Title Participants Abstract "Test-Retest Reliability of Cognitive-Motor Interference Assessments in Walking With Various Task Complexities in Persons With Multiple Sclerosis" "Renee VELDKAMP, Anders Romberg, Paivi Hämäläinen, Xavier GIFFROY, Lousin MOUMDJIAN, Carmela LEONE, Peter FEYS, Ilse BAERT" "Background. Simultaneous execution of motor and cognitive tasks can result in worsened performance on one or both tasks, indicating cognitive-motor interference (CMI). A growing amount of research on CMI in persons with multiple sclerosis (pwMS) is observed. However, psychometric properties of dual-task outcomes have been scarcely reported. Objective. To investigate the between-day test-retest reliability of the motor and cognitive dual-task costs (DTCs) during multiple CMI test conditions with various task complexities in pwMS and matched healthy controls (HCs). Methods. A total of 34 pwMS (Expanded Disability Status Scale score 3.0 ± 0.8) and 31 HCs were tested and retested on 3 single cognitive, 4 single motor, and 12 cognitive-motor dual tasks. Cognitive tasks included serial subtraction by 7, titrated digit span backward, and auditory vigilance. Motor tasks were walking at self-selected speed, over obstacles, crisscross, and while carrying a water-filled cup. Outcome measures were cognitive and motor DTC, calculated as percentage change of dual-task performance compared with single-task performance. Intraclass correlations (ICCs) and Spearman correlation coefficients were calculated as appropriate. Results. For DTCmotor of gait speed, ICCs ranged from 0.45 to 0.81 and Spearman correlations from 0.74 to 0.82. For DTCcognitive, ICCs ranged from −0.18 to 0.49 and Spearman correlations from −0.28 to 0.26. Reliability depended on the type of motor and cognitive task. Conclusion. Reliability of the DTCmotor was, overall, good, whereas that of the DTCcognitive was poor. The “walking” and “cup” dual-task conditions were the most reliable regardless of the integrated cognitive task." "Differential effects and discriminative validity of motor and cognitive tasks varying in difficulty on cognitive–motor interference in persons with multiple sclerosis" "Renee VELDKAMP, Alon Kalron, Ilse BAERT, Paivi Hamalainen, Andrea Tacchino, Mieke D'HOOGE, Xavier GIFFROY, Fanny VAN GEEL, Joke RAATS, Karin CONINX, Bart VAN WIJMEERSCH, Peter FEYS" "Background: Cognitive-motor interference (CMI) has been well recognized in persons with multiple sclerosis (pwMS); however, there are limited data on effects of task difficulty.Objective: Examine (1) the effects of motor and cognitive tasks varying in difficulty on the magnitude of CMI and (2) the discriminative validity of CMI between pwMS and healthy controls (HC).Methods: Nine cognitive-motor dual-task (DT) conditions (combinations of three cognitive and three walking tasks) were examined. Outcome measures were DT-performance and dual-task cost (DTC) of gait parameters and correct answers. Task differences and overall group-effects were analysed by mixed model analysis, plus the Wilcoxon signed-rank tests or multivariate analysis of variances (MANOVAs), respectively.Results: Task effects were examined in 82 pwMS (Expanded Disability Status Scale (EDSS): 3.3 +/- 1.0) and discriminative validity in a subsample (35 pwMS and 33 HC). Motor-DTC and DT-performance were affected by difficulty of both the cognitive task (p < 0.001) and the walking condition (p" "Design, Development, and Testing of an App for Dual-Task Assessment and Training Regarding Cognitive-Motor Interference (CMI-APP) in People With Multiple Sclerosis: Multicenter Pilot Study" "Andrea Tacchino, Renee VELDKAMP, Karin CONINX, Jens BRULMANS, Sam PALMAERS, Paivi Hamalainen, Mieke D'HOOGE, Ellen VANZEIR, Alon Kalron, Giampaolo Brichetto, Peter FEYS, Ilse BAERT" "Background: Dual tasking constitutes a large portion of most activities of daily living; in real-life situations, people need to not only maintain balance and mobility skills, but also perform other cognitive or motor tasks at the same time. Interest toward dual-task training (DTT) is increasing as traditional interventions may not prepare patients to adequately face the challenges of most activities of daily living. These usually involve simultaneous cognitive and motor tasks, and they often show a decline in performance. Cognitive-motor interference (CMI) has been investigated in different neurological