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ID 390 – Association between intraepidermal nerve fiber density and quantitative sensory testing in the patients with possible small fiber neuropathy
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Abstracts / Clinical Neurophysiology 127 (2016) e18–e132
ID 363 – Development of novel paradigms for social neuroscience – Ongoing bilateral project—T. Kašpárek a,b, Z., Krpoun a,c, L. Landa a,d, M. Kolárˇová a,c (a Department of Psychology and Psychosomatics, Faculty of Medicine, Masaryk University, Brno, Czech Republic, b Department of Psychiatry, Faculty Hospital Brno, Masaryk University, Czech Republic, c Department of Psychology, Faculty of Arts, Masaryk University, Brno, Czech Republic, d Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic) The purpose of this paper is to present preliminary results of an ongoing project whose main aim is to create and apply novel paradigms for social neuroscience research (project identification 72p12; period 03/2015-12/2015; investor: Ministry of Education, Youth and Sports of the CR; project type: AKTION). The bilateral project will take advantage of the long-term focus and methodological expertise in human electrophysiology (electroencephalography – EEG, even-related potentials – ERPs) and functional magnetic resonance imaging (fMRI) at the SCAN Unit, Faculty of Psychology, University Vienna, and newly established technological facilities (high-density EEG/ERPs, fMRI) with availability of target subject groups at the Department of Psychiatry, Masaryk University Brno. The project will include (1) developing a set of behavioral paradigms implemented for EEG/ERP and fMRI, (2) collecting pilot data using these paradigms, (3) establishing methods of data analysis, (4) training of students and lab staff in electrophysiological and neuroimaging methods and (5) organizing a meeting of broader neuroscientific communities from both institutions to promote collaboration and preparation of scientific projects that would take advantage of the newly developed solutions and acquainted skills. doi:10.1016/j.clinph.2015.11.190
ID 385 – Temperature dependent changes in HCN channel current (Ih) in human motor axons of different threshold. Implications for generation of febrile seizures—C.E.G. Moore a,b, H.J. Cockerill a,c, O. Marmoy a,c (a Department of Neurophysiology, Queen Alexandra Hospital, Portsmouth, UK, b University of Portsmouth, UK, c Aston University, UK) Objective: Mechanisms underlying seizure initiation are complex. Hyperthermia increases pyramidal cell activity and mutations in the hyperpolarisation-activated-cyclic-nucleotide-modulated-chan nels-(HCN) in patients with febrile seizures show temperature dependent changes in channel kinetics. Changes of axonal excitability in response to hyperthermia was studied in vivo, in human. Methods: Axonal excitability of high (40%) and low (10–20%) threshold motor axons was assessed before and after warming (6 °C). Temperature was maintained using a waterbath and measured using a thermistor placed near the stimulating cathode. Results: Seven female subjects were studied with ethics committee approval. At 40% tracking, axonal excitability showed reduced superexcitability, faster accommodation to depolarization and reduced accommodation to hyperpolarisation (Howells et al., 2013). Low threshold fibers showed the same changes with the marked exception of the response to hyperpolarisation which was significantly increased (p < 0.02). Conclusions: The effect of hyperthermia on inward rectification to hyperpolarisation (HCN channel function) is increased in low threshold fibers and decreased in higher threshold fibers. Higher HCN
function (Ih current) increases resting membrane potential in low threshold fibers. Key message: This temperature related increase in Ih may contribute to initiation of seizures. Modulation of HCN channels may be a novel target for drug development in epilepsy. doi:10.1016/j.clinph.2015.11.191
