Perhaps no other field in otolaryngology has expanded as rapidly as the evaluation and management of hearing loss in children. From safer and higher-resolution imaging techniques to more focused genetic analyses, the old ratio of congenital sensorineural hearing loss, 25-25-50, idiopathic-acquired-genetic, is rapidly changing as many idiopathic causes for hearing loss are being elucidated, and many specific causes of genetic hearing loss have been discovered. With the widespread mandate of newborn hearing screening in every state, children with hearing loss are being identified earlier and, ideally, diagnosed by 3 months of age with intervention by 6 months of age. However, diagnosing the cause of hearing loss in the young child remains challenging, and clinicians are left to ponder who should be tested, when, and what tests to order. Genotype-phenotype correlations and techniques from linkage algorithms to whole genome screening have mapped deafness and other associated traits to specific chromosomes in the human genome, allowing researchers and clinicians to identify many of the causes of both syndromic and nonsyndromic pediatric sensorineural hearing loss. Interestingly, the genetic analysis of hearing loss has shed light on the structure, physiology, function, and development of the cochlea and other inner ear structures. With over 100 specific genes identified whose mutation causes hearing loss (with likely more by the time this is published!), keeping up with the science is quite challenging for clinicians (see the Hereditary Hearing Loss homepage at hereditaryhearingloss.org ).
Whether to order computed tomography (CT) or magnetic resonance imaging (MRI) is often a question asked at otolaryngology meetings in the evaluation of children with hearing loss. The answer, of course, depends on the clinical question being asked and the nature of the hearing loss. One article in this issue comprehensively discusses imaging for pediatric hearing loss, the ideal study, when to pursue it, and what to look for.
Cytomegalovirus (CMV) is now recognized as the most common viral cause of congenital hearing loss and a likely cause of progressive hearing loss. Although the optimal diagnostic test as well as management of CMV remains in flux, this common virus needs to be recognized as an important part of the newborn hearing loss diagnostic effort.
Management options for children with hearing loss include any number of interventions from individualized education programs to surgery to hearing aids (conventional and bone conducting), cochlear implantation, and even brain stem implants. Several articles address these options for children with both conductive and sensorineural hearing loss, including an entire article addressing the child with unilateral hearing loss, an often difficult clinical scenario to assess and manage.
In summary, we asked the world’s leading pediatric otologic clinicians and scientists to present the most up-to-date, evidence-based recommendations to guide clinicians—otolaryngologists, pediatricians, audiologists, speech-language therapists, and other hearing health care professionals—in the workup and habilitation of these children. And what is coming down the road? Better cochlear implant technology and coding strategies, auditory brainstem implant technology, and finally, gene therapy or stem cell therapy for sensorineural hearing loss are all exciting prospects for the near and distant future.
We also cannot thank enough the authors who have generously donated their time and expertise to make this issue of Otolaryngologic Clinics of North America a practical, informative, exciting, and relevant addition to the ever-expanding literature on hearing loss in children, and who provide outstanding care for these children every day.