Assessment of Fatigue in Multiple Sclerosis

Abstract

One of the most frequent symptoms in multiple sclerosis (MS) is fatigue. It has a major impact on quality of life as well as on professional activity. Even nowadays it is still unclear what constitutes an adequate assessment of the perceived fatigue.The following overview will discuss different possibilities to assess fatigue with the help of questionnaires, clinical interviews or the objective measurement of cognitive performance. Furthermore, a structured guideline for the assessment of fatigue will be proposed. Clinical criteria for MS related fatigue include the main symptoms, their everyday relevance, the possible causal relation with the cause of disease (the underlying MS), as well as an exclusion of other possible somatic or psychological reasons. It is recommended to use the “Würzburger Erschöpfungs-Inventar bei Multipler Sklerose (WEIMUS)” (English: Würzburg Fatigue Inventory for Multiple Sclerosis) and especially the “Fatigue Scale for Motor and Cognitive Functions” (FSMC), as these questionnaires distinguish between motor and cognitive fatigue and due to the larger number of research studies using the FSMC. Moreover, the presence of depression, quality of sleep and daytime sleepiness should be assessed. In addition, general cognitive performance as well as performance during monotonous stimulation (vigilance) should be assessed. This may be relevant for the evaluation of a patient’s capacity to work, and for determining prognosis, as there are indications for a relation to relapse frequency, a change from a clinically isolated syndrome (CIS) to an MS diagnosis with an increase of brain atrophy.All in all, it can be said, that despite the growing convergence of diagnostic criteria, the available studies of the objective as well as the subjective assessment of fatigue are still not sufficient and further research is needed.

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

“…Fatigue questionnaires presuppose internal averaging of the amount of fatigue experienced during a certain time frame. 1 This has been a problem for studies evaluating short-term interventions, as in some questionnaires patients are asked to evaluate their fatigue in timeframes of up to 4 weeks. As we are interested in the change in fatigue experienced in daily life from before the inpatient stay to afterwards, we (I) chose the WEIMuS 34 as the primary outcome measure to assess the fatigue experienced during the past week and (II) established the primary endpoint to be 1–2 weeks after participants have returned home (T 2 ).…”

“… 35 The FSMC provides cut-off scores to classify cases of no (total score <43), mild (≥43), moderate (≥53) and severe (≥63) fatigue, which makes it especially suitable as a tool for classification of fatigue severity. 1 35 …”

Influence of combined functional resistance and endurance exercise over 12 weeks on matrix metalloproteinase-2 serum concentration in persons with relapsing-remitting multiple sclerosis – a community-based randomized controlled trial

“…The FSMC has defined cut-off scores to differentiate between mildly (≥43 sum score), moderately (≥53 sum score) and severely (≥63 sum score) fatigued patients using 20 items with ten items for each dimension [46]. The German version shows excellent test-retest reliability [47].…”

Heart rate variability and fatigue in MS: two parallel pathways representing disseminated inflammatory processes?

“…However, the mere presence of fatigue and PANS-related changes of HRV is only a weak argument for a causal interrelation. In the following section, we will specify features of fatigue in MS (based on Sander et al [48]), which allow a formulation of more specific predictions.…”