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P1040: Intracerebral study of cortical activation during dissociated arousals
Abstracts of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339
S325
P1037 Neurophysiological evaluation of spinal excitability in patients affected by primary restless legs syndrome
P1039 Polycardiorespiratory polygraphy diagnostic accuracy in mild to moderate obstructive sleep apnea hypopnea syndrome
P. Congiu 1 , G. Milioli 2 , G. Gioi 1 , P. Tacconi 3 , M.L. Fantini 4 , F. Marrosu 3 , L. Parrino 2 , M. Puligheddu 1 1 University of Cagliari, Sleep Center, Neurophysiology Unit, Monserrato, Cagliari, Italy; 2 University of Parma, leep Disorder Center, Parma, Italy; 3 University of Cagliari, Neurology Unit, Monserrato -CA, Italy; 4 EA7890, University of Auvergne, Clermont-Ferrande, France
K. Rahnama 1 , A. Ferre 1 , J. Vila 2 , O. Romero 1 1 Vall d’Hebron Hospital, Neurophysiology, Barcelona, Spain; 2 Vall d’Hebron Hospital, Otorhinolaryngologist, Barcelona, Spain
Question: Restless legs syndrome (RLS) is a frequent condition, but its pathophysiology is not completely understood. The dopaminergic system has a primary role, and some studies have highlighted a condition of spinal hyper-excitability. The aim of our study is to explore this hypothesis through the electrophysiological evaluation of patients affected by primary RLS. Methods: 15 women affected by primary RLS and 17 age-matched females (controls) were selected. All subjects underwent nerve conduction studies (NCS) evaluation to exclude any secondary causes of lower limb paresthesias and to evaluate spinal excitability. According to a previous study, we considered two parameters, the duration of F waves (FWD) of the tibial and ulnar nerves, and the ratio between FWD and the duration of the corresponding compound muscle action potential (FWD/CMAPD). Results: None of the subjects (both RLS and controls) included in our study showed alterations in the nerve conduction velocities. Compared to the control group, significantly higher values were found in RLS patients for the mean FWD for both ulnar (p<0.05) and tibial (p<0.01) nerves and for the mean FWD/CMAPD ratio average (p<0.001). Conclusions: The results of our study indicate a widespread spinal motoneuronaI hyper-excitability. Such condition could be mainly due to an abnormal modulation within the interneuronal system. Presently, RLS diagnosis is based exclusively on clinical criteria. The FWD/CMAPD ratio can help to shed light on the pathogenesis of RLS, is easily obtainable and can represent an instrumental diagnostic tool especially in cases of evening lower leg discomfort of unclear interpretation.
P1038 Evaluation of H reflex excitability during motor imagery in patients with the restless legs syndrome and healthy individuals F. Yavlal 1 , R. Inan 2 , G. Benbir 3 , D. Karadeniz 3 , M. Kiziltan 3 1 Bahcesehir University Faculty of Medicine, Neurology, Istanbul, Turkey; 2 Lutfi Kirdar Kartal Training and Research Hospital, Neurology, Istanbul, Turkey; 3 Istanbul University Cerrahpasa Faculty of Medicine, Neurology, Istanbul, Turkey Questions: Motor Imagery (MI) is suggested that the neural processes associated with the motor imagery are similar to the realization of that particular movement. The increase of the excitability belonging to TMS, reflexes and the cycles related with the delayed responses has been shown. Restless Legs Syndrome (RLS) is a sleeping disorder characterized by an abnormal sensation, legs in particular. The relationship between the desire of walking and the temporary relief of patients is known. The increase of excitability through TMS and segmental reflexes at the different levels of the CNS has been reported. In our study we aimed to investigate the difference on the excitability of the H reflex during the imagery of walking in RLS patients and healthy individuals. Methods: 11 RLS (3 M, 8 F. Average Age: 41.2) and 15 (8 M, 7 F. Average Age: 38.4) gender and age matched control, in total 26 subjects were included to the study. HR is studied in the supine position, while 1: resting and 2: simulating of walking and the ratio of Hmax/Mmax were obtained. The Hmax/Mmax ratios of the two groups were compared. Results: There was no difference between M responses, HR latencies and resting Hmax/Mmax ratios in the RLS patients and control subjects. The Hmax/Mmax ratio during resting period was 44.6+ 26.6 and MI Hmax/Mmax ratio was 51.9+32.7 in the control group, whereas resting Hmax/Mmax ratio was 49.4+22.5 and MI Hmax/Mmax ratio was 40.1+23.1 in the RLS group. Conclusion: Hmax was increased during MI at the control group, whereas it was decreased at the RLS group. This finding was interpreted as the imagination of walking decreases the spinal excitability in patients with RLS.
