Electrodiagnostic Medicine A Practical Approach Nestor Galvez-Jimenez Alexandra Soriano John A. Morren Editors 123 Electrodiagnostic Medicine Nestor Galvez-Jimenez Alexandra Soriano • John A. Morren Editors Electrodiagnostic Medicine A Practical Approach Editors Nestor Galvez-Jimenez Alexandra Soriano Braathen Neurological Center Braathen Neurological Center Cleveland Clinic Florida Cleveland Clinic Florida Weston, FL Weston, FL USA USA Cleveland Clinic Lerner College of Cleveland Clinic Lerner College of Medicine of Case Western Reserve Medicine of Case Western Reserve University University Cleveland, OH Cleveland, OH USA USA John A. Morren Neuromuscular Center Neurological Institute Cleveland Clinic, and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University Cleveland, OH USA ISBN 978-3-030-74996-5 ISBN 978-3-030-74997-2 (eBook) https://doi.org/10.1007/978-3-030-74997-2 © Springer Nature Switzerland AG 2021 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland Dedication to Dr. Virgilio Salanga We have been privileged to have worked with some of the best electrodiagnosticians, neurologists, residents, and fellows at Cleveland Clinic. Asa Wilbourn, Maurice Hanson, Kerry Levin, Robert Shields, Richard Lederman, Hiroshi Mitsumoto, and many others come to mind immediately. However, for most of us Dr. Virgilio Salanga, to whom this work is dedicated, had a major influence, and as a consequence made a lasting impact on our interest and understanding in electrodiagnostic medicine. Actually, Virgil taught generations of residents and fellows, both in Ohio and in Florida, many of whom went on to prestigious academic and practice positions in the USA and internationally. Upon his retirement he was the holder of the John and Margaret Krupa distinguished Chair in Neurology at Cleveland Clinic Florida (CCFla) and Chairman of Neurology at CCFla. Virgil is a Magna Cum Laude graduate with a Doctor of Medicine and Surgery degree from the University of Santo Thomas School of Medicine, in Manila, Philippines. After mixed surgery and internal medicine internships at Michael Reese Hospital and Medical Center in Chicago, Virgil went on to do his residency and neurophysiology training at the Mayo Clinic in Rochester, Minnesota, where he was a student of Edward H. Lambert and Jasper Daube. In Rochester, he confided to us on more than one occasion; he had some of his best formative years, having worked under Arthur Waltz and interacted with Thoralf Sundt both from Mayo, when working on his Master of Science thesis on Regional Cerebral Blood Flow During Stimulation of the Seventh Cranial Nerve. The resultant degree was granted by the University of Minnesota. He had the privilege to study and collaborate with many others who became well- known electrodiagnosticians in their own right, such as Asa Wilbourn, H. Royden Jones Jr., Ludwig Gutmann, Ram Ayyar, and many others. Virgil rose through the ranks at Cleveland Clinic in Cleveland to Vice-chair of Neurology and subsequently moved to Florida in 1988 (with Maurice Hanson and technologist Mary Ronnenberg) to establish the Department of Neurology and the Neurophysiology Laboratory at the Cleveland Clinic in Florida. Upon his retirement, the department had grown to a very busy and academic unit with neurology residents and fellows, in addition to many rotating medical students. Many of us who had the privilege to study and work under him at various times in our academic and professional career, particularly in electrodiagnostic medicine and neurology, were the recipients of an unabated commitment to teaching and excellence. We could not wait to the time of day to be in his office for review of the procedures performed during the day, especially those complex studies in which we wanted to hear his explanation and critical thinking. He was very generous with his time despite the daily clinical responsibility. He was firm, but non-judgmental, and he always expected the best from all of us, never accepting less. In addition, his high-yield lectures were all well attended by residents, fellows, staff, and technologists. In spirit, this book is the product of the sum of those interactions with our mentors in Cleveland, Ohio, but particularly with Virgilio Salanga to whom this book is dedicated, and to CCFla in which most of the authors and editors have made their academic practice and/or formative years. Foreword It is with immense pleasure that I write the foreword to this book that is col- laboratively authored by a former colleague, trainees, and laboratory tech- nologists at the Cleveland Clinic—Florida, along with other alumni of the Cleveland Clinic—Ohio. I greatly admire with pride and satisfaction follow- ing the careers of my former colleague, Dr. Nestor Galvez-Jimenez, and my former residents and fellows, Drs. Michelle Dompenciel, Raghav Govindarajan, Ramon Lugo, John A. Morren, and Alexandra Soriano. They are all astute clinicians and accomplished electrodiagnosticians. This book is well written and organized, replete with visually enhancing anatomical and technical illustrations, starting with the underlying principles and practices, optimal techniques of nerve conduction