Peter Feys

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.

Upper limb intention tremor in persons with multiple sclerosis (pwMS) affects the ability to perform activities of daily life and is difficult to treat. The study investigated the effect of peripheral upper limb cooling on tremor severity and functional performance in MS patients with intention tremor. In experiment 1, 17 patients underwent two 15 min cooling conditions for the forearm (cold pack and cryomanchet) and one control condition. In experiment 2, 22 patients underwent whole arm cooling for 15 min using multiple cold packs. In both experiments, patients were tested at four time points (pre- and post-0, -25 and -50 min cooling) on unilateral tasks of the Test Evaluant les Membres supérieurs des Personnes Agées (TEMPA), Fahn’s tremor rating scale (FTRS), Nine Hole Peg Test (NHPT). In experiment 1, the mean FTRS ranged from 13.2 to 14.1 across conditions. A two-way ANOVA showed mainly time effects, showing that cooling the forearm significantly reduced the FTRS, the performance on the NHPT, and three out of four items of the TEMPA, mostly independent of the cooling modality. In experiment 2, the mean FTRS was 13.1. A repeated measures ANOVA showed that cooling the whole arm reduced the FTRS and time needed to execute two out of four items of the TEMPA. These effects occurred immediately after cooling lasting at least 25 min. Cooling the whole upper limb led to a clinically noticeable effect on tremor severity and improved functional performance, which was pronounced during the first half-hour after cooling.