Clinical Anatomy of the Cranial Nerves Clinical Anatomy of the Cranial Nerves Paul Rea AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Academic Press is an imprint of Elsevier Academic Press is an imprint of Elsevier 32 Jamestown Road, London NW1 7BY, UK The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK Radarweg 29, PO Box 211, 1000 AE Amsterdam, The Netherlands 225 Wyman Street, Waltham, MA 02451, USA 525 B Street, Suite 1800, San Diego, CA 92101-4495, USA First published 2014 Copyright r 2014 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. 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To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library ISBN: 978-0-12-800898-0 For information on all Elsevier publications visit our website at store.elsevier.com ACKNOWLEDGMENTS There are several people whom I would like to thank in making this book possible. First I would like to express my gratitude to Elsevier for having the time, patience, and faith in me while putting this together. They have really been the backbone to helping me realize my dream in publishing this. I would like to dedicate this book to my mother Nancy, father Paul, and dearest brother Jaimie. Thank you for being there and supporting me throughout everything—I am so proud of you all! Thank you also to Jennifer Rea—my sister-in-law—but more like a sister to me. I would also like to extend a special note of thanks to David Kennedy. Also, thanks to Christine and Susan Kennedy! Thank you to a dear friend who has gone but not been forgotten— Mark Peters. I am also most grateful to all the years of great friendship and banter that Dr. Richard Locke has given me. Cheers! A note of enormous thanks goes to Ms. Caroline Morris who helped to create the images throughout this book. Without her help it would not have been possible to create these high-quality pictures. Also, thank you to a dear colleague and amazing mentor who has supported me from when I first started my career as an anatomist through to where I am today—Dr. John Shaw-Dunn. Finally, thank you to our donors and their families. PREFACE Having personally studied Medicine and now in the privileged position of teaching human anatomy to medical, dental, and science students, one area that has always been a challenge to understand is the anatomy of the cranial nerves. They are perhaps the most complex set of nerves in the human body. Within such a small territory, they supply so many struc- tures, some absolutely essential to life. However, one thing that has been even more of a challenge was to take the anatomy of each nerve and understand the clinical application of that nerve or collection of nerves. Many resources are currently available for human anatomy training but not always in an appropri- ately succinct and clinically relevant fashion. Therefore, this book is incredibly unique as a resource as each cranial nerve is dealt with on a chapter-by-chapter basis. The key anatomical points are highlighted including origins, relevant branches, divisions, ganglia, and relations in summary form for easier understanding and referencing. It then takes the reader through, in a step-by-step process, how to clinically examine each of the cranial nerves in turn after dealing with the underpinning anatomy. Useful hints and tips are provided from the clinical and academic expertise of the author to ensure the reader has an applied understanding, but also are able to communicate effectively to the patient during the examination. Following on from this, common pathologies of each of the cranial nerves are given to try and help explain clinical findings on examination. At the end of each chapter on a cranial nerve, interesting clinical questions and answers are dealt with to explain some of the reasoning behind the clinical presenta- tion relating it back to the previous work, but also expanding ensuring the reader undertakes applied lateral thinking. This book combines anatomical knowledge, pathology, clinical examination, and explanation of clinical findings, drawing together material which is in general scattered throughout anatomical text- books, arising every time that a nerve is dealt with in other resources. This way, everything will be to hand for the learner in a format that x Preface will be used as a reference point, instructing on anatomy, but also how to examine the functioning of this anatomy in the patient. It would be envisaged that this book would be a primary book as a quick reference guide, but it can also be used alongside the readers’ other resources from their clinical experience and training, including lecture/tutorial notes, textbooks, and workbooks, as it would be pulling together material covered in so many fields including pathology, sur- gery, clinical examination, and anatomy. For each of the chapters on the 12 pairs of the cranial nerves (i.e., 12 separate chapters for each nerve), the same format is used for each one: • The Anatomy—Summary A brief summary statement giving the foundation knowledge of the nerve, its primary components, and what it supplies and its func- tions are. • The Anatomy—In More Detail This section will detail the nerve’s origin, course, intracranial pathway, site of exit from the skull, extracranial course, and to its termination. This section will give a succinct and comprehensive account of the important features of the nerve including its components, related ganglion (ganglia), important branches, and particular relations as relevant to the clinical applications related to that nerve. The purpose of this section is to provide the relevant anatomy that the reader will be able to apply to the patient at the bedside or other clinical setting. Tables will provide an easy way for the reader to identify key materials as relevant to each nerve. Images of digitally captured and professionally processed plastinated anatomical specimens will highlight the nerve, structure(s) it supplies, and anatomical relations to other structures. • The Clinical Application This section is in two parts. The first section will be related to test- ing the nerve at the bedside. It is a simple step-by-step format pro- viding an easy to read account of what to do. Included in this section are hints and tips as to best practice, based on the extensive experience of the author. This will help the examiner of the cranial nerves feel more confident and also instil an air of confidence and trust from the patient by proven hints and tips that are relevant and work. The second part of this section will be a brief comment on advanced testing which may involve more technical examinations Preface xi and equipment to be used on the patient or the relevant practitioner to contact for further specialist advice. • Pathologies This section details the most common pathologies to affect each nerve. It will also describe (as relevant) the branches that can be affected at the site of a pathology, and how this will be manifest in the clinical presentation. Summary tables are provided for ease of finding material based on a patient’s symptoms or nerve (branches) involved. This provides the reader with a form of mini-diagnosis, though should be seen as a guide subject to further investigation of the underlying pathology. • Interesting Clinical Questions The final section will provide an opportunity for lateral thinking and consolidation of the knowledge gained from the section on each nerve. It will pose problems in a question and answer format mak- ing the reader think about the clinical applications of the anatomy and providing a detailed description of the reasoning from an ana- tomical and clinical perspective. OVERALL PURPOSE This book is intended to enhance learning and enable the learner to take control of understanding the cranial nerves not just from the anatomical perspective but also the applied clinical examination and related pathol- ogies which may be encountered. It can be used by a wide variety of specialists who are involved in detailed examination of a patient’s cranial nerves.