ID 390 – Association between intraepidermal nerve fiber density and quantitative sensory testing in the patients with possible small fiber neuropathy—M. Nebuchennykh b, S. Løseth a,b, S. Lindal a,c, E. Olsen a, S.I. Mellgren a,b (a Neuromuscular Disease Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Norway, b Department of Neurology and Neurophysiology, University Hospital of Northern Norway, Tromsø, Norway, c Department of Pathology, University Hospital of Northern Norway, Tromsø, Norway) Objective: To evaluate sensitivity of quantitative sensory testing (QST) and skin biopsy with assessment of intraepidermal nerve fiber density (IENFD) in patients with symptoms and clinical findings of small fiber neuropathy (SFN). Methods: This is a retrospective study on 179 patients (age 48.7 ± 14.0 (8–82 years old), 64 men, 115 woman) examined from January 2012 to March 2015. All patients underwent nerve conduction studies (NCS), QST and skin biopsy for assessment of IENFD. Results: NCS were normal in 85% of patients. Mean IENFD in the total patient group was 6.1 ± 2.7 fibers per mm (0.9–17.0). 94 patients (52%) had reduced IENFD. 82 patients (46%) had abnormalities on QST (in 2 and more parameters). However, only 43 patients (24%) had both abnormalities on QST and reduced IENFD. There were normal findings on both QST and IENFD in 29 patients (16%). Conclusions: There is a rather lower concordance between the results of QST and IENFD. It remains unclear if diagnosis of SFN can be excluded in cases of normal findings both on QST and skin biopsy. Key message: Both skin biopsy and QST should be performed in patients with suspected SFN. doi:10.1016/j.clinph.2015.11.192
ID 396 – On the relationship between inter saccadic interval and object velocity in a reaching movement task—O.C. Banea, J. Casanova-Molla, M. Morales, C. Cabib, R. Arca, M. Brum, J. VallsSolé (Department of Neurology, Hospital Clinic, Barcelona, Spain) Objective: We aimed to investigate hand movement onset (HMO), saccadic reaction time (SRT) and the interval between the initial saccade and the corrective saccade (ISI) during a reaching movement task. Methods: Seven subjects, aged 29–39, participated in the study. We projected a scene of a penalty striker-goalkeeper combination and we asked participants to stop the ball (target) by using a linear joystick with the dominant hand. Two series of 20 trials at target velocities of 700 and 1400 pixels/s were performed. The eyemovement angle was 20° from initial fixation point. We measured eye saccade duration (SD) and peak velocity (PV), HMO latency, SRT and ISI in trials in which the subject stopped the ball.
Abstracts / Clinical Neurophysiology 127 (2016) e18–e132
ID 363 – Development of novel paradigms for social neuroscience – Ongoing bilateral project—T. Kašpárek a,b, Z., Krpoun a,c, L. Landa a,d, M. Kolárˇová a,c (a Department of Psychology and Psychosomatics, Faculty of Medicine, Masaryk University, Brno, Czech Republic, b Department of Psychiatry, Faculty Hospital Brno, Masaryk University, Czech Republic, c Department of Psychology, Faculty of Arts, Masaryk University, Brno, Czech Republic, d Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic) The purpose of this paper is to present preliminary results of an ongoing project whose main aim is to create and apply novel paradigms for social neuroscience research (project identification 72p12; period 03/2015-12/2015; investor: Ministry of Education, Youth and Sports of the CR; project type: AKTION). The bilateral project will take advantage of the long-term focus and methodological expertise in human electrophysiology (electroencephalography – EEG, even-related potentials – ERPs) and functional magnetic resonance imaging (fMRI) at the SCAN Unit, Faculty of Psychology, University Vienna, and newly established technological facilities (high-density EEG/ERPs, fMRI) with availability of target subject groups at the Department of Psychiatry, Masaryk University Brno. The project will include (1) developing a set of behavioral paradigms implemented for EEG/ERP and fMRI, (2) collecting pilot data using these paradigms, (3) establishing methods of data analysis, (4) training of students and lab staff in electrophysiological and neuroimaging methods and (5) organizing a meeting of broader neuroscientific communities from both institutions to promote collaboration and preparation of scientific projects that would take advantage of the newly developed solutions and acquainted skills. doi:10.1016/j.clinph.2015.11.190
