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Motor sequence learning in persons with multiple sclerosis (pwMS) and healthy controls (HC) under implicit or explicit learning conditions has not yet been investigated in a stepping task. Given the prevalent cognitive and mobility impairments in pwMS, this is important in order to understand motor learning processes and optimize rehabilitation strategies. Nineteen pwMS (the Expanded Disability Status Scale = 3.4 ± 1.2) and 18 HC performed a modified serial reaction time task by stepping as fast as possible on a stepping tile when it lit up, either with (explicit) or without (implicit) knowledge of the presence of a sequence beforehand. Motor sequence learning was studied by examining response time changes and differences between sequence and random blocks during the learning session (acquisition), 24 h later (retention), and in three dual-task (DT) conditions at baseline and retention (automaticity) using subtracting sevens, verbal fluency, and vigilance as concurrent cognitive DTs. Response times improved and were lower for the sequenced compared with the random blocks at the post- and retention tests (P's < 0.001). Response times during DT conditions improved after learning, but DT cost improved only for the subtracting sevens DT condition. No differences in learning were observed between learning conditions or groups. This study showed motor sequence learning, by acquisition and retention, in a stepping task in pwMS with motor impairments, to a similar degree as HC and regardless of learning conditions. Whether automaticity increased remains unclear.

Evidence for using auditory-motor coupling in neurological rehabilitation to facilitate walking is increasing. However, the distinction between spontaneous and intended coupling and its underlying mechanisms is yet to be investigated. In this study, we include 30 persons with multiple sclerosis and 30 healthy controls (HCs) in an experiment with two sessions in which participants were asked to walk to music with various tempi, matching their preferred walking cadence (PWC) up to 10% above in incremental steps of 2%. In the first session, no instructions were given to synchronize. In the second, participants were instructed to synchronize steps to the beats. Spontaneous synchronization was possible at 0% and +2% of the PWC, and fewer persons with multiple sclerosis were able to do so compared with HCs. Instruction was needed to synchronize at above +2% tempo in all participants. In the instructed session, the +6% condition marked a cutoff for cognitively impaired persons, as they were no longer able to synchronize. Based on our findings, we constructed a model illustrating that spontaneous entrainment is limited, operating during spontaneous coupling at only 0% and +2% of the PWC, and that at a higher tempo, entrainment requires intentional synchronization, with an active cognitive control mechanism.

Objectives - Walking impairments are common in individuals with multiple sclerosis. Trunk control is a prerequisite for walking; however, knowledge regarding whether core stability and balance training influence walking is limited. This study aimed to investigate the immediate and long‐term effects of a group‐based, individualized, comprehensive core stability and balance intervention (GroupCoreDIST) compared with those of standard care on walking. Methods - This assessor‐blinded, prospective randomized controlled trial included 80 participants (Expanded Disability Status Scale scores 1–6.5) randomly allocated to GroupCoreDIST, conducted in groups of three for 60 min three times per week for 6 weeks (18 sessions) or standard care (n = 40/40). One participant attended no posttests, leaving 79 subjects for intention‐to‐treat analysis. The assessments were performed at baseline and at Weeks 7, 18, and 30. Outcomes included the 2‐min walk test (2MWT), 10‐m walk test‐preferred/fast/slow speed (10MWT), Multiple Sclerosis Walking Scale‐12 (MSWS‐12), Patient Global Impression of Change‐walking (PGIC‐walking), Rivermead Visual Gait Assessment (RVGA), and ActiGraphsWgt3X‐BT activity monitors (ActiGraph). The statistical analyses included repeated‐measures mixed models performed in IBM SPSS Version 24. Results - There were no significant between‐group differences in the outcome measurements at baseline. The mean differences between groups were significant at all follow‐up time points in favour of GroupCoreDIST for the 2MWT, 16.7 m at 7 weeks (95% CI [8.15, 25.25], 15.08 m at 18 weeks (95% CI [6.39, 23.77]) and 16.38 m at 30 weeks (95% CI [7.65, 25.12]; and the PGIC‐walking, 0.89 points at 7 weeks (95% CI [1.34, 0.45]), 0.97 points at 18 weeks (95% CI [1.42, 0.52]), and 0.93 points at 30 weeks (95% CI [1.39, 0.48]; all p ≤ .001). The 10MWT‐fast speed and the MSWS‐12 showed significant between‐group differences at 7 and 18 weeks and the RVGA at 7 weeks. No between‐group differences were found regarding activity level (ActiGraph) or the 10MWT‐preferred or slow speed. Conclusion - Compared with standard care, GroupCoreDIST significantly improved walking immediately after the intervention for up to 24 weeks of follow‐up.

Freezing of gait (FOG) in patients with Parkinson's disease (PD) is a common problem of unknown origin, which possibly reflects a general motor control deficit. We investigated the relationship between the frequency of freezing episodes during gait and during a bimanual task in control and subjects with PD with and without FOG. Group differences in spatiotemporal characteristics were also examined as well as the effects of visual cueing. Twenty patients with PD in the off-phase of the medication cycle and five age-matched controls performed a repetitive drawing task in an anti-phase pattern on a digitizer tablet. The task was offered at two different speeds (comfortable and maximal) and two different amplitudes (small and large) with and without visual cueing. The results showed that freezing episodes in the upper limbs occurred in only 10.4% of patient trials and that their occurrence was correlated with FOG scores (Spearman's rho = 0.64). Overall, few spatiotemporal differences were found between freezers, non-freezers and controls, except for an overshooting of the target amplitude in controls. Effects of visual cueing were largely similar in all groups, except for the variability of relative phase, which decreased in non-freezers and controls, and was unaffected in freezers. Despite the fact that general motor differences between subgroups were small, freezing episodes were manifest during a bimanual repetitive upper limb task and were correlated to FOG. Further study into upper limb movement breakdown is warranted to understand the parallel deficits that lead up to FOG.

Deficient eye and hand movements are present in patients with multiple sclerosis. In the present study, eye and hand movements were simultaneously measured during visually guided wrist step-tracking tasks in 16 patients with intention tremor and 15 healthy controls. The coupling between eye and hand movements was analyzed during simultaneous eye-hand tracking, and interactions were studied by comparing the coordinated eye-hand condition with isolated eye- or hand-tracking conditions. Despite movement abnormalities, the onset of eye and hand movements was highly correlated and an invariant coupling between the saccadic completion time and hand peak velocity was found, suggesting that the temporal coupling was very much preserved. The differences between the experimental tracking conditions suggest that, in MS patients with intention tremor, the ocular system influenced the hand movements. Intention tremor amplitude was reduced when there was no preceding saccadic eye movement, whereas conversely, eye movements were not affected by different hand tremor severity.