populations, but limited evidence is present for people with multiple sclerosis (MS). The use of computerized tools is mandatory to allow the application of more standardized assessment and rehabilitation intervention protocols and easier implementation of multicenter and multilanguage studies. Objective: To describe the design and development of CMI-APP, an adaptive and interactive technology tablet-based app, and to present the preliminary results of a multicenter pilot study involving people with MS performed in several European centers for evaluating the feasibility of and adherence to a rehabilitation program based on CMI-APP. Methods: CMI-APP includes user-friendly interfaces for personal data input and management, assessment of CMI, and DTT. A dedicated team developed CMI-APP for Android tablets above API level 14 (version 4.0), using C# as the programming language and Unity and Visual Studio as development tools. Three cognitive assessment tests for working memory, information processing speed, and sustained attention and four motor assessment tests for walking at different difficulty levels were implemented. Dual cognitive-motor tasks were performed by combining single cognitive and motor tasks. CMI-APP implements exercises for DTT involving the following 12 cognitive functions: sustained attention, text comprehension, verbal fluency, auditory discrimination, visual discrimination, working memory, information processing speed, auditory memory, visual memory, verbal analog reasoning, visual analog reasoning, and visual spatial planning, which can be performed during walking or stepping on the spot. Fifteen people with MS (mean age 52.6, SD 8.6 years; mean disease duration 9.4, SD 8.4 years; mean Expanded Disability Status Scale score 3.6, SD 1.1) underwent DTT (20 sessions). Adherence to the rehabilitation program was evaluated according to the percentage of performed sessions, perceived exertion during the training (Borg 15-point Ratings of Perceived Exertion [RPE] Scale), and subjective experience of the training (Intrinsic Motivation Inventory [IMI]). Results: The adherence rate was 91%. DTT was perceived as ""somewhat difficult"" (mean RPE Scale score 12.6, SD 1.9). IMI revealed that participants enjoyed the training and felt that it was valuable and, to some extent, important, without feelings of pressure. They felt competent, although they did not always feel they could choose the exercises, probably because the therapist chose the exercises and many exercises had few difficulty levels. Conclusions: CMI-APP is safe, highly usable, motivating, and well accepted for DTT by people with MS. The findings are fundamental for the preparation of future large-sample studies examining CMI and the effectiveness of DTT interventions with CMI-APP in people with MS." "Profiling cognitive-motor interference in a large sample of persons with progressive multiple sclerosis and impaired processing speed: results from the CogEx study" "Renee VELDKAMP, Mieke D'HOOGE, B. M. Sandroff, J. DeLuca, D. Kos, A. Salter, A. Feinstein, M. P. Amato, G. Brichetto, J. Chataway, R. Farrell, N. D. Chiaravalloti, U. Dalgas, M. Filippi, J. Freeman, R. W. Motl, C. Meza, M. Inglese, M. A. Rocca, G. Cutter, Peter FEYS, CogEx Res Team" "BackgroundPerforming cognitive-motor dual tasks (DTs) may result in reduced walking speed and cognitive performance. The effect in persons with progressive multiple sclerosis (pwPMS) having cognitive dysfunction is unknown.ObjectiveTo profile DT-performance during walking in cognitively impaired pwPMS and examine DT-performance by disability level.MethodsSecondary analyses were conducted on baseline data from the CogEx-study. Participants, enrolled with Symbol Digit Modalities Test 1.282 standard deviations below normative value, performed a cognitive single task ([ST], alternating alphabet), motor ST (walking) and DT (both). Outcomes were number of correct answers on the alternating alphabet task, walking speed, and DT-cost (DTC: decline in performance relative to the ST). Outcomes were compared between EDSS subgroups (= 6). Spearman correlations were conducted between the DTCmotor with clinical measures. Adjusted significance level was 0.01.ResultsOverall, participants (n = 307) walked slower and had fewer correct answers on the DT versus ST (both p < 0.001), with a DTCmotor of 15.8% and DTCcognitive of 2.7%. All three subgroups walked