Cummings Review of Otolaryngology 1st Edition PDF

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Access to the eBook is limited to the first individual who redeems the PIN, located on the inside cover of this book, at expertconsult.inkling.com and may not be transferred to another party by resale, lending, or other means. CUMMINGS REVIEW OF OTOLARYNGOLOGY This page intentionally left blank       CUMMINGS REVIEW OF OTOLARYNGOLOGY HARRISON W. LIN, MD Assistant Professor Department of Otolaryngology—Head and Neck Surgery University of California, Irvine Irvine, California DANIEL S. ROBERTS, MD, PhD Division of Otolaryngology—Head and Neck Surgery University of Connecticut Farmington, Connecticut JEFFREY P. HARRIS, MD, PhD Distinguished Professor Division Chief Division of Otolaryngology—Head and Neck Surgery University of California, San Diego San Diego, California Foreword by CHARLES W. CUMMINGS, MD Distinguished Service Professor Department of Otolaryngology—Head and Neck Surgery Professor, Department of Oncology Johns Hopkins Medical Institutions Baltimore, Maryland 1600 John F. Kennedy Blvd. Ste 1800 Philadelphia, PA 19103-2899 CUMMINGS REVIEW OF OTOLARYNGOLOGY ISBN: 978-0-323-40194-4 Copyright © 2017 by 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. Details on how to seek permission, further infor- mation about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Pub- lisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treat- ment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluat- ing and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. With respect to any drug or pharmaceutical products identified, readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of practitioners, relying on their own experience and knowledge of their patients, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. 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 li- ability, 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 Names: Lin, Harrison W., author. | Roberts, Daniel S. (Daniel Stewart), 1974- author. | Harris, Jeffrey P. (Jeffrey Paul), 1949- author. Title: Cummings review of otolaryngology / Harrison W. Lin, Daniel S. Roberts, Jeffrey P. Harris ; foreword by Charles W. Cummings. Other titles: Review of otolaryngology Description: Philadelphia, PA : Elsevier, | Includes index. Identifiers: LCCN 2016027590 (print) | LCCN 2016028336 (ebook) | ISBN 9780323401944 (pbk. : alk. paper) | ISBN 9780323427999 () Subjects: | MESH: Otorhinolaryngologic Diseases | Otorhinolaryngologic Surgical Procedures | Outlines Classification: LCC RF46 (print) | LCC RF46 (ebook) | NLM WV 18.2 | DDC 616.2/1--dc23 LC record available at https://lccn.loc.gov/2016027590 Content Strategist: Belinda Kuhn Content Development Specialist: Kathryn M. DeFrancesco and Cara-Beth Lillback Publishing Services Manager: Hemamalini Rajendrababu Project Manager: Dr. Atiyaah Muskaan Design Direction: Renee Duenow Marketing Manager: Melissa Fogarty Printed in China Last digit is the print number: 9 8 7 6 5 4 3 2 1  Contributors Amir Afrogheh, BChD, MChD John L. Go, MD Clinical Research Fellow Associate Professor Head and Neck Pathology Director of Head and Neck Imaging Massachusetts General Hospital Department of Radiology Harvard Medical School Division of Neuroradiology Boston, Massachusetts University of Southern California Consultant Pathologist, NHLS Los Angeles, California Senior Lecturer/Specialist Chapter 12 Head and Neck Radiology University of the Western Cape Cape Town, South Africa Sachin Gupta, MD Chapter 11 Head and Neck Pathology Attending, Otology and Neurotology Department of Otolaryngology—Head and Neck Surgery Brian S. Chen, MD Walter Reed National Military Medical Center Staff Surgeon, Otology and Neurotology Washington, DC Department of Otolaryngology—Head and Neck Surgery Chapter 2 Otology and Neurotology William Beaumont Army Medical Center El Paso, Texas Allen S. Ho, MD Chapter 2 Otology and Neurotology Assistant Professor of Surgery Department of Surgery Jennifer Derebery, MD Cedars-Sinai Medical Center Associate, House Ear Clinic Los Angeles, California Clinical Professor of Otolaryngology Chapter 5 Head and Neck Surgery University of Southern California Los Angeles, California Marc H. Hohman, MD Chapter 8 Otolaryngic Allergy Facial Plastic and Reconstructive Surgeon Associate Director, Otolaryngology Residency Program Jayme Rose Dowdall, MD Madigan Army Medical Center Instructor Tacoma, Washington Department of Otology and Laryngology Assistant Professor Harvard Medical School Department of Surgery Boston, Massachusetts Uniformed Services University of the Health Sciences Chapter 7 Laryngology Bethesda, Maryland Chapter 3 Facial Plastic and Reconstructive Surgery William C. Faquin, MD, PhD Director, Head and Neck Pathology Kiran Kakarala, MD Massachusetts General Hospital Assistant Professor Massachusetts Eye and Ear Infirmary Department of Otolaryngology—Head and Neck Surgery Associate Professor of Pathology University of Kansas School of Medicine Harvard Medical School Kansas City, Kansas Boston, Massachusetts Chapter 5 Head and Neck Surgery Chapter 11 Head and Neck Pathology Elliot Kozin, MD Daniel Fink, MD Department of Otolaryngology Assistant Professor, Laryngology and Voice Disorders Harvard Medical School Department of Otolaryngology—Head and Boston, Massachusetts Neck Surgery Chapter 8 Otolaryngic Allergy Louisiana State University Health Sciences Center Chapter 9 Sleep Medicine Baton Rouge, Louisiana Chapter 7 Laryngology Shelby Leuin, MD Assistant Clinical Professor M. Boyd Gillespie, MD, MSc Pediatric Otolaryngology Professor Rady Children’s Hospital Department of Otolaryngology—Head and University of California, San Diego Neck Surgery San Diego, California Medical University of South Carolina Chapter 6 Pediatric Otolaryngology Charleston, South Carolina Chapter 9 Sleep Medicine v vi CONTRIBUTORS Aaron Lin, MD, MA Peter M. Sadow, MD, PhD Pediatric Otolaryngologist Associate Director, Head and Neck Pathology Department of Head and Neck Surgery Pathology Service Southern California Permanente Medical Group Massachusetts General Hospital Downey, California Associate Professor Chapter 6 Pediatric Otolaryngology Department of Pathology Harvard Medical School James Lin, MD Associate Director, Head and Neck Pathology Associate Professor Department of Otolaryngology Department of Otolaryngology Massachusetts Eye and Ear Infirmary Kansas University Medical Center Boston, Massachusetts Kansas City, Kansas Chapter 11 Head and Neck Pathology Chapter 2 Otology and Neurotology Ryan J. Smart, MD, DMD Theodore McRackan, MD Oral and Maxillofacial Surgeon Assistant Professor Clinical Instructor of Surgery-University of North Dakota Director, Lateral Skull Base Surgery School of Medicine, Staff Surgeon Department of Otolaryngology Essentia Health Medical University of South Carolina West Fargo, North Dakota Charleston, South Carolina Chapter 10 Oral Surgery Chapter 2 Otology and Neurotology Srinivas M. Susarla, MD, DMD Anandh G. Rajamohan, MD Department of