Cochlear implants were found to improve the cognitive function, speech perception and depressive symptoms of older adults with profound hearing loss.
Approximately 1 in 3 Americans aged 65 and over have some form of hearing loss. Though many of these individuals benefit from conventional treatments, such as hearing aids, those with more severe hearing loss may require a cochlear implant.
A cochlear implant is a small electronic device that stimulates the auditory nerve in the ear. The implant consists of two parts: an external section that holds a microphone, transmitter/stimulator and speech processor, and an internal section made up of electrodes that are placed under the skin behind the ear. An external magnetic disk connects the two parts.
The researchers - including Dr. Isabelle Mosnier of Assistance Publique-Hopitaux de Paris in France - note that hearing loss has been associated with increased risk of cognitive decline. A 2011 study reported by Medical News Today, for example, found adults with mild to severe hearing loss were up to five times more likely to develop dementia.
However, the team says it is unclear how cochlear implantation for elderly patients with profound hearing loss affects cognitive function.
80% of worst performers on cognitive tests improved scores after cochlear implantation
To find out, Dr. Mosnier and colleagues analyzed 94 patients aged between 65 and 85 years who had profound, postlingual hearing loss - in which hearing loss occurs after speech development - and had received a cochlear implant.
Patients' speech perception, depressive symptoms, cognitive function and overall quality of life were assessed prior to undergoing cochlear implantation and at 6 and 12 months after the procedure.
At 12 months after cochlear implantation, the researchers found patients showed major improvements in cognitive function; 80% of patients who achieved abnormal scores on two or three out of six cognitive tests - making them the worst-performing patients - prior to cochlear implantation only achieved abnormal scores on one of the tests a year after the procedure.
Improvements in cognitive function were seen as early as 6 months after cochlear implantation, according to the study results.
What is more, improvements in speech perception in both quiet and noisy environments were found at 6 and 12 months following cochlear implantation.
The team also identified significant improvements in depressive symptoms, with 76% of patients showing no depressive symptoms at 12 months after cochlear implantation, compared with 59% with no depressive symptoms prior to having the procedure.
The authors note that the number of people over the age of 60 is expected to double by 2050, meaning there will be a significant rise in the number of individuals with cognitive impairment and dementia.
As such, the researchers stress the importance of finding interventions that could delay the onset of such conditions, and they believe their findings could aid the search. They add:
"Our study demonstrates that hearing rehabilitation using cochlear implants in the elderly is associated with improvements in impaired cognitive function.
Further research is needed to evaluate the long-term influence of hearing restoration on cognitive decline and its effect on public health."
In October 2014, Medical News Today reported on a study by a researcher from the University of California-Los Angeles, in which he revealed how a personalized treatment plan reversed cognitive decline in a small number of patients with memory loss.