Browsing by Author "Radovanovic, Sasa (6604015284)"

Background Gait pattern is frequently impaired in multiple sclerosis (MS), however gait characteristics in patients with different MS phenotypes have not been fully elucidated. Methods We analyzed spatio-temporal gait pattern characteristics in patients with relapsing-remitting (RR, n=52) and primary-progressive (PP, n=18) MS in comparison with age-matched healthy controls (HC, n=40). All subjects performed a standardized simple walking task, a dual motor- motor task, a dual motor-mental task, and a triple combined motor-mental task at a GAITRite electronic walkway of 5.5 m active area. We measured: cycle time (CT), stride length (SL), swing time (ST), double support time (DST), gait velocity (GV) and calculated symmetry index (SI) for CT, SL and ST. Results With each task performed, CT and DST in the total MS group were significantly longer while SL was significantly shorter and GV significantly lower than in HC. ST was similar in the total MS patient group and HC. In both MS patients and HC, CT and DST increased and SL and GV decreased over repeated assessments. Dual and triple tasks while walking influenced walking performance in both MS patients and HC. Although patients with PPMS differed significantly from those with RRMS in the majority of gait parameters, the subgroup analysis in patients matched for age and disability (Expanded Disability Status Scale Score -EDSS, 3.0–5.0) showed similar gait performance in RRMS and PPMS patients having the same level of disability, except for CT and ST- symmetry parameters that were more impaired in the PPMS group. The EDSS score correlated significantly with CT, DST, SL and GV, but no significant correlation was found with ST except at the triple combined motor-mental task. Conclusion A disturbed gait pattern in MS patients with different MS phenotypes depends on disability and reflects a cognitive-motor interference. © 2017 Elsevier B.V.

Background Gait pattern is frequently impaired in multiple sclerosis (MS), however gait characteristics in patients with different MS phenotypes have not been fully elucidated. Methods We analyzed spatio-temporal gait pattern characteristics in patients with relapsing-remitting (RR, n=52) and primary-progressive (PP, n=18) MS in comparison with age-matched healthy controls (HC, n=40). All subjects performed a standardized simple walking task, a dual motor- motor task, a dual motor-mental task, and a triple combined motor-mental task at a GAITRite electronic walkway of 5.5 m active area. We measured: cycle time (CT), stride length (SL), swing time (ST), double support time (DST), gait velocity (GV) and calculated symmetry index (SI) for CT, SL and ST. Results With each task performed, CT and DST in the total MS group were significantly longer while SL was significantly shorter and GV significantly lower than in HC. ST was similar in the total MS patient group and HC. In both MS patients and HC, CT and DST increased and SL and GV decreased over repeated assessments. Dual and triple tasks while walking influenced walking performance in both MS patients and HC. Although patients with PPMS differed significantly from those with RRMS in the majority of gait parameters, the subgroup analysis in patients matched for age and disability (Expanded Disability Status Scale Score -EDSS, 3.0–5.0) showed similar gait performance in RRMS and PPMS patients having the same level of disability, except for CT and ST- symmetry parameters that were more impaired in the PPMS group. The EDSS score correlated significantly with CT, DST, SL and GV, but no significant correlation was found with ST except at the triple combined motor-mental task. Conclusion A disturbed gait pattern in MS patients with different MS phenotypes depends on disability and reflects a cognitive-motor interference. © 2017 Elsevier B.V.

Objective In this study, we analyzed the influence of artificially imposed attention variations using the auditory oddball paradigm on the cortical activity associated to motor preparation/execution. Methods EEG signals from Cz and its surrounding channels were recorded during three sets of ankle dorsiflexion movements. Each set was interspersed with either a complex or a simple auditory oddball task for healthy participants and a complex auditory oddball task for stroke patients. Results The amplitude of the movement-related cortical potentials (MRCPs) decreased with the complex oddball paradigm, while MRCP variability increased. Both oddball paradigms increased the detection latency significantly (p < 0.05) and the complex paradigm decreased the true positive rate (TPR) (p = 0.04). In patients, the negativity of the MRCP decreased while pre-phase variability increased, and the detection latency and accuracy deteriorated with attention diversion. Conclusion Attention diversion has a significant influence on MRCP features and detection parameters, although these changes were counteracted by the application of the laplacian method. Significance Brain–computer interfaces for neuromodulation that use the MRCP as the control signal are robust to changes in attention. However, attention must be monitored since it plays a key role in plasticity induction. Here we demonstrate that this can be achieved using the single channel Cz. © 2016 International Federation of Clinical Neurophysiology

Objective In this study, we analyzed the influence of artificially imposed attention variations using the auditory oddball paradigm on the cortical activity associated to motor preparation/execution. Methods EEG signals from Cz and its surrounding channels were recorded during three sets of ankle dorsiflexion movements. Each set was interspersed with either a complex or a simple auditory oddball task for healthy participants and a complex auditory oddball task for stroke patients. Results The amplitude of the movement-related cortical potentials (MRCPs) decreased with the complex oddball paradigm, while MRCP variability increased. Both oddball paradigms increased the detection latency significantly (p < 0.05) and the complex paradigm decreased the true positive rate (TPR) (p = 0.04). In patients, the negativity of the MRCP decreased while pre-phase variability increased, and the detection latency and accuracy deteriorated with attention diversion. Conclusion Attention diversion has a significant influence on MRCP features and detection parameters, although these changes were counteracted by the application of the laplacian method. Significance Brain–computer interfaces for neuromodulation that use the MRCP as the control signal are robust to changes in attention. However, attention must be monitored since it plays a key role in plasticity induction. Here we demonstrate that this can be achieved using the single channel Cz. © 2016 International Federation of Clinical Neurophysiology