Music and Vibroacoustic Stimulation in People with Rett Syndrome – A Neurophysiological Study Märith Bergström-Isacsson Thesis submitted for degree of Doctor of Philosophy Aalborg University, Denmark 2011 ii Music and Vibroacoustic Stimulation in People with Rett Syndrome – A Neurophysiological Study Märith Bergström-Isacsson Thesis submitted for degree of Doctor of Philosophy 2011 Supervisors: Professor Tony Wigram, Professor Christian Gold and Associate Professor Ulla Holck Co-supervisor: Docent Bengt Lagerkvist MD Consultant: Peter O.O. Julu MD PhD Department of Communication and Psychology Faculty of Humanities Aalborg University Denmark iii Declaration I confirm that this thesis: Music and Vibroacoustic Stimulation in People With Rett Syndrome – A Neurophysiological Study and the research it contains, has not previously been submitted as a whole or in parts, or submitted for assessment for a prize at an institution of higher education in Denmark or abroad. Märith Bergström-Isacsson iv ―And whenever the tormenting spirit from God troubled Saul, David would play the harp. Then Saul would feel better, and the tormenting spirit would go away” 1 Sam 16:23 v vi Abstract Background: Rett syndrome (RTT) is a neurodevelopmental disorder which affects basic body functions including the central control of the autonomic nervous system in the brainstem. Music is used by parents and carers in different situations, e.g. to calm down, to activate, to motivate and in communication. The aim of the study was to examine what effect musical stimuli had on the control functions of the autonomic nervous system, and on cortical emotional reactions, in participants with RTT. Methods: The study included 35 participants with RTT who were referred to the Swedish Rett Center for routine brainstem assessment during the period 2006-2007, and 11 children with a normal development. A repeated measures design was used, and physiological data were collected from a neurophysiological brainstem assessment. To identify facial expressions elicited by possible pathological brainstem activities, data were also collected from video analyses of facial expressions using the Facial Action Coding System (FACS). The control situation was the physiological baseline of the participant‘s own autonomic function at rest. After establishing a baseline the participants were exposed to six musical stimuli. Horn was chosen to elicit an arousal response and Activating (parents‘ choice) a sympathetic response. Calming (parents‘ choice), VT (Vibroacoustic stimulation), VT+Mu (VT combined with calming music) and Mu (that same music without vibrations) were expected to elicit a parasympathetic response. The continuous dependent variables measured were: Cardiac Vagal Tone (CVT), Cardiac Sensitivity to Baroreflex (CSB), Mean Arterial blood Pressure (MAP) and the Coefficient of Variation of Mean Arterial blood Pressure (MAP-CV). These parameters were used to categorise brainstem responses as parasympathetic (calming) response, sympathetic (activating) response, arousal (alerting) response and unclear response. The analyses were supplemented by case vignettes, where additional physiological parameters were also taken into account. Facial expressions were coded and categorised into positive emotions, negative emotions and ambiguous responses. These expressions were then related to results from brainstem assessment and the music used. Results: Continuous responses showed that Calming and VT increased CVT significantly in the RTT group. Horn elicited a similar response in both groups (decrease in CSB, indicating an arousal). In the RTT group, the expected categorical responses related to the hypotheses were observed in 7% for Horn, 36% for Activating, 39% for Calming, 52% vii for VT, 32% for VT+Mu and 28% for Mu. The FACS analyses indicated that a majority of the RTT participants had specific disorder-related movement patterns in their facial expressions. The findings from analysing the case vignettes also disclosed the impact of blood gases and breathing patterns on RTT participants‘ physiological responses to the music and on their facial expressions. Conclusion: Musical stimuli have measurable effects on brainstem autonomic functions in RTT and non-clinical individuals, but it is not possible to foresee responses to different kinds of music. The disorder-related movement patterns in facial expressions found in RTT individuals occurred spontaneously and may not directly indicate emotion. Brainstem assessment is a new method to observe and analyse autonomic responses to music. In combination with brainstem assessment, FACS can be used for identifying and separating pure brainstem triggered facial responses from facial expressions of emotions elicited from the cortex. However, FACS is a new method related to both RTT and music therapy, and presents a new area for further research. The findings from this present study might help caregivers, teachers and therapists to be more observant of specific details, which would ultimately benefit people with RTT. viii Acknowledgements I am extremely grateful to the many people who have given generously of their time, experience, wisdom, patience and support throughout this challenging process. This includes anyone not specifically mentioned who knows that they have supported and helped me towards the completion of this thesis. First and foremost, I would like to acknowledge Professor Tony Wigram, who inspired, supported, and supervised me from the very beginning, until his health prevented him. His warm, humoristic and embracing personality allowed me to grow, and inspired me to broaden this project further than I might otherwise have done. I am so sorry that he could not follow me all the way. Many thanks to Professor Christian Gold, whose patience has been tested innumerable times as he explained to me and challenged me, first as a statistics consultant, and later as my main supervisor. Very special thanks to Docent Bengt Lagerkvist, for his unconditional support and guidance, whenever I needed it. My thanks are also due to Associate Professor Ulla Holck, for her brilliant remarks and insight. And to Dr Peter Julu, who invented the NeuroScope that made this research study possible, for allowing me to be part of the ―brainstem team‖, for guiding me into the world of neurophysiology and for sharing his knowledge. I would also like to express my thanks to Dr Ingegerd Witt Engerström, who first invited me to work at the Swedish Rett Center, and has encouraged me ever since. I would furthermore like to acknowledge all my colleagues at the Rett Center, both past and present. Special thanks to Åsa-Sara Sernheim who created the picture of the brain, as well as the picture on the cover. I am also extremely grateful to Stig Hansen, who helped me with many important technical details, pedagogical explanations and translations; and to Flora Apartopoulos who helped me collect data also during weekends. Special thanks to: All the PhD students and staff at Aalborg University, for their insights and the wonderful discussions we shared throughout the PhD journey. FACS coder Priyanka Agrawal, who came all the way from India. ix Hilary Hocking, for scrutinising and revising the language of the thesis, down to the last detail. Also to my family: My wonderful husband Mats, and my beloved children Camilla and Fredrik, who carried me through. My mother Ellen, my brother Patric and his wife Karin, who supported me and took an interest in my research. Last but not least, I am indebted to all those who participated in this study. I dedicate this thesis to all of you. This study was supported by the Rett Center and Jämtland County Council, Aalborg University, Sävstaholm Foundation and the Olu Birgit Jeppson Foundation. x Table of Contents ABSTRACT ............................................................................................................................................... VII ACKNOWLEDGEMENTS ........................................................................................................................ IX TABLE OF CONTENTS ............................................................................................................................ XI LIST OF TABLES .................................................................................................................................... XVI LIST OF FIGURES ............................................................................................................................... XVIII LIST OF APPENDICES ........................................................................................................................... XX LIST OF ABBREVIATIONS .................................................................................................................. XXI CHAPTER ONE ............................................................................................................................................ 1 1. INTRODUCTION................................................................................................................................ 1 1.1. BACKGROUND FOR THE STUDY...................................................................................................... 1 1.2. CLINICAL AND PERSONAL MOTIVATION FOR THE STUDY ............................................................... 3 1.3. RESEARCH CONTEXT AND CONTENT .............................................................................................. 5 1.4. RESEARCH QUESTIONS .................................................................................................................