slower during the DT versus ST, with DTCmotor different from zero (p's < 0.001). Only the EDSS >= 6 group had fewer correct answers on the DT versus ST (p < 0.001), but the DTCcognitive did not differ from zero for any of the groups (p >= 0.039).ConclusionDual tasking substantially affects walking performance in cognitively impaired pwPMS, to a similar degree for EDSS subgroups." "Cognitive-motor dual-task interference : a systematic review of neural correlates" "Carmela Leone, Peter Feys, Lousin Moumddjian, Emanuele D'Amico, Mario Zappia, Francesco Patti" "Cognitive-motor Interference in Individuals With a Neurologic Disorder: A Systematic Review of Neural Correlates" "Renee VELDKAMP, Mieke GOETSCHALCKX, Hanneke E Hulst, Alice Nieuwboer, Kathleen Grieten, Ilse BAERT, Carmela LEONE, Lousin MOUMDJIAN, Peter FEYS" "Comparing 16 different dual-tasking paradigms in individuals with multiple sclerosis and healthy controls : working memory tasks indicate cognitive-motor interference" "Carmela Leone, Lousin Moumddjian, Francesco Patti, Ellen Vanzeir, Ilse Baert, Renee Veldkamp, Bart Van Wijmeersch, Peter Feys" "The impact of vestibular function on cognitive–motor interference : a case–control study on dual-tasking in persons with bilateral vestibulopathy and normal hearing" "Maya Danneels, Ruth Van Hecke, Laura Leyssens, Raymond van de Berg, Ingeborg Dhooge, Dirk Cambier, Stefan Delrue, Vincent Van Rompaey, Leen Maes" "Bilateral vestibulopathy (BV) is a chronic vestibular disorder, characterized by bilaterally absent or significantly impaired vestibular function. Symptoms typically include, but are not limited to, unsteadiness and movement-induced blurred vision (oscillopsia). This prospective case–control study aimed to elucidate the impact of BV on cognitive and motor performance and on cognitive–motor interference. Cognitive and motor performance, as well as cognitive–motor interference were measured in persons with BV and normal hearing using the 2BALANCE dual-task protocol. The experimental group was matched to a healthy control group based on age, sex, and educational level. The 2BALANCE protocol comprises cognitive tests assessing visuospatial memory, mental rotation, visual and auditory response inhibition, visual and auditory working memory, and processing speed. The cognitive tests were performed in single-task condition (while seated), and in dual-task condition (during a static and a dynamic motor task). The static motor task consisted of balancing on a force platform with foam pad. The dynamic motor task consisted of walking at a self-selected speed. These motor tasks were also performed in single-task condition. A generalized estimating equations model was used to investigate group differences for all cognitive and motor outcome measures. The estimated marginal means, as well as the odds ratios (OR), and their 95% confidence intervals (CI) were calculated. For the backward digit recall test, a baseline measurement was performed and analyzed using a student-t test. A total of 22 patients with BV and normal hearing and 22 healthy control subjects were assessed [mean age (SD), BV = 53.66 (13.35) and HC = 53.21 (13.35), 68% male]. The BV group had poorer mental rotation skills in single-task condition, compared to the control group [odds ratio (OR) = 2.30, confidence interval (CI) = 1.12–4.73, P  =  0.024]. Similarly, auditory and visual working memory were also poorer in the BV group in single-task condition (P = 0.028 and P = 0.003, respectively). The BV group also performed poorer on the mental rotation task and the visual response inhibition task in dual-task condition (OR = 2.96, CI = 1.57–5.59, P  <  0.001 and OR = 1.08, CI = 1.01–1.16, P  =  0.032, respectively). Additionally, an interaction effect, indicating increased cognitive–motor interference in the BV group, was observed for mental rotation, response inhibition, and auditory working memory (P  =  0.003 to 0.028). All static motor outcome parameters indicated more postural sway in the BV group compared to the control group for all test conditions (P  <  0.001 to 0.026). No group differences were noted for the dynamic motor task. These findings suggest a link between vestibular function and cognitive performance, as well as a greater interference between cognitive and motor performance in BV, compared to healthy controls." "Association of bilateral vestibulopathy with and without