Induction of cognitive fatigue in MS patients through cognitive and physical load

Abstract

The objective of the study was to investigate whether cognitive fatigue in patients with multiple sclerosis (MS) is a spontaneous phenomenon or whether it can be provoked or exacerbated through cognitive effort and motor exercise. Thirty two patients with definite MS and cognitive fatigue according to the Fatigue Scale for Motor and Cognitive Functions (FSMC ≥ 22) performed attention tests (alertness, selective, and divided attention subtests from the TAP test battery for attention performance) twice during rest (baseline), and before and after treadmill training and cognitive load (a standardised battery of neuropsychological tests lasting 2.5 hours). Subjective exhaustion was assessed with a 10-point rating scale. Tonic alertness turned out to be the most sensitive test and showed significantly increased reaction times after treadmill training and after cognitive load. Patients' subjective assessment of exhaustion (10-point rating scale) and the objective test results were discrepant. In contrast, healthy control subjects (N = 20) did not show any decline of performance in the subtest alertness after cognitive or physical load. Data favour the concept that fatigue is induced by physical and mental load. Discrepancies between subjective and objective assessment offer therapeutic options. The common notion of a purely "subjective" lack of physical and/or mental energy should be reconsidered.

Do Cognitive and Physical Fatigue Tasks Enhance Pain, Cognitive Fatigue, and Physical Fatigue in People With Fibromyalgia?

“…One limitation in our study is that we did not screen our subjects for chronic fatigue syndrome, a common comorbidity with FM. In people with multiple sclerosis, traumatic brain injury, cancer, and cognitive fatigue syndrome, both cognitive fatiguing tasks and physical fatiguing tasks increase perceived cognitive fatigue ().…”

Neural correlates of effort-dependent and effort-independent cognitive fatigue components in patients with multiple sclerosis

“…Patients completed the Fatigue Scale of Motor and Cognition (FSMC) 15 questionnaire, as well as the Becks Depression Inventory (BDI) 16 on the day of the experiment. Participants performed in the alertness task from the Test-battery of Attentional Performance (TAP), 17 a simple visual reaction task shown to be sensitive to cognitive fatigue [18][19][20] before and after the MRI measurement. vision (FOV) = 192 mm, flip angle = 80°, TR = 2.5 seconds, TE = 30 ms while participants performed in the N-back task.…”

Neuropsychological Training of Attention Improves MS-Related Fatigue: Results of a Randomized, Placebo-Controlled, Double-Blind Pilot Study

“…In the meantime, other groups have independently shown an association between alertness and the subjective feeling of fatigue: Weinges-Evers et al[3] reported higher reaction times in alertness in patients with higher levels of fatigue (Fatigue Severity Scale ≥4.0) compared to those without fatigue in a large study with 110 MS patients, whereas other neuropsychological tests could not differentiate between both groups [3]. Accordingly, measurement of alertness has been proposed as the most sensitive test for evaluating fatigue [21], and mean reaction times in the subtest “Alertness” were significantly higher in MS patients with fatigue compared to healthy controls, with an increase during cognitive load, which was in contrast to the results in controls who showed a decrease in reaction times after cognitive demanding tasks [4]. …”