Plastic Surgery Assistant Professor Johns Hopkins Hospital Department of Radiology Baltimore, Maryland Division of Neuroradiology Chapter 3 Facial Plastic and Reconstructive Surgery University of Southern California Chapter 10 Oral Surgery Los Angeles, California Chapter 12 Head and Neck Radiology Jonathan Ting, MD, MS Department of Otolaryngology—Head and Neck Surgery Douglas D. Reh, MD Indiana University School of Medicine Associate Professor Zionsville, Indiana Otolaryngology—Head and Neck Surgery Chapter 4 Rhinology and Endoscopic Sinus Surgery Johns Hopkins Medicine Baltimore, Maryland Aaron Wieland, MD Chapter 4 Rhinology and Endoscopic Sinus Surgery Assistant Professor of Surgery Department of Surgery Brian Kip Reilly, MD Division of Otolaryngology—Head and Neck Surgery Assistant Professor of Otolaryngology University of Wisconsin Children’s National Medical Center Madison, Wisconsin Washington, DC Chapter 5 Head and Neck Surgery Chapter 6 Pediatric Otolaryngology  Foreword The mission of the comprehensive text Cummings Otolaryngology/Head and Neck Surgery is to present, in accessible fashion, information that allows the readership exposure to the most current core content of the specialty. This review mirrors that mission. Congratulations to Drs. Lin, Roberts, and Harris for their excellent work. Medical contributions are expanding at a rate that makes currency of knowledge almost unattainable. Clinical- and compliance-related demands leach away discretionary time previously used to “keep up.” This review book con- solidates and highlights the content of its parent to allow rapid review and acquisition of new knowledge. It also presents a vehicle for specialty board examination preparation. Kudos to the editors for this most helpful initiative. Charles W. Cummings 2016 vii Preface Cummings Review of Otolaryngology is a review book designed for physicians taking the otolaryn- gology written and oral board, recertification, and in-service examinations; the otolaryngology intern, resident, and fellow trainees looking to augment their knowledge base; and medical students preparing for subinternships and residency training. If you are reading this book, you likely have performed at a high level on written examinations for most of your life. Although Cummings Review of Otolaryngology and other texts will prepare you for written examinations in the field of otolaryngology in a systematic and logical way, excelling on clinical rounds and on oral board examinations is a skill that improves with familiarity of oral testing formats and compartmentalizing your fund of knowledge in an organized, easily accessible manner. We believe that this book is the primary and go-to resource that a medical student or resi- dent will read before clinical rounds with the attending surgeon, a complex surgical case, a mock oral board examination, or the American Board of Otolaryngology examinations. The learn- ing and information conveyed through the book will allow readers to have the most important clinical information—such as a differential diagnosis, clinical algorithm, treatment options, or a list of how-to’s—instantly accessible in their memory to respond quickly to questions in a clinical or testing situation, to facilitate teaching of other residents and medical students, and to assist in patient management. This organized and structured way of thinking is central to success in the oral board format, as well as in clinical rotations and patient care. Harrison W. Lin Daniel S. Roberts Jeffrey P. Harris viii  Acknowledgments We would like to acknowledge all of our teachers and mentors, who have dedicated their lives to both the highest level of patient care and passing on their craft to subsequent generations of surgeons. They serve as continued inspiration toward our academic pursuits. In addition, we wish to thank the students and trainees whose probing questions constantly push us to stay current and to serve as a stimulus for our own creativity. Harrison W. Lin Daniel S. Roberts Jeffrey P. Harris ix This page intentionally left blank        Contents 1 Preparing for Clinical Rounds and Board Examinations, 1 2 Otology and Neurotology, 4 3 Facial Plastic and Reconstructive Surgery, 27 4 Rhinology and Endoscopic Sinus Surgery, 54 5 Head and Neck Surgery, 75 6 Pediatric Otolaryngology, 114 7 Laryngology, 147 8 Otolaryngic Allergy, 176 9 Sleep Medicine, 190 10 Oral Surgery, 200 11 Head and Neck Pathology, 213 12 Head and Neck Radiology, 247 Index, 285 xi This page intentionally left blank        Preparing for Clinical Rounds and 1 Board Examinations number and a list of five examiners who will likely be among INTRODUCTION the most prominent and published names in our field. Over Most residents who completed a general surgical internship will 40 minutes, you will be tested on three cases in each of five remember the “five W’s” that can cause post-operative fever, rooms with different sub-specialty topics, which include head including wind (pneumonia or atelectasis), water (urinary tract and neck surgical oncology, otology and neurotology, facial infection), walking (deep venous thrombosis), wound (wound plastic and reconstructive surgery, and two general otolaryngol- infection), and wonder drug (drug reaction). Those that are under- ogy rooms. General cases encompass rhinology, sleep, allergy, going or completed otolaryngology training will furthermore pediatric otolaryngology, laryngology, and other general oto- recall being asked to recount the auditory pathway and peaks of laryngology topics. One room will focus on allergy, rhinology, the auditory brainstem response, to describe the innervation and and sleep, and the other will focus on laryngology and pediatric actions of the laryngeal muscles, or to discuss the reconstructive otolaryngology. The examiners will be accessing your ability to ladder, among many other questions in the clinic, on rounds, or discuss eloquently the diagnostic workups, treatment options, in the operating room. Undoubtedly, these well-described and complications, and, at times, management of emergencies for time-tested clinical pearls are critically important in the context each of the presented cases. of both examinations and everyday patient care, particularly to Success on the oral board exam depends on an ability to the resident trainee rotating through busy clinical services while communicate an organized and structured thought process. trying to simultaneously read, learn how to operate, and provide Oral board formats are similar to the workup of a patient in a the highest quality clinical care. Time is a luxury students and clinic. Points are attained by starting with the chief complaint residents unfortunately do not have, and consequently they are and obtaining a thorough history of the present illness, past best served by learning quickly, efficiently, and effectively. medical history, past surgical history, family history, social his- We wrote the Cummings Review of Otolaryngology in an effort tory, list of medications and allergies, and