The nature of fatigue in multiple sclerosis

Prevalence and Associated Clinical Characteristics of Walking-Related Motor, Cognitive, and Fatigability in Progressive Multiple Sclerosis: Baseline Results From the CogEx Study

BACKGROUND

People with progressive multiple sclerosis (PMS) present motor (eg, walking) and cognitive impairments, and report fatigue. Fatigue encompasses fatigability which is objectively measured by the capacity to sustain a motor or cognitive task.

OBJECTIVE

To investigate the prevalence of walking and cognitive fatigability (CF) and the associated clinical characteristics in a large sample of PMS patients.

METHODS

PMS patients (25-65 years old) were included from 11 sites (Europe and North America), having cognitive impairment (1.28 standard deviation below normative data for the symbol digit modality test [SDMT]). Walking fatigability (WF) was assessed using the distance walk index (DWI) and CF using the SDMT (scores from the last 30 seconds compared to the first 30 seconds). Additional measures were: cognitive assessment-Brief International Cognitive Assessment for multiple sclerosis (MS), cardiorespiratory fitness, 6-minute walk, physical activity, depressive symptoms, perceived fatigue-Modified Fatigue Impact Scale (MFIS), MS impact-MSIS-29, and walking ability.

RESULTS

Of 298 participants, 153 (51%) presented WF (DWI = -28.9 ± 22.1%) and 196 (66%) presented CF (-29.7 ± 15%). Clinical characteristics (EDSS, disease duration, and use of assistive device) were worse in patients with versus without WF. They also presented worse scores on MSIS-29 physical, MFIS total and physical and reduced physical capacity. CF patients scored better in the MSIS-29 physical and MFIS psychosocial, compared to non-CF group. Magnitude of CF and WF were not related.

CONCLUSIONS

Half of the cognitively-impaired PMS population presented WF which was associated with higher disability, physical functions, and fatigue. There was a high prevalence of CF but without strong associations with clinical, cognitive, and physical functions.

TRIAL REGISTRATION NUMBER

The "CogEx-study," www.clinicaltrial.gov identifier number: NCT03679468.

Brain connectivity changes underlying depression and fatigue in relapsing-remitting multiple sclerosis: A systematic review

Multiple Sclerosis (MS) is an autoimmune disease affecting the central nervous system, characterised by neuroinflammation and neurodegeneration. Fatigue and depression are common, debilitating, and intertwined symptoms in people with relapsing-remitting MS (pwRRMS). An increased understanding of brain changes and mechanisms underlying fatigue and depression in RRMS could lead to more effective interventions and enhancement of quality of life. To elucidate the relationship between depression and fatigue and brain connectivity in pwRRMS we conducted a systematic review. Searched databases were PubMed, Web-of-Science and Scopus. Inclusion criteria were: studied participants with RRMS (n ≥ 20; ≥ 18 years old) and differentiated between MS subtypes; published between 2001-01-01 and 2023-01-18; used fatigue and depression assessments validated for MS; included brain structural, functional magnetic resonance imaging (fMRI) or diffusion MRI (dMRI). Sixty studies met the criteria: 18 dMRI (15 fatigue, 5 depression) and 22 fMRI (20 fatigue, 5 depression) studies. The literature was heterogeneous; half of studies reported no correlation between brain connectivity measures and fatigue or depression. Positive findings showed that abnormal cortico-limbic structural and functional connectivity was associated with depression. Fatigue was linked to connectivity measures in cortico-thalamic-basal-ganglial networks. Additionally, both depression and fatigue were related to altered cingulum structural connectivity, and functional connectivity involving thalamus, cerebellum, frontal lobe, ventral tegmental area, striatum, default mode and attention networks, and supramarginal, precentral, and postcentral gyri. Qualitative analysis suggests structural and functional connectivity changes, possibly due to axonal and/or myelin loss, in the cortico-thalamic-basal-ganglial and cortico-limbic network may underlie fatigue and depression in pwRRMS, respectively, but the overall results were inconclusive, possibly explained by heterogeneity and limited number of studies. This highlights the need for further studies including advanced MRI to detect more subtle brain changes in association with depression and fatigue. Future studies using optimised imaging protocols and validated depression and fatigue measures are required to clarify the substrates underlying these symptoms in pwRRMS.

The relation between the symbol digit modalities test, fatigue, depression, and anxiety symptoms in a Belgian MS cohort

BACKGROUND

Multiple sclerosis (MS) is associated with high prevalence of cognitive impairment, ranging from 40 to 80%. The purpose of this single-center retrospective study was to examine the relation between cognitive function, as measured by Symbol Digit Modalities Test (SDMT), with fatigue, anxiety, and depression symptoms in a Belgian cohort of patients with MS.

METHODS

Sociodemographic and clinical data were analyzed in 66 (F:40, M:26) Belgian patients with a diagnosis of MS. The cognitive function was assessed with the oral version of SDMT, depression and anxiety symptoms with the Hospital Anxiety and Depression scale (HAD), fatigue symptoms with the French valid version of the Fatigue Impact Scale in MS (EMIF-SEP), which is a scale composed of four dimensions (cognitive, physical, social, and psychological) allowing a multidimensional evaluation of fatigue.

RESULTS

The multivariate linear regression analysis demonstrated that lower SDMT scores were associated with higher EDSS score and psychological dimension of fatigue symptoms. No association were found between SDMT and anxiety or depression symptoms. Conversely, higher depression and anxiety symptoms were associated with higher total fatigue symptoms, but lower physical dimension of fatigue symptoms. Higher anxiety symptoms were also independently associated with higher social dimension of fatigue symptoms.

CONCLUSION

A complex relationship exists between cognitive performance, fatigue, and neuropsychiatric symptoms in Belgian people with MS. The level of disability and fatigue adversely affects the cognitive function in MS, whereas depression and anxiety seem to not have a significant effect. A more complex relationship exists between fatigue and neuropsychiatric symptoms, with a divergent interplay between the different dimensions of fatigue that supports the multidimensional approach to assessing fatigue in MS.

Sociodemographic and Clinical Determinants of Fatigue in Multiple Sclerosis

Fatigue is the most common and disabling symptom in patients with multiple sclerosis (PwMS), representing one of the main determinants of reduced quality of life among PwMS due to its interference with social activities and work capacity. This study aimed to identify the sociodemographic determinants of fatigue in a cohort of 150 PwMS and 100 healthy controls (HCs). Fatigue was assessed using one of the most suitable and appropriate tools for measuring the degree of fatigue: the Modified Fatigue Impact Scale (MFIS). By comparing the median scores for the MFIS, we observed that the PwMS group had significantly higher MFIS scores than the HCs (p = 0.0001). In PwMS, MFIS scores correlated positively with age, total number of relapses, total disease duration, disability status, and Beck Depression Inventory-II score and negatively with cognitive performance. Patients with relapsing-remitting MS had significantly lower fatigue levels than those with secondary progressive MS (p = 0.0010). Fatigue levels were significantly lower among male than female PwMS (p = 0.0120). Other determinant factors of fatigue in our study proved to be the marital and occupational status, as well as the presence of children, but in a linear multivariate regressions analysis with MFIS score as the dependent variable, the fatigue levels were influenced only by sex, occupational status, marital status, children status, and BDI-II test results. Considering the significant impact of fatigue on the quality of life of PwMS, clinicians must diagnose fatigue as early as possible, identify its modifiable determinants, and manage it effectively to increase their quality of life.

