- Email: [email protected]
17. Oscillations in the basal ganglia – Cognitive aspects
Society Proceedings / Clinical Neurophysiology 123 (2012) e9–e15
15. Intraoperative monitoring of evoked potentials in scoliosis surgery at University Hospital Brno—M. Neˇmec a, P. Praksová a, M. Leznar b, M. Repko b, V. Tichy´ b, M. Mokrá c, H. Horálková c, J. Bednarˇík a (a Clinic of Neurology, Brno, Czech Republic, b Orthopedic Clinic, Brno, Czech Republic, c Clinic of Anesthesiology, Resuscitation and Intensive Care, Brno, Czech Republic) Aim: The aim of our study was the evaluation of sensitivity and specificity of intraoperative monitoring (IOM) of evoked potentials (EP) in scoliosis and developmental spinal deformities surgery in our hospital. Materials and methods: we evaluated retrospectively all intraoperative monitoring of motor (MEP) and somatosensory evoked potentials (SEP) during surgery of scoliosis and spinal deformities at Orthopedic clinic of University Hospital Brno between January 2003 and August 2011. Results: Altogether 407 IOM using MEP and SEP were performed in 333 female and 74 male patients (mean age, 14,9; range, 2– 45 years). No evoked responses were recorded during three surgeries due to technical reasons. Retrospectively, with respect to postoperative neurological status we identified 391 true negative monitoring, 1 false negative monitoring, 10 true positive monitoring (significant EP changes which disappeared during surgery after targeted intervention were observed or these changes remained and correlated with postoperative neurological deficit), and 2 false positive monitoring. Significant permanent neurological deficit was observed in 2 patients (0.50%). Conclusion: Combined MEP and SEP IOM showed 91% sensitivity and 99.5% specificity in prediction of postoperative neurological status. Permanent neurological deficit was observed in 0.50% of surgeries. These findings correspond to those referred by other authors.
doi:10.1016/j.clinph.2011.10.027
16. Influence of water on the character of a surface EMG signal (WaS-EMG)—D. Pánek a, D. Jurák b, D. Pavlu˚ a, V. Krajcˇa c, a a ˇ J. Cemusová ( Department of Physiotherapy, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic, b Department of Swimming, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic, c Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University, Kladno, Czech Republic) Introduction: We present our personal experience with Water Surface Electromyography (WaS-EMG), and we compare our results with sources in the literature. Methodology: We started with a series of experiments conducted in the Swimming Sports Laboratory at FTVS, UK. We registered muscle activity with the help of a telemetric surface EMG instrument TelemyoMini 16 by Neurodata. Results: It is necessary to ensure a permanent water resistant of surface electrodes and also to attach loose cables of electrodes, because their movement in water leads to artifacts in the frequency band 0–20 Hz. For stipulating maximum voluntary contraction, it is recommended movement in a dry environment. The change in the degree of the activity of muscles in water is more dependent on its speed than in a dry environment. Stabilization of the temperature of a muscle and the ambient water takes approximately 15 min. Conclusion: There is no primary influence on the EMG signal in water. The specificity of the watery environment leads, in comparison with a dry, to different muscle timing, a change in the proportional representation of the activity of agonist–antagonist muscles,
e13
and various compensatory mechanisms that follow from postural instability during movements in water. Acknowledgement: This work was elaborated with the help of the research plan VZ MŠMT Czech Republic MSM 0021620864. doi:10.1016/j.clinph.2011.10.028