review of systems. to provide a highly-efficient learning instrument to its read- After completing the full history, the examinee should ask to ers. Clinical pearls such as the “five W’s”, “E.C.O.L.I.”, and the perform a physical exam, first asking for the patient’s vital signs. reconstructive ladder organize and compartmentalize informa- If there is an emergency, you will be expected to discuss basic tion into packets that most anyone at this level of education life support and assess the patient’s airway, breathing, and circu- and training can swiftly consume, digest and incorporate into lation. A brief summary statement with pertinent information their long-term memory. This book provides this compartmen- from the history and physical, along with a comprehensive dif- talization of otolaryngology and all of its depth, breadth, and ferential diagnosis, should be provided at some point after the complexity, and offers readers the foundation upon which they initial assessment is completed. Asking for additional informa- can build and expand their fund of knowledge with articles, tion such as laboratory tests, imaging, and audiograms will also textbooks, and discussions with senior residents and attend- be necessary in many cases. Pathology is typically incorporated ings. Although this text will importantly augment the knowl- into several cases during the testing day. Imaging, pathologic edge base of the reader in a systematic and organized manner, slides, and test results will give you an opportunity to refine success on clinical rounds and on in-service and board exami- your differential diagnosis as needed. nations will be further optimized with better understanding of As you discuss the case with your examiner, he or she may how to prepare for attending rounds and improved familiar- focus, narrow, expedite, or redirect your questioning if nec- ity of the testing formats. This chapter provides a systematic essary. When medical treatment or surgery is indicated, you approach to these tasks. should be able to recite the various options in management, the risks and benefits of each, and the postoperative care protocols. You may need to recognize and manage complications in the ORAL EXAMINATIONS postoperative setting. Familiarity with the format of oral exams will provide the infra- structure upon which the examinee can prepare for success. For most residents and medical students, written exams have PEARLS FOR SUCCESS ON ORAL EXAMS been the mainstay of testing, with far less training in the oral S tay organized. You are provided a pencil and paper and exam format. To begin, the American Board of Otolaryngology are welcome to take notes as needed. oral examination takes place over a weekend in a hotel in the Do not go directly to the diagnosis, even if it may seem city of Chicago, Illinois, near O’Hare International Airport. You obvious to you. Rather, the goal during a case is to obtain have the option of staying in the hotel, in a neighboring hotel points (check marks) by logically moving through the walking or shuttle distance away, or in your own accommoda- workup of a patient and verbally stating all history questions tions. Based on the first letter of your last name, you will have you should ask, studies you should obtain, diagnoses you your exam on Saturday morning, Saturday afternoon, Sunday should consider, and treatment options you may offer. morning, or Sunday afternoon. At the exam, you receive a Demonstrate an organized and linear thought process. 1 2 CHAPTER 1 | PREPARING FOR CLINICAL ROUNDS AND BOARD EXAMINATIONS T his review book provides you with the lists to be Skype to practice with your co-residents or other residents memorized so that you have easy access to what you want preparing for the exam. If you take the time to prepare mock and need to say for many questions that may arise in exam case files (on Microsoft PowerPoint, for instance) your oral exam. If you are presented with a patient with with radiology and pathology images from your own files, hoarseness, simply recite the list of key history questions publications, or Google searches, and practice going through for a patient with hoarseness. If you are presented with a the formal routine of taking an oral board exam, the actual patient with ear drainage, ask the key questions to ask of all exam will seem much more familiar and easier. patients presenting to an otology clinic. If your patient has Bringing other viewpoints, standards of care, and opinions pediatric hearing loss, describe the list of tests you could is another benefit of talking to and studying with co-fellows offer and recommend to the parents. If you are performing or residents of other programs. This is especially true for parotid surgery and are asked how you would go about graduates of smaller residency programs who may have only finding the facial nerve, simply recount the list of five ways been exposed to a limited number of subspecialty-trained to find the trunk of the facial nerve. If you believe that a attending physicians. Discussing the “board answers,” that rhinoplasty patient could benefit from an increase in tip is, what you should say in the board exam, rather than projection, mention the three ways you could accomplish your local surgeon’s independent viewpoint, would serve that. Memorizing the lists in this book will arm you with you well. For instance, your otology-attending physician an organized and comprehensive depth and breadth of may have gone forward with a stapedectomy in the setting knowledge that will help you to remain cool, calm, and of a persistent stapedial artery or overhanging facial collected and succeed in your exam. nerve, but the “board answer” may be to abort. It would When providing a differential diagnosis use a mnemonic to be appropriate to bring up the fact that you may have stay organized. Although this may seem to you artificial, it is witnessed a successful completion of this case by a more an effective way to recite calmly and easily a thorough list of experienced surgeon, but you would abort the case and possible diagnoses. Pick one of the examples and stick with refer it to a more seasoned otologist. it, write it down on your provided piece of paper, and refer Examiners are on your side. If you feel yourself starting to to it when needed to guide you. panic or tighten up, ask for a second and relax. You are “KITTENS” (K—congenital; I—infectious, iatrogenic; likely doing better than you think. TT—toxins, trauma; E—endocrine; N—neoplastic; You need to pass the written exam to take the oral exam. S—systemic) If you passed the written exam, chances are heavily in your “VITAMIN-C” (V—vascular; I—infectious, inflammatory; favor that you will pass the oral exam. T—toxins, trauma; A—autoimmune; M—metabolic; I—iatrogenic; N—neoplastic; C—congenital) DIFFERENTIAL DIAGNOSIS “VINDICATE” (V—vascular; I—infectious, inflammatory; N—neoplastic; D—drugs; I—iatrogenic; C—congenital; AND CLINICAL ROUNDS A—autoimmune; T—trauma, toxins; E—endocrine) Cummings Review of Otolaryngology