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S29.D CAP, arousal, and central pattern generators
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2nd WASM World Congress, Bangkok, 4–8 February 2007 / Sleep Medicine 8 Suppl. 1 (2007) S11–S47
provides new insights and offers new challenges. These include more integrative approaches to sleep stability, sleep-related motor activation, parasomnias and epilepsy. This symposium will provide an update and aim to stimulate new direction of enquiry. • Chair: Robert Thomas, Harvard Medical School • Co-chair: Mario Terzano, University of Parma • 1st speaker: Robert Thomas • 2nd speaker: Liborio Parrino, University of Parma • 3rd speaker: Christian Guilleminault, Stanford Medical School • 4th speaker/discussant: Carlo Alberto Tassinari, University of Bologna The dimension of sleep stability (vs. sleep stages) continues to be offer new insights into the physiology and pathology of sleep. This symposium will cover new approaches to assess and use sleep stability using ECG-based cardiopulmonary coupling, the role of state instability in the pathogenesis of NREM parasomnias, and the relationship of motor and epileptic activation during sleep to a range of phasic activities during sleep. Leading researchers will present new data and sumamrize the state of the art in these individual areas. Conflict of interest: Patent submitted – sleep spectrograms using ECGbased cardiopulmonary coupling.
S29.A Integrated sleep stability states R.J. Thomas. Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA The dimension of sleep stability has seen a focus on EEG patterns. However, age, disease and individual variability pose challenges and limitations. Moreover, sleep is not a single-channel state, but an integrated state of existence, as specific physiological signatures differentiate wake, NREM and REM sleep. A method to assess sleep stability is presented, using a single-channel ECG. The technique is the cross-product coherence of heart rate variability and ECG-derived respiration, providing a measure of cardiopulmonary coupling. The resultant sleep spectrogram demonstrates a bimodal/bistable nature of sleep, and spontaneous switches between stable and unstable states in health and disease. Stable sleep state is characterized by temporal stability of respiration, ECG sinus arrhythmia, blood pressure dipping, non-Cyclic Alternating Pattern (non-CAP) nonrapid eye movement (NREM) sleep, stable arousal thresholds, and HFC on the sleep spectrogram. Conversely, unstable sleep state is characterized by temporal instability of respiration (in disease states, apneas and hypopneas), cyclic variation in heart rate, CAP NREM sleep, fluctuating arousal thresholds, and LFC on the sleep spectrogram. REM sleep with SDB takes on characteristics of LFC. SDB markedly increases LFC as a percentage of NREM sleep, and a subset of LFC, ELFC correlates with apneas and severe hypopneas. Narrow band ELFC is a marked of chemoreflex modulation of sleep apnea, and predicts positive airway pressure titration failure. The mode of the cortical slow oscillation has distinct relationships with state as recognized by the sleep spectrogram. A range of arousing stimuli can increase LFC and disrupt the slow oscillation, an outcome that can have serious consequences for the function of sleep.
S29.B Cyclic Alternating Pattern and parasomnias C. Guilleminault. Stanford University Sleep Disorders Center, Stanford, CA, USA The electrophysiology of NREM parasomnias remains to be fully explained. The presence of both ‘hypersynchronous slow delta’ and ‘burst of delta waves’ have been reported in sleepwalkers, but their significance is controversial. These EEG patterns are similar to phase A1 (and possibly A2) of the CAP. Proper analysis of the sleep EEG of sleepwalkers should integrate CAP analysis. Sleepwalkers on a non-sleepwalking night present instability of NREM sleep, as demonstrated by this analysis. This instability is similar to the one noted in UARS patients. Subtle sleep disorders associated with chronic sleepwalking constitute the unstable NREM sleep background on which sleepwalking events occur. A subtle associated sleep disorder should be systematically searched for and treated in the presence of sleepwalking with abnormal CAP. Triggers of parasomnias from sleep may have a common impact on mechanisms that increase NREM instability.