ID 385 – Temperature dependent changes in HCN channel current (Ih) in human motor axons of different threshold. Implications for generation of febrile seizures—C.E.G. Moore a,b, H.J. Cockerill a,c, O. Marmoy a,c (a Department of Neurophysiology, Queen Alexandra Hospital, Portsmouth, UK, b University of Portsmouth, UK, c Aston University, UK) Objective: Mechanisms underlying seizure initiation are complex. Hyperthermia increases pyramidal cell activity and mutations in the hyperpolarisation-activated-cyclic-nucleotide-modulated-chan nels-(HCN) in patients with febrile seizures show temperature dependent changes in channel kinetics. Changes of axonal excitability in response to hyperthermia was studied in vivo, in human. Methods: Axonal excitability of high (40%) and low (10–20%) threshold motor axons was assessed before and after warming (6 °C). Temperature was maintained using a waterbath and measured using a thermistor placed near the stimulating cathode. Results: Seven female subjects were studied with ethics committee approval. At 40% tracking, axonal excitability showed reduced superexcitability, faster accommodation to depolarization and reduced accommodation to hyperpolarisation (Howells et al., 2013). Low threshold fibers showed the same changes with the marked exception of the response to hyperpolarisation which was significantly increased (p < 0.02). Conclusions: The effect of hyperthermia on inward rectification to hyperpolarisation (HCN channel function) is increased in low threshold fibers and decreased in higher threshold fibers. Higher HCN
function (Ih current) increases resting membrane potential in low threshold fibers. Key message: This temperature related increase in Ih may contribute to initiation of seizures. Modulation of HCN channels may be a novel target for drug development in epilepsy. doi:10.1016/j.clinph.2015.11.191
ID 390 – Association between intraepidermal nerve fiber density and quantitative sensory testing in the patients with possible small fiber neuropathy—M. Nebuchennykh b, S. Løseth a,b, S. Lindal a,c, E. Olsen a, S.I. Mellgren a,b (a Neuromuscular Disease Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Norway, b Department of Neurology and Neurophysiology, University Hospital of Northern Norway, Tromsø, Norway, c Department of Pathology, University Hospital of Northern Norway, Tromsø, Norway) Objective: To evaluate sensitivity of quantitative sensory testing (QST) and skin biopsy with assessment of intraepidermal nerve fiber density (IENFD) in patients with symptoms and clinical findings of small fiber neuropathy (SFN). Methods: This is a retrospective study on 179 patients (age 48.7 ± 14.0 (8–82 years old), 64 men, 115 woman) examined from January 2012 to March 2015. All patients underwent nerve conduction studies (NCS), QST and skin biopsy for assessment of IENFD. Results: NCS were normal in 85% of patients. Mean IENFD in the total patient group was 6.1 ± 2.7 fibers per mm (0.9–17.0). 94 patients (52%) had reduced IENFD. 82 patients (46%) had abnormalities on QST (in 2 and more parameters). However, only 43 patients (24%) had both abnormalities on QST and reduced IENFD. There were normal findings on both QST and IENFD in 29 patients (16%). Conclusions: There is a rather lower concordance between the results of QST and IENFD. It remains unclear if diagnosis of SFN can be excluded in cases of normal findings both on QST and skin biopsy. Key message: Both skin biopsy and QST should be performed in patients with suspected SFN. doi:10.1016/j.clinph.2015.11.192
ID 396 – On the relationship between inter saccadic interval and object velocity in a reaching movement task—O.C. Banea, J. Casanova-Molla, M. Morales, C. Cabib, R. Arca, M. Brum, J. VallsSolé (Department of Neurology, Hospital Clinic, Barcelona, Spain) Objective: We aimed to investigate hand movement onset (HMO), saccadic reaction time (SRT) and the interval between the initial saccade and the corrective saccade (ISI) during a reaching movement task. Methods: Seven subjects, aged 29–39, participated in the study. We projected a scene of a penalty striker-goalkeeper combination and we asked participants to stop the ball (target) by using a linear joystick with the dominant hand. Two series of 20 trials at target velocities of 700 and 1400 pixels/s were performed. The eyemovement angle was 20° from initial fixation point. We measured eye saccade duration (SD) and peak velocity (PV), HMO latency, SRT and ISI in trials in which the subject stopped the ball.