Cochlear implants, age and dementia

Darius Kohan, an otologist-otolaryngologist in New York (who was my cochlear implant surgeon at New York Eye and Ear Infirmary), told me he implanted a patient who was 95 years 6 months old.

The patient is still using the implant 21/2 years after surgery. Even dementia may not be a disqualifier, the surgeons said, assuming that the patient is not violent or likely to destroy

the external parts of the implant. A study published last summer on implantees with dementia found a significant cognitive improvement a year later. The patients also received regular

auditory rehabilitation. It was not clear from the study whether it was the implant itself or the aural rehab that made the difference in improved cognitive abilities. Jack Wazen, a partner

at the Silverstein Institute and director of research at the Ear Research Foundation in Sarasota, Fla. (and a fellow board of trustees member with me for the Hearing Loss Association of

America), was the most conservative of those interviewed on the question of dementia, saying he routinely implants those with mild to moderate cognitive decline, but not those with severe

decline. All agree on the importance of auditory rehab for older patients. As Hodgson put it, "Auditory rehab helps get the most out of the process. This is amazing and life-changing

technology, so why wouldn't we want to maximize the impact on someone's life?" He added that younger implant recipients might still be in the workforce and get stimulation

from their everyday environment. The older recipients are less likely to get that stimulation. Also important, as all the surgeons agreed, is a social support system. This doesn't

necessarily mean a companion in the home, but a regular conversation partner is essential. Social interaction is important in general for quality of life. The one issue on which the surgeons

differed was which ear to implant: the worse or the better one. With younger implantees, the decision is usually to implant the worse ear, to preserve the natural hearing in the good ear,

often using a hearing aid in the good ear. But an elderly person may have been deaf for some time in the bad ear, and thus less likely to benefit from the implant. Although most said that

they would consider implanting the deaf ear, they might not if the ear had been deaf for a long period of time. Wazen specified five years or more. Hodgson pointed out that "the longer

the duration of hearing loss, the higher the chance of diminished benefit due to deterioration of sensory elements in the inner ear." Both Lalwani and Kohan said they would implant the

worse ear. Kohan's reasoning is that if the patient is still able to hear with the hearing aid ear, there may still be enough plasticity in the brain, with crossover from the nonhearing

ear, to make an implant in the deaf ear function. Lalwani went further: "I would always implant the deaf ear. One does not lose anything from doing so. If the outcome is less than

satisfactory, the other ear could always be implanted down the road."