Neuropsychiatric Status of Patients With Multiple Sclerosis Across Disease Duration Intervals

OBJECTIVES

The neuropsychiatric sequelae of multiple sclerosis (MS) are important predictors of morbidity and mortality. The authors examined how symptoms of depression, anxiety, fatigue, subjective cognitive impairment, and objective cognitive dysfunction varied with disease duration. They also explored changes in the use of disease-modifying therapies, psychotropic medications, and psychotherapies in relation to disease duration.

METHODS

A retrospective sample of 464 people with MS was stratified into three groups based on disease duration: <5 years (N=129), 5-10 years (N=101), and >10 years (N=234). Symptoms of depression and anxiety were recorded with the Hospital Anxiety and Depression Scale (HADS); fatigue, with the five-item version of the Modified Fatigue Impact Scale (MFIS-5); subjective cognitive impairment, with the five-item version of the Perceived Deficits Questionnaire (PDQ-5); and cognition, with the Minimal Assessment of Cognitive Function in MS (MACFIMS).

RESULTS

There were between-group differences in anxiety symptoms (p<0.01) and degree of cognitive impairment (p=0.03), but there were no differences in depressive symptoms, fatigue, or subjective cognitive difficulties. Anxiety was higher during the first 5 years after diagnosis, and cognitive dysfunction was higher when assessed more than 10 years after diagnosis. With longer disease duration, a greater proportion of participants received psychotropic medications (p<0.01), and lower proportions received disease-modifying therapies (p<0.01) or psychotherapies (p<0.01).

CONCLUSIONS

Findings indicated that rates of some neuropsychiatric symptoms, such as anxiety and cognitive dysfunction, may shift with disease duration, whereas other symptoms, such as fatigue and depression, may not. These findings highlight the importance of closely monitoring the mental state of people with MS over time.

Monoaminergic network abnormalities: a marker for multiple sclerosis-related fatigue and depression

OBJECTIVE

To investigate monoaminergic network abnormalities in patients with multiple sclerosis (MS) according to their fatigue and depressive status through a positron emission tomography (PET)-based constrained independent component analysis (ICA) on resting state (RS) functional MRI (fMRI).

METHODS

In this prospective study, 213 patients with MS (mean age=40.6±12.5 years; 94/119 men/women; 153 relapsing-remitting; 60 progressive) and 62 healthy controls (HCs, mean age=39.0±10.4 years; 30/32 men/women) underwent neurological, fatigue, depression and RS fMRI assessment. Patterns of dopamine, norepinephrine-related and serotonin-related RS functional connectivity (FC) were derived by ICA, constrained to PET atlases for dopamine, norepinephrine and serotonin transporters, obtained in HCs' brain.

RESULTS

Compared with HCs, patients with MS showed abnormalities in all three explored monoaminergic networks, mostly with decreased RS FC within PET-guided monoaminergic networks in frontal regions and subcortical areas including the cerebellum and thalamus, and increased RS FC in temporo-parieto-occipital cortical areas, including bilateral precunei.MS-related fatigue was associated with decreased RS FC within the PET-guided dopamine network in the left thalamus and left cerebellum, and with increased RS FC within the PET-guided serotonin network in the left middle occipital gyrus. MS-related depression was associated with more distributed abnormalities involving the three explored monoaminergic networks, resulting in overall reduced RS FC in the frontal lobe, limbic areas and the precuneus.

CONCLUSIONS

Patients with MS present diffuse dysregulation in the monoaminergic networks. Specific alterations in these networks were associated with fatigue and depression, providing a pathological marker for these bothersome symptoms and putative targets for their treatment.

Physical and mental fatigue in post-COVID syndrome and their associations over time: A small-sample ESM-study to explore fatigue, quality of sleep and behaviours

OBJECTIVE

Post-COVID syndrome leaves millions of people with severe fatigue, yet little is known about its nature in daily life. In this exploratory study, momentary associations between physical and mental fatigue, quality of sleep and behaviours over two weeks in patients with post-COVID syndrome were assessed.

METHOD

Data on fatigue levels, quality of sleep and behaviours was collected for 14 consecutive days using the experience sampling method in ten ex-hospitalised patients with post-COVID syndrome.

RESULTS

Multilevel linear regression modelling showed strong associations between physical and mental fatigue (β = 0.61, p ≤0.001), significant both between and within individuals. Sleeping more hours at night was associated with less physical and mental fatigue the following day (β = -0.35, p = .001; β = -0.27, p = .008). Strenuous relaxation (B = 0.45, p ≤0.001; B = 0.28, p = .004) and social contacts (B = -0.33, p = .003; B = -0.22, p = .02) were associated with physical and mental fatigue at the same measurement point. Performing household chores decreased physical and mental fatigue (B = -0.29, p = .02; B = -0.30, p = .006) two hours later on the same day, whereas eating and drinking increased physical fatigue (B = 0.20, p = .05) two hours later on the same day.

CONCLUSION

Physical fatigue and mental fatigue were strongly associated and revealed fluctuations in fatigue levels between individuals, which might suggest potentially different post-COVID subgroups. Indications for potential risk and beneficial behaviours for fatigue were found.

Perception of Physical Demand, Mental Demand, and Performance: A Comparison of Two Voice Interventions for Parkinson's Disease

PURPOSE

The purpose of the study was to examine the effect of two voice intervention approaches for hypophonia secondary to Parkinson's disease (PD) on self-reported measures of physical demand, mental demand, and vocal performance.

METHOD

Thirty-four persons with hypophonia secondary to PD were assigned to one of three groups: Lee Silverman Voice Treatment (LSVT) LOUD (n = 12), SpeechVive (n = 12), and nontreatment clinical control (n = 10). The LSVT LOUD and the SpeechVive participants received 8 weeks of voice intervention following the standardized protocol previously described for each approach. To confirm the effectiveness of each voice intervention, sound pressure level (dB SPL) data were analyzed for the experimental and control participants for a monologue sample obtained pretreatment, midtreatment, and posttreatment. During the voice intervention period, the LSVT LOUD and the SpeechVive participants were instructed to complete a modified version of the National Aeronautics and Space Administration Task Load Index rating scale to indicate the mental and physical demand required to complete the intervention activities, and to indicate how well they performed in completing the assigned vocal tasks.

RESULTS

The LSVT LOUD and the SpeechVive participants demonstrated a significant posttreatment increase in SPL (dB), in comparison to the clinical controls, thus confirming a positive intervention effect. The LSVT LOUD participants reported significantly higher ratings of physical and mental demand over the course of treatment, in comparison to the SpeechVive participants.

CONCLUSION

Consideration of the mental and physical demand associated with two voice intervention approaches, commonly used for PD, may help to foster improved therapeutic compliance and treatment outcomes.

Predicting Multiple Sclerosis Outcomes During the COVID-19 Stay-at-home Period: Observational Study Using Passively Sensed Behaviors and Digital Phenotyping

BACKGROUND

The COVID-19 pandemic has broad negative impact on the physical and mental health of people with chronic neurological disorders such as multiple sclerosis (MS).

OBJECTIVE

We presented a machine learning approach leveraging passive sensor data from smartphones and fitness trackers of people with MS to predict their health outcomes in a natural experiment during a state-mandated stay-at-home period due to a global pandemic.

METHODS

First, we extracted features that capture behavior changes due to the stay-at-home order. Then, we adapted and applied an existing algorithm to these behavior-change features to predict the presence of depression, high global MS symptom burden, severe fatigue, and poor sleep quality during the stay-at-home period.

