regional brain volumes. Our findings may advance our understanding of the neural substrates underlying CI characteristic for early RRMS.

Functional correlates of cognitive dysfunction in clinically isolated syndromes

Cognitive dysfunction can be identified in patients with clinically isolated syndromes suggestive of multiple sclerosis using ocular motor testing. This study aimed to identify the functional neural correlates of cognitive dysfunction in patients with clinically isolated syndrome using MRI. Eighteen patients with clinically isolated syndrome and 17 healthy controls were recruited. Subjects underwent standard neurological and neuropsychological testing. Subjects also underwent functional MRI (fMRI) during a cognitive ocular motor task, involving pro-saccade (direct gaze towards target) and anti-saccade (direct gaze away from target) trials. Ocular motor performance variables (averaged response time and error rate) were calculated for each subject. Patients showed a trend towards a greater rate of anti-saccade errors (p = 0.09) compared to controls. Compared to controls, patients exhibited increased activation in the right postcentral, right supramarginal gyrus, and the right parietal operculum during the anti-saccade>pro-saccade contrast. This study demonstrated that changes in functional organisation of cognitive brain networks is associated with subtle cognitive changes in patients with clinically isolated syndrome.

A Pilot Study to Assess At-Home Speed of Processing Training for Individuals with Multiple Sclerosis

Objective

Cognitive impairment is a common symptom of multiple sclerosis (MS), yet treatment is currently limited. The primary goal of this pilot study was to assess the feasibility and acceptability of an at-home, five-week computerized speed of processing (SOP) training intervention for MS patients. In addition, we examined the utility of the intervention to improve speed of information processing, memory, executive function, and health-related quality of life (HRQOL).

Method

Fifteen subjects were assigned five weeks of SOP training, two times per week, for a total of ten sessions. Subjects were trained on five computerized SOP tasks that required processing of increasingly complex visual stimuli in successively shorter presentation times. Subjects were given a neuropsychological test battery that included measures of speed of information processing, verbal memory, visual spatial memory, and executive function. Subjects were also administered patient-reported outcome (PRO) measures to assess HRQOL, depression, and work productivity. Neuropsychological and PRO batteries were completed at baseline and after five weeks.

Results

Eighty percent of subjects completed the five-week intervention (n = 12). Significant improvements were observed on some, but not all, measures of speed of information processing, verbal memory, and executive function. There were no significant changes in HRQOL.

Conclusion

This pilot study supports the feasibility of an at-home SOP training intervention for individuals with MS. SOP training was associated with improvements in several cognitive domains. Larger, randomized controlled trials are warranted.

Does cognitive dysfunction correlate with neurofilament light polypeptide levels in the CSF of patients with multiple sclerosis?

Objective

To investigate whether neurofilament light polypeptide (NfL) level in cerebrospinal fluid (CSF), currently a prognostic biomarker of neurodegeneration in patients with multiple sclerosis (MS), may be a potential biomarker of cognitive dysfunction in MS.

Methods

This observational case–control study included patients with MS. CSF levels of NfL were determined using enzyme-linked immunosorbent assay. Cognitive function was measured with the Brief International Cognitive Assessment for MS (BICAMS) battery and Paced Auditory Serial Addition Test (PASAT3), standardized to the Greek population.

Results

Of 39 patients enrolled (aged 42.7 ± 13.6 years), 36% were classified as cognitively impaired according to BICAMS z-scores (–0.34 ± 1.13). Relapsing MS was significantly better than progressive forms regarding BICAMS z-score (mean difference [MD] 1.39; 95% confidence interval [CI] 0.54, 2.24), Symbol Digit Modality Test score (MD 1.73; 95% CI 0.46, 3.0) and Greek Verbal Learning Test (MD 1.77; 95% CI 0.82, 2.72). An inversely proportional association between CSF NfL levels and BICAMS z-scores was found in progressive forms of MS (r_p = –0.944).

Conclusions

This study provides preliminary evidence for an association between CSF NfL levels and cognition in progressive forms of MS, which requires validation in larger samples.

Identifying risk factors for cognitive issues in multiple sclerosis

INTRODUCTION

Cognitive impairment (CI) in Multiple Sclerosis (MS) has progressively regained clinical and research interest and is currently recognized as a debilitating and burdensome problem for these patients. Studying risk and protecting factors that may influence the development and course of CI is currently an area of increasing interest, due to the potential for preventive strategies. Areas covered: In this narrative review the authors briefly addressed the physiopathologic basis, assessment and management of CI in MS and then focused on identifying modifiable and not modifiable risk factors for CI in MS, providing an overview of the current knowledge in the field and indicating avenues for future research. Expert opinion: Improving our understanding of potentially modifiable environmental and lifestyle risk factors or protective factors for CI is important in order to prompt preventive strategies and orient patient counselling and clinical management. To this aim, we need to enhance the current level of evidence linking lifestyle factors to cognition and evaluate some factors that were only preliminary addressed in research. Moreover, we need to explore the role of each factor into the subject cognitive outcome, next to the possible interactions between different environmental factors as well as between environmental and genetic factors.

