Departamento de Fisiología Instituto de Biología Facultad de Medicina Facultad de Ciencias Universidad de la República ACTAS DE FISIOLOGIA Ricardo A. Velluti, Editor Universidad de la República, Facultad de Medicina Departamento de Fisiología Volumen 7 2001 Av. Gral. Flores 2125. 11800 Montevideo, Uruguay Fax: (5982) 924 8784 E-mail: [email protected] Versión electrónica: http://www.rau.edu.uy/universidad/medicina/ Montevideo, Uruguay Departamento de Fisiología Instituto de Biología Facultad de Medicina Facultad de Ciencias Universidad de la República Comité Editorial Washington Buño, Madrid Roberto Caldeyro Barcia, Montevideo † Elio García-Austt, Montevideo Omar S. Macadar, Montevideo Héctor Mazzella, Montevideo Juan A. Roig, México José P. Segundo, Los Angeles Omar Trujillo-Cenóz, Montevideo Comité Editorial Asociado Luis Acerenza Federico Dajas Francisco R. Morales Cristina Arruti Máximo Drets Elia Núnes Luis Barbeito Ricardo Ehrlich Harol Núñez Lina Bettucci Gustavo Folle Eduardo Osinaga Michel Borde Julio Hernández Marisa Pedemonte Gustavo Brum Magela Laviña Gonzalo Pizarro Ruben Budelli Enrique Lessa Eugenio Prodanov Angel Caputi Gloria Martínez Rafael Radi Alberto Cirio Eduardo Mizraji Julio C. Velluti Jaime M. Monti NAVIGARE NECESSE World Federation of Sleep Research Societies (WFSRS) Latin American Sleep Society (LASS) “2001 Sleep Odyssey” Congress. Physiological Basis for Sleep Medicine Ricardo A. Velluti - Chairman WFSRS Executive Committee Ennio Vivaldi – Vice President Adrian R. Morrison – Secretary General and Acting Treasurer Pier Luigi Parmeggiani – Chair of International Congress Program Committee Charles George – Membership Chairman Ron Grunstein – Chair of Education Committee Markku Partinen – Coordinating Secretary LASS Committee Local Liaison Committee Sérgio Tufik – President Marisa Pedemonte - Chairperson Rafael Salin-Pascual – Vice President Cecilia Orellana Luiz Menna Barreto – Secretary Cristina Scavone Lu Seabra – Secretary José L. Peña Monica Andersen – Secretary Daniel Lorenzo Francisco Hora José P. Arcos Sérgio Barros Vieira Julio E. Real Jaime M. Monti Sleep Research Society of Uruguay (SRSU) Ricardo A. Velluti - President Jaime M. Monti – Secretary Cecilia Orellana - Treasurer José P. Arcos Alberto Rodríguez 10th A N N I V E R S A R Y of the WFSRS Cannes 1991 – Punta del Este 2001 Michael H. Chase - Founding President S Y M P O S I A Symposium 1 Computer based methods for sleep research Chairperson: Thomas Penzel (Germany) Ennio Vivaldi, Universidad de Chile, Santiago, Chile Gerhard Klosch, University of Vienna, Austria Thomas Penzel, Hospital of Philipps-University, Germany Bob Kemp, Westeinde Hospital, The Netherland Symposium 2 Functional significance of hypothalamic temperature changes during sleep Chairperson: Pier Luigi Parmeggiani (Italy) Andrea Fuller, University of Witwatersrand, South Africa Pier Luigi Parmeggiani, University of Bologna, Italy Dennis McGinty, University of California Los Angeles, CA, USA Eus Van Someren, Netherlands I. for Brain Research, The Netherland Roberto Amici, University of Bologna, Italy 10 Actas de Fisiología 7, 2001 MODEL-BASED ANALYSIS OF THE NEURONAL SLOW-WAVE GENERATOR Bob Kemp Sleep Centre, MCH - Westeinde Hospital, Den Haag, The Netherlands Slow wave bursts do not reflect sleep depth bursts. The same holds for other EEG rhythms: they wax and wane while brain state appears to remain constant. This is con- firmed by physiological models of the rhythm-generating neuronal systems: simula- tions by an electronic version of these models produce realistically looking EEG with waxing and waning (bursting) rhythms while all model parameters, including ‘sleep depth’, are kept constant. These findings strongly suggest that the amplitude of EEG rhythms is not only influenced by the underlying brain state. This is even more so since EEG amplitudes are strongly affected by anatomy (skull size and thickness). Still, sleep depth is commonly quantified using slow-wave amplitude. The physiological models contain a neuronal feedback loop that oscillates slow- wave rhythms. Slow-wave bursting is caused by random external activity because at one time, the random activity accidentally builds up an oscillating rhythm in the loop, while later it can accidentally counteract to it. So, amplitude variations reflect external- noise characteristics rather than sleep depth. The models also show which EEG characteristic is directly related to sleep depth. The neuronal feedback loop accumulates the present slow-wave and inserts it into the upcoming EEG. Physiological sleep depth is reflected by the strength of the feedback loop. Therefore, deeper sleep implies a stronger feedback, causing more of the present slow-wave to be inserted in the next EEG segment. So, sleep