is a powerful tool for rapid For pathology questions, describe the finding you see on learning and review for medical students, interns, and junior the image, even if you are unable to provide the correct residents rounding in the hospital and preparing for “pimp” diagnosis. After all, you are not a pathologist and neither questions, as well as for residents studying for oral and written is your examiner. The correct diagnosis is obviously in-service and board exams. Even though other review books preferred, but some credit may possibly be obtained for an provide summaries of information of what could be said during accurate description of the pathological specimen. an oral examination or in response to a “pimp” question, our Ask for one test or imaging study at a time. If you are book provides a logical, systematic approach that can be applied correct in asking for the study, you will be presented the to any oral exam format; to frequently asked questions by chief results and will need to interpret them accurately in an residents, fellows, and attending physicians; and to address any organized fashion that demonstrates to your examiner clinical situation: what questions should you ask in the history, what your knowledge and abilities. findings are you looking for on physical exam, what is the differential Review computed tomography (CT) and magnetic diagnosis, what are the critical findings on radiology and pathology stud- resonance (MR) images by stating (1) the type of imaging, ies, what are the treatment options, what is your best option, what are (2) the view, (3) the type of sequences if applicable, and (4) ways to perform this, and what is your postoperative management? Once roughly where the slice is within the series. For example, these lists are reviewed and memorized, the reader will have an you could state, “this is an axial CT of the neck, soft-tissue armamentarium of knowledge that can be instinctively accessed windows, with contrast, at the level of the larynx,” or “this and effectively used in any clinical or examination scenario. is an MR of the temporal bone, coronal cuts, T1 imaging For further detail, you will often need to go to the reference with contrast, at the level of the internal auditory canal.” books and other texts to explain in more detail many of the key You may be provided with and asked to interpret a stack “buzzwords” that are in this review book. Obviously, the more of images from the same scan, and not just one isolated senior in training you are, the better these terms will make sense image. Be systematic and help yourself by stating the normal to you and stay with you. However, these lists, if memorized early in anatomy, which both demonstrates to your examiner your training, can serve the trainee exceedingly well on rounds, in the familiarity with the anatomy and helps build a mental image clinic, in the operating room, and on exams. For instance, a medi- in your brain of where you are. As you should have learned cal student or intern may have difficulty explaining exactly where by now, recognition and familiarity with normal help you the soft-tissue triangles are located, but a sub-intern will routinely be identify abnormal. Partial credit can be given for an accurate asked to recite the subunits of the nose by facial-plastics attending radiologic description of the abnormal findings whether or physicians. Similarly, a student may not know exactly where the not the correct diagnosis is obtained. greater superficial petrosal nerve travels, but may be asked to name all Take advantage of any opportunity to take mock branches of the facial nerve or surgical landmarks of the middle examinations. Do not miss formal mock exams that may be cranial fossa. Being able to learn such packets of information from provided by your residency programs during your chief year, this review book and accurately recite them when put on the spot and if doing a fellowship, consider getting together with your could easily and favorably affect the enthusiasm of the attending co-fellows in other subspecialties to practice together. If you and resident physicians for the sub-intern and dramatically elevate are not in a fellowship, consider going on Google Talk or the student’s position on the program’s rank list.  CHAPTER 1 | PREPARING FOR CLINICAL ROUNDS AND BOARD EXAMINATIONS 3 PEARLS FOR SUCCESS ON WRITTEN EXAMS D o not perseverate on one or a handful of questions and jeopardize your ability to read and intelligently answer AND CLINICAL ROUNDS all questions fully. As with most computer tests you have P reparation and repetition are the keys to success. Use the previously taken, you can always go back within a section list format to “pimp” question your fellow residents and to questions about which you are unsure. If you have medical students early and often. Cross off lists that are absolutely no idea what the answer may be, just guess, and already memorized, and work to memorize as much of the minimize time wasted. If you have narrowed it down to two book as possible. In doing so, the number of humiliatingly or three choices, take a short amount of time to decide awkward silences that follow being asked a “pimp” question what the best guess would be. will be minimized. Oftentimes the question will ask for the “best” answer or The American Board of Otolaryngology written “next” course of action. Try to avoid overthinking the examination is a long test, comprising eight 50-minute question; for example, you may be tempted to establish the sections, and is completed on a computer at a local diagnosis of an unvaccinated child acutely presenting with testing center. After signing in, providing all required drooling and stridor, and want to visualize the supraglottis, forms of identification, and putting all of your but the “next” and “best” course of action may be to belongings in a locker, you will be taken to the testing establish the airway and intubate the child. room, where you are provided a whiteboard, marker, “Pimping” on clinical rounds is often formulated toward and eraser for any notes you may want to take. The clock one answer, or a short list (eg, what would you need to see starts once you log in and click to start a section, and the on pathology for a follicular thyroid carcinoma diagnosis, “break clock” starts once you complete each section. You or what are the subsites of the hypopharynx?), and because are given a total of 60 minutes of break time to spend of the limited time of early morning rounds, you will be as you wish, and you will need to allot sufficient time to expected to answer quickly. Unfortunately, the questions eat lunch, which you will need to bring and store in the can often be in a frustrating “what am I thinking?” format locker. (eg, what exam finding in particular would you expect in Undoubtedly, to become a medical student and a patient with necrotizing otitis externa, or what is special otolaryngology resident, you will have had to perform at about adenoid cystic carcinoma, or what else could it be?); the highest