RESULTS

Using data collected between November 2019 and May 2020, the algorithm detected depression with an accuracy of 82.5% (65% improvement over baseline; F₁-score: 0.84), high global MS symptom burden with an accuracy of 90% (39% improvement over baseline; F₁-score: 0.93), severe fatigue with an accuracy of 75.5% (22% improvement over baseline; F₁-score: 0.80), and poor sleep quality with an accuracy of 84% (28% improvement over baseline; F₁-score: 0.84).

CONCLUSIONS

Our approach could help clinicians better triage patients with MS and potentially other chronic neurological disorders for interventions and aid patient self-monitoring in their own environment, particularly during extraordinarily stressful circumstances such as pandemics, which would cause drastic behavior changes.

Validation of Discrete and Regression-Based Performance and Cognitive Fatigability Normative Data for the Paced Auditory Serial Addition Test in Multiple Sclerosis

Cognitive fatigability is an objective performance decrement that occurs over time during a task requiring sustained cognitive effort. Although cognitive fatigability is a common and debilitating symptom in multiple sclerosis (MS), there is currently no standard for its quantification. The objective of this study was to validate the Paced Auditory Serial Addition Test (PASAT) discrete and regression-based normative data for quantifying performance and cognitive fatigability in an Ontario-based sample of individuals with MS. Healthy controls and individuals with MS completed the 3″ and 2″ versions of the PASAT. PASAT performance was measured with total correct, dyad, and percent dyad scores. Cognitive fatigability scores were calculated by comparing performance on the first half (or third) of the task to the last half (or third). The results revealed that the 3″ PASAT was sufficient to detect impaired performance and cognitive fatigability in individuals with MS given the increased difficulty of the 2″ version. In addition, using halves or thirds for calculating cognitive fatigability scores were equally effective methods for detecting impairment. Finally, both the discrete and regression-based norms classified a similar proportion of individuals with MS as having impaired performance and cognitive fatigability. These newly validated discrete and regression-based PASAT norms provide a new tool for clinicians to document statistically significant cognitive fatigability in their patients.

Cognitive Fatigue Predicts Cognitive Failure in Multiple Sclerosis Patients and Healthy Controls: A Case-Control Study

OBJECTIVE

Fatigue and cognitive deficits are frequent symptoms of multiple sclerosis (MS). However, the exact nature of their co-occurrence is not fully understood. We sought to determine the impact of cognitive and physical fatigue on subjective cognitive deficits in MS patients and healthy controls.

METHODS

Self-reports of fatigue (FSMC), depression (CES-D), cognitive deficits (CFQ), and personality traits (NEO-FFI, ANPS) among 30 MS inpatients and 30 healthy controls were analyzed using hierarchical regression models. The frequency of cognitive mistakes was used as the dependent variable and the extent of cognitive and physical fatigue as the independent variable.

RESULTS

Cognitive fatigue was the only unique and significant predictor of cognitive mistakes in both groups, explaining 13.3% of additional variance in the MS group after correcting for age, mood, and physical fatigue. Physical fatigue had no significant impact on cognitive mistakes. While age had an impact on cognitive mistakes and depression in healthy controls, this association was not significant in MS patients. Depression was significantly correlated with cognitive mistakes and cognitive fatigue in MS patients.

CONCLUSIONS

The interplay of cognitive fatigue and subjective cognitive impairment can be generalized, with the exception of the variables of age and depression, which were shown to have differing impacts on cognitive mistakes in MS patients and healthy controls, respectively. Cognitive fatigue was linked to cognitive mistakes even after correcting for overlapping items in MS patients only. Future research should further investigate the link between cognitive fatigue and attention lapses in daily life by using various objective assessments.

The Effect of Depression on Health-Related Quality of Life Is Mediated by Fatigue in Persons with Multiple Sclerosis

The interrelations between fatigue, depression and health-related quality of life (HRQoL) in persons with multiple sclerosis (PwMS) are complex, and the directionality of the effects is unclear. To address this gap, the current study used a longitudinal design to assess direct and indirect effects of fatigue and depression on HRQoL in a one-year follow-up survey. A sample of 210 PwMS from the nationwide Swiss MS Registry was used. HRQoL was assessed using the European Quality of Life 5-Dimension 5-Level questionnaire. Path analysis on HRQoL, with fatigue and depression as predictors, was applied. Fatigue was measured by the Modified Fatigue Impact Scale (MFIS), including physical, cognitive and psychosocial subscales, and non-somatic depressive symptomatology was examined with the Beck Depression Inventory-Fast Screen (BDI-FS). Fatigue acted as a fully mediating variable (B = -0.718, SE = 0.253) between non-somatic depressive symptomatology and HRQoL. This indirect effect became apparent in the physical (B = -0.624, SE = 0.250), psychosocial (B = -0.538, SE = 0.256) and cognitive subscales (B = -0.485, SE = 0.192) of fatigue. In contrast, non-somatic depressive symptomatology did not act as a mediator. Our findings provide novel and clinically relevant longitudinal evidence showing that the debilitating effect of non-somatic aspects of depression on HRQoL was fully mediated and therefore explainable via fatigue.

Comprehensive Approach to Management of Multiple Sclerosis: Addressing Invisible Symptoms-A Narrative Review

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system, leading to neurodegeneration and manifesting as a variety of symptoms. These can include "invisible" symptoms, not externally evident to others, such as fatigue, mood disorders, cognitive impairments, pain, bladder/bowel dysfunction, sexual dysfunction, and vision changes. Invisible symptoms are highly prevalent in people living with MS, with multifactorial etiology and potential to impact the disease course. Patient experiences of these symptoms include both physical and psychosocial elements, which when unaddressed negatively influence many aspects of quality of life and perception of health. Despite the high impact on patient lives, gaps persist in awareness and management of these hidden symptoms. The healthcare provider and patient author experiences brought together here serve to raise the profile of invisible symptoms and review strategies for a team-based approach to comprehensive MS care. We summarize the current literature regarding the prevalence and etiology of invisible symptoms to convey the high likelihood that a person living with MS will contend with one or more of these concerns. We then explore how open communication between people living with MS and their care team, stigma mitigation, and shared decision-making are key to comprehensive management of invisible symptoms. We recommend validated screening tools and technological advancements that may be incorporated into MS care to regularly monitor these symptoms, offering insight into how healthcare providers can both educate and listen to patients, with the goal of improved patient quality of life. By pairing clinical knowledge with an understanding and consideration of the patient perspective, providers will be equipped to foster a patient-centered dialogue that encourages shared decision-making. Invisible symptoms of MS.

Instrumentally assessed gait quality is more relevant than gait endurance and velocity to explain patient-reported walking ability in early-stage multiple sclerosis

BACKGROUND AND PURPOSE

People with multiple sclerosis (PwMS) often report walking limitations even when the gold standard Expanded Disability Status Scale (EDSS) indicates normal walking endurance/autonomy. The present multicenter study on early-stage PwMS aims at analyzing which aspects are associated with patient-reported walking limitations measured with the 12-item Multiple Sclerosis Walking Scale (MSWS-12).