S29.C Cyclic Alternating Pattern – an update L. Parrino. Department of Neurology, University of Parma, Parma, Italy This presentation will update the last 5 years work on the CAP, the cyclic alternating pattern (CAP), the electro-encephalogram (EEG) marker of arousal instability during sleep. Starting from the limits and drawbacks of conventional sleep parameters (macrostructure), investigation of the underground world (microstructure) is extensively carried out with particular attention to K-complexes and other arousal-related phasic events of non-rapid eye movement (NREM) sleep. The continuity between conventional and non-conventional arousals is stressed in the light of autonomic function and motor activity evidence. The similarities and differences between CAP and arousals are thoroughly illustrated as well as the putative biological bases of these phenomena. The oscillatory nature of CAP, the involvement of CAP in the modulation of EEG synchrony, the sleep-maintenance properties of CAP in response to arousing stimuli, the clinical applications of CAP parameters and the promising availability of automatic scoring systems are highlighted. S29.D CAP, arousal, and central pattern generators C.A. Tassinari. University of Bologna, Department of Neurological Sciences, Bologna, Italy Several electrophysiological patterns are evolutionarily conserved. In some seizures, the epileptic discharge acts as a trigger for the appearance of behaviors which are the expression of inborn motor patterns, related to Central Pattern Generators, mainly located outside the cerebral cortex in the meso-diencephalic-pontine regions and the spinal cord. The concept may be extended to parasomnias, whose motor expression is the same as in epileptic seizure since they result from the activity of the same Central Pattern Generator. Arousal systems play a neurophysiologic role in protecting and tailoring sleep duration and depth. When they appear in NREM sleep, arousal responses are not limited to a single EEG pattern but are part of a continuous spectrum of EEG modifications ranging from high-voltage slow rhythms to low amplitude fast activities. The hierarchic features of arousal responses are reflected in the phase A subtypes of CAP (cyclic alternating pattern) including both slow arousals (dominated by the <1 Hz oscillation) and fast arousals (ASDA arousals). CAP is an infraslow oscillation with a periodicity of 20−40 s that participates in the dynamic organization of sleep and in the activation of motor events. Physiologic and pathologic motor activities during NREM sleep are always associated with a stereotyped arousal pattern characterized by an initial increase in EEG delta power and heart rate, followed by a progressive activation of faster EEG frequencies. Arousal can appear either spontaneously or be elicited by internal (epileptic burst) or external (noise, respiratory disturbance) stimuli. Whether the outcome is a physiologic movement, a muscle jerk or a major epileptic attack will depend on a number of ongoing factors (sleep stage, delta power, stability state) but all events share the common trait of arousalactivated phenomena.
S30. Sleep disorders and nocturnal epilepsy: from comorbidity to treatment
S30.1 Symposium summary M. Zucconi. Sleep Disorders Center, Department of Neurology, H San Raffaele Institute, Milan, Italy • Chair: Marco Zucconi, Milan, Italy • Co-chair: Claudio Bassetti • 1st speaker: Marco Zucconi • 2nd speaker: Lino Nobili, Milan, Italy • 3rd speaker: Raffaele Manni, Pavia, Italy • Discussant: Claudio Bassetti, Zurich, Switzerland Sleep disturbances are more than twice as prevalent in persons with partial epilepsy compared with normal subjects. Even on seizure-free nights, people with sleep related epilepsy may have more sleep disruptions than
2nd WASM World Congress, Bangkok, 4–8 February 2007 / Sleep Medicine 8 Suppl. 1 (2007) S11–S47
provides new insights and offers new challenges. These include more integrative approaches to sleep stability, sleep-related motor activation, parasomnias and epilepsy. This symposium will provide an update and aim to stimulate new direction of enquiry. • Chair: Robert Thomas, Harvard Medical School • Co-chair: Mario Terzano, University of Parma • 1st speaker: Robert Thomas • 2nd speaker: Liborio Parrino, University of Parma • 3rd speaker: Christian Guilleminault, Stanford Medical School • 4th speaker/discussant: Carlo Alberto Tassinari, University of Bologna The dimension of sleep stability (vs. sleep stages) continues to be offer new insights into the physiology and pathology of sleep. This symposium will cover new approaches to assess and use sleep stability using ECG-based cardiopulmonary coupling, the role of state instability in the pathogenesis of NREM parasomnias, and the relationship of motor and epileptic activation during sleep to a range of phasic activities during sleep. Leading researchers will present new data and sumamrize the state of the art in these individual areas. Conflict of interest: Patent submitted – sleep spectrograms using ECGbased cardiopulmonary coupling.
S29.A Integrated sleep stability states R.J. Thomas. Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA The dimension of sleep stability has seen a focus on EEG patterns. However, age, disease and individual variability pose challenges and limitations. Moreover, sleep is not a single-channel state, but an integrated state of existence, as specific physiological signatures differentiate wake, NREM and REM sleep. A method to assess sleep stability is presented, using a single-channel ECG. The technique is the cross-product coherence of heart rate variability and ECG-derived respiration, providing a measure of cardiopulmonary coupling. The resultant sleep spectrogram demonstrates a bimodal/bistable nature of sleep, and spontaneous switches between stable and unstable states in health and disease. Stable sleep state is characterized by temporal stability of respiration, ECG sinus arrhythmia, blood pressure dipping, non-Cyclic Alternating Pattern (non-CAP) nonrapid eye movement (NREM) sleep, stable arousal thresholds, and HFC on the sleep spectrogram. Conversely, unstable sleep state is characterized by temporal instability of respiration (in disease states, apneas and hypopneas), cyclic variation in heart rate, CAP NREM sleep, fluctuating arousal thresholds, and LFC on the sleep spectrogram. REM sleep with SDB takes on characteristics of LFC. SDB markedly increases LFC as a percentage of NREM sleep, and a subset of LFC, ELFC correlates with apneas and severe hypopneas. Narrow band ELFC is a marked of chemoreflex modulation of sleep apnea, and predicts positive airway pressure titration failure. The mode of the cortical slow oscillation has distinct relationships with state as recognized by the sleep spectrogram. A range of arousing stimuli can increase LFC and disrupt the slow oscillation, an outcome that can have serious consequences for the function of sleep.
