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P126. Functional connectivity of resting state EEG in MS patients: Follow-up over two years
Society Proceedings / Clinical Neurophysiology 126 (2015) e63–e170
References Cipresso P, Carelli L, Solca F, et al. The use of P300-based BCIs in amyotrophic lateral sclerosis: from augmentative and alternative communication to cognitive assessment. Brain Behav 2012;2:479–98. Kübler A, Furdea A, Halder S, Hammer EM, Nijboer F, Kotchoubey B. A brain–computer interface controlled auditory event-related potential (P300) spelling system for locked-in patients. Ann N Y Acad Sci 2009;1157:90–100. Lugo ZR, Rodriguez J, Lechner A, Ortner R, Gantner IS, Laureys S, et al. A vibrotactile P300-based BCI for consciousness detection and communication. Clin EEG Neurosci 2014.
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centro-parietal regions in the upper alpha band may be a more dynamic marker. However, on average, patients neither experience a change in clinical status, cognitive function nor fatigue during the observation period. Thus it remains unclear whether reduced beta-connectivity represents a marker of state or of trait. Disclosure: The study has been financially supported by grants of the Swiss National Science Foundation (grants # 33CM30-124115/1; # 33CM30–140338; # 326030–128775/1) and the Swiss Multiple Sclerosis Society.
doi:10.1016/j.clinph.2015.04.252 doi:10.1016/j.clinph.2015.04.253
P126. Functional connectivity of resting state EEG in MS patients: Follow-up over two years—M. Hardmeier a, F. Hatz a, I.K. Penner b, Y. Naegelin a, H. Bousleiman a,c, C. Schindler c, L. Kappos a, P. Fuhr a (a Universitätsspital Basel, Neurologie, Basel, Switzerland, b Universität Basel, Kognitive Psychologie Methodologie, Basel, Switzerland, c Swiss Tropical and Public Health Institute, Basel, Switzerland) Background: Functional connectivity is a promising tool to characterize and analyze alterations of oscillating brain activity. In MS the significance of such alterations is not well known. Objective: To explore the dynamics of functional connectivity in MS over time. Methods: 57 RRMS-patients (76% female; median age: 38.4 yrs, interquartile range (IQR): 33.2–44.5 yrs; median EDSS: 2.0; IQR: 1.5–3.0) and 35 normal controls (80% female; median age: 38.4 yrs, IQR: 30.4–43.2 yrs) received a 256 channel EEG at baseline and at years 1 and 2, and were assessed by the EDSS, the symbol digit modalities test (SDMT) and the fatigue scale for motor and cognitive functions (FSMC, Penner et al., 2009). Functional connectivity between 22 regions was determined by the phase lag index (PLI, Stam et al., 2007) using TAPEEG (Hatz et al., 2014). The connectomes and the average connectivity of each region were calculated in four frequency bands (theta, lower and upper alpha, beta) and compared between groups and over time by permutation t-tests and ANOVA. Result: Compared with normal controls, patients had reduced cognitive processing speed (SDMT: 56.2 vs. 63.8, p0.1). Connectivity in the beta-band was reduced in MS patients, most significantly over left temporo-parieto-occipital regions (p). Conclusions: Reduced connectivity over the left temporo-parieto-occipital regions in the beta-band discriminates between groups of MS patients and healthy controls, but does not change over time, whereas connectivity over the right
P127. Mirror motor activity and its relation to white matter in the posterior midbody of the corpus callosum—B. Sehm, C. Steele, A. Villringer, P. Ragert (Max Planck Institute for Human Cognitive and Brain Sciences, Neurology, Leipzig, Germany) Cortical activity during simple unimanual actions is typically lateralized to contralateral sensorimotor areas, while a more bilateral pattern is observed with an increase in task demands. In parallel, increasing task demands are associated with subtle mirror muscle activity in the resting hand, implying a relative loss in motor selectivity. The corpus callosum (CC) is crucially involved in unimanual tasks by mediating both facilitatory and inhibitory interactions between bilateral motor cortical systems, but its association with mirror motor activity is yet unknown. Here we used diffusion-weighted imaging (DWI) and bilateral EMG measurements during a unimanual task to investigate potential relationships between white matter microstructure of the CC and mirror EMG activity. Participants performed a unimanual pinch force task with both hands. 4 parametrically increasing force levels were exerted while electromyographic (EMG) activity was recorded bilaterally from first dorsal interosseus muscles. Consistent with previous findings, mirror EMG activity increased as a function of force. Additionally, there was a significant relationship between the slope of mirror EMG increases and fractional anisotropy in transcallosal fibres connecting both primary motor cortices. No significant relationships were found for fibres connecting dorsal premotor cortices or supplementary motor area, indicating the local specificity of the observed brain–physiology relationship. doi:10.1016/j.clinph.2015.04.254
Fig. 1. Topographies of group differences over time. Color of nodes represents T-values (negative T-values: HC > MS); Links with p < 0.01 are plotted.