studies, and electro- myography. Then specific disorders of the peripheral nervous system are dis- cussed clinically and how properly performed electrodiagnostic studies will complement the clinical neurological assessment. This book will be a valu- able resource in the field of electrodiagnostic medicine that trainees and existing practitioners will find very helpful. Beginners and experts and men- tors and mentees will find this book a user-friendly guide in correctly per- forming and reporting clinically meaningful nerve conduction studies and electromyography. Finally, I am deeply humbled and appreciative that this book is dedicated to me by the editors. It is often said: Teaching is an art that takes time and patience. And that is certainly true of teaching electrodiagnostic studies. I remember how I myself was taught this discipline by my mentors, the late Dr. Jasper Daube and Dr. Edward Lambert, at the Mayo Clinic-Rochester. I am grateful and pleased to have contributed to the training and mentoring of several of the coauthors of this book. I wish them even more success in the future. Virgilio D. Salanga Department of Neurology Cleveland Clinic – Florida Weston, FL, USA vii Preface Few Antecedent Words of Gratitude from NGJ When one of us (NGJ) was approached by Springer to work on a book proj- ect, the decision to work on a book on electrodiagnostic medicine was easy. The field of electrodiagnostic medicine has grown exponentially with a solid body of evidence based on careful critical thinking, research, mathematical thought, and engineering with the appropriate interfacing of neurophysiologi- cal and neuroanatomical concepts. Hence, electrodiagnostic medicine is a field with an interdisciplinary nature to the science, study performance, and approach to patients. Therefore, producing a book of this nature (as has been wisely said many times) is not done in isolation but is the product of a “vil- lage.” Having asked Drs. John A. Morren and Alexandra Soriano to join me on this project was one of the wisest decisions I made when organizing this project. This is now our work as a team effort. They added editorial expertise, breath of knowledge, a fresh look, and attention to detail so important in projects of this type, particularly as it pertains to electrodiagnostic medicine. My heartfelt thanks go particularly to John A. Morren who added clarity of thought and made what appears complex to explain easy for the reader to understand. This work is as much his work as everyone else’s. He read and editorialized each chapter and attended to my many phone calls no matter how basic some of those were to make sure we all understood what was con- veyed in each chapter. It was the best decision to have John provide his insight and knowledge and Alex adding her expertise in the performance and under- standing on single fiber EMG, an area in which she excels like no one I know, and her ability to write electrodiagnostic reports, which is not as easy as many would make you believe. In addition, I have to give thanks to our technolo- gists from Cleveland Clinic in Ohio and Florida who gave their time and expertise and in many instances were willing to be models for the atlas. My thanks also go to Jessica Galvez, BSc, MEd, PsyD candidate, who, in spite of a busy doctoral study schedule, managed to participate as model for some of the laboratory pictures that needed to be replaced on short notice, saving the day for us. Finally, I will be remiss if I do not acknowledge all the invited authors, all authorities, and accomplished electrodiagnosticians who took time from their very busy schedules to participate in this project. ix x Preface Using the Book One of the critical challenges facing trainees and experienced electrodiagnos- ticians alike is the attention to detail when performing nerve conduction stud- ies (NCS) and needle electrode examination (NEE). This is needed for the coherent interpretation of findings, including when to discard that relatively unimportant finding, recognize an artifact, and ultimately know how to put all the pieces together for a cogent EDX diagnosis. Words matter, and sentences matter in a way that can hardly be more epitomized than with the explana- tions and conclusions in EDX medicine. Some may argue that an imprecise word or a superfluous comment may lead to confusion and unnecessary assessments by the referring physician, or in the worst-case scenario, even an unnecessary surgical procedure. The book begins with Chap. 1, which is intended to provide the novice and expert alike with the neurophysiology and neuroanatomical fundamentals on the theory and principles for the practice and understanding of EDX studies. In addition, it provides general concepts on the assessment of common neuro- muscular complaints and how to use the EDX techniques to approach and study these patients. More often than not, patients come with symptoms or complaints, and less so with established neuromuscular diagnoses. Hence, the hope is to provide enough knowledge to get a handle on EDX thought process for an appropriate work-up. Chapter 2 describes the most common NCS tech- niques in great detail using actual