METHODS

Eighty-two PwMS (EDSS ≤ 2.5) were assessed using the Fullerton Advanced Balance Scale-short (FAB-s), the Fatigue Severity Scale (FSS) and the 6-min Walk Test (6MWT), the latter administered also to 21 healthy subjects. Participants performed the 6MWT wearing three inertial sensors on ankles and trunk. Instrumented metrics describing gait velocity (stride length and frequency) and quality (regularity, symmetry, instability) were computed from sensor data. Fatigue (FSS), balance (FAB-s), walking endurance (6MWT) and instrumented metrics were entered in a multiple regression model with MSWS-12 as dependent variable.

RESULTS

Gait symmetry, gait instability, fatigue and balance were significantly associated with self-rated walking ability, whilst walking endurance and velocity were not. Fatigue, balance, gait symmetry and instability were more impaired in participants reporting mild-to-moderate (MS_MM-PWL , 25 ≤ MSWS-12 < 75) compared to those reporting none-to-minimal (MS_nm-PWL , 0 ≤ MSWS-12 ≤ 25) perceived walking limitations. Compared to healthy subjects, gait symmetry and stability were reduced in MS_nm-PWL and MS_MM-PWL , even in those participants with EDSS ≤ 1.5.

CONCLUSION

Instrumentally assessed gait quality aspects (symmetry and instability) are associated with patient-reported walking ability in early-stage PwMS and seem sensitive biomarkers to detect subtle impairments even in the earliest stages of the disease (EDSS ≤ 1.5). Future studies should assess their ability to follow walking change due to MS progression or pharmacological/rehabilitation interventions.

Quality of life in multiple sclerosis: The differential impact of motor and cognitive fatigue

Background

Multiple sclerosis is a chronic disease leading to reduced quality of life.

Objectives

To investigate whether motor and cognitive fatigue impact differently on aspects of quality of life among patients with multiple sclerosis, independently from bodily disability.

Methods

79 patients with multiple sclerosis from Aalborg University Hospital, Denmark were included in an observational, cross-sectional study. Each subject completed two separate questionnaires regarding fatigue (Fatigue Scale for Motor and Cognitive Functions and Modified Fatigue Impact Scale) and one regarding quality of life (Short Form 36). Disability was measured with the Expanded Disability Status Scale (EDSS)-scores obtained from patient records.

Results

All fatigue scores were significantly correlated to all areas of quality of life (p < 0,05). This remained significant after adjustment for age, disease duration and EDSS-score. When looking at each type of fatigue separately, cognitive fatigue correlated mainly with mental health aspects of quality of life and motor fatigue with physical health areas of quality of life.

Conclusion

Increased motor and cognitive fatigue lead to a differential reduction in physical and mental quality of life, independently of bodily disability. This underlines the importance of proper assessment and treatment of fatigue among patients with multiple sclerosis.

Outcome measures for physical fatigue in individuals with multiple sclerosis: a systematic review

INTRODUCTION

Physical fatigue can be a common reason for early retirement or sick leave since it appears in the earliest stages of multiple sclerosis (MS). Therefore, a prompt and accurate diagnosis is essential. This systematic review aims to identify and describe the instruments used to assess physical fatigue in MS patients with consideration for the languages used to validate the instruments and their methodological qualities.

AREA COVERED

This study has been carried out through 'Medline,' 'Scopus,' 'Cinhal,' and 'Web of Science' databases for all the papers published before 24 January 2020. Three independent authors have chosen the eligible studies based upon pre-set criteria of inclusion. Data collection, data items, and assessment of the risk of bias: the data extraction approach was chosen based on the Cochrane Methods. For data collection, the authors followed the recommendations from the COSMIN initiative. Study quality and risk of bias were assessed using the COSMIN Check List.

EXPERT OPINION

119 publications have been reviewed. The 45 assessment scales can be divided into specific scales for physical fatigue and specific scales for MS. The most popular tools are the Fatigue Severity Scale and the Modified Fatigue Impact Scale.

Chronic fatigue and depression due to multiple sclerosis: Immune-inflammatory pathways, tryptophan catabolites and the gut-brain axis as possible shared pathways

Chronic fatigue and major depression (MDD)-like symptoms are common manifestations of multiple sclerosis (MS), both with huge impact on quality of life. Depression can manifest itself as fatigue, and depressive symptoms are often mistaken for fatigue, and vice versa. The two conditions are sometimes difficult to differentiate, and their relationship is unclear. Whether chronic fatigue and depression occur primarily, secondarily or coincidentally with activated immune-inflammatory pathways in MS is still under debate. We have carried out a descriptive review aiming to gain a deeper understanding of the relationship between chronic fatigue and depression in MS, and the shared pathways that underpin both conditions. This review focuses on immune-inflammatory pathways, the kynurenine pathway and the gut-brain axis. It seems likely that proinflammatory cytokines, tryptophan catabolites (the KYN pathway) and the gut-brain axis are involved in the mechanisms causing chronic fatigue and MDD-like symptoms in MS. However, the evidence base is weak, and more research is needed. In order to advance our understanding of the underlying pathological mechanisms, MS-related fatigue and depression should be examined using a longitudinal design and both immune-inflammatory and KYN pathway biomarkers should be measured, relevant clinical characteristics judiciously registered, and self-report instruments for both fatigue and depression should be used.

Fatigue Profiles in Patients with Multiple Sclerosis are Based on Severity of Fatigue and not on Dimensions of Fatigue

Fatigue related to Multiple Sclerosis (MS) is considered a multidimensional symptom, manifesting in several dimensions such as physical, cognitive, and psychosocial fatigue. This study investigated in 264 patients with severe primary MS-related fatigue (median MS duration 6.8 years, mean age 48.1 years, 75% women) whether subgroups can be distinguished based on these dimensions. Subsequently, we tested whether MS-related fatigue consists of a single common unidimensional factor. Subscale scores on four self-reported fatigue questionnaires, including the Checklist of Individual Strength, the Modified Fatigue Impact Scale, the Fatigue Severity Scale and the SF36 vitality, were used in a cluster analysis to identify patients with similar fatigue characteristics. Next, all 54 items were included in exploratory factor analysis to test unidimensionality. Study results show that in patients with a treatment indication for primary MS-related fatigue, fatigue profiles are based on severity and not on the various dimensions of fatigue. The three profiles found, suggested one underlying fatigue dimension, but this could not be confirmed. Factor analysis of all 54 items resulted in 8 factors, confirming the multidimensional construct of the included fatigue questionnaires.

Exploring the feasibility of a mild and short 4-week combined upper limb and breathing exercise program as a possible home base program to decrease fatigue and improve quality of life in ambulatory and non-ambulatory multiple sclerosis individuals

PURPOSE

To evaluate the feasibility of a combined upper limb and breathing exercise for a home-based program and to explore its effect on primary fatigue and quality of life in ambulatory and non-ambulatory individuals with multiple sclerosis (MS) in a short time.

METHOD

Nineteen individuals with MS were assigned into semi-controlled pre-post feasibility study based on Expanded Disability Status Scale (EDSS) status and divided into two groups: exercise (five ambulatory, five non-ambulatory; EDSS 1.0-8.0) and related control with no exercise (four ambulatory, five non-ambulatory; EDSS 1.0-7.5). Exercise group performed combined upper limb and breathing exercise in a controlled group (2 days/week, 60 min/session) accompanied by independent home exercise (3 days/week, ≥ 20 min/session). Participants underwent measures of fatigue impact (Modified Fatigue Impact Scale (MFIS) and quality of life (RAND Medical outcomes study 36-item short-form health survey (SF-36)) before and after a 4-week period.

