A Model Based Approach to Apraxia in Parkinson’s Disease by Lauren King A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Master of Science in Kinesiology Waterloo, Ontario, Canada, 2010 © Lauren King 2010 AUTHOR'S DECLARATION I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii ABSTRACT This thesis provides new insight into how learned skilled movements are affected in a disease with basal ganglia damage, within what task demands these deficits can be detected, and how this detection can occur within the constraints of primary motor symptoms. Hence the purpose of this thesis was threefold. Firstly, the aim was to take a model-based approach to apraxia in PD, in order to determine the nature of the errors in reference to other populations that experience apraxia. Apraxia by definition cannot be the product of primary motor deficits, weakness, sensory loss, or lack of comprehension, therefore the second objective of the study was to detect apraxia while remaining true to these prerequisites. The third objective was to extend the examination of apraxia beyond the upper limbs, and investigate the relationship between upper limb and lower limb apraxia, as well as the relationship between freezing (which shares similarities with gait apraxia) and upper limb and lower apraxia. Overall, the most common pattern of apraxia identified in this PD group was impairment at both pantomime and imitation, suggesting issues with executive function. However, there are other results that suggest an issue with visuomotor transformation may be superimposed on this executive function deficit, including a higher frequency of participants impaired at imitation and a very pronounced impairment at meaningless gestures. To ensure that these deficits are not the product of primary motor symptoms, correlation analyses were conducted between gestural impairment and total motor impairment, cardinal symptom impairment, and degree of asymmetry of these symptoms. While there was a significant correlation of total motor severity and gestural impairment, there were no significant correlations between cardinal motor symptoms and total gestural impairment, or limb specific gestural impairment and the degree of motor asymmetry. These results indicate that the outward manifestation of primary motor symptoms does not necessarily correspond with iii gestural impairment, however the overall relationship (total UPDRS) hints to an indirect influence of the basal ganglia on healthy praxis. With regards to the third objective, the lower limb assessment turned out to be very consistent with the results yielded in the upper limb assessment. While there were similar frequencies of impairment in both pantomime and imitation, the upper limb and lower limbs assessments were found to correlate very strongly. This is a promising result, because the lower limb battery is easy to administer, there are typically less motor symptoms to deal with, and preliminary analyses show a high inter-rater reliability established. Furthermore, there was a higher proportion of freezers with apraxia compared to non-freezers, and this is the first study to reveal this. All these results taken together are evidence of similar underlying mechanisms for these impairments (upper limb apraxia, lower limb apraxia, and freezing). The model-based approach to studying apraxia in both the upper and lower limbs of PD, enables us to determine the frequencies, patterns and severities of apraxia, and better equips us to predict which systems are more susceptible to deterioration. This thesis project has hopefully created a framework for determining coping strategies and future interventions for apraxia, specifically in basal ganglia disordered populations. iv ACKNOWLEDGEMENTS For my Masters I had the privilege of having not one, but two very talented supervisors. Dr. Quincy Almeida took me under his wing when I was an undergraduate, and has taught me too many skills to mention here. I admire your passion for research and the difference you’ve made for so many people. Most importantly, I would like to say thank you for forcing me to strive for a standard far beyond ordinary, and for setting the example to do so. Dr. Eric Roy has been a great mentor since I began graduate studies at University of Waterloo. I am so grateful to be one of the many to experience the way your great mind works, but to also get to know you personally for your huge heart. Thank you for all of your insight and the opportunities you have created for me. I would also like to extend thanks to Pam Bryden and Richard Staines for sitting on my thesis committee and lending their expertise, but for also being helpful and down to earth. The team of students and researchers at the Sun Life Movement Disorders Research and Rehabilitation Centre (MDRC), including Michael Sage, Chad Lebold, Rose Johnston, Rachel van Oostveen, Matt Brown, Trish Knobl, and Rachel Boehm deserve a hefty thank you for their assistance in a number of areas, but especially moral support. A sincere thank you goes to Mark Gravely, and Vessela Stamenova for their knowledge and training. Also thank you to the wonderful friends, students and faculty at University of Waterloo for their contributions to the project, as well as my numerous student volunteers (too many to name here). Thank you to Rhiannon Rose and Christian de Milleville for their help establishing inter-rater reliability for the lower limb apraxia battery. I am also greatly indebted to Craig MacDonald for dealing with all my computer problems, and always doing so with a smile. A very special thank you to all the participants involved in project, for not only your participation but your enthusiasm and determination in better understanding Parkinson’s disease. You are a warm and constant reminder for why I am here. I would not be who and where I am without my parents, David and Patricia, who support me morally, financially, and with their physical presence in just about everything I do. Finally my greatest reserve of gratitude goes to my husband and best friend Dave, as this thesis would not have seen completion without your encouragement and your faith in me when my motivation dwindled at times. Thank you for your unwavering support and love throughout the many ups and downs of this project. This project is dedicated to Kay Onazuk and her ongoing battle with PD that has now spanned over two decades. I love you with all my heart. There is not enough space to personally thank everyone that has positively impacted this project, so for those unnamed, I am truly grateful for the contribution you have made, big or small. v TABLE OF CONTENTS AUTHOR'S DECLARATION ................................................................................................................... ii ABSTRACT ................................................................................................................................................ iii ACKNOWLEDGEMENTS ....................................................................................................................... v TABLE OF CONTENTS .......................................................................................................................... vi LIST OF TABLES ................................................................................................................................... viii LIST OF FIGURES ................................................................................................................................... ix CHAPTER 1: THESIS INTRODUCTION & OBJECTIVES ................................................................ 1 1.1 AN OVERVIEW OF LIMB APRAXIA ................................................................................................. 2 1.2 MODELS OF APRAXIA ..................................................................................................................... 4 1.3 AN OVERVIEW OF PARKINSON’S DISEASE ................................................................................ 11 1.4 THE ROLE OF THE BASAL GANGLIA IN PRAXIS ........................................................................ 14 1.5 APRAXIA IN DISEASE OF THE BASAL GANGLIA ........................................................................ 17 1.6 PROPOSED RESEARCH ................................................................................................................. 18 CHAPTER 2: A MODEL-BASED APPROACH TO APRAXIA IN PARKINSON’S DISEASE .... 20 2.1 INTRODUCTION ............................................................................................................................. 20 2.2 METHODS ........................................................................................................................................ 26 2.3 RESULTS .......................................................................................................................................... 31 2.4 DISCUSSION .................................................................................................................................... 41 CHAPTER 3: A NOVEL APPROACH FOR DISCERNING APRAXIA FROM PRIMARY MOTOR DEFICITS IN PARKINSON’S DISEASE ............................................................................. 49 3.1 INTRODUCTION ............................................................................................................................