Cognitive Fatigability, not Fatigue predicts employment status in patients with MS three months after rehabilitation

Comments on energy conservation treatments for MS-related fatigue and a new proposal

Psychological treatments of MS-related fatigue mostly depend on energy conservation programs. We argue that the evidence for energy conservation training is weak - in contrast to some reviews on this topic. The reasons for our concerns are the use of informed passive control groups allowing negative placebo effects, the lack of predefined primary outcome parameter, statistically rather than clinically significant effects, and the use of insensitive fatigue questionnaires. We propose to base psychological interventions not on a view of fatigue as a constant loss of mental energy but as a subjective representation ("feeling") of an inflammatory state, which draws away attentional capacity. This conceptualization allows to develop a three-step treatment approach: Getting short-term control on fatigue, extinction to reduce fatigue-related avoidance behavior, and a systematic increase of activities by pacing. Our proposal depends on the techniques, that can interrupt ongoing feelings of fatigue and can serve as a basis for extinction. We propose that Progressive Muscle Relaxation might be such a technique. The advantage of our model is that it shares similarities with well-established treatments for phobias and chronic pain and we discuss the shared set of assumptions. Hopefully, this will help to improve the treatment of fatigue in future.

Management of multiple sclerosis fatigue in the digital age: from assessment to treatment

Fatigue is one of the most disabling symptoms of Multiple Sclerosis (MS), affecting more than 80% of patients over the disease course. Nevertheless, it has a multi-faceted and complex nature, making its diagnosis, evaluation, and treatment extremely challenging in clinical practice. In the last years, digital supporting tools have emerged to support the care of people with MS. These include not only smartphone or table-based apps, but also wearable devices or novel techniques such as virtual reality. Furthermore, an additional effective and cost-efficient tool for the therapeutic management of people with fatigue is becoming increasingly available. Virtual reality and e-Health are viable and modern tools to both assess and treat fatigue, with a variety of applications and adaptability to patient needs and disability levels. Most importantly, they can be employed in the patient's home setting and can not only bridge clinic visits but also be complementary to the monitoring and treatment means for those MS patients who live far away from healthcare structures. In this narrative review, we discuss the current knowledge and future perspectives in the digital management of fatigue in MS. These may also serve as sources for research of novel digital biomarkers in the identification of disease activity and progression.

[The problem of long/post-COVID in expert assessments]

Assessing long/post-COVID syndrome (PCS) following an infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a multidisciplinary challenge due to the diverse and complex symptoms. Besides discipline-specific evaluation of infection-related organ damage, the main issue is expert objectivity and causality assessment regarding subjective symptoms. The consequences of long/PCS raise questions of insurance rights in all fields of law. In cases of persistent impairment of performance, determining reduction in earning capacity is crucial for those affected. Recognition as an occupational disease (BK no. 3101) is vital for employees in healthcare and welfare sectors, along with occupational accident recognition and assessing the illness's consequences, including the reduction in earning capacity (MdE) in other sectors or work areas. Therefore, expert assessments of illness consequences and differentiation from previous illnesses or damage disposition are necessary in all areas of law, individually based on corresponding organ manifestations in medical fields and interdisciplinarily for complex late sequelae, for instance, by internists with appropriate qualifications for pulmonary or cardiac manifestations and neurologists, psychiatrists, and neuropsychologists for neurological and psychiatric manifestations, etc.

Effects of repetitive twice-weekly transcranial direct current stimulations on fatigue and fatigability in people with multiple sclerosis

Fatigue is associated with a dramatically decreased quality of life in people with multiple sclerosis (pwMS). It refers to a constant subjective feeling of exhaustion and performance decline, known as fatigability. However, inconsistency and heterogeneity in defining and assessing fatigue have led to limited advances in understanding and treating MS-associated fatigue. Transcranial direct current stimulation (tDCS) has emerged as a promising, non-pharmaceutical treatment strategy for subjective fatigue. However, whether repetitive tDCS also have long-term effects on time-on-task performance has not yet been investigated. This pseudorandomized, single-blinded, and sham-controlled study investigated tDCS effects on behavioral and electrophysiological parameters. 18 pwMS received eight twice-weekly 30 min stimulations over the left dorsolateral prefrontal cortex. Fatigability was operationalized as time-on-task-related changes in reaction time variability and P300 amplitude. Additionally, subjective trait and state fatigue ratings were assessed. The results revealed an overall decrease in subjective trait fatigue ratings that lasted at least four weeks after the stimulations. However, the ratings declined after both anodal and sham tDCS. No effects were found on subjective state fatigue and objective fatigability parameters. Linear Mixed Models and Bayesian Regression models likewise favored the absence of a tDCS effect on fatigability parameters. The results confirm the complex relationship between MS-associated fatigue and fatigability. Reliable and clinically relevant parameters need to be established to extend the potential of tDCS for treating fatigability. Furthermore, our results indicate that consecutive stimulations rather than twice-weekly stimulations should be the preferred stimulation scheme in future studies.

Cognitive fatigue-related sensory gating deficits in people with multiple sclerosis

BACKGROUND

Cognitive fatigue is highly prevalent in people with multiple sclerosis (pwMS) and significantly limits their quality of life. Fatigue can be subdivided into a subjective feeling of constant (trait) or current (state) exhaustion, as well as an objective performance decline, also known as fatigability. However, the current fatigue diagnosis in pwMS is purely subjective, leaving fatigability mostly unattended. Sensorimotor and sensory gating deficits have recently been described as possible objective markers for fatigability in healthy subjects. Thus, this study aimed to investigate the potential of prepulse inhibition (PPI) ratios and the P50 sensory gating suppression as surrogate markers for cognitive fatigue in pwMS.

