Question:
My adult son (age 36) with DS has moderate to severe hearing loss in one ear. He also has a cholesteatoma in that ear and he will have surgery this fall to remove that. His surgeon has suggested that he would likely be a good candidate for an Osia (a bone-anchored hearing aid that is entirely below the skin) and that he could insert that at the same time as the cholesteatoma surgery. My son is scheduled for an evaluation soon to determine if he is a candidate for an Osia. We have mixed feelings about this as despite his hearing loss he is very verbal and communicates very well. We worry about complications and wonder if there is any data on how adults with DS do with bone anchored hearing aids and specifically with Osias, which have no abutment and connect with the processor by magnet.
Answer:
Hearing involves several steps as the sound passes from the ear to the brain. The ear is divided into three parts: the outer, middle, and inner ear. Hearing impairment, which is a common problem for adults with Down syndrome (DS), can be associated with any of the three parts of the ear. Conductive hearing loss is due to impaired transmission from the outer or middle ear to the inner ear. Sensorineural hearing loss is due to impairment of the inner ear. Mixed hearing loss has components of both conductive and sensorineural hearing loss.
Conductive hearing loss may be treated with medications, surgery, and/or removal of cerumen (ear wax) or foreign bodies. A cholesteatoma, a collection of abnormal skin in the middle ear, can damage the small bones in the middle ear and cause conductive hearing loss. Treatment consists of careful cleaning of the ear, antibiotics, and eardrops. Larger cholesteatomas may require surgical removal. More information on cholesteatomas can be found on the website of the National Institutes of Health (NIH) at this link.
For sensorineural hearing loss, some form of hearing aid may be necessary. Audiologists will typically recommend hearing aids when the hearing loss is significant enough to impair daily function (such as conversational speech).
Traditional or typical hearing aids amplify the sound and use the outer and middle ear to transmit amplified sound to the inner ear. Additional information on the process of hearing aid evaluation and use is available at this link.
Bone conduction hearing aids bypass the outer and middle ear and transmit the sound directly to the inner ear through bone. A bone conduction hearing aid/implant can be used when a person has a conductive hearing loss (typically that is not correctable by other means); a unilateral (one side only), profound, sensorineural hearing loss; or a mixed hearing loss.
The website of the company Cochlear LTD describes their products including the Baha® Start, Cochlear Baha® system, and the Cochlear Osia® system. All three are described as bone conduction hearing systems. The Baha® Start does not require surgery. It is fastened to the head with a band or strap-like system that can be easily removed. The Cochlear Baha® and the Cochlear Osia® systems both require surgical implantation. The transducer (that delivers the signal to the bone) is different for the two systems. The Osia® system does not have a direct connection from the implanted piece to the piece that is worn on the head. The Baha® system has an abutment that directly connects the two pieces. (Please note that there are other companies that make bone conduction hearing aids. We are not advocating for one over the others and we do not have financial or other connections to any of the companies. We focus on the products of Cochlear LTD in this answer because the Osia® system is mentioned in the question).
As far as their use in people with DS, we found articles on the Baha® system but not specifically on the Osia® system. In a study done in the United Kingdom (UK), Sheehan and Hans (2006) reported on use of the Baha® (implantable) system in people with DS. Forty-three individuals with DS were studied. The total age range was 3-64 years, with an overall average age at implantation of 21.8 years. Eleven were 20 or older at the time of the implantation. The study noted that there were some complications. According to the article, “the majority of early complications, and all late complications were related to soft tissue problems” (e.g., local infection, skin breakdown, and skin overgrowth). The overall satisfaction with the hearing system was high. The authors concluded:
“BAHA is a valuable method of hearing amplification in children with Down syndrome. It should be considered not as a primary method of amplification, but in the overall management of individuals with Down syndrome after conventional hearing aids and/or ventilation tubes have been considered or already failed. The survey shows a high patient and carer satisfaction with the system, despite short term early soft tissue complications.”
The authors did not disclose in the article any financial relationship they may or may not have had with Cochlear LTD, which is now a standard disclosure in publications but was not at the time of this publication.
A similar study, also done in the UK, reported on children only. McDermott et al. (2008) reported on the use of the Baha® system in 15 children with an age range of 2-15 years at implantation. They concluded:
“Baha has an important role in the overall management of individuals with Down syndrome after conventional hearing aids and/or ventilation tubes have been considered or already failed. This study has shown a 20% rate of soft tissue reaction and there were no fixture losses in this group. No significant increase in complication rates was identified in children with Down syndrome. Finally, there was a significantly improved quality of life in children with Down syndrome after receiving their Baha®. There was a high patient/carer satisfaction with Baha®.”
The authors did not disclose in the article any financial relationship they may or may not have had with Cochlear LTD, which is now a standard disclosure in publications but was not at the time of this publication.
In addition, the Cochlear Ltd website includes a testimonial about the use of Baha® system by a girl with Down syndrome. It can be found at this link.
While we did not find data in the medical literature on the use of the Osia® system in people with DS, we did find data on the successful use of the similar Baha® system in people with DS. Most of the data are from children with DS but there is a small amount of data on the successful use of the Baha® system in adults with DS.
Having a thorough pre-operative assessment and review by the audiologist and surgeon, following the surgeon’s post-operative recommendations carefully, and following up appropriately with the ENT, audiologist, and speech and language pathologist per their recommendations will likely reduce complications and improve the benefit obtained from the device.