RESULTS

The MFIS (physical, psychosocial, total) showed statistically significant group-by-time interaction in ambulatory (p = 0.033, d = 1.60; p = 0.039, d = 1.59; p = 0.033, d = 1.62) and non-ambulatory individuals (p = 0.009, d = 2.42; p = 0.018, d = 1.96; p = 0.0008, d = 3.92). Physical functioning (SF-36) showed statistically significant group-by-time interaction in ambulatory (p = 0.014, d = 2.14) but no significance in non-ambulatory (p = 0.368, d = 0.68) individuals. Despite the absent statistical significance, there were large intervention effects on MFIS cognitive scores for ambulatory (d = 1.28) and non-ambulatory (d = 1.47), and on other SF-36 scores for ambulatory (general health: d = 1.76 and pain: d = 1.02) and non-ambulatory (physical limitation: d = 1.03 and emotional well-being: d = 0.94) individuals.

CONCLUSION

Our 4-week program reduced some aspects of fatigue and improved some aspects of quality of life in a small group of ambulatory and non-ambulatory individuals with MS. Good feasibility and significant positive changes from baseline warrant further exploratory work.

TRIAL REGISTRATION

Name of the registry: The Impact of Exercise Training on Living Quality in Multiple Sclerosis. Registration: The study was registered at www.clinicaltrial.gov on July 14, 2017. First participant enrollment: August 28, 2017. URL: 602-01/17-01-147; Trial registration ID: NTC03222596.

The neuropsychiatry of multiple sclerosis

Multiple sclerosis is the most common disabling neurological illness affecting young and middle-aged adults. Although attention has tended to focus mainly on its neurological manifestations, reports of the presence of neuropsychiatric symptoms date back to the writings of Charcot in 1877. This article details the neuropsychiatric sequelae of multiple sclerosis and the evidence base for available treatments.

Anxiety Modifies the Association between Fatigue and Verbal Fluency in Cognitively Normal Adults

OBJECTIVE

In the present study, we examined the association between self-reported fatigue and verbal fluency in a sample of healthy adults. Given the co-occurrence of anxiety and depressive symptoms with fatigue, we examined whether these affective dimensions would modify this association.

METHOD

Fifty-nine cognitively normal adults took part in the study. Fatigue symptoms were assessed using the Fatigue Severity Scale (FSS), depressive symptomatology with the Center for Epidemiologic Studies Depression Scale (CES-D), and situational anxiety using the state subscale of the State-Trait Anxiety Inventory (STAI-S).We used a composite measure of verbal fluency comprising letter fluency and semantic fluency as the outcome measure.

RESULTS

Multiple regression analyses revealed higher fatigue was associated with better verbal fluency when STAI-S scores were high. We did not find a significant interaction between the FSS and CES-D.

CONCLUSION

Greater situational anxiety levels may buffer against the negative influence of fatigue on verbal fluency in non-clinical populations, consistent with previous research showing that moderate levels of anxiety can benefit cognitive function. Whether subthreshold depressive symptoms modify the association between fatigue and verbal fluency is still unclear. Measures that assess different symptom dimensions specific to depression would help to clarify this issue.

Does the Modified Fatigue Impact Scale offer a more comprehensive assessment of fatigue in MS?

Background: As a symptom of multiple sclerosis (MS), fatigue is difficult to manage because of its unknown etiology, the lack of efficacy of the drugs tested to date and the absence of consensus about which would be the ideal measure to assess fatigue. Objective: Our aim was to assess the frequency of fatigue in a sample of MS patients and healthy controls (HC) using two fatigue scales, the Fatigue Severity Scale (FSS) and the Modified Fatigue Impact Scale (MFIS) with physical, cognitive and psychosocial subscales. We also studied the relationship fatigue has with depression, disability and interferon beta. Methods: Three hundred and fifty-four individuals (231 MS patients and 123 HC) were included in this cross-sectional study. Fatigue was assessed using the FSS and MFIS. Depression was measured by the Beck Depression Inventory (BDI), and disability by the Expanded Disability Status Scale (EDSS). A status of fatigue was considered when the FSS≥ 5, of non-fatigue when the FSS≤4, and scores between 4.1 and 4.9 were considered doubtful fatigue cases. Results: Fifty-five percent of MS patients and 13% of HC were fatigued. The global MFIS score positively correlated with the FSS in MS and HC (r=0.68 for MS and r=0.59 for HC, p<0.0001). Nonetheless, the MFIS physical subscale showed the strongest correlation score with the FSS (r=0.75, p<0.0001). In addition, a prediction analysis showed the physical MFIS subscale to be the only independent predictor of FSS score (p<0.0001), suggesting other aspects of fatigue, as cognition and psychosocial functions, may be explored by the FSS to a lesser extent. Depression also correlated with fatigue (r=0.48 for the FSS and r=0.7 for the MFIS, p<0.0001) and, although EDSS correlated with fatigue as well, the scores decreased after correcting for depression. Interferon beta showed no relationship with fatigue. Conclusions: Fatigue is a frequent symptom found in MS patients and clearly related with depression. Each fatigue scale correlates with one another, indicating that they are measuring similar constructs. Nevertheless, spheres of fatigue as cognition and psychosocial functions are probably better measured by the MFIS, although this hypothesis will need to be confirmed with appropriate psychometrical testing.

Effect of neurofeedback training on depression and fatigue in patients with multiple sclerosis

Depression and fatigue are common symptoms of multiple sclerosis (MS) and are the primary determinants of impaired quality of life in this demyelinating neurological disease. Untreated depression is associated with suicidal ideation, impaired cognitive function and poor adherence to immunomodulatory treatment. For these reasons, systematic screening and management of depressive symptoms and fatigue is recommended for all patients with MS. The objective of this study was to evaluate the effectiveness of neurofeedback in treating depression and fatigue in persons with MS. We conducted a randomized trial with 24 MS patients with primary fatigue and depression. Participants were randomized into two groups: neurofeedback training group (16 sessions of NFB) or treatment as usual. Participants were evaluated at 3 time points (baseline, end of the treatment, and 2-month follow-up) using the Fatigue Severity Scale and Depression subscale of the Hospital Anxiety and Depression Scale as outcome measures. A repeated measures analysis of variance was used to examine differences between the groups. NFB significantly reduced symptoms of depression and fatigue in patients with MS patients, compared to treatment as usual (p < .05), and these effects were maintained the 2-month follow-up (p < .05).

Capturing the post-exertional exacerbation of fatigue following physical and cognitive challenge in patients with chronic fatigue syndrome

OBJECTIVE

To design and validate an instrument to capture the characteristic post-exertional exacerbation of fatigue in patients with chronic fatigue syndrome (CFS).

METHODS

Firstly, patients with CFS (N=19) participated in five focus group discussions to jointly explore the nature of fatigue and dynamic changes after activity, and inform development of a self-report instrument - the Fatigue and Energy Scale (FES). The psychometric properties of the FES were then examined in two case-control challenge studies: a physically-demanding challenge (moderate-intensity aerobic exercise; N=10 patients), and a cognitively-demanding challenge (simulated driving; N=11 patients). Finally, ecological validity was evaluated by recording in association with tasks of daily living (N=9).

RESULTS

Common descriptors for fatigue included 'exhaustion', 'tiredness', 'drained of energy', 'heaviness in the limbs', and 'foggy in the head'. Based on the qualitative data, fatigue was conceptualised as consisting of 'physical' and 'cognitive' dimensions. Analysis of the psychometric properties of the FES showed good sensitivity to the changing symptoms during a post-exertional exacerbation of fatigue following both physical exercise and driving simulation challenges, as well as tasks of daily living.

