And yet, newborns cannot tell doctors or parents what they hear. Physiological events in the inner ear and the electrical activity of the brain can.
Explore This IssueDecember 2013
Hearing tests in newborns record otoacoustic emissions of the hair cells in the inner ear and the auditory brainstem response of babies exposed to sound. Patients who test poorly should receive a more detailed evaluation by an audiologist to determine which frequencies are affected and the severity of the loss. Sometimes close monitoring is all that’s needed, but in worst case scenarios, children can be given amplification devices “so they can begin the journey of language learning,” said Dr. Francis.
Genetic diagnosis of hearing loss later in life is a related field that is coming into its own, and there may be more than 200 different genes involved in deafness.
With the rapid progress in genetic sequencing methods allowing for increases in speed and capacity while decreasing costs, genetic testing is becoming routine in hearing loss evaluation. Comprehensive screenings are currently able to solve about half of the cases of nonsyndromic deafness, said Eliot Shearer, an MD/PhD student and researcher at the University of Iowa’s Molecular Otolaryngology and Renal Research Laboratories in Iowa City. Shearer helped to develop a clinical diagnostic tool called the OtoSCOPE, which has been available for clinical use for more than a year. This test can screen genes known to cause deafness.
Genetic testing is helpful in terms of counseling patients about prognosis and saves patients from unnecessary tests to rule out syndromic causes of deafness.
Still, to a certain degree, the genetics of deafness is a new enough field that, while testing can help characterize the biology of hearing loss, there’s not much impact on treatment decisions at this time, said Dr. Francis. Amplification, electrical stimulation and rehabilitation remain the go-to approaches.
Cancers Caused by HPV
Another area where preventive medicine is likely to play a larger role in otolaryngology practice is human papilloma virus (HPV) testing. In addition to its better known outcome of cervical cancer in women, HPV can cause oropharyngeal cancer in both women and men.
“Oropharygeal cancers are the fastest growing cancers in the United States,” said Dr. O’Malley. Almost everyone has been or will be exposed to HPV, which is transmitted through sexual contact, at some point during their lives. Some of those exposures will result in active infections, and some of those will cause cytological abnormalities that can convert to cancerous growth.