17. Oscillations in the basal ganglia – Cognitive aspects— M. Bocˇková a, J. Chládek b, P. Jurák b, J. Halámek b, M. Balázˇ a, I. Rektor a (a First Department of Neurology, Masaryk University, St. Anne’s Hospital, Brno, Czech Republic, b Institute of Scientific Instruments of the Academy of Sciences of the Czech Republic, v.v.i., Brno, Czech Republic) Background: The aim of this work was to study high- frequency oscillations in the subthalamic nucleus and internal pallidum linked to cognitive and motor activities using event-related de/synchronizations (ERD/S) methodology. Methods: Intracerebral EEG was recorded in two patients suffering from dystonia, one patient with essential tremor and two patients with Parkinson’ disease from the subthalamic nucleus and globus pallidum internum using depth brain electrodes, which were implanted because of DBS surgery treatment. The subjects performed two cognitive motor tasks with writing of single letters with increasing load on executive functions. Results: We have found local desynchronization in the alpha and beta frequency bands and synchronization in the gamma band around 60–90 Hz regardless of structure or diagnosis. Beta ERD was amplified with increasing cognitive load. Far field high frequency activity was missing in the patients with Parkinson’s disease what is probably related to the pathophysiology of the disease. Conclusions: Deep knowledge of the electrophysiological phenomena and oscillations in the basal ganglia could probably help us in the future with the deep brain stimulation parameter settings in order to optimize the therapeutic effect and minimize the undesirable side effects. doi:10.1016/j.clinph.2011.10.029
18. Treatment-induced change of cortical activation: fMRI evidence of the central effect of BoNT-A—P. Hluštík, R. Opavsky´, ˇ ovsky´ T. Veverka, M. Nevrly´, K. Farníková, P. Otruba, P. Kan (Department of Neurology, Faculty of Medicine and Dentistry, Palacky´ University Olomouc, Czech Republic) The central mechanism of idiopathic dystonia is presumably localized within the brain although there has been no direct evidence for involvement of specific brain structures. Similarly, the exact cerebral correlate of post-stroke spasticity is unknown. We have performed a series of investigation with aiming to localize the potential central mechanisms. In four fMRI studies, we used botulinum toxin A (BoNT-A) injections to study sensorimotor processing changes at different levels of central nervous system. In the first three studies, we recorded cortical activation changes in patients with post-stroke arm spasticity who performed either a sequential finger movement or its mental simulation. fMRI showed increased activation of the non-motor structures (posterior cingulum/precuneus, prefrontal cortex), which decreased or normalized following BoNT-A treatment. In the fourth study, the impact of BoNT-A treatment on the cortex activation pattern in cervical dystonia has been studied; a significant decrease in the activation of premotor cortex was demonstrated.
15. Intraoperative monitoring of evoked potentials in scoliosis surgery at University Hospital Brno—M. Neˇmec a, P. Praksová a, M. Leznar b, M. Repko b, V. Tichy´ b, M. Mokrá c, H. Horálková c, J. Bednarˇík a (a Clinic of Neurology, Brno, Czech Republic, b Orthopedic Clinic, Brno, Czech Republic, c Clinic of Anesthesiology, Resuscitation and Intensive Care, Brno, Czech Republic) Aim: The aim of our study was the evaluation of sensitivity and specificity of intraoperative monitoring (IOM) of evoked potentials (EP) in scoliosis and developmental spinal deformities surgery in our hospital. Materials and methods: we evaluated retrospectively all intraoperative monitoring of motor (MEP) and somatosensory evoked potentials (SEP) during surgery of scoliosis and spinal deformities at Orthopedic clinic of University Hospital Brno between January 2003 and August 2011. Results: Altogether 407 IOM using MEP and SEP were performed in 333 female and 74 male patients (mean age, 14,9; range, 2– 45 years). No evoked responses were recorded during three surgeries due to technical reasons. Retrospectively, with respect to postoperative neurological status we identified 391 true negative monitoring, 1 false negative monitoring, 10 true positive monitoring (significant EP changes which disappeared during surgery after targeted intervention were observed or these changes remained and correlated with postoperative neurological deficit), and 2 false positive monitoring. Significant permanent neurological deficit was observed in 2 patients (0.50%). Conclusion: Combined MEP and SEP IOM showed 91% sensitivity and 99.5% specificity in prediction of postoperative neurological status. Permanent neurological deficit was observed in 0.50% of surgeries. These findings correspond to those referred by other authors.