levels on written exams at nearly all points of being able to list off a differential diagnosis or key findings your education. Most of you will unlikely need to follow the for a particular pathology quickly would maximize your test-taking suggestions in this book, or already have your chance of naming the desired answer. own effective test-preparation routines. That said, however, Remember to include a differential diagnosis in your it is anecdotally reported that 10-15% of examinees fail the presentations because this will help you in your learning. otolaryngology written board exam every year. Accordingly, Remember your patients. Success on written exams do not underestimate the difficulty of and level of and with frequently encountered “pimp” questioning is performance needed to pass the exam. It has been shown facilitated by correlating your clinical experiences with your that performance on in-service examinations correlates medical knowledge. Use a key figure or a list of pathologic closely with performance on the board examination, and, features presented in this book to associate with a clinical consequently, you and your program director should experience. You will never forget facts that are associated be able to determine the intensity at which you should with patient care. prepare for the written exam. The radiology and pathology images in Cummings Review Given the length of the exam, prepare your mental of Otolaryngology are arranged in a high-yield format for endurance as the test date approaches by taking full exams in otolaryngology. Review these images before your weekend days during which you study for 3 to 4 consecutive in-service, written, and oral board exams. These images hours without breaks in the morning and again in the represent some of the most frequently encountered afternoon after a brief lunch break. Determine how much pathologies in our field, and you may find many on your caffeine you will need to optimize your attentiveness and exams. minimize mental fatigue as you enter the seventh and We wish you success on your written and oral examinations eighth hours of study and test taking. Remember that those and congratulate you in your choice of a career in otolaryngol- final questions are worth just as much as the first set of ogy, head and neck surgery. questions.  2 Otology and Neurotology TEMPORAL BONE ANATOMY SUPERIOR VIEW OF THE LEFT TEMPORAL Temporal bone portions BONE (Fig. 2.2) a. Squamous Key Points b. Petrous The arcuate eminence typically corresponds to the superior c. Tympanic semicircular canal, but not always. d. Mastoid The greater superficial petrosal nerve (GSPN) exits from the geniculate ganglion of the facial nerve; the geniculate LATERAL VIEW OF THE LEFT TEMPORAL ganglion is dehiscent without bony covering in about 10-20% of temporal bones. BONE (Fig. 2.1) Key Points MEDIAL VIEW OF LEFT TEMPORAL BONE The temporal line approximates the floor level of the middle fossa ±5 mm. (Fig. 2.3) The sigmoid and lateral sinuses are typically anterior and Key Points superior to the emissary vein, respectively. T he lateral portion of the internal auditory canal (IAC) is The Macewen triangle, which is located posterior and called the fundus, and the medial portion is called the porus. superior to the spine of Henle, approximates the lateral Bill’s bar is named after William House. It separates the facial landmark of the mastoid antrum. nerve from the superior vestibular nerve at the fundus of Spine of Macewen Henle triangle Tympano- squamous suture line Cribriform area Tympanic Tympano- bone mastoid Temporal suture line squama EAC Temporal line Zygomatic process Mastoid portion Foramen for mastoid emissary vein Zygomatic root Digastric Glenoid groove Articular fossa tubercle of Mastoid zygomatic Styloid process process process FIGURE 2.1 Lateral view of left temporal bone surface shows squamous, tympanic, and mastoid portions. (From Francis HW, Niparko JK. Temporal Bone Dissection Guide. New York, NY: Thieme; 2011 and Flint PW, Haughey BH, Lund VJ, et al. Cummings Otolaryngology—Head and Neck Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 127-1.) 4  CHAPTER 2 | OTOLOGY AND NEUROTOLOGY 5 the IAC. Identification of Bill’s bar allows early identification digastric muscle. The anterior border of the digastric of the facial nerve, likely uninvolved with pathology (ie, a groove is the stylomastoid foramen. vestibular schwannoma arising from a vestibular nerve). The cochlear aqueduct is inferior and parallel to the IAC. INFERIOR VIEW OF THE LEFT TEMPORAL THE AURICLE BONE (Fig. 2.4) BLOOD SUPPLY Key Points T he styloid process is anteromedial to the stylomastoid E  xternal carotid artery foramen. Superficial temporal artery (anterior) Medial and superior to the mastoid tip is the digastric Posterior auricular (posterior) groove, which is the origin of the posterior belly of the EAR CANAL Depression of trigeminal Petrous apex Ridge for L ateral one-third is cartilaginous (has cerumen glands and ganglion superior petrosal hair follicles) sinus Medial two-thirds are bony (no cerumen glands or hair follicles) Groove for Bony-cartilaginous junction is a route of disease spread greater superficial Arcuate Fissures of Santorini: natural fissures in anterior petrosal nerve eminence cartilaginous ear canal that allows the spread of disease to the superficial parotid Groove for Foramen of Huschke: anteroinferior bony defect that middle typically obliterates during development; patency meningeal allows the spread of disease to the deep parotid lobe/ artery temporomandibular joint (TMJ) EARDRUM (Fig. 2.5) 1.  anubrium (handle of malleus) M 2. Anterior malleolar fold FIGURE 2.2 Superior view of left temporal bone shows petrous and squamous 3. Posterior malleolar fold portions forming the floor of the middle fossa and anterior limit of the posterior 4. Pars flaccida (has no fibrous layer between the keratin- fossa. (From Francis HW, Niparko JK. Temporal Bone Dissection Guide. New York, NY: izing squamous epithelium and middle ear mucosa); Thieme; 2011 and Flint PW, Haughey BH, Lund VJ, et al. Cummings Otolaryngology— space medial to pars flaccida and lateral to malleus neck: Head and Neck Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 127-2.) Prussack’s space Superior petrosal sulcus Temporal squama Sigmoid sulcus Zygomatic process Subarcuate fossa Petrous portion c Bill bar d b Falciform a crest IAC Operculum of Cochlear endolymphatic aqueduct duct FIGURE 2.3 The posterior surface features of the left temporal bone include the fundus of the IAC. Foramina for cranial nerve VIII: cochlear (a), inferior vestibular (b), and superior vestibular (c) divisions and cranial nerve VII (d) are shown. (From Francis HW, Niparko JK. Temporal Bone Dissection Guide. New York, NY: Thieme; 2011 and Flint PW, Haughey BH, Lund VJ, et al. Cummings Otolaryngology—Head and Neck Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 127-3.) 