hearing loss with cognitive-motor interference" "Maya Danneels, Ruth Van Hecke, Laura Leyssens, Raymond van de Berg, Ingeborg Dhooge, Dirk Cambier, Vincent Van Rompaey, Leen Maes" "IMPORTANCE The past years, evidence suggested that the primary symptoms traditionally associated with bilateral vestibulopathy (BV) do not represent the full picture of this patient population. Recent literature also demonstrated cognitive impairment. However, although multitasking and dual-tasking are widely present in everyday activities, most of these studies assessed cognitive function only in single-task conditions. OBJECTIVE To uncover the association of BV with and without hearing loss with cognitive and motor performance and cognitive-motor interference. DESIGN, SETTING, AND PARTICIPANTS This prospective case-control study assessed persons with an isolated BV and persons with BV and a concomitant hearing loss compared with a healthy control group. Data were analyzed in December 2022. The study was conducted at Ghent University (Ghent, Belgium). Data collection took place between March 26, 2021, and November 29, 2022. MAIN OUTCOMES AND MEASURES All participants completed the 2BALANCE dual-task protocol, comprising a static and a dynamic motor task that was combined with 5 visual cognitive tasks. These cognitive tasks assessed mental rotation, visuospatial memory, working memory, response inhibition (executive function), and processing speed. All cognitive tasks were performed in a single-task condition (while seated) and in a dual-task condition (combined with a static and a dynamic motor task). The static task comprised balancing on a force platform with foam pad, and the dynamic task comprised walking at a self-selected speed on the GAITRiteWalkway. Both motor tasks were performed in the single-task and dual-task condition. RESULTS Nineteen persons with BV and hearing loss (mean [SD] age, 56.70 [10.12] years; 10 women [52.6%]), 22 persons with an isolated BV (mean [SD] age, 53.66 [13.35] years; 7 women [31.8%]), and 28 healthy control participants were included (mean [SD] age, 53.73 [12.77] years; 12 women [42.9%]). Both patient groups had mental rotation and working memory impairment in a single-task condition and slower processing speed when walking (ie, during the dynamic dual-task condition). Additionally, the patient group with hearing loss had impaired visuospatial memory and executive function deficits in single-task and dual-task conditions, while this could only be elicited when performing a motor task in persons with isolated BV (ie, when dual-tasking). CONCLUSION AND RELEVANCE The findings of this case-control study suggest an association between vestibular function and cognitive and motor performance, even greater in persons with a concomitant hearing loss than in persons with an isolated BV." "Cognitive-motor interference in persons with multiple sclerosis during five upper limb motor tasks with different complexity" "Joke Raats, Ilse Lamers, Ilse Baert, Barbara Willekens, Renee Veldkamp, Peter Feys" "Background: Cognitive-motor interference in multiple sclerosis has been well examined during walking, but not during upper limb (UL) performance. Objectives: To examine the dual-task cost (DTC) in persons with multiple sclerosis (pwMS) and healthy controls (HC) in various type and complexity of UL motor tasks. Method: In total, 30 pwMS without major UL impairment and 30 HC performed five different UL tasks, in single condition and combined with the phonemic word list generation task. The percent change in performances was evaluated by the motor, cognitive, and combined DTC. The motor tasks consisted of four unimanual (sustained hand grip strength, box-and-block test, Purdue pegboard test, finger tapping task) and one bimanual task (Purdue pegboard test). Group and task differences were analyzed with unpaired and paired t-tests, respectively, and overall effect with a multivariate analysis of variance. Results: The motor DTC ranged between 10% (Purdue pegboard bimanual) and 35% (box-and-block test). The cognitive DTC ranged between -8% (finger tapping test) and +21% (bimanual Purdue pegboard). The magnitude of the combined DTC did not differ significantly between pwMS and HC in any task. Conclusion: DTC is influenced by the complexity of the UL task, but was not significantly different between HC and cognitive intact, but mildly motor disabled pwMS."