METHODS

PPI and P50 sensory gating ratios were assessed before and after a 30-min fatigability-inducing AX- continuous performance task. Subjective trait fatigue was operationalized via self-report questionnaires, subjective state fatigue via visual analog scales (VAS), and fatigability via the change in both gating ratios. The data were analyzed using Linear Mixed Models and Pearson correlations.

RESULTS

We included 18 pwMS and 20 healthy controls (HC) in the final analyses. The task-induced fatigability was more pronounced in pwMS. While the initial PPI and P50 ratios were similar in both groups, P50 sensory gating was significantly disrupted after fatigability induction in pwMS. PPI, on the other hand, decreased in both groups. Moreover, initial P50 sensory gating ratios were negatively associated with subjective trait fatigue in pwMS, indicating that higher trait fatigue is associated with disrupted sensory gating. Finally, fatigability-related changes in P50 sensory gating were associated with the changes in VAS ratings, but only in HC.

CONCLUSIONS

This study demonstrated that P50 sensory gating is a promising objective fatigue and fatigability parameter. Importantly, P50 sensory gating correlated with subjective trait and state fatigue ratings. Our results extend the subjective fatigue diagnosis and broaden the understanding of pathophysiological neuronal mechanisms in MS-related fatigue. This is the first study to present fatigue-related disruption of sensory gating in pwMS.

Randomised controlled pilot and feasibility study of multimodal agility-based exercise training (MAT) versus strength and endurance training (SET) to improve multiple sclerosis-related fatigue and fatigability during inpatient rehabilitation (ReFEx): study protocol

INTRODUCTION

Subjective fatigue and objectively assessed fatigability are common symptoms in persons with multiple sclerosis (pwMS). Recent work has suggested a positive effect of balance and motor control training (BMCT) in reducing fatigue. It is unclear whether this effect can also be attained during inpatient rehabilitation. Multimodal agility-based exercise training (MAT) has been developed as a framework that incorporates BMCT with added agility components but has not been applied to pwMS. Therefore, this study will evaluate the feasibility of a randomised controlled trial comparing MAT against strength and endurance training (SET) for the improvement of MS-related fatigue and fatigability in a German neurological rehabilitation centre.

METHODS AND ANALYSIS

A total of 24 pwMS (Expanded Disability Status Scale ≤5.0, Fatigue Scale for Motor and Cognitive Functions ≥53) will be randomly assigned to either SET or land and water-based MAT for 4-6 weeks during inpatient rehabilitation. Assessments of subjective fatigue, motor and cognitive fatigability, cognitive and cardiorespiratory performance, and balance confidence will be performed at admission and discharge. Subjective fatigue will also be assessed at 1, 4 and 12 weeks after discharge. Feasibility outcomes will include patients' acceptance of study procedures and interventions, recruitment rate, retention rate, time needed to complete baseline assessments, intervention adherence and fidelity. All quantitative outcomes will be reported descriptively. A total of 12 pwMS (6 per group) will be interviewed to gain insights into participants' experiences during study participation.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Ethics Committee of the University of Bonn (reference number: 543/20). Dissemination of findings is planned via peer-reviewed journals, conferences and media releases.

TRIAL REGISTRATION NUMBER

DRKS00023943.

[Neurological and psychiatric expert assessment of post-COVID syndrome]

Infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to a multiorgan disease and subsequently to very different clinical manifestations of coronavirus disease 2019 (COVID-19). In addition to acute symptoms, the long-term complaints in the context of the infection, known as long or post-COVID syndrome, are increasingly attracting attention. With respect to social insurance systems, expert opinions of such problems will become more and more important, whereby neurological and psychiatric symptoms are the most frequent complaints. In addition to the legal principles of the medico-legal assessment with a focus on statutory accident insurance, this overview article discusses the principles of expert assessment and presents landmarks for the expert opinion of the most frequent neurological and psychiatric symptoms occurring in the context of post-COVID syndrome.

Prominent Fatigue but No Motor Fatigability in Non-Hospitalized Patients With Post-COVID-Syndrome

Objectives

Fatigue is a frequent and often disabling symptom in patients with post-COVID syndrome. To better understand and evaluate the symptom of motor fatigue in the context of the post-COVID syndrome, we conducted treadmill walking tests to detect the phenomenon of motor fatigability or to evaluate whether evidence of organic lesions of the motor system could be found, similar to patients with multiple sclerosis.

Method

Twenty-nine non-hospitalized patients with post-COVID syndrome completed the Fatigue Scale for Motor and Cognitive Function (FSMC) questionnaire to determine the trait component of subjective fatigue before they were tested on a treadmill walking at a moderate speed for up to 60 min or until exhaustion. During the walking test oxygen uptake, ventilation and acceleration data of both feet were collected. To determine motor performance fatigability, the Fatigue Index Kliniken Schmieder (FKS) was calculated using the attractor method.

Results

The average walking duration was 42.7 ± 18.6 min with 15 subjects stopping the walking test prematurely. The FSMC score revealed a severe cognitive (37.6 ± 8.2) and motor (37.1 ± 7.8) fatigue averaged over all subjects but only two subjects showed an FKS above the normal range (>4), representing performance fatigability. There was no significant correlation between subjective fatigue (FSMC) and FKS as well as walking time. Absolute values of oxygen uptake and ventilation were in the normal range reported in literature (r = 0.9, p < 0.05), although eight subjects did not produce a steady-state behavior.

Conclusion

Almost all patients with post-COVID syndrome and subjectively severe motor fatigue, did not show motor fatigability nor severe metabolic anomalies. This is argued against organic, permanent damage to the motor system, as is often seen in MS. Many of the patients were - to our and their own surprise - motorically more exertable than expected.