Cochlear implants for CMT may improve hearing, quality of life
Analysis reportedly first to study patient quality of life after implantation
Cochlear implants are a safe and reliable way to improve hearing, speech, and quality of life for people with Charcot-Marie-Tooth disease (CMT), according to a case series.
This study provides “more evidence supporting the potential benefit of cochlear implantation among CMT patients,” researchers wrote. “The present analysis is also the first to report the post-implantation [quality of life] among CMT patients, offering a more comprehensive understanding of the impact of [cochlear implants].”
The study, “Cochlear Implantation in Charcot-Marie-Tooth Patients: Speech Perception and Quality of Life,” was published in the Annals of Otology, Rhinology & Laryngology.
CMT encompasses a group of conditions affecting the peripheral nervous system, the network of nerves that supply movement and sensation to the arms and legs. It is caused by mutations that drive damage in nerve cells or interfere with the formation of myelin, a coating around nerve fibers that ensures efficient signal transmission.
CMT can damage cochlear nerves, lead to hearing loss
The disease can damage cochlear nerves, which send signals from the inner ear to the brain. This may reduce a patient’s ability to hear and lead to hearing loss.
Cochlear implants, small electronic devices that help provide a sense of sound to people with hearing loss, have been shown in isolated cases to improve speech perception in CMT patients. However, “given the scarcity of reports, there is still a limited ability to fully predict the impact of the surgery on speech perception and quality of life,” the researchers wrote.
In the study, researchers at the University of California, Davis, reported on five patients with CMT, who underwent cochlear implantation at different medical centers. Four of the patients were from the same family and had CMT type 1A, the most common subtype of CMT.
The patients’ mean age at the time of first implantation was 56 years, and they were followed up for a mean of 29 months (nearly 2.5 years). Before implantation, patients had severe to profound hearing loss. They also had little to no ability to correctly repeat words and to perceive speech in the implanted ear.
After surgery, the results of their pure tone average, which is used as a calculation for hearing impairment for speech understanding, were within the mild hearing loss range. Speech perception also improved, though results were variable.
Each patient also completed the Cochlear Implant Quality of Life-10 Global Questionnaire, which features 10 questions in six domains: communication, emotional, entertainment, environment, listening effort, and social.
Their mean overall score was 42.7 (maximum is 100), with patients being satisfied with their listening to the television or radio, having conversations in a quiet environment, and feeling comfortable being themselves. Conversely, their worst scores were related to understanding strangers in a noisy place.
“To the best of our knowledge, this is the largest cohort of cochlear implantation in CMT patients and the first to report [quality of life] outcomes,” the researchers wrote. However, “it remains a small population of patients restricting our ability to draw strong conclusions from their outcomes.”
The scientists note future studies should use patient-reported measures to assess the ability to hear sounds and the impact on quality of life.
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