Mechanisms of neurobehavioral abnormalities in multiple sclerosis: Contributions from neural and immune components

Multiple sclerosis-related neurobehavioral abnormalities are one of the main components of disability in this disease. The same pathological processes that explain demyelination periods and neurodegeneration also allow the comprehension of neurobehavioral abnormalities. Inflammation in the central nervous system caused by cells of the immune system, especially lymphocytes, and by resident cells, such as astrocytes and microglia, directly modulate neurotransmission and synaptic physiology, resulting in behavioral changes (such as sickness behavior) and amplifying the degenerative mechanisms that occur in multiple sclerosis. In addition, neuronal death caused by glutamate-mediated excitotoxicity, alterations in GABAergic, serotonergic, and dopaminergic neurotransmission, and the mechanisms of axon damage are of foremost importance to explain the reduction in brain volume and the associated cognitive decline. Neuroinflammation and neurodegeneration are not isolated phenomena and various instances of interaction between them have been described. This presents attractive targets for the development of therapeutic strategies for this neglected component of multiple sclerosis related disability.

Monitoring cognitive change in multiple sclerosis using a computerized cognitive battery

Background

Cognitive monitoring that can detect short-term change in multiple sclerosis is challenging. Computerized cognitive batteries such as the CogState Brief Battery can rapidly assess commonly affected cognitive domains.

Objectives

The purpose of this study was to establish the acceptability and sensitivity of the CogState Brief Battery in multiple sclerosis patients compared to controls. We compared the sensitivity of the CogState Brief Battery to that of the Paced Auditory Serial Addition Test over 12 months.

Methods

Demographics, Expanded Disability Status Scale scores, depression and anxiety scores were compared with CogState Brief Battery and Paced Auditory Serial Addition Test performances of 51 patients with relapsing-remitting multiple sclerosis, 19 with secondary progressive multiple sclerosis and 40 healthy controls. Longitudinal data in 37 relapsing-remitting multiple sclerosis patients were evaluated using linear mixed models.

Results

Both the CogState Brief Battery and the Paced Auditory Serial Addition Test discriminated between multiple sclerosis and healthy controls at baseline (p<0.001). CogState Brief Battery tasks were more acceptable and caused less anxiety than the Paced Auditory Serial Addition Test (p<0.001). In relapsing-remitting multiple sclerosis patients, reaction time slowed over 12 months (p<0.001) for the CogState Brief Battery Detection (mean change -34.23 ms) and Identification (-25.31 ms) tasks. Paced Auditory Serial Addition Test scores did not change over this time.

Conclusions

The CogState Brief Battery is highly acceptable and better able to detect cognitive change than the Paced Auditory Serial Addition Test. The CogState Brief Battery could potentially be used as a practical cognitive monitoring tool in the multiple sclerosis clinic setting.

Validation of the brief international cognitive assessment for multiple sclerosis (BICAMS) in the Portuguese population with multiple sclerosis

Background

The validation of international cognitive batteries in different multiple sclerosis (MS) populations is essential. Our objective was to obtain normative data for the Portuguese population of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) and assess its reliability.

Methods

The BICAMS was applied to 105 MS patients and 60 age, gender and education matched healthy controls (HC). In order to test its reliability, BICAMS was re-administered in a subset of 25 patients after a 7-month interval.

Results

Most participants were women, with a mean age of 37, 21 years and a mean of 14,08 years of education. The vast majority of the MS patients (92.4%) had the relapsing remitting type, 58.1% were professionally active, mean disease duration was 6.52 years, median EDSS score was 1.5 (range: 0–6.0) and the median MSSS score was 2.01 (IQR range: 3.83). The MS group presented significantly higher scores of anxiety and depression than HC and 47,4% had fatigue. The MS group performed significantly worse than the control group across the three neuropsychological tests, yielding the following values: SDMT: t(165) = 3.77, p = .000; CVLT-II: t(165) = 2.98, p = .003; and BVMT-R: t(165) = 2.94, p = .004. The mean raw scores for Portuguese normative data were as follows: SDMT: 58.68 ± 10.02; CVLT-II: 60.47 ± 10.12; and BVMT-R: 24.68 ± 5.52. Finally, test–retest reliability coefficients for each test were as follows: SDMT: r = .90; CVLT-II: r = .71; and BVMT-R: r = .84.

Conclusions

The Portuguese version of BICAMS here in described is a reliable monitoring instrument for identifying MS patients with cognitive impairment.

Recommendations for cognitive screening and management in multiple sclerosis care

Purpose:

To promote understanding of cognitive impairment in multiple sclerosis (MS), recommend optimal screening, monitoring, and treatment strategies, and address barriers to optimal management.

Methods:

The National MS Society (“Society”) convened experts in cognitive dysfunction (clinicians, researchers, and lay people with MS) to review the published literature, reach consensus on optimal strategies for screening, monitoring, and treating cognitive changes, and propose strategies to address barriers to optimal care.

Recommendations:

Based on current evidence, the Society makes the following recommendations, endorsed by the Consortium of Multiple Sclerosis Centers and the International Multiple Sclerosis Cognition Society: