The Changing Indications for Cochlear Implantation

Theodore R. McRackan, MD Otology, Neurotology, and Skull Base Surgery

By Ted McRackan, MD, co-editor of Otology, Neurotology, and Skull Base Surgery: Clinical Reference Guide

Cochlear implantation is the gold standard for treatment of severe to profound sensorineural hearing loss. Cochlear implants (CIs) were approved by the Food and Drug Administration (FDA) in 1985 and have been suggested to be the most successful neural prosthesis created to date. Over 300,000 cochlear implants have been performed worldwide, with over 50,000 performed in the past year alone. Cochlear implantation involves a surgical procedure whereby an electrode array is placed in the cochlea of the inner ear, which is organized in a tonotopic fashion with decreasing characteristic frequency along its length. Modern CIs contain between 12 and 22 electrodes, which are spaced with the intention of each electrode stimulating a unique area of the spiral ganglia of the auditory nerve. Cochlear implants work by having an external microphone and an external processor convert an acoustic signal to an electrical signal. It is then sent to a speech processor, which is designed to enhance the signal and reduce noise before sending the information to the spiral ganglion through the CI electrode array.

Cochlear implantation is currently at an exciting time point due to the combination of improving technology and proven outcomes that has led to rapid expansion of its indications. The FDA approved the first single-channel CI electrode for adults in 1984, followed by the multichannel electrode in 1987. Cochlear implants were then approved in 1990 for children older than 2 years, in 1998 for children over 18 months, and ultimately in 2000 for children older than 12 months. There has been a recent push to implant children younger than 12 months due to evidence that children implanted at this age are more likely to catch up to normal-hearing peers at an earlier time point. Three major obstacles have hampered this movement. First, obtaining accurate hearing diagnostic testing in a timely manner can often be difficult in those less than 12 months. Second, there is a slight increased risk of surgical complications due to the low blood volume in this age group. Third, it can be extremely difficult to perform cochlear implant programming in this age group. Nonetheless, the clear benefits of early implantation likely outweigh these risks. Pediatricians, audiologists, and otolaryngologists are encouraged to identify infants with hearing loss as soon as possible for hearing rehabilitation. The earlier this is performed, the earlier children with profound hearing loss can be identified, and the earlier they can be implanted, leading to better CI outcomes.

Use of cochlear implantation in patients with residual hearing has been another area of rapid expansion. It was initially thought that all hearing would be lost with cochlear implantation and that if hearing was preserved, patients would not be able to process electrical and acoustic hearing. However, through the trials of the Cochlear Hybrid electrode and the MED-EL EAS electrode, it appears that both are possible. Through these and other trials, most patients had preserved residual hearing after cochlear implantation. Additionally, these patients showed improved hearing outcomes compared to patients without residual hearing. At the present time, it is not clear whether this preserved hearing is sustainable over time. This is an active area of investigation and will continue to be studied for years. Nevertheless, this technology has greatly expanded the indications for cochlear implantation beyond traditional candidacy.

As discussed above, it was previously thought that individuals would not be able to process combined electrical and acoustic hearing. However, cochlear implantation in patients with residual hearing proved this incorrect. This has led to the more widespread use of CIs in individuals with single-sided deafness. Current standard treatment for single-sided deafness includes devices that essentially ignore the deafened ear. However, with cochlear implantation, hearing can be restored to that ear. This was initially performed in patients with severe tinnitus in the deafened ear but is now being more commonly performed in the absence of tinnitus. Further work is certainly needed to develop a more comprehensive understanding of cochlear implantation in this population, but preliminary data show decreased head shadow effect and improvement in binaural summation, spatial release from masking, and potentially sound localization.

Beyond cochlear implantation, the use of auditory brainstem implants (ABIs) in children is another area of expansion. Although this has been performed in Europe for years, it is only more recently being performed in the non-neurofibromatosis type II population in the United States. Several centers have active clinical trials to perform ABIs in children unlikely to benefit from cochlear implantation due to either absent cochlear nerves or cochlear malformations. This is an unfortunate population as they have limited hearing rehabilitation options. Auditory brainstem implants provide an opportunity for hearing in this population, and the neurotology community is excited to hear the results of these trials.

We have come a long way since Bill House developed the first single-channel CI. As outcomes and technology continue to improve, the indications for cochlear implantation will grow. The audiology and otology communities are eager to see what the future holds for cochlear implantation.

About the Author
Dr. Theodore R. McRackan is an assistant professor of otolaryngology at the Medical University of South Carolina. He received his medical degree from the Medical University of South Carolina and completed his otolaryngology residency at Vanderbilt University. Dr. McRackan then completed his fellowship in neurotology-skull base surgery at the House Ear Clinic. His professional interests include neurotologic outcomes and quality of life research. Dr. McRackan and Derald E. Brackmann, MD co-edited Otology, Neurotology, and Skull Base Surgery, which serves as both a study resource for qualifying exams and a portable clinical reference guide. This text features a concise and approachable outline format, contributions by leaders in the field, and key topics such as anatomy and embryology, hearing loss, cochlear implantation, skull base tumors, vestibular disorders, and pediatric otology. View sample pages and place your order at www.PluralPublishing.com.

A Tribute To Marion Downs

As many of you know, Dr. Marion Downs passed away recently. Here we post a nice tribute written by Dr. Jerry Northern that he shared with us.

Dr. Marion Downs Passes Away at Age 100 World-renowned Audiologist and Pioneer for Infant Hearing Screening

Dr. Marion Downs Passes Away at Age 100
World-renowned Audiologist and Pioneer for Infant Hearing Screening

Dr. Marion P. Downs, an innovator in the field of pediatric audiology and a tireless advocate for the early identification of hearing loss, passed away on November 13th, 2014. During her extraordinary career at the University of Colorado Health Sciences Center, Dr. Downs developed and evaluated techniques for testing hearing in babies and young children and for fitting them with hearing aids. Dr. Downs created the first universal infant hearing-screening program in 1963 in Denver, CO. She relentlessly pursued making the identification and management of hearing loss in infants and children an important medical, educational, and public health issue. Her professional publications and lectures brought worldwide attention to the importance of early intervention for hearing loss. Today, in the United States, more than 96% of all infants born in the US receive a newborn hearing screening thanks largely to her efforts. Numerous international countries have followed her lead in establishing universal infant hearing screening programs. Continue reading

Oral, Head and Neck Cancer Awareness Week

Oral, Head & Neck Cancer Awareness Week

Oral, Head and Neck Cancer Awareness Week®

The 16th Annual Oral, Head and Neck Cancer Awareness Week® (OHANCAW), sponsored by the Head and Neck Cancer Alliance, is scheduled for April 14-20, 2013. OHANCAW is a weeklong series of events promoting awareness of oral, head, and neck cancer, highlighted by a day of free oral cancer screenings throughout the United States.

According to a brand new Harris Interactive survey, 71 percent of Americans say they have not been examined by a medical professional for oral, head, and neck cancer. Given the rise in oral cancers related to human papillomavirus (HPV), screening for early detection of this disease is more than important than ever. The Academy is urging you to participate by conducting a free screening at your medical practice, clinic, hospital or medical university. To find screening locations in your area, please visit the Head and Neck Cancer Alliance website, www.OHANCAW.com for more information.

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Our Featured Titles

Head and neck cancer is often easily treatable if detected early, but often it is not. For Oral, Head and Neck Cancer Awareness Week we are featuring a few of our related titles. These selected books comprehensively address diagnosis, treatment and patient rehabilitation of head and neck cancers.

Cutaneous Malignancy of the Head and NeckCutaneous Malignancy of the Head and Neck: A Multidisciplinary Approach

Randal Weber, MD, FACS, Brian Moore, MD, FACS

For the first time, a true multidisciplinary approach to cutaneous malignancy of the head and neck is presented, as international experts in head and neck surgical oncology, dermatology, Mohs micrographic surgery, plastic and reconstructive surgery, radiation oncology, and medical oncology present state-of-the-art techniques and promising horizons in the treatment of cutaneous malignancy of the head and neck. Whether in primary care or a specialty practice, this text should prove invaluable to any practitioner who treats patients with skin cancer of the head and neck. This is the only textbook on this subject that comprehensively addresses patient management – from diagnosis, treatment (in all forms, including chemotherapy and radiation), and reconstruction.

 

Practical Head and Neck OncologyPractical Head and Neck Oncology

Edited by: Guy Petruzzelli, M.D., P.h.D.

Otolaryngologists-head and neck surgeons, plastic/reconstructive and oral/maxillofacial surgeons, radiation and medical oncologists, and other clinicians interested in caring for patients with tumors of the head and neck will find this text to be a concise resource providing critical and useful information for the systematic and efficient evaluation, diagnosis, and comprehensive treatment planning and monitoring therapy for patients with malignant head and neck tumors. Bringing together experts in the management of patients with malignant tumors of the upper aerodigestive tract, students and residents will find this text an excellent reference for preparing to care for these challenging and fascinating patients.