Introduction: The gold standard in OSAHS diagnosis is the nocturnal polysomnography (PSG). Nowadays is allowed to use polycardiorespiratory polygraphy (PCR) in patients with high pretest probability of OSAHS. The PCR has some limitations that can infraestimate the AHI; impossibility to score sleep time, respiratory effort related to arousal and hypopneas related to arousal without oxygen desaturation. Objective: Evaluate the polycarodiorespiratory poligraphy (CRP) diagnostic accuracy in patientes with mild to moderate OSAHS. Methods: We evaluate 96 patients with AHI <30 in PCR and compare with the conventional polysomnography (PSG). Results: We studied 96 patients 69% male 30% female with a mean age 52±12.5 years, mean body mass index (BMI) 27.7±3.6, mean Epworth sleepiness scale 7.54±4.8 and mean AHI in PCR 11.6±7.8. PCR show a OSAHS prevalence of 26% normal, 39.6% mild and 34.4 moderate in the selected patients. When we compare PSG with PCR we observe statistical differences in the compute the AHI (19.2±14.9 & 11.6±7.8)and RDI (22.1±14.8 & 11.6±7.8). The mean difference in AHI and RDI are 7.6±12.0 and 10.4±12.1 respectively. When we obtain normal results with PCR we observe in PSG a 76% (IAH) or 48% (RDI) of mild to moderate OSAHS. When we obtain mild OSAHS with PCR we observe in PSG 42.1% (IAH) or 47% (RDI) moderate and 15.7% (IAH) or 21% (RDI) sever OSAHS. When we obtain moderate OSAHS with PCR we observe in PSG 21.2% (IAH) or 18% (RDI) mild and 42.5% (IAH) or 51% (RDI) sever OSAHS. Conclusions: PCR in mild to moderate OSAHS patients can infraestimate significantly the degree of OSAHS severity.
P1040 Intracerebral study of cortical activation during dissociated arousals N. Frezel 1 , S. Boudet 2 , N. Reyns 3 , W. Szurhaj 1,4 1 CHRU Lille, clinical neurophysiology, Lille, France; 2 Faculé Libre de Médecine, Université Nord de France, Lille, France; 3 CHRU Lille, Neurosurgery, Lille, France; 4 Lille II University, EA 4559, Lille, France Background: Dissociated arousals are characterized by behavioural arousal and slow-waves on ElectroEncephaloGram, that suggest the persistence of sleep. Our purpose was to determine, with intracerebral recordings, the changes in electrical activity in different cortical areas (sensori-motor and non-sensori-motors areas) during dissociated arousal states, in comparison with normal arousals. Methods: Dissociated and normal arousals were recorded in a fifteen years-old male with drug-resistant right parietal epilepsy. We analyzed the activity from non epileptic areas, recorded in: pre- and post-central gyri, middle and superior frontal gyri, cingulated gyrus, hippocampus, middle temporal gyrus, superior and inferior parietal lobes. Time-frequency analyses were performed from 2 minutes before up 2 minutes after the beginning of the arousal. Results: Five dissociated arousals were compared with 3 normal arousals. In dissociated arousals, we observed a blockage of very low frequencies rhythms in all areas, suggesting an arousal of the whole cortex. In motor cortex, higher frequencies rhythms occurred, similarly to a normal arousal. In other areas, a synchronization around 1.8 Hz was observed during the dissociated arousal states. This synchronization was never observed in normal arousals. Conclusion: The slow-wave sleep is interrupted in all cortical areas during dissociated arousal state. The activity of motor cortex seem to be similar to normal arousals, whereas a probably pathologic 1.8 Hz synchronization is observed in non-motor areas.
P1041 Is home video telemetry-polysomnography (HVT-P) feasible? P. Muthinji, N. Mullatti, D. Amin, F. Brunnhuber King’s College Hospital, Clinical Neurophysiology, London, United Kingdom Background: HVT at King’s College Hospital has been successfully used
S325
P1037 Neurophysiological evaluation of spinal excitability in patients affected by primary restless legs syndrome
P1039 Polycardiorespiratory polygraphy diagnostic accuracy in mild to moderate obstructive sleep apnea hypopnea syndrome
P. Congiu 1 , G. Milioli 2 , G. Gioi 1 , P. Tacconi 3 , M.L. Fantini 4 , F. Marrosu 3 , L. Parrino 2 , M. Puligheddu 1 1 University of Cagliari, Sleep Center, Neurophysiology Unit, Monserrato, Cagliari, Italy; 2 University of Parma, leep Disorder Center, Parma, Italy; 3 University of Cagliari, Neurology Unit, Monserrato -CA, Italy; 4 EA7890, University of Auvergne, Clermont-Ferrande, France
K. Rahnama 1 , A. Ferre 1 , J. Vila 2 , O. Romero 1 1 Vall d’Hebron Hospital, Neurophysiology, Barcelona, Spain; 2 Vall d’Hebron Hospital, Otorhinolaryngologist, Barcelona, Spain
Question: Restless legs syndrome (RLS) is a frequent condition, but its pathophysiology is not completely understood. The dopaminergic system has a primary role, and some studies have highlighted a condition of spinal hyper-excitability. The aim of our study is to explore this hypothesis through the electrophysiological evaluation of patients affected by primary RLS. Methods: 15 women affected by primary RLS and 17 age-matched females (controls) were selected. All subjects underwent nerve conduction studies (NCS) evaluation to exclude any secondary causes of lower limb paresthesias and to evaluate spinal excitability. According to a previous study, we considered two parameters, the duration of F waves (FWD) of the tibial and ulnar nerves, and the ratio between FWD and the duration of the corresponding compound muscle action potential (FWD/CMAPD). Results: None of the subjects (both RLS and controls) included in our study showed alterations in the nerve conduction velocities. Compared to the control group, significantly higher values were found in RLS patients for the mean FWD for both ulnar (p<0.05) and tibial (p<0.01) nerves and for the mean FWD/CMAPD ratio average (p<0.001). Conclusions: The results of our study indicate a widespread spinal motoneuronaI hyper-excitability. Such condition could be mainly due to an abnormal modulation within the interneuronal system. Presently, RLS diagnosis is based exclusively on clinical criteria. The FWD/CMAPD ratio can help to shed light on the pathogenesis of RLS, is easily obtainable and can represent an instrumental diagnostic tool especially in cases of evening lower leg discomfort of unclear interpretation.
P1038 Evaluation of H reflex excitability during motor imagery in patients with the restless legs syndrome and healthy individuals F. Yavlal 1 , R. Inan 2 , G. Benbir 3 , D. Karadeniz 3 , M. Kiziltan 3 1 Bahcesehir University Faculty of Medicine, Neurology, Istanbul, Turkey; 2 Lutfi Kirdar Kartal Training and Research Hospital, Neurology, Istanbul, Turkey; 3 Istanbul University Cerrahpasa Faculty of Medicine, Neurology, Istanbul, Turkey Questions: Motor Imagery (MI) is suggested that the neural processes associated with the motor imagery are similar to the realization of that particular movement. The increase of the excitability belonging to TMS, reflexes and the cycles related with the delayed responses has been shown. Restless Legs Syndrome (RLS) is a sleeping disorder characterized by an abnormal sensation, legs in particular. The relationship between the desire of walking and the temporary relief of patients is known. The increase of excitability through TMS and segmental reflexes at the different levels of the CNS has been reported. In our study we aimed to investigate the difference on the excitability of the H reflex during the imagery of walking in RLS patients and healthy individuals. Methods: 11 RLS (3 M, 8 F. Average Age: 41.2) and 15 (8 M, 7 F. Average Age: 38.4) gender and age matched control, in total 26 subjects were included to the study. HR is studied in the supine position, while 1: resting and 2: simulating of walking and the ratio of Hmax/Mmax were obtained. The Hmax/Mmax ratios of the two groups were compared. Results: There was no difference between M responses, HR latencies and resting Hmax/Mmax ratios in the RLS patients and control subjects. The Hmax/Mmax ratio during resting period was 44.6+ 26.6 and MI Hmax/Mmax ratio was 51.9+32.7 in the control group, whereas resting Hmax/Mmax ratio was 49.4+22.5 and MI Hmax/Mmax ratio was 40.1+23.1 in the RLS group. Conclusion: Hmax was increased during MI at the control group, whereas it was decreased at the RLS group. This finding was interpreted as the imagination of walking decreases the spinal excitability in patients with RLS.
Introduction: The gold standard in OSAHS diagnosis is the nocturnal polysomnography (PSG). Nowadays is allowed to use polycardiorespiratory polygraphy (PCR) in patients with high pretest probability of OSAHS. The PCR has some limitations that can infraestimate the AHI; impossibility to score sleep time, respiratory effort related to arousal and hypopneas related to arousal without oxygen desaturation. Objective: Evaluate the polycarodiorespiratory poligraphy (CRP) diagnostic accuracy in patientes with mild to moderate OSAHS. Methods: We evaluate 96 patients with AHI <30 in PCR and compare with the conventional polysomnography (PSG). Results: We studied 96 patients 69% male 30% female with a mean age 52±12.5 years, mean body mass index (BMI) 27.7±3.6, mean Epworth sleepiness scale 7.54±4.8 and mean AHI in PCR 11.6±7.8. PCR show a OSAHS prevalence of 26% normal, 39.6% mild and 34.4 moderate in the selected patients. When we compare PSG with PCR we observe statistical differences in the compute the AHI (19.2±14.9 & 11.6±7.8)and RDI (22.1±14.8 & 11.6±7.8). The mean difference in AHI and RDI are 7.6±12.0 and 10.4±12.1 respectively. When we obtain normal results with PCR we observe in PSG a 76% (IAH) or 48% (RDI) of mild to moderate OSAHS. When we obtain mild OSAHS with PCR we observe in PSG 42.1% (IAH) or 47% (RDI) moderate and 15.7% (IAH) or 21% (RDI) sever OSAHS. When we obtain moderate OSAHS with PCR we observe in PSG 21.2% (IAH) or 18% (RDI) mild and 42.5% (IAH) or 51% (RDI) sever OSAHS. Conclusions: PCR in mild to moderate OSAHS patients can infraestimate significantly the degree of OSAHS severity.
P1040 Intracerebral study of cortical activation during dissociated arousals N. Frezel 1 , S. Boudet 2 , N. Reyns 3 , W. Szurhaj 1,4 1 CHRU Lille, clinical neurophysiology, Lille, France; 2 Faculé Libre de Médecine, Université Nord de France, Lille, France; 3 CHRU Lille, Neurosurgery, Lille, France; 4 Lille II University, EA 4559, Lille, France Background: Dissociated arousals are characterized by behavioural arousal and slow-waves on ElectroEncephaloGram, that suggest the persistence of sleep. Our purpose was to determine, with intracerebral recordings, the changes in electrical activity in different cortical areas (sensori-motor and non-sensori-motors areas) during dissociated arousal states, in comparison with normal arousals. Methods: Dissociated and normal arousals were recorded in a fifteen years-old male with drug-resistant right parietal epilepsy. We analyzed the activity from non epileptic areas, recorded in: pre- and post-central gyri, middle and superior frontal gyri, cingulated gyrus, hippocampus, middle temporal gyrus, superior and inferior parietal lobes. Time-frequency analyses were performed from 2 minutes before up 2 minutes after the beginning of the arousal. Results: Five dissociated arousals were compared with 3 normal arousals. In dissociated arousals, we observed a blockage of very low frequencies rhythms in all areas, suggesting an arousal of the whole cortex. In motor cortex, higher frequencies rhythms occurred, similarly to a normal arousal. In other areas, a synchronization around 1.8 Hz was observed during the dissociated arousal states. This synchronization was never observed in normal arousals. Conclusion: The slow-wave sleep is interrupted in all cortical areas during dissociated arousal state. The activity of motor cortex seem to be similar to normal arousals, whereas a probably pathologic 1.8 Hz synchronization is observed in non-motor areas.
P1041 Is home video telemetry-polysomnography (HVT-P) feasible? P. Muthinji, N. Mullatti, D. Amin, F. Brunnhuber King’s College Hospital, Clinical Neurophysiology, London, United Kingdom Background: HVT at King’s College Hospital has been successfully used