Cochlear implants: Better sounds, better hearing
What is a cochlear implant? Cochlear implant is a boon for the hearing-impaired children and adults. It is a...
What is a cochlear implant? Cochlear implant is a boon for the hearing-impaired children and adults. It is a device, which converts sound signals to electrical signals and stimulate cochlea of inner ear and transfer them through auditory nerve to brain.
How does it differ from a regular hearing aid? Regular hearing aid works by amplifying the sound and send the amplified sound to the hearing impaired ear. It works for the people who still do have little bit of hearing left. It cannot work for total deaf people, where Cochlear Implant can work.
Does the cochlear implant restore normal hearing for people who are deaf? Not really. But it can simulate the normal hearing process and will bring back the near normal hearing and with appropriate speech therapy can get the good speech.
Are cochlear Implants experimental devices? No. They are have been in use since 1970. They are FDA approved for use in children and adults.
Who need these implants? They are necessary for kids who do not develop speech because of total impaired hearing (prelingual); and people who acquired speech, but lost hearing later because of infections or trauma- post lingual
What are the causes for pre lingual hearing loss? Hereditary hearing loss constitutes around 50-60%, acquired constitutes 20-25% and unknown reasons 20-25%.
What are the causes of post lingual hearing loss? Post lingual hearing loss can be because of brain infections like meningitis and also inner ear infections.
How to evaluate the candidacy of cochlear implants? When we diagnose the child that he is not responding to loud noise, he needs to be seen by an ENT specialist or Pediatric ENT specialist. ENT specialist will perform the audiological evaluation by BERA (Brain stem evoked response audiometry) to confirm the diagnosis of hearing loss. If the hearing loss is profound to severe, he need to be on hearing aids for at least six months and regular speech therapy given. After evaluating his speech gain after six months we will decide whether to go with the hearing aid or Cochlear Implant. If there is sufficient speech acquisition with the hearing aid, he doesn't need Cochlear Implant unless the patient request for them. If the child is not getting the sufficient speech acquisition as per the age, he needs to undergo Cochlear Implantation.
How soon can the surgery be done? Earlier the age of cochlear implantation, better the benefits. As the age increases the benefits of surgery reduce. The ideal age is between first year and second year of birth. Neural plasticity of the brain is lost as the child grows older.
What are all the tests required before cochlear implant