 

Head and Neck UltrasonographyHead and Neck Ultrasonography

Edited by: Lisa Orloff, M.D.

Beautifully illustrated in full-color, Head and Neck Ultrasonography is regarded as the first, as well as the definitive, English-language textbook of head and neck ultrasonography by and for clinicians and surgeons. This book comprehensively and effectively addresses fundamentals of ultrasound physics, equipment, normal head and neck ultrasound anatomy, and technique. Individual chapters cover specific anatomy and pathology. Interventional ultrasonography and dynamic ultra-sonography is discussed and new directions and techniques in ultrasonography are presented. Head and Neck Ultrasonography is unique in both its thoroughness and in its relevance to the clinical setting, where ultrasonographic examination is a dynamic and interactive process between physician and patient. In addition to numerous valuable examples of still ultrasound images throughout the text, a CD-ROM with video clips illustrating both the process and the interpretation of specific examinations and procedures is provided with the text.

 

Head and Neck CancerHead and Neck Cancer: Treatment, Rehabilitation, and Outcomes

Elizabeth Ward, Ph.D., Corina van As Brooks, Ph.D.

A team of expert authors from the medical and allied health communities describe recent advances in the management of head and neck cancer through a greater understanding of cancer cell growth and mechanisms, as well as the expansion of rehabilitation strategies across the allied health profession. In addition to introducing new information, the book covers both the theoretical and clinical knowledge from an international perspective to support basic training of therapists in practice as well as graduate students, all illuminated with case examples – from swallowing disorders, through non-surgical voice restoration, to rehabilitation following total laryngeal surgery – on an accompanying DVD. As the first book in recent years to cover both current theory and clinical practice, this will prove an essential textbook and practical clinical reference for the H&N cancer rehabilitation team.

 

Meeting the Challenges of Oral and Head and Neck CancerMeeting the Challenges of Oral and Head and Neck Cancer: A Guide for Survivors and Caregivers, Second Edition

Co-Editors: Nancy Leupold, M.A., James Sciubba, D.M.D., Ph.D.

This volume has been expanded, updated, and polished and thus constitutes an even more comprehensive resource of valuable scientific, psychological, sociological, therapeutic, financial, and practical information for the patient afflicted with head and neck cancer and his or her family. Appreciation of these principles [in this book] and others too numerous to mention will soften the impact of the cancer and facilitate the care of, as well as the caring for, the patient afflicted with head and neck cancer. Concise, practical, and packed with information, Meeting the Challenges of Oral and Head and Neck Cancer: A Guide for Survivors and Caregivers, Second Edition is a valuable resource to assist those who need help overcoming the many difficult issues that confront them or their loved ones struggling with oral or head and neck cancer. This book has been helpful for parents and survivors; doctors often buy or recommend it for their patients.

 

Otolaryngology- Head and Neck SurgeryOtolaryngology-Head and Neck Surgery: Clinical Reference Guide, Third Edition

Edited by: Raza Pasha, M.D.

The bestselling pocketguide – Otolaryngology-Head and Neck Surgery: Clinical Reference Guide – is back in an extensively revised, up-to-date, and expanded third edition. Spanning the breadth of the entire field, this “high-yield” book retains a “by residents, for residents” feel, while also including expert content useful to accomplished physicians. Students, residents, attendings, and speech/hearing professionals will find the highly organized, outline format to be useful for clinical situations as well as a last minute cram for morning rounds. The guide has proven essential for board review as well as a quick source for primary care providers. In addition to all the great features that have made this sought after book a runaway success, the new edition features A comprehensive update featuring the latest diagnostic and treatment information A brand new sleep medicine chapter, providing critical information for this rapidly expanding subspecialty Expanded and revised information, notably in sections covering plastics; rhinology; otology/neurotology; H&N cancer; and general otolaryngology.

Best-Selling Pediatric Craniofacial Reference

Charles Moore’s multi-disciplinary reference offers you a range of perspectives in diagnosing, assessing and successfully treating pediatric facial trauma.

This practical reference offers the viewpoints of a team of clinicians distills the wisdom and expertise of an oral surgeon, neurosurgeon, dentist, ophthalmologist, otolaryngologist, radiologist, plastic surgeon, and craniomaxillofacial surgeon. Order your copy today!