References Cipresso P, Carelli L, Solca F, et al. The use of P300-based BCIs in amyotrophic lateral sclerosis: from augmentative and alternative communication to cognitive assessment. Brain Behav 2012;2:479–98. Kübler A, Furdea A, Halder S, Hammer EM, Nijboer F, Kotchoubey B. A brain–computer interface controlled auditory event-related potential (P300) spelling system for locked-in patients. Ann N Y Acad Sci 2009;1157:90–100. Lugo ZR, Rodriguez J, Lechner A, Ortner R, Gantner IS, Laureys S, et al. A vibrotactile P300-based BCI for consciousness detection and communication. Clin EEG Neurosci 2014.
e153
centro-parietal regions in the upper alpha band may be a more dynamic marker. However, on average, patients neither experience a change in clinical status, cognitive function nor fatigue during the observation period. Thus it remains unclear whether reduced beta-connectivity represents a marker of state or of trait. Disclosure: The study has been financially supported by grants of the Swiss National Science Foundation (grants # 33CM30-124115/1; # 33CM30–140338; # 326030–128775/1) and the Swiss Multiple Sclerosis Society.
doi:10.1016/j.clinph.2015.04.252 doi:10.1016/j.clinph.2015.04.253
P126. Functional connectivity of resting state EEG in MS patients: Follow-up over two years—M. Hardmeier a, F. Hatz a, I.K. Penner b, Y. Naegelin a, H. Bousleiman a,c, C. Schindler c, L. Kappos a, P. Fuhr a (a Universitätsspital Basel, Neurologie, Basel, Switzerland, b Universität Basel, Kognitive Psychologie Methodologie, Basel, Switzerland, c Swiss Tropical and Public Health Institute, Basel, Switzerland) Background: Functional connectivity is a promising tool to characterize and analyze alterations of oscillating brain activity. In MS the significance of such alterations is not well known. Objective: To explore the dynamics of functional connectivity in MS over time. Methods: 57 RRMS-patients (76% female; median age: 38.4 yrs, interquartile range (IQR): 33.2–44.5 yrs; median EDSS: 2.0; IQR: 1.5–3.0) and 35 normal controls (80% female; median age: 38.4 yrs, IQR: 30.4–43.2 yrs) received a 256 channel EEG at baseline and at years 1 and 2, and were assessed by the EDSS, the symbol digit modalities test (SDMT) and the fatigue scale for motor and cognitive functions (FSMC, Penner et al., 2009). Functional connectivity between 22 regions was determined by the phase lag index (PLI, Stam et al., 2007) using TAPEEG (Hatz et al., 2014). The connectomes and the average connectivity of each region were calculated in four frequency bands (theta, lower and upper alpha, beta) and compared between groups and over time by permutation t-tests and ANOVA. Result: Compared with normal controls, patients had reduced cognitive processing speed (SDMT: 56.2 vs. 63.8, p0.1). Connectivity in the beta-band was reduced in MS patients, most significantly over left temporo-parieto-occipital regions (p). Conclusions: Reduced connectivity over the left temporo-parieto-occipital regions in the beta-band discriminates between groups of MS patients and healthy controls, but does not change over time, whereas connectivity over the right
P127. Mirror motor activity and its relation to white matter in the posterior midbody of the corpus callosum—B. Sehm, C. Steele, A. Villringer, P. Ragert (Max Planck Institute for Human Cognitive and Brain Sciences, Neurology, Leipzig, Germany) Cortical activity during simple unimanual actions is typically lateralized to contralateral sensorimotor areas, while a more bilateral pattern is observed with an increase in task demands. In parallel, increasing task demands are associated with subtle mirror muscle activity in the resting hand, implying a relative loss in motor selectivity. The corpus callosum (CC) is crucially involved in unimanual tasks by mediating both facilitatory and inhibitory interactions between bilateral motor cortical systems, but its association with mirror motor activity is yet unknown. Here we used diffusion-weighted imaging (DWI) and bilateral EMG measurements during a unimanual task to investigate potential relationships between white matter microstructure of the CC and mirror EMG activity. Participants performed a unimanual pinch force task with both hands. 4 parametrically increasing force levels were exerted while electromyographic (EMG) activity was recorded bilaterally from first dorsal interosseus muscles. Consistent with previous findings, mirror EMG activity increased as a function of force. Additionally, there was a significant relationship between the slope of mirror EMG increases and fractional anisotropy in transcallosal fibres connecting both primary motor cortices. No significant relationships were found for fibres connecting dorsal premotor cortices or supplementary motor area, indicating the local specificity of the observed brain–physiology relationship. doi:10.1016/j.clinph.2015.04.254
Fig. 1. Topographies of group differences over time. Color of nodes represents T-values (negative T-values: HC > MS); Links with p < 0.01 are plotted.