doi:10.1016/j.clinph.2011.10.027
16. Influence of water on the character of a surface EMG signal (WaS-EMG)—D. Pánek a, D. Jurák b, D. Pavlu˚ a, V. Krajcˇa c, a a ˇ J. Cemusová ( Department of Physiotherapy, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic, b Department of Swimming, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic, c Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University, Kladno, Czech Republic) Introduction: We present our personal experience with Water Surface Electromyography (WaS-EMG), and we compare our results with sources in the literature. Methodology: We started with a series of experiments conducted in the Swimming Sports Laboratory at FTVS, UK. We registered muscle activity with the help of a telemetric surface EMG instrument TelemyoMini 16 by Neurodata. Results: It is necessary to ensure a permanent water resistant of surface electrodes and also to attach loose cables of electrodes, because their movement in water leads to artifacts in the frequency band 0–20 Hz. For stipulating maximum voluntary contraction, it is recommended movement in a dry environment. The change in the degree of the activity of muscles in water is more dependent on its speed than in a dry environment. Stabilization of the temperature of a muscle and the ambient water takes approximately 15 min. Conclusion: There is no primary influence on the EMG signal in water. The specificity of the watery environment leads, in comparison with a dry, to different muscle timing, a change in the proportional representation of the activity of agonist–antagonist muscles,
e13
and various compensatory mechanisms that follow from postural instability during movements in water. Acknowledgement: This work was elaborated with the help of the research plan VZ MŠMT Czech Republic MSM 0021620864. doi:10.1016/j.clinph.2011.10.028
17. Oscillations in the basal ganglia – Cognitive aspects— M. Bocˇková a, J. Chládek b, P. Jurák b, J. Halámek b, M. Balázˇ a, I. Rektor a (a First Department of Neurology, Masaryk University, St. Anne’s Hospital, Brno, Czech Republic, b Institute of Scientific Instruments of the Academy of Sciences of the Czech Republic, v.v.i., Brno, Czech Republic) Background: The aim of this work was to study high- frequency oscillations in the subthalamic nucleus and internal pallidum linked to cognitive and motor activities using event-related de/synchronizations (ERD/S) methodology. Methods: Intracerebral EEG was recorded in two patients suffering from dystonia, one patient with essential tremor and two patients with Parkinson’ disease from the subthalamic nucleus and globus pallidum internum using depth brain electrodes, which were implanted because of DBS surgery treatment. The subjects performed two cognitive motor tasks with writing of single letters with increasing load on executive functions. Results: We have found local desynchronization in the alpha and beta frequency bands and synchronization in the gamma band around 60–90 Hz regardless of structure or diagnosis. Beta ERD was amplified with increasing cognitive load. Far field high frequency activity was missing in the patients with Parkinson’s disease what is probably related to the pathophysiology of the disease. Conclusions: Deep knowledge of the electrophysiological phenomena and oscillations in the basal ganglia could probably help us in the future with the deep brain stimulation parameter settings in order to optimize the therapeutic effect and minimize the undesirable side effects. doi:10.1016/j.clinph.2011.10.029
18. Treatment-induced change of cortical activation: fMRI evidence of the central effect of BoNT-A—P. Hluštík, R. Opavsky´, ˇ ovsky´ T. Veverka, M. Nevrly´, K. Farníková, P. Otruba, P. Kan (Department of Neurology, Faculty of Medicine and Dentistry, Palacky´ University Olomouc, Czech Republic) The central mechanism of idiopathic dystonia is presumably localized within the brain although there has been no direct evidence for involvement of specific brain structures. Similarly, the exact cerebral correlate of post-stroke spasticity is unknown. We have performed a series of investigation with aiming to localize the potential central mechanisms. In four fMRI studies, we used botulinum toxin A (BoNT-A) injections to study sensorimotor processing changes at different levels of central nervous system. In the first three studies, we recorded cortical activation changes in patients with post-stroke arm spasticity who performed either a sequential finger movement or its mental simulation. fMRI showed increased activation of the non-motor structures (posterior cingulum/precuneus, prefrontal cortex), which decreased or normalized following BoNT-A treatment. In the fourth study, the impact of BoNT-A treatment on the cortex activation pattern in cervical dystonia has been studied; a significant decrease in the activation of premotor cortex was demonstrated.