depth is directly reflected by the fraction (a %) of the current slow wave which is also seen in the next EEG segment. This % is exactly what our analyzer measures [1]. The analyzer output %, dubbed slow-wave microcontinuity, directly reflects physi- ological sleep depth. Because slow-wave shape is analyzed rather than amplitude, not- sleep-related parameters such as random external activity and skull anatomy have rel- atively little influence. The same is true for artifacts. Microcontinuity analysis duplicates the effects of temazepam and ultradian rhyth- micity as shown by traditional delta (amplitude or power) plots. But these effects are clearly distinguished from the (large) effect of gender on slow wave amplitude: micro- continuity is not affected at all by gender [2]. Microcontinuity shows how temazepam attenuates slow waves while slow-wave sleep and subjective sleep quality remain pos- itively correlated [3]. Thus, slow-wave microcontinuity (shape) more closely reflects physiological sleep depth. 1. Kemp B, Zwinderman AH, Tuk B, Kamphuisen HAC, Oberyé JJL. Analysis of a sleep- dependent neuronal feedback loop: the slow-wave microcontinuity of the EEG. IEEE-BME 47(9), 2000: 1185-1194 2. Mourtazaev MS, Kemp B, Zwinderman AH, Kamphuisen HAC. Age and gender affect different characteristics of slow-waves in the sleep EEG. Sleep 18, 1995:557-564. 3. Kemp B. Temazepam-induced subjective sleep quality, EEG slow waves and sleep spin- dles. J Sleep Res 9 (suppl 1), 2000: 98. Actas de Fisiología 7, 2001 11 THE POLYGRAPHIC AND CLINICAL DATABASE OF THE SIESTA PROJECT: A NEW APPROACH TO COMPUTER BASED SLEEP ANALYSIS Gerhard Klösch(1), Bob Kemp(2), Thomas Penzel(3), Alois Schlögl(4), Ernst Trenker(5), Georg Gruber(6), Josef Zeitlhofer(7), Werner M. Herrmann(8), Sari Leena Himanen(9), Dieter Kunz(10), Manel J. Barbanoj(11), Joarchim Röschke(12) and Georg Dorffner(13) 1,7 Department of Neurology, University of Vienna, Austria; 2 Sleep Center, Westeinde Hospital, Den Haag, The Netherlands; 3 Medical Policlinic of Philipps- University Marburg, Germany; 4 Institute for Biomedical Engineering, University of Technology Graz, Austria; 5 Brain Research Institute, University of Vienna, Austria; 6 Department of Psychiatry, University of Vienna, Austria; 8 Laboratory of Clinical Psychophysiology, Department of Psychiatry, Benjamin Franklin Hospital, Free University of Berlin, Germany; 9 Department of Clinical Neurophysiology, Tampere University Hospital, Finland; 10 Department of Psychiatry and Psychotherapy, Lübeck, Germany, 11 Àrea d´Investigació Farmacologica, Institut de Recerca de l´Hospital de la Santa Creu i Sant Pau, UAB, Spain; 12 Department of Psychiatry, University of Mainz, Germany; 13 Austrian Research Institute for Artificial Intelligence, Vienna, Austria For more than thirty years standard all- night sleep recordings have been based on visual interpretation of one electroencephalograhic (EEG), two eye movements (EOG) and one submental muscle activity (EMG) signal trace. However numerous sleep stud- ies have concluded that sleep recordings cannot be limited to these traditional four channel recordings. A greater number of physiological signals and a variety of subjec- tive and objective psychophysiological parameters including mood and cognitive per- formance have to be considered. In the SIESTA-project*, performed by a consortium of 16 clinical and bio-engi- neering centres spread all over Europe, multi-channel sleep recordings from 194 healthy subjects (15 males and 15 females out of each decade, aged 20 to 90 years) and from 98 patients with selected sleep disorders were collected. The standardised recording pro- tocol included 14 days of activity monitoring and sleep diary, two nights of polysom- nography and several psychometric tests to assess vigilance, sleepiness and perfor- mance. In addition to the standard EEG-, EOG- and EMG-channels, various physio- logical parameters including O2-saturation, ECG, excursion of chest and abdomen, nasal airflow as well as limb movements were recorded. All biosignals and standard (Rechtschaffen and Kales) sleep scorings were stored in European Data Format (EDF) and are available on CD-ROM. Based on this database new algorithms (e.g. continuous parameters NonREM-, REM-sleep and wakefulness) were developed to overcome the limitations of visual sleep scoring. (*) The project was supported by a grant from the European Union Biomed-2 BMH4-CT97- 2040. 12 Actas de Fisiología 7, 2001 ANALYSIS OF RESPIRATION, HEART RATE AND OXIMETRY IN SLEEP STUDIES Thomas Penzel, Ulrich Brandenburg, Sven Rostig and Jörg-Hermann Peter Department of Pneumology, Hospital of Philipps-University, Baldingerstr. 1, Marburg, Germany Abstract: Computer based sleep analysis focuses on the automatic detection