QUANTITATIVE EEG ANALYSIS OF INDIVIDUALS WITH CHRONIC PAIN Ramona D. Burroughs, M.S. Dissertation Prepared for the Degree of DOCTOR OF PHILOSOPHY UNIVERSITY OF NORTH TEXAS December 2015 APPROVED: Charles A. Guarnaccia, Ph.D., Committee Chair Eugenia Bodenhamer-Davis, Ph.D., Committee Co-Chair Timothy Lane, Ph.D., Committee Member Clifton Edward Watkins, Ph.D., Committee Member Vicki Campbell, Ph.D., Chair of the Department of Psychology Constantinos Tsatsoulis, Interim Dean of the Toulouse Graduate School Burroughs, Ramona D. Quantitative EEG Analysis of Individuals with Chronic Pain. Doctor of Philosophy (Health Psychology and Behavioral Medicine), December 2015, 75 pp., 15 tables, 71 titles. Recent advances in neuroimaging and electromagnetic measurement technology have permitted the exploration of structural and functional brain alterations associated with chronic pain. A number of cortical and subcortical brain regions have been found to be involved in the experience of chronic pain (Baliki et al., 2008; Jensen et al., 2010). Evidence suggests that living with chronic pain shapes the brain from both an architectural and a functional perspective, and that individuals living with chronic pain display altered brainwave activity even at rest. Quantitative EEG (qEEG) is a method of spectral analysis that utilizes a fast Fourier transform algorithm to convert analog EEG signals into digital signals, allowing for precise quantification and analysis of signals both at single electrode locations and across the scalp as a whole. An important advance that has been permitted by qEEG analysis is the development of lifespan normative databases against which individual qEEGs can be compared (Kaiser, 2006; Thatcher et al, 2000). Pilot data utilizing qEEG to examine brainwave patterns of individuals with chronic pain have revealed altered EEG activity at rest compared to age- and gender-matched healthy individuals (Burroughs, 2011). The current investigation extended the findings of the pilot study by utilizing qEEG to examine a larger sample of individuals with chronic pain. Individuals with chronic pain displayed significantly reduced slow wave activity in frontal, central, and temporal regions. Findings will be presented in terms of specific patterns of altered EEG activity seen in individuals with chronic pain. Copyright 2015 by Ramona D. Burroughs ii ii ACKNOWLEDGEMENTS Boundless gratitude to Dr. Genie Davis for her teaching excellence and wise mentorship during my graduate school years. My years under her guidance in the unique and unparalleled UNT Neurotherapy Lab gave me the opportunity to combine clinical work, research, teaching, supervision, and professional development in a wonderful synergy. I am grateful for her teaching and leadership, and for giving me opportunities to grow and develop as a professional in the intellectually fascinating and clinically exciting fields of rehabilitation psychology, quantitative EEG, and neurofeedback. I am so grateful to my colleagues and students who made the process a joy and provided wonderful learning experiences, and to my clients who gave me the privilege of sharing their healing journeys. Thank you to Richard Davis, M.S., for sharing his years of clinical expertise and insight, as well as for his generosity in allowing me to use his Neuroguide software to run the analyses for this study. Thank you to Dr. Chuck Guarnaccia for his unwavering support, guidance, and leadership throughout this process, and for encouraging my development in clinical health psychology and behavioral medicine. Thank you to Dr. Tim Lane for his support and encouragement of my research goals, his gentle leadership, and for his outstanding class in psychopathology. Thank you to Dr. Ed Watkins for his perpetual kindness and support of my research goals. Thank you to my husband Kevin for his unwavering support during my educational years. A heartfelt thank you to my parents and brother for their love, support, encouragement, and intellectual stimulation over a lifetime. iii iii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS .......................................................................................................... iii LIST OF TABLES ........................................................................................................................ vi Chapter I. INTRODUCTION ................................................................................................................1 Literature Review...........................................................................................................1 Measuring Brain Activity ........................................................................................1 Methods of Experimental Pain Induction ................................................................3 Acute Pain in the Normal Brain ...............................................................................3 EEG Changes in Experimentally-Induced Acute Pain ............................................5 Functional Alterations in Chronic Pain: Changes in Brain Activity........................8 EEG Alterations in Chronic Pain ...........................................................................10 Structural Alterations in Chronic Pain: Architectural Changes in the Brain .........12 Clinical Improvements in Pain Following EEG Modulation .................................14 Summary of Pain Findings in the Brain .................................................................18 Previous Research by this Author ................................................................................19 Aims of the Current Study ...........................................................................................21 Hypotheses of the Current Study .................................................................................22 II. METHOD ...........................................................................................................................24 Participants ...................................................................................................................24 Procedure .....................................................................................................................25 Apparatus and Measurement........................................................................................26 iv iv Data Analysis ...............................................................................................................26 III. RESULTS ....................................................................................................................28 Significant Findings – Group Averaged Z Scores .......................................................28 Trends in Group Data...................................................................................................30 Patterns of Significant Deviations – Decreased Slow Activity ...................................31 Patterns of Significant Deviations – Increased Fast Activity ......................................34 IV. DISCUSSION ..............................................................................................................38 Summary of Findings of the Current Study .................................................................41 Comparisons with Prior Research ................................................................................43 Medication Effects .......................................................................................................45 Sleep .............................................................................................................................48 Implications of the Current Study ................................................................................50 REFERENCES .......................................................................................................................67 v v LIST OF TABLES Table 1 Patient Characteristics .................................................................................................... 52 Table 2 Averaged Absolute Power Z-scores in the Eyes Open Condition .................................... 53 Table 3 Averaged Relative Power Z-scores in the Eyes Open Condition..................................... 54 Table 4 Averaged Power Ratio Z-scores in the Eyes Open Condition ......................................... 55 Table 5 Averaged Absolute Power Z-scores in the Eyes Closed Condition ................................. 56 Table 6 Averaged Relative Power Z-scores in the Eyes Closed Condition .................................. 57 Table 7 Averaged Power Ratio Z-scores in the Eyes Closed Condition....................................... 58 Table 8 Percentage of Individuals with Significantly Decreased Absolute Power Values by Site (Eyes Open) ....................................................................................................................... 59 Table 9 Percentage of Individuals with Significantly Decreased Absolute Power Values (Eyes Closed) .............................................................................................................................. 60 Table 10 Percentage of Individuals with Significantly Decreased Relative Power Values by Site (Eyes Open) ....................................................................................................................... 61 Table 11 Percentage of Individuals with Significantly Decreased Relative Power Values by Site (Eyes Closed) ...................................................................................................................