CONCLUSION

The 'fatigue' experienced by patients with CFS covers both physical and cognitive components. The FES captured the phenomenon of a post-exertional exacerbation of fatigue commonly reported by patients with CFS. The characteristics of the symptom response to physical and cognitive challenges were similar. Both the FES and the challenge paradigms offer key tools to reliably investigate biological correlates of the dynamic changes in fatigue.

Fatigue in Multiple Sclerosis: Neural Correlates and the Role of Non-Invasive Brain Stimulation

Multiple sclerosis (MS) is a chronic progressive inflammatory disease of the central nervous system (CNS) and the major cause of non-traumatic disability in young adults. Fatigue is a frequent symptom reported by the majority of MS patients during their disease course and drastically affects their quality of life. Despite its significant prevalence and impact, the underlying pathophysiological mechanisms are not well elucidated. MS fatigue is still considered the result of multifactorial and complex constellations, and is commonly classified into “primary” fatigue related to the pathological changes of the disease itself, and “secondary” fatigue attributed to mimicking symptoms, comorbid sleep and mood disorders, and medications side effects. Radiological, physiological, and endocrine data have raised hypotheses regarding the origin of this symptom, some of which have succeeded in identifying an association between MS fatigue and structural or functional abnormalities within various brain networks. Hence, the aim of this work is to reappraise the neural correlates of MS fatigue and to discuss the rationale for the emergent use of noninvasive brain stimulation (NIBS) techniques as potential treatments. This will include a presentation of the various NIBS modalities and a suggestion of their potential mechanisms of action in this context. Specific issues related to the value of transcranial direct current stimulation (tDCS) will be addressed.

Fatigue in chronic hepatitis C infection: Understanding patients' experience from a cognitive-behavioural perspective

OBJECTIVES

Fatigue is a leading concern of patients with chronic hepatitis C virus (HCV) infection. Despite its clinical significance, fatigue in HCV is poorly understood and therefore invariably under-treated. A cognitive-behavioural approach offers a framework to understand and treat fatigue, but the characteristics of fatigue in chronic HCV infection have not been documented from a cognitive-behavioural perspective. This study captured the common and unique aspects of fatigue from a cognitive-behavioural perspective in individuals with HCV infection and clinically significant fatigue.

DESIGN

Cross-sectional, qualitative using a critical realism approach.

METHODS

Fourteen individuals (64% women; age >18 years) participated in semi-structured interviews. The interviews documented the features, course, and perceived antecedents of fatigue; fatigue-specific cognitions; fatigue management behaviours; and the functional impact of fatigue.

RESULTS

Participants' descriptions included the aspects of fatigue that have been targets of cognitive-behavioural therapy in other medical conditions, including attributing fatigue to the illness; expectation of chronicity; low control; and fatigue-driven coping. There were also components of fatigue experience that appear to be unique characteristics of fatigue related to HCV, including predominantly physical fatigue; high acceptance of fatigue; and liver-protective diet as a fatigue management behaviour.

CONCLUSIONS

This was the first study to document the experience of fatigue in chronic HCV infection in a cognitive-behavioural framework. The findings suggest that the cognitive-behavioural approach can be applied to fatigue in chronic HCV infection. This would open an avenue to alleviate fatigue and thus improve the primary patient-reported outcome of the disease.

STATEMENT OF CONTRIBUTION

What is already known on this subject? Fatigue is a key patient-reported outcome measure of chronic hepatitis C virus (HCV) infection. Fatigue management is not part of the standard care, because fatigue is poorly characterized in this population. What does this study add? A cognitive-behavioural approach can be applied to understand fatigue in HCV infection. Identified aspects of fatigue (antecedents, consequences, cognitions, behaviours) that can be treatment targets. Cognitive-behavioural therapy would open a new treatment avenue to alleviate fatigue in HCV infection.

Neuropsychological correlates of multiple sclerosis across the lifespan

Multiple sclerosis can adversely affect cognitive functioning whether the disease has an adult or pediatric onset. The research thus far suggests that pediatric MS shares many features with adult MS but is also unique in several respects. One particular characteristic of pediatric MS is that, while physical disability develops more slowly as compared with adult patients, the impact of cognitive deficits in children may be more substantial as they are in a period of life during which they acquire many skills that are needed to transition into independently functioning adults. Our review takes a lifespan approach to MS, comparing and contrasting the neuropsychology (i.e., cognitive, psychological, and psychosocial factors) of these two populations. Understanding how MS manifests across the lifespan has important implications for tailoring assessment and treatment for individuals with MS as they transition from childhood to adulthood, and later life.

The Hungarian validation of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) battery and the correlation of cognitive impairment with fatigue and quality of life

BACKGROUND

Multiple Sclerosis (MS) causes not only somatic, but also cognitive impairment regardless of the patients׳ age or the course of the disease. The Brief International Cognitive Assessment for MS (BICAMS) test, published in 2011, is a short cognitive questionnaire: a fast, reliable, sensitive and specific tool for the evaluation of the patients׳ cognitive state.

OBJECTIVES

Our primary objective was to assess the validity of the Hungarian version of the BICAMS test. Our secondary objective was to evaluate the impact of the cognitive impairment on the patient׳s quality of life and fatigue׳s impact on the patients׳ cognitive state.

METHODS

65 RR-MS patients and 65 age, sex and education matched healthy control (HC) subjects completed the test and were retested after 3 weeks. The patients also completed the MS Quality of Life 54 (MSQoL54) and the Fatigue Impact Scale (FIS) assessments. Group differences were calculated by paired sample T-tests. The test-retest reliability was measured by intraclass correlation coefficients. To analyze the difference between the test-retest performances of the two groups we used two-way repeated measures ANOVA where the BICAMS battery was the single composite outcome and one-way repeated measures ANOVA. To assess the impact of the cognitive decline on the patients׳ quality of life and fatigue׳s impact on the cognitive state, we examined the correlations between results in the BICAMS and the MSQoL54 and FIS.

RESULTS

We found significant difference (p ≤ 0.001, p = 0.017 in the first CVLT-II assessment) between MS patients and members of the HC group in all four evaluated parameters of BICAMS test in both sessions. The correlation coefficients were very strong between the tests and retests (r > 0.8; p < 0.001; r = 0.678, p < 0.001 between the CVLT-II assessments). We found that the HC group performed significantly (p = 0.020) better in the retest sessions as compared to their original performance than the patients did and this difference is solely due to the difference between the CVLT-II performances. We have found significant negative correlation between the patients׳ cognitive function and the fatigue score (r < -0.3, p < 0.05). Seven of the MSQoL-54 subscales correlated with the BICAMS performance (r > 0.3; < 0 .05).

CONCLUSIONS

The Hungarian version of the BICAMS test is a valid and reliable method for the evaluation of MS patients׳ cognitive function. It seems that because of the short retest period, the members of the HC group remembered the CVLT-II words thus performed better than the patients did. Also apparently fatigue can have a negative impact on the patients׳ cognitive state, and cognitive impairment could worsen the patients׳ quality of life.

Relations between mood characteristics, circadian preferences, and functionality in multiple sclerosis

OBJECTIVE

Multiple sclerosis (MS) is a progressive disorder that results in demyelinization of the nerve fibers of the central nervous system. We aimed to determine chronobiological and mood features in patients with MS.