6 CHAPTER 2 | OTOLOGY AND NEUROTOLOGY Foramen of cochlear Carotid Keel between canal aqueduct carotid and jugular bulb Jugular spine Caroticotympanic canaliculus Jugular fossa Stylomastoid foramen Sulcus for occipital artery EAC Glenoid Digastric fossa groove Zygomatic Mastoid Styloid root process Tympano- process squamous suture line FIGURE 2.4 Inferior View of the Left Temporal Bone. Note the linear relationship between the stylomastoid fora- men, digastric groove, and styloid process. (From Francis HW, Niparko JK. Temporal Bone Dissection Guide. New York, NY: Thieme; 2011 and Flint PW, Haughey BH, Lund VJ, et al. Cummings Otolaryngology—Head and Neck Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 127-5.) 5. L ong process of the incus 6. Promontory behind the eardrum * * 7. Fibrous tympanic annulus (not present along the pars 4 flaccida) 2 3 8. Umbo 5 9. Lateral or short process of the malleus 9 10. Opening of the Eustachian tube 1 MIDDLE EAR 6 8 1. E pitympanum (superior to the annulus) a. Prussack’s space b. Anterior epitympanum (Supratubal recess) - compart- 10 7 ment anterior to the malleus head c. Posterior epitympanum compartment posterior to the cog (communicates with the mastoid via the aditus ad antrum into the antrum) 2. Mesotympanum (at the level of the annulus, superiorly/ inferiorly) 3. Hypotympanum (below the level of the annulus) FIGURE 2.5 Surface features of the left TM include the manubrium of the mal- 4. Eustachian tube (protympanum): connects and ventilates leus (mallear stria, 1); anterior mallear fold (2); posterior mallear fold (3); pars the anterior mesotympanic space to the nasopharynx flaccida, or Shrapnell membrane (4); long process of incus (5); pars tensa, through 5. Above the Eustachian tube is the supratubal recess (STR) which the promontory and round window are visible (6); tympanic annulus (7); a. The posterior boundary cochleariform process (inferi- umbo (8); lateral process (9); Eustachian tube opening (10); and anterior and orly) and the cog (superiorly); the former is where the posterior tympanic spines (asterisks). The anterior and posterior tympanic spines tensor tympani tendon takes a 90-degree turn from are the borders of the bony gateway to the epitympanum (notch of Rivinus). (From the medial wall of the middle ear and inserts onto the Flint PW, Haughey BH, Lund VJ, et al. Cummings Otolaryngology—Head and Neck malleus Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 127-8.) b. The medial wall will house the geniculate ganglion; it may be dehiscent by the cholesteatoma 8. T he suspensory ligaments and mesenteries of the ossicles 6. Sinus tympani in the posterior mesotympanic space, separate the aeration of the epitympanum and mesotym- medial to the descending facial nerve, posterior to the panum, and connect oval window (separated by the ponticulus) and round a. Anterior to the stapes (isthmus tympani anticus) window niche (separated by the subiculum) and of b. Posterior to the stapes (isthmus tympani oticus) variable posterior extension; cholesteatoma may hide 9. The long process of the incus has a single blood supply here without collaterals predisposing it to erosion 7. Facial recess is lateral to the vertical facial nerve but 10. The stapedius tendon is innervated by the facial nerve, medial to the chorda tympani nerve, which, in turn, is and it comes out of the pyramidal eminence and inserts onto medial to the annulus the neck of the stapes.  CHAPTER 2 | OTOLOGY AND NEUROTOLOGY 7 Meatal foramen Internal auditory artery Labyrinthine segment Geniculate ganglion and fossa Tympanic First genu segment Lateral semicircular canal M Supratubal recess I Superficial petrosal nerve and artery Second genu S Cochleariform EP process Mastoid segment Stylomastoid artery Annular ligament of stylomastoid foramen Round window Facial nerve Digastric ridge Styloid process Posterior belly, digastric muscle FIGURE 2.6 Anatomy of the Infratemporal Portion of the Facial Nerve and Associated Middle Ear Struc- tures. Shown are sites of vulnerability to injury (arrowheads). Perigeniculate region: Susceptibility of the genicular fossa to fracture also increases the risk of nerve injury via nerve compression and ischemia in the narrow meatal foramen and labyrinthine segment. The first genu of the facial nerve is tethered by the GSPN, which increases susceptibility to shearing injuries; vascular watershed area between branches of the external carotid artery and posterior circulation, the geniculate ganglion is susceptible to injury during surgical dissection in the STR of the anterior epitympanum. Tympanic segment: The nerve is most frequently dehiscent above the oval window and distal tympanic segment; the second genu is susceptible to injury in cholesteatoma surgery because of pathologic dehiscence or distorted anatomy and failure to identify important surgical landmarks. Mastoid segment: In the lower portion of its vertical course and just distal to the stylomastoid foramen, the nerve is positioned lateral to the tympanic annulus and is therefore susceptible to injury during surgery of the EAC. EP, Eminence pyramidale; I, incus; M, malleus; S, stapes. (From Francis HW. Facial nerve emergencies. In Eisele D, McQuone S, eds. Emergencies of the Head and Neck. St. Louis, MO: Mosby; 2000 and Flint PW, Haughey BH, Lund VJ, et al. Cum- mings Otolaryngology—Head and Neck Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 127-9.) 11. T  ensor tympani innervation by V3 and inserts into the 4. L abyrinthine segment, 3-5 mm, the narrowest portion, neck of the malleus and completely enclosed in bone, leaving it most suscep- tible to compression from edema (Bell’s) and trauma (temporal bone fracture) COURSE OF THE FACIAL NERVE, 5. Geniculate ganglion at the first genu of the facial nerve RIGHT-EAR PARASAGITTAL VIEW 6. Facial nerve in the inner ear enters just posterior and superior to the cochleariform process (Fig. 2.6) 7. Courses over the superior border of the oval window (tym- panic segment, 10-12 mm) KEY POINTS a. Dehiscent here up to 25-55% of the temporal bones, 1. E xits the brainstem (cisternal or the cerebellopontine leaving it susceptible to injury/inflammatory mediators angle [CPA] portion) 14-17 mm 8. Second or mastoid genu 2. Enters the porus of the IAC and courses to the fundus 9. Mastoid or descending facial nerve, 12-15 mm (meatal portion, 8-10 mm) 10. Exits at the stylomastoid foramen 3. Intratemporal facial nerve’s bony housing = fallopian a. Exit is surrounded by the posterior belly of the digas- canal tric and skull-base periosteum 8 CHAPTER 2 | OTOLOGY AND NEUROTOLOGY 11. F  acial nerve functions c. S pecial sensory fibers (anterior two-thirds tongue taste a. Special visceral efferent (facial nucleus to the stape- to the solitary nucleus) dius, posterior belly digastric, stylohyoid muscle, and d. Somatic sensory fibers (posterior external auditory muscles of facial expression) canal [EAC] and conchal skin of the auricle to the b. General visceral efferents (superior salivatory nucleus spinal trigeminal nucleus) in the nervus intermedius to the geniculate ganglion to e. Visceral afferent fibers (nasal mucosa to solitary nucleus) the lacrimal gland, nasal mucosa, and submandibular and sublingual glands) MASTOID AND PETROUS APEX Axis of REGIONS OF TEMPORAL BONE rotation PNEUMATIZATION Incus 1. Mastoid Malleus 2. Petrous apex Cochlear 3. Perilabyrinthine vestibule 4. Accessory (zygomatic, squamous, occipital, and styloid) AIR CELL TRACTS Stapes 1. Posterosuperior (sinodural) Ear 2. Posteromedial (retrofacial and retrolabyrinthine) canal 3. Subarcuate 4. Perilabyrinthine TM 5. Peritubal AUDITORY ANATOMY AND A Fulcrum PHYSIOLOGY PV EXTERNAL EAR li 1. A uricle resonance frequency 5300 Hz lm Stapes 2. Ear canal resonance frequency 3000 Hz AFP “piston” 3. Allows localization via a. Interaural time difference Axis of b. Interaural intensity difference rotation PEC ATM TM EARDRUM/OSSICULAR CHAIN (Fig. 2.7) “piston” 1.  