individuals in pictures demonstrating the performance of the studies, detailing the pertinent anatomical localization within the segment being evaluated, in addition to helpful tips and common pitfalls. Chapter 3 provides a pictorial survey on the anatomical localization, and appropriate placement of the needle electrode, with similarly helpful tips and common pitfalls for each muscle that may be examined. Further, in Chap. 4, a deeper understanding of the electronics and neurophysiology relating to NEE is facilitated, with explanation of normal and abnormal findings on NEE. This was provided masterfully by Bryan Tsao, MD, who is a leading expert in this area, known for his excellent teaching of the topic, particularly at sessions of the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM). This is followed by other excellent chapters written by experts in their respective fields and/or academic practices with the hope of providing added insight on the fundamentals of electrodiagnostically assess- ing patients with neuromuscular conditions. Therefore, these chapters delve into the major conditions often encountered in a busy neuromuscular medicine practice. Chapter 5 expands on the mononeuropathies of the upper and lower extremities with their respective EDX assessments written by Ramon Lugo, MD, and Alexandra Soriano, MD. Chapter 6 written by Megha Dhamne, MD, and John A. Morren, MD, deals with the EDX assessment and nuances of polyneuropathies in a very scholarly fashion. For Chap. 7 on brachial plexopa- thies, we were extremely lucky to have Mark Ferrante, MD, who is a renowned national and international expert on the topic. He gives his insight and tremen- dous knowledge on the EDX assessment of patients with brachial plexus lesions. One of us (NGJ) had the privilege to be at the EMG laboratory during residency training when Mark was a fellow at our institution working with Asa Preface xi Wilbourn and witnessed how between them, “the book” on the EDX assess- ment of the brachial plexus and plexopathies was essentially rewritten the way we know it today. Chapter 8 provides another scholarly discussion by Karen Karwa, MD, and John A. Morren, MD, on radiculopathies, the work-up for which is commonly requested in EDX medicine, yet continues to be a source of spurious interpretations and repeat studies, particularly when coming from less experienced laboratories. A major source for neuromuscular consultations and complex EDX assessment is that for patients with disorders of the motor neuron and mimicker conditions. Michelle Dompenciel, MD, provides a dis- cussion of the topic in Chap. 9, and more importantly provides the EDX approach to this complex group of patients. Michelle is an accomplished elec- trodiagnostician, and we were excited in having her contribute this important chapter. Chapter 10 by Elanagan Nagarajan, MD, and Raghav Govindarajan, MD, well known in the area of neuromuscular medicine, provides an overview of the pathophysiology and clinical and EDX assessment of patients with neu- romuscular junction transmission disorders. Dr. Govindarajan is quite active in the AANEM and one of his main area of interest is that of neuromuscular junction disorders. Their insight and approach to the work-up of these patients, with an emphasis on technical proficiency and interpretation accu- racy of this somewhat complex aspect of electrodiagnostic medicine, is of great benefit to the reader. Chapter 11 is contributed by Alexandra Soriano, MD. Alex is an accomplished electrodiagnostician particularly in the assess- ment, performance, and interpretation of single fiber EMG. She gets referrals from all over the region and country and has been a source of inspiration and along with John A. Morren has provided her expertise and meticulous atten- tion to detail on all matters of EDX medicine. Chapter 12, written by Payam Soltanzadeh, MD, provides an excellent overview, with discourse on core concepts and fundamentals pertaining to the assessment and interpretation of EDX studies in patients with myopathies. The book concludes with Chap. 13 spearheaded by Alex Soriano, MD, and further refined by John A. Morren, MD, providing a succinct overview on how to write an EDX report, particu- larly in keeping with the recommendations set forth by the AANEM. Just as the practice of EDX medicine is both an art and science, so is the ability to write an EDX report, as this chapter elaborates. It is the sincere hope of the editors of this work that we have provided a fresh overview on the subject of electrodiagnostic medicine and that this book will serve as a primer to many laboratories, as it will be in ours. We anticipate that it will be very helpful as reference companion, especially to instructors and lifelong learners in the field (not excluding former and future residents and fellows). We also hope that our readers have ever-increasing gratification in the practice of high-quality electrodiagnostic medicine that is not only a meaningful tribute to their mentors in the field but a great service to patients who trust us to do the best for them. Weston, FL Nestor Galvez-Jimenez Weston, FL Alexandra Soriano Cleveland, OH John A. Morren