METHODS

The sample comprised 75 patients with MS (54 women and 21 men) and 50 healthy individuals (38 women and 12 men). Sixty-three patients were relapsing-remitting MS and twelve patients had secondary progressive-type MS. Mood characteristics were assessed using subscales of the Profile of Mood States (POMS). Chronotypical characteristics were determined by the Morningness-Eveningness Questionnaire (MEQ). Univariate and structural equation modeling was applied to untangle the possible connections between variables.

RESULTS

Both relapsing-remitting and secondary progressive patients scored higher on the depression-dejection and fatigue-inertia scales of the POMS than healthy individuals. Circadian preferences did not differ significantly between these groups. Patients using glatiramer acetate and other types of drugs had greater severity of functional impairment measured relative to interferon-beta treatment group. Glatiramer acetate had more negative effects on mood than interferon-beta therapy. This finding may be the result of significantly higher duration of disease and higher symptom severity scores in glatiramer acetate group.

CONCLUSIONS

In the structural equation model, gender was found to be predictive for characteristics of mood.

Association between perceived fatigue and gait parameters measured by an instrumented treadmill in people with multiple sclerosis: a cross-sectional study

BACKGROUND

Multiple sclerosis (MS) is a multi-focal progressive disorder of the central nervous system often resulting in diverse clinical manifestations. Symptomatic fatigue is quite common in people with MS (PwMS), with prevalence as high as 85%. Nevertheless, it remains poorly understood and its association with walking capabilities unclear. Therefore, the objective of this investigation was to examine the relationship between symptomatic fatigue and spatio-temporal parameters of gait in PwMS based on an instrumented treadmill.

METHODS

One hundred and twenty-four relapsing-remitting patients diagnosed with MS, 84 women and 40 men aged 42.6 (S.D = 11.9), participated in this investigation. A convenience sample of 25 apparently healthy subjects, 15 women and 10 men aged 40.3 (S.D = 11.1), served as controls. Gait spatiotemporal parameters were obtained using the Zebris FDM-T Treadmill (Zebris1 Medical GmbH, Germany). The Modified Fatigue Impact Scale (MFIS), a self-reported questionnaire, was used to determine the level of symptomatic fatigue in the MS study group. PwMS were divided into two groups: fatigued and non-fatigued.

RESULTS

Forty-four PwMS were classified as suffering from fatigue (mean MFIS = 52.0, S.D = 13.7); 80 were classified as non-fatigued (mean MFIS = 14.5, S.D = 14.5). Individuals in the fatigued group walked slower than those in the non-fatigued group; 1.7 (S.D = 2.4) vs. 2.4 (S.D = 1.0); P < 0.001, respectively. Moreover, fatigued patients took smaller steps, had a shorter stride length, prolonged stance, double support phase and a shorter single support phase compared to the non-fatigued group. In the total group, fatigue was significantly correlated with 10 (out of 14) spatiotemporal parameters of gait, however, correlation scores <0.40 were considered as weak correlations. According to step one of the linear logistic regression analysis, the temporal gait component was found to explain 5.1% of the variance related to symptomatic fatigue, R2 = 0.051, χ2 (1) = 6.511, P = 0.011. Step two of the model added the gait spatial component, thus increasing the explaining variance to 9.3%; R2 = 0.093, χ2 (2) = 12.12, P = 0.002. The asymmetry gait parameter did not contribute to the equation.

CONCLUSIONS

Perceived fatigue is related to walking speed in PwMS, nevertheless its contribution to level of fatigue is limited.

Clinically significant fatigue: prevalence and associated factors in an international sample of adults with multiple sclerosis recruited via the internet

Background

Fatigue contributes a significant burden of disease for people with multiple sclerosis (PwMS). Modifiable lifestyle factors have been recognized as having a role in a range of morbidity outcomes in PwMS. There is significant potential to prevent and treat fatigue in PwMS by addressing modifiable risk factors.

Objectives

To explore the associations between clinically significant fatigue and demographic factors, clinical factors (health-related quality of life, disability and relapse rate) and modifiable lifestyle, disease-modifying drugs (DMD) and supplement use in a large international sample of PwMS.

Methods

PwMS were recruited to the study via Web 2.0 platforms and completed a comprehensive survey measuring demographic, lifestyle and clinical characteristics, including health-related quality of life, disability, and relapse rate.

Results

Of 2469 participants with confirmed MS, 2138 (86.6%) completed a validated measure of clinically significant fatigue, the Fatigue Severity Scale. Participants were predominantly female from English speaking countries, with relatively high levels of education, and due to recruitment methods may have been highly pro-active about engaging in lifestyle management and self-help. Approximately two thirds of our sample (1402/2138; 65.6% (95% CI 63.7–67.7)) screened positive for clinically significant fatigue. Bivariate associations were present between clinically significant fatigue and several demographic, clinical, lifestyle, and medication variables. After controlling for level of disability and a range of stable socio-demographic variables, we found increased odds of fatigue associated with obesity, DMD use, poor diet, and reduced odds of fatigue with exercise, fish consumption, moderate alcohol use, and supplementation with vitamin D and flaxseed oil.

Conclusion

This study supports strong and significant associations between clinically significant fatigue and modifiable lifestyle factors. Longitudinal follow-up of this sample may help clarify the contribution of reverse causation to our findings. Further research is required to explore these associations including randomized controlled trials of lifestyle interventions that may alleviate fatigue.

Fatigue in multiple sclerosis: a look at the role of poor sleep

Fatigue is a frequent and debilitating symptom of multiple sclerosis (MS) with rates ranging anywhere from 53 to 90%. Despite its high prevalence and grave impact on overall functioning and quality of life, the accurate definition, quantification, and etiology of fatigue have plagued the MS literature and clinical care for decades. With regard to its etiology, MS-related fatigue has been construed as being either primary or secondary. Primary fatigue is purported to be related to centrally mediated processes of the disease whereas secondary fatigue is thought to be a result of the host of factors that may accompany MS (e.g., depression, sleep disturbance). The present paper focuses on secondary fatigue and the role of sleep disturbance, in particular. Despite the intuitive assumption that sleep problems could contribute to fatigue, sleep problems in MS have gone fairly unrecognized until recently. The present paper provides a brief review of the literature pertaining to the prevalence and nature of sleep problems in MS as well as their association with fatigue. A replication of this author’s and others work is presented further demonstrating that sleep disturbance is a significant contributor to fatigue in MS when taking into account disease variables, depression, and sleep disturbance.

The Neuro-Immune Pathophysiology of Central and Peripheral Fatigue in Systemic Immune-Inflammatory and Neuro-Immune Diseases

Many patients with systemic immune-inflammatory and neuro-inflammatory disorders, including depression, rheumatoid arthritis, systemic lupus erythematosus, Sjögren's disease, cancer, cardiovascular disorder, Parkinson's disease, multiple sclerosis, stroke, and chronic fatigue syndrome/myalgic encephalomyelitis, endure pathological levels of fatigue. The aim of this narrative review is to delineate the wide array of pathways that may underpin the incapacitating fatigue occurring in systemic and neuro-inflammatory disorders. A wide array of immune, inflammatory, oxidative and nitrosative stress (O&NS), bioenergetic, and neurophysiological abnormalities are involved in the etiopathology of these disease states and may underpin the incapacitating fatigue that accompanies these disorders. This range of abnormalities comprises: increased levels of pro-inflammatory cytokines, e.g., interleukin-1 (IL-1), IL-6, tumor necrosis factor (TNF) α and interferon (IFN) α; O&NS-induced muscle fatigue; activation of the Toll-Like Receptor Cycle through pathogen-associated (PAMPs) and damage-associated (DAMPs) molecular patterns, including heat shock proteins; altered glutaminergic and dopaminergic neurotransmission; mitochondrial dysfunctions; and O&NS-induced defects in the sodium-potassium pump. Fatigue is also associated with altered activities in specific brain regions and muscle pathology, such as reductions in maximum voluntary muscle force, downregulation of the mitochondrial biogenesis master gene peroxisome proliferator-activated receptor gamma coactivator 1-alpha, a shift to glycolysis and buildup of toxic metabolites within myocytes. As such, both mental and physical fatigue, which frequently accompany immune-inflammatory and neuro-inflammatory disorders, are the consequence of interactions between multiple systemic and central pathways.