ardrum: footplate ratio 20:1 (26 dB advantage) E 2. Ossicular chain lever ratio 1.3:1 (2.3 dB advantage) B 3. Theoretical gain of eardrum/ossicular chain: 28 dB 4. Actual gain or eardrum/ossicular chain: 20 dB FIGURE 2.7 Schematic of the Middle Ear System. (A) Motion of the ossicular chain along its axis of rotation is illustrated. (B) Area of the TM (ATM) divided by area of the footplate (AFP) represents the area ratio (ATM/AFP). The length of the manubrium COCHLEA (Fig. 2.8) (lm) divided by the length of the incus long process (li) is the lever ratio (lm/li). PEC, External canal sound pressure; PV, sound pressure of the vestibule. (From Merchant  ibratory wave: oval window → scala vestibuli (perilymph 1. V SN, Rosowski JJ. Auditory physiology. In Glasscock ME, Gulya AJ, eds. Glasscock- filled) → helicotrema → scala tympani (perilymph filled) → Shambaugh Surgery of the Ear. 5th ed. Hamilton, ON: Decker; 2003:64, fig. 129-2.) round window To vestibular Reissner membrane system Helicotrema Stapes Acoustic energy Scala vestibuli Scala tympani (perilymph) Scala media Round Cochlear (endolymph) window partition FIGURE 2.8 Schematic Showing Sound Propagation in the Cochlea. As sound energy travels through the external and middle ears, it causes the stapes footplate to vibrate. The vibration of this footplate results in a compressional wave on the inner ear fluid. Because the pressure in the scala vestibuli is higher than that in the scala tympani, this sets up a pressure gradient that causes the cochlear partition to vibrate as a traveling wave. Because the basilar membrane varies in its stiffness and mass along its length, it is able to act as a series of filters that respond to specific sound frequencies at specific locations along its length. (From Geisler CD. From Sound to Synapse: Physiology of the Mammalian Ear. New York, NY: Oxford University Press; 1998:51 and Flint PW, Haughey BH, Lund VJ, et al. Cummings Otolaryngology—Head and Neck Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 129-6.)  CHAPTER 2 | OTOLOGY AND NEUROTOLOGY 9 Reticular lamina 2. B asilar membrane (Fig. 2.9) is a. Tonotopic: high frequencies at basal region (stiffer) Phalangeal process OHCs b. Lower frequencies at apical region (more flexible) Neul space c. Stiffness difference allows it to be a frequency filter 3. Vibratory wave → deflection of hair cell stereocilia → Reissner membrane potassium influx → depolarization (resting potential in endolymph +60-100 mV relative to perilymph) → action potential at first level neurons of spiral ganglion (Fig. 2.10) Stria 4. Potassium recirculated back through supporting cells and vascularis Deiters cells back into the perilymph via the stria vascularis Spiral ligament Scala media CENTRAL AUDITORY PATHWAYS (Fig. 2.11) Tectorial Tunnel of membrane 1. A uditory nerve Reticular lamina Corti Phalangeal process OHCs Inner Inner spiral 2. C  ochlear nuclei Nuel space hair cell sulcus a. Dorsal cochlear nucleus Claudius Border cells b. Anterior ventral cochlear nucleus cells of Held c. Posterior ventral cochlear nucleus (the majority of audi- tory fibers cross the midline) Limbus 3. Superior olivary complex Hensen 4. Lateral lemniscus cells Deiters Pillars of Spiral 5. Inferior colliculus Basilar cells Corti lamina 6. Medial geniculate body membrane Habenula 7. Auditory cortex perforata Cochlear nerve FIGURE 2.9 Cross section of the organ of Corti showing the major cellular STAPEDIUS REFLEX structures. (From Flint PW, Haughey BH, Lund VJ, et al. Cummings Otolaryngol- 1. Auditory nerve → cochlear nucleus → interneurons → bilat- ogy—Head and Neck Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 128-2.) eral facial motor nuclei → bilateral stapedius tendons Actin Tip links Stereocilia Scala vestibuli with perilymph Stria vascularis Tectorial Cuticular Reissner membrane Spiral plate membrane Scala media ligament with endolymph Nucleus Inner hair cell Potassium Potassium channel ions Spiral limbus Synaptic Connexin vesicles channels Supporting cells Basilar Cochlear OHCs membrane nerve Scala tympani with perilymph Supporting A B cells FIGURE 2.10 Mechanoelectrical transduction of the auditory signal depends on the recycling of potassium ions in the organ of Corti. (A) Schematic cross-sectional view of the human cochlea. The scala media (cochlear duct) is filled with endolymph, and the scala vestibuli and tympani are filled with perilymph. The endolymph of the scala media bathes the organ of Corti, located between the basilar and tectorial membranes and containing the inner and OHCs. A relatively high concentration of potassium in the endolymph of the scala media relative to the hair cell creates a cation gradient maintained by the activity of the epithelial supporting cells, spiral ligament, and stria vascularis. (B) Cells contain stereo- cilia along the apical surface and are connected by tip links. The potassium gradient is essential to enable depolarization of the hair cell following influx of potassium ions in response to mechanical vibration of the basilar membrane, deflec- tion of stereocilia, displacement of tip links, and opening of gated potassium channels. Depolarization results in calcium influx through channels along the basolateral membrane of the hair cell, which causes degranulation of neurotransmitter vesicles into the synaptic terminal and propagates an action potential along the auditory nerve. Gap junction proteins between the hair cells (potassium channel, yellow) and epithelial supporting cells (connexin channels, red) allow for the flow of potassium ions back to the stria vascularis, where they are pumped back into the endolymph. (From Willems PJ. Genetic causes of hearing loss. N Engl J Med. 2000;342(15):1101-1109 and Flint PW, Haughey BH, Lund VJ, et al. Cummings Otolaryngology—Head and Neck Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 129-4.) 