APHASIA and BRAIN ORGANIZA TION

Transcription

1 APHASIA and BRAIN ORGANIZA TION

2 APPLIED PSYCHOLINGUISTICS AND COMMUNICATION DISORDERS APPLIED PSYCHOLINGUISTICS AND MENTAL HEALTH Edited by R. W. Rieber PSYCHOLOGY OF LANGVAGE AND THOUGHT Essays on the Theory and History of Psycholinguistics Edited by R. W. Rieber COMMUNICATION DISORDERS Edited by R. W. Rieber APHASIA AND BRAIN ORGANIZATION Ivar Reinvang A Continuation Order Plan is available for this series. A continuation order will bring delivery of each new volume immediately upon publication. Volumes are billed only upon actual shipment. For further information please contact the publisher.

3 APHASIA and BRAIN ORGANIZATION lvar Reinvang Sumums Hospital mul lustilulc of Psychology UHiversi~; of Oslo Oslo, Nmway SPRINGER SCIENCE+BUSINESS MEDIA, LLC

4 Library of Congress Cataloging in Publication Data Reinvang, lvar. Aphasia and brain organization. (Applied psycholinguistics and communication disorders) Bibliography: p. Includes index. I. Aphasia. 2. Cognitive disorders. 3.Brain-Wounds and injuries-complications and sequelae. 4. Neuropsychology. I. Title. II. Series. RC424.7.R !6.85' ISBN ISBN (ebook) DOI / Springer Science+Business Media New York Originally published by Plenum Press, New York in 1985 Softcover reprint of the hardcover Ist edition 1985 All rights reserved No part of this book may bc reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher

5 PREFACE This book presents the work on aphasia coming out of the Institute for Aphasia and Stroke in Norway during its 10 years of existence. Rather than reviewing previously presented work, it was my desire to give a unified analysis and discussion of our accumulated data. The empirical basis for the analysis is a fairly large group (249 patients) investigated with a standard, comprehensive set of procedures. Tests of language functions must be developed anew for each language, but comparison of my findings with other recent comprehensive studies of aphasia is faciliated by close parallels in test methods (Chapter 2). The classification system used is currently the most accepted neurological system, but I have operationalized it for research purposes (Chapter 3). The analyses presented are based on the view that aphasia is an aspect of a multidimensional disturbance of brain function. Findings of associated disturbances and variations in the aphasic condition over time have been dismissed by some as irrelevant to the study of aphasia as a language deficit. My view is that this rich and complex set of findings gives important clues to the organization of brain functions in humans. I present analyses of the relationship of aphasia to neuropsychological disorders in conceptual organization, memory, visuospatial abilities and apraxia (Chapters 4, 5, and 6), and I study the variations with time of the aphasic condition (Chapter 8). No study of aphasia is complete without an analysis of its clinicoanatomical basis. Testing the assumptions of the classical model of aphasia, I can only partly confirm them. My analyses reveal that V

6 vi PREFACE in many cases interachans between severallesion sites are important in determining deficits that are often thought to have a more circumscribed clinicoanatomical basis. In taking such a broad view of aphasia, my theoretical framework has been influenced by concepts from general systems theory. The theoretical chapters of the book (Chapters 1 and 9) present and develop this type of approach sufficiently to account for the main aspects of my findings and to suggest some new lines of investigation for the future. I should like to acknowledge the help and support of several friends and colleagues. First of all, K. Sundet performed the statistical analyses and discussed all the statistical problems with me. P. Barenstein examined my CT scans and scored them in a standardized system. K. Willmes made available to me the system for analysis of CT scans used in the Aachen aphasia laboratory. He also advised me on problems of choosing appropriate statistical models. My wife, T. Bjorg, did the artwork for the book. A special ward of thanks to M. Taylor Sarno, who read an earlier version of this monograph and gave me every help and encouragement to develop it for publication. Finally, I must thank the Norwegian National Health Association for their support of my work during several years, including the time period during which the book was written. IVAR REINVANG

7 CONTENTS Chapter 1. Approaches to the Study of Aphasia 1.1. Clinical and Theoretical Approaches Historical Approaches Localization Theory of Language-to- Brain Relation Criticism of Basic Premises Criticisms of Assumptions Regarding the Nature of Aphasia or the Types of Aphasie Disturbances Systems Theory Approach Applications of Systems Theory Concepts in Neuropsychology Localization of Function in Light of Systems Theory The Present Study Chapter 2. Operationalization of a Model 2.1. The Model Broca Area Posterior Language Area Arcuate Fasciculus Aphasia Test Construction and Standardization vii

8 viii CONTENTS Test Variables Selection of Tasks Similarity to Other Aphasia Tests Choice of Normative Sampie Standardization Statistical Properties Relation to Background Variables System of Gradation Chapter 3. Types of Aphasia 3.1. Classification System of the Norsk Grunntest for Afasi Definitions of Speech Classification Definitions of Aphasia Types Subjects Stability of Classification Comparison with Typology of W AB Levels of Classification Sampie Structure Conclusion Chapter 4. Selective Aphasias 4.1. Types of Selective Aphasias Modality-Specific Aphasias Material-Specific Aphasias Models of Selective Aphasias Studies of Sensory Mechanisms and Language in Normals The Present Study Material-Specific Deficits Modality-Specific Deficits Conclusion

9 CONTENTS ix Chapter 5. Memory and Learning Deficits 5.1. Normal Memory Verbal Memory Verbal Learning The Relation of Verbal Memory and Learning to Language Function Verbal Memory and Learning in Aphasics Verbal Memory Verbal Learning Nonverbal Memory and Learning Conclusion Present Study Tests The Structure of Memory in Aphasia ~ Relations of Memory to Aphasia Group Discussion Conclusion Chapter 6. Defects of Visual Nonverbal Abilities 6.1. Visual Nonverbal Functions in Aphasia Apraxia The Present Study Tests of Nonverbal Abilities Tests of Motor Function Apraxia Results Discussion Chapter 7. Localization of Lesion in Aphasia 7.1. Status of the Localization Model 7.2. New Candidates for Status as Language Areas

10 x CONTENTS The "Limbic System" The "Lenticular Zone" Medial Structures The Present Study Method Results Analysis of Test Parameters Lesions and Their Context Conclusion Chapter 8 0 Recovery and Prognosis 801. The Recovery Process Recovery of Nonverbal Functions Prognosis Mechanisms of Recovery Relearning or Facilitation Reorganization of Function Release of Vicarious Neural Structures and Functional Relocalization Complementary Redifferentiation of Function The Present Study Recovery Pattern Prognosis Relations between Fundions in Acute and Chronic Patients Conclusions Chapter 9 0 The Organized Response of the Brain to Injury 901. Evidence for Organized Complexity A Proposed Systemic Model Abstract Model

11 CONTENTS xi Neural Model Clinical Evidence on Hemispheric Relationships Within-Hemispheric Specialization and Differentiation in Humans The Effect of Lesions and the Systemic Basis of Recovery Testing the Model Application of the Model to the Present Findings General Applications of the Model Concluding Remarks References Appendix Index