Impact of a switch to fingolimod versus staying on glatiramer acetate or beta interferons on patient- and physician-reported outcomes in relapsing multiple sclerosis: post hoc analyses of the EPOC trial

Background

The Evaluate Patient OutComes (EPOC) study assessed physician- and patient-reported outcomes in individuals with relapsing multiple sclerosis who switched directly from injectable disease-modifying therapy (iDMT; glatiramer acetate, intramuscular or subcutaneous interferon beta-1a, or interferon beta-1b) to once-daily, oral fingolimod. Post hoc analyses evaluated the impact of a switch to fingolimod versus staying on each of the four individual iDMTs.

Methods

Overall, 1053 patients were randomized 3:1 to switch to fingolimod or remain on iDMT. The primary endpoint was the change in Treatment Satisfaction Questionnaire for Medication (TSQM) Global Satisfaction score. Secondary endpoints included changes in scores for TSQM Effectiveness, Side Effects and Convenience subscales, Beck Depression Inventory-II (BDI-II), Fatigue Severity Scale (FSS), Patient-Reported Outcome Indices for Multiple Sclerosis (PRIMUS) Activities, 36-item Short-Form Health Survey (SF-36) Mental Component Summary (MCS) and Physical Component Summary (PCS) and mean investigator-reported Clinical Global Impressions of Improvement (CGI-I). All outcomes were evaluated after 6 months of treatment.

Results

Changes in TSQM Global Satisfaction scores were superior after a switch to fingolimod when compared with scores in patients remaining on any of the iDMTs (all p <0.001). Likewise, all TSQM subscale scores improved following a switch to fingolimod (all p <0.001), except when compared with glatiramer acetate for the TSQM Side Effects subscale (p = 0.111). FSS scores were found to be superior for fingolimod versus remaining on subcutaneous interferon beta-1a and interferon beta-1b, BDI-II scores were significantly improved for fingolimod except for the comparison with intramuscular interferon beta-1a, and SF-36 scores were superior with fingolimod compared with remaining on interferon beta-1b (MCS and PCS; p = 0.030 and p = 0.022, respectively) and subcutaneous interferon beta-1a (PCS only; p = 0.024). Mean CGI-I scores were superior with fingolimod when compared with continuing treatment with any of the iDMTs (all p <0.001).

Conclusions

After 6 months, a switch to fingolimod showed superiority compared with remaining on each iDMT for a range of patient- and physician-reported outcomes, including global satisfaction with treatment.

Trial registration

ClinicalTrials.gov NCT01216072.

Integrity of hypothalamic fibers and cognitive fatigue in multiple sclerosis

Cognitive fatigue is a common and disabling symptom of multiple sclerosis (MS), but little is known about its pathophysiology. The present study investigated whether the posterior hypothalamus, which is considered as the waking center, is associated with MS-related cognitive fatigue. We analyzed the integrity of posterior hypothalamic fibers in 49 patients with relapsing-remitting MS and 14 healthy controls. Diffusion tensor imaging (DTI) parameters were calculated for fibers between the posterior hypothalamus and, respectively, the mesencephalon, pons and prefrontal cortex. In addition, DTI parameters were computed for fibers between the anterior hypothalamus and these regions and for the corpus callosum. Cognitive fatigue was assessed using the Fatigue Scale for Motor and Cognitive Functions. Analyses of variance with repeated measures were performed to investigate the impact of cognitive fatigue on diffusion parameters. Cognitively fatigued patients (75.5%) showed a significantly lower mean axial and radial diffusivity for fibers between the posterior hypothalamus and the mesencephalon than cognitively non-fatigued patients (Group(⁎)Target area(⁎)Diffusion orientation: F=4.047; p=0.023). For fibers of the corpus callosum, MS patients presented significantly higher axial and radial diffusivity than healthy controls (Group(⁎)Diffusion orientation: F=9.904; p<0.001). Depressive mood, used as covariate, revealed significant interaction effects for anterior hypothalamic fibers (Target area(⁎)Diffusion orientation(⁎)Depression: F=5.882; p=0.021; Hemisphere(⁎)Diffusion orientation(⁎) Depression: F=8.744; p=0.008). Changes in integrity of fibers between the posterior hypothalamus and the mesencephalon appear to be associated with MS-related cognitive fatigue. These changes might cause an altered modulation of hypothalamic centers responsible for wakefulness. Furthermore, integrity of anterior hypothalamic fibers might be related to depression in MS.

Postural response latencies are related to balance control during standing and walking in patients with multiple sclerosis

OBJECTIVE

To understand and examine the relation between postural response latencies obtained during postural perturbations and representative measures of balance during standing (sway variables) and walking (trunk motion).

DESIGN

Cross-sectional.

SETTING

University medical center.

PARTICIPANTS

Persons with multiple sclerosis (MS) (n=40) were compared with similar aged control subjects (n=20). There were 20 subjects with MS in the normal walking velocity group and 20 subjects with MS who had slow walking velocity based on a timed 25-foot walk (T25FW) of <5 seconds.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Postural response latency, sway variables, trunk motion variables.

RESULTS

We found that subjects with MS with both slow or normal walking velocities had significantly longer postural response latencies than the healthy control group. Postural response latency was not correlated with the T25FW. Postural response latency was significantly correlated with center of pressure sway variables during quiet standing (root mean square: ρ=.334, P=.04; range: ρ=.385, P=.017; mean velocity: ρ=.337, P=.038; total sway area: ρ=.393, P=.015). Postural response latency was also significantly correlated with motion of the trunk during walking (sagittal plane range of motion: ρ=.316, P=.05; SD of transverse plane range of motion: ρ=-.43, P=.006).

CONCLUSIONS

These findings clearly indicate that slow postural responses to external perturbations in patients with MS contribute to disturbances in balance control during both standing and walking.

Multiple sclerosis and pregnancy: current considerations

Multiple sclerosis is the most common neurological disease of young adults that causes major disability. In Romania, it is estimated that this disease has a prevalence of 35–40 per 100,000 inhabitants. It is a disease that begins at the age of 20–40 years and is 2-3 times more common in women than in men. More than half of patients with MS develop the disease in their fertile period of life; therefore, MS patients use contraceptive methods while being under our treatment. Since several therapeutic options have been implemented with good efficiency in the disease stabilization, increasingly more patients begin to wonder about the possibility of having a child and about the possible risks of pregnancy. The evolution during pregnancy and the lactation period has been favorable, with lower relapses and side effects comparable to those in the general population. In addition, babies born to mothers with MS have not had a significantly different mean gestational age or birth weight compared to babies born to healthy mothers.