10 CHAPTER 2 | OTOLOGY AND NEUROTOLOGY b. E  xcitatory with angular acceleration in the direction of the leading canal, and inhibitory in the coplanar, lag- ging canal; therefore, Auditory i. Ampullopetal flow of the perilymph in the lateral cortex canals is excitatory ii. Ampullofugal flow of the perilymph in the superior and posterior canals is excitatory OTOLITHIC ORGANS (LINEAR Medial geniculate body Inferior colliculus ACCELEROMETERS) 1. S accule: vertical acceleration 2. Utricle: horizontal acceleration, head tilt INNERVATION Lateral lemniscus Lateral lemniscal 1. S uperior vestibular nerve nuclei a. Utricle DAS b. Superior semicircular canal Cochlear nucleus c. Lateral semicircular canal Superior IAS Dorsal olivary 2. Inferior vestibular nerve VAS Ventral a. Saccule complex b. Posterior semicircular canal Auditory nerve EUSTACHIAN TUBE 1. T wo-thirds cartilaginous; one-third bony 2. Tensor veli palatini is the primary dilator FIGURE 2.11 Illustration of the major central ascending auditory pathways 3. Aging leads to increased slope of the tube, as well as for sound entering via the right cochlea. Commissural pathways and descending increased length, diameter, and efficiency of the opening feedback projections from higher centers are not depicted. DAS, Dorsal acoustic stria; IAS, intermediate acoustic stria; VAS, ventral acoustic stria. (From Flint PW, 4. Ostmann fat pad: metabolically sensitive adipose in the Haughey BH, Lund VJ, et al. Cummings Otolaryngology—Head and Neck Surgery. lateral wall of the Eustachian tube distally (rapid weight 6th ed. Philadelphia, PA: Saunders; 2015, fig. 128-6.) loss can cause atrophy of the fat pad and results in patulous Eustachian tube syndrome) VESTIBULAR ANATOMY AND AUDIOLOGIC TESTING PHYSIOLOGY AUDIOGRAM (Fig. 2.13) COPLANAR SEMICIRCULAR CANALS  = right-ear air conduction O (ANGULAR ACCELEROMETERS) (Fig. 2.12) X = left-ear air conduction 1. H orizontal canals Δ = right-ear air masked 2. L  eft anterior (superior), right posterior  = left-ear air masked 3. Right anterior (superior), left posterior < = right unmasked bone a. Basal firing rate from each ampulla > = left unmasked bone Right PC Left PC Left and Left AC Right AC right LC 30 A B FIGURE 2.12 Orientation of Semicircular Canals. (A) The horizontal canal is tilted 30 degrees upward from a horizontal plane at its anterior end. (B) Vertical canals are oriented at roughly 45 degrees from the midsagittal plane. AC, Anterior canal; LC, lateral canal; PC, posterior canal. (Modified from Barber HO, Stockwell CW. Manual of Electronys- tagmography. St. Louis, MO: Mosby-Year Book; 1976 and Flint PW, Haughey BH, Lund VJ, et al. Cummings Otolaryngol- ogy—Head and Neck Surgery. 6th ed. Philadelphia, PA: Saunders; 2015, fig. 130-2.)  CHAPTER 2 | OTOLOGY AND NEUROTOLOGY 11 [ = right masked bone 3. Exostoses ] = left masked bone 4. Osteoma 5. Glomus tympanicum 6. Aberrant carotid artery CROSSOVER 7. Cholesteatoma, uncomplicated 1. B one: 0-10 dB 8. Uncomplicated chronic otitis media (OM) 2. Air (headphones): 35-50 dB 9. Coalescent mastoiditis 3. Air (insert headphones): 60-65 dB 10. Glomus tympanicum versus jugulare if visible lesion is below the annulus (examine the jugular plate) 11. Inner ear malformations OBJECTIVE MEASURES UP THE a. Lateral canal dysplasia AUDITORY PATHWAY b. Enlarged vestibular aqueduct 1. O toacoustic emissions (OAEs) (spontaneous, transient c. Cochlear dysplasia evoked, distortion product: outer hair cell (OHC) function 12. Labyrinthitis ossificans 2. Ecog: summating potential/action potential (SP/AP) ratio; 13. Superior canal dehiscence/inner ear third windows AP = wave I auditory brainstem response (ABR); >0.35-0.5 abnormal (hydrops or inner ear third window) MAGNETIC RESONANCE IMAGING IS 3. ABR (five waves): BETTER FOR SOFT-TISSUE ANATOMY: THE a. Distal eighth nerve b. Proximal eighth nerve STUDY OF CHOICE FOR INTRACRANIAL c. Cochlear nuclei PATHOLOGY d. Superior olivary complex 1. CPA lesions e. Lateral lemniscus a. Vestibular schwannoma i. Tumor diagnosis: b. Meningioma (1) No wave V c. Epidermoid (2) Prolongation I-III (interaural) d. Eighth nerve deficiency (highly weighted T2 images: (3) Prolongation I-V (interaural) FIESTA or CISS sequences) (4)  SNHL poral bones) ii. Less facial weakness (6-14%) a. Subarcuate iii. Less risk CSF leakage b. Sinodural b. Otic capsule disrupting 2. Anterior petrous apex (10% pneumatized in temporal bones) i. SNHL likely a. Peritubal ii. Facial weakness (30-50%) b. Retrofacial iii. Increased risk CSF leak (8x otic capsule sparing) c. Infralabyrinthine d. Infracochlear e. Glenoid fossa (Ramandier and Lempert) FACIAL NERVE TRAUMA (Fig. 2.14) 1. Sunderland classification GRADENIGO SYNDROME (TRIAD) a. First degree: neuropraxia (conduction block) b. Second degree: axonotmesis (axons cut, but their endo- 1. D raining ear neurium stays intact; no synkinesis) 2. R  etro-orbital pain c. Third degree: neurotmesis (endoneurium disrupted; 3. I psilateral abducens palsy synkinesis possible on regeneration) d. Fourth degree: neurotmesis transects entire trunk COMPLICATIONS OF ACUTE AND (endoneurium and perineurium); epineurium intact CHRONIC OTITIS MEDIA e. Fifth degree: neurotmesis (all three layers cut; endo-, peri-, and epineurium) 1. Extracranial a. Acute mastoiditis b. Coalescent mastoiditis (erosion of mastoid air cell CEREBROSPINAL FLUID OTORHINORRHEA septations) (Fig. 2.15) c. Chronic mastoiditis 1. V ery rarely will traumatic CSF otorhinorrhea require d. Masked mastoiditis (partially treated with antibiotics but surgery still painful) 2. The use of antibiotics prophylaxis for meningitis is e. Subperiosteal abscess controversial i. Postauricular (through the cribriform area, with direct extension through bone, and/or thrombophlebitic) ii. Bezold (medial wall of mastoid tip medial to SCM HEARING LOSS FROM TEMPORAL muscle into the neck) BONE TRAUMA iii. Luc’s (zygomatic root) O ssicular injuries f. Petrous apicitis 1. Incudostapedial joint separation (82%) g. Labyrinthine fistula 2. Dislocation incus (57%) h. Facial paralysis 3. Fracture stapes crura (30%) i. Suppurative labyrinthitis 4. Fixation ossicles in epitympanum (25%) j. Encephalocele 5. Malleus fracture (11%) k. Cerebrospinal fluid (CSF) leakage Bottom-line evaluation of temporal bone fractures 2. Intracranial 1. Any facial function on admission? If not documented, a. Meningitis assume there was no facial function b. Epidural abscess 2. Otorrhea? Observe and put on bed rest and conserva- c. Subdural empyema tive measures to avoid drops; can become confused with d. Brain abscess “CSF otorrhea” e. Lateral/sigmoid sinus thrombosis 3. Dizzy/HL? Take supportive measures and observe CHL f. Otitic hydrocephalus for at least 6 months because subluxations can resolve; for SNHL, can try steroids if allowable given other injuries TEMPORAL BONE TRAUMA 4. Get a CT of temporal bones: at the very least, ensure that there are no carotid canal injuries/sphenoid WHAT YOU SHOULD CARE ABOUT sinus fluid (The latter may be more indicative of 1.  acial motion present/not present on initial evaluation F carotid injury than carotid canal fracture); if either 2. Otorrhea: that is, CSF are noted perform CT angiography (CTA) versus true 3. Potential carotid canal injury angiogram. 4. Dizziness HEARING LOSS IN ADULTS TYPES OF FRACTURES 1. Old system HISTORY a. Longitudinal fracture (80%) 1. Tinnitus i. Conductive hearing loss (CHL) > SNHL 2. Vertigo ii. Tympanic membrane (TM