S29.B Cyclic Alternating Pattern and parasomnias C. Guilleminault. Stanford University Sleep Disorders Center, Stanford, CA, USA The electrophysiology of NREM parasomnias remains to be fully explained. The presence of both ‘hypersynchronous slow delta’ and ‘burst of delta waves’ have been reported in sleepwalkers, but their significance is controversial. These EEG patterns are similar to phase A1 (and possibly A2) of the CAP. Proper analysis of the sleep EEG of sleepwalkers should integrate CAP analysis. Sleepwalkers on a non-sleepwalking night present instability of NREM sleep, as demonstrated by this analysis. This instability is similar to the one noted in UARS patients. Subtle sleep disorders associated with chronic sleepwalking constitute the unstable NREM sleep background on which sleepwalking events occur. A subtle associated sleep disorder should be systematically searched for and treated in the presence of sleepwalking with abnormal CAP. Triggers of parasomnias from sleep may have a common impact on mechanisms that increase NREM instability.
S29.C Cyclic Alternating Pattern – an update L. Parrino. Department of Neurology, University of Parma, Parma, Italy This presentation will update the last 5 years work on the CAP, the cyclic alternating pattern (CAP), the electro-encephalogram (EEG) marker of arousal instability during sleep. Starting from the limits and drawbacks of conventional sleep parameters (macrostructure), investigation of the underground world (microstructure) is extensively carried out with particular attention to K-complexes and other arousal-related phasic events of non-rapid eye movement (NREM) sleep. The continuity between conventional and non-conventional arousals is stressed in the light of autonomic function and motor activity evidence. The similarities and differences between CAP and arousals are thoroughly illustrated as well as the putative biological bases of these phenomena. The oscillatory nature of CAP, the involvement of CAP in the modulation of EEG synchrony, the sleep-maintenance properties of CAP in response to arousing stimuli, the clinical applications of CAP parameters and the promising availability of automatic scoring systems are highlighted. S29.D CAP, arousal, and central pattern generators C.A. Tassinari. University of Bologna, Department of Neurological Sciences, Bologna, Italy Several electrophysiological patterns are evolutionarily conserved. In some seizures, the epileptic discharge acts as a trigger for the appearance of behaviors which are the expression of inborn motor patterns, related to Central Pattern Generators, mainly located outside the cerebral cortex in the meso-diencephalic-pontine regions and the spinal cord. The concept may be extended to parasomnias, whose motor expression is the same as in epileptic seizure since they result from the activity of the same Central Pattern Generator. Arousal systems play a neurophysiologic role in protecting and tailoring sleep duration and depth. When they appear in NREM sleep, arousal responses are not limited to a single EEG pattern but are part of a continuous spectrum of EEG modifications ranging from high-voltage slow rhythms to low amplitude fast activities. The hierarchic features of arousal responses are reflected in the phase A subtypes of CAP (cyclic alternating pattern) including both slow arousals (dominated by the <1 Hz oscillation) and fast arousals (ASDA arousals). CAP is an infraslow oscillation with a periodicity of 20−40 s that participates in the dynamic organization of sleep and in the activation of motor events. Physiologic and pathologic motor activities during NREM sleep are always associated with a stereotyped arousal pattern characterized by an initial increase in EEG delta power and heart rate, followed by a progressive activation of faster EEG frequencies. Arousal can appear either spontaneously or be elicited by internal (epileptic burst) or external (noise, respiratory disturbance) stimuli. Whether the outcome is a physiologic movement, a muscle jerk or a major epileptic attack will depend on a number of ongoing factors (sleep stage, delta power, stability state) but all events share the common trait of arousalactivated phenomena.
S30. Sleep disorders and nocturnal epilepsy: from comorbidity to treatment
S30.1 Symposium summary M. Zucconi. Sleep Disorders Center, Department of Neurology, H San Raffaele Institute, Milan, Italy • Chair: Marco Zucconi, Milan, Italy • Co-chair: Claudio Bassetti • 1st speaker: Marco Zucconi • 2nd speaker: Lino Nobili, Milan, Italy • 3rd speaker: Raffaele Manni, Pavia, Italy • Discussant: Claudio Bassetti, Zurich, Switzerland Sleep disturbances are more than twice as prevalent in persons with partial epilepsy compared with normal subjects. Even on seizure-free nights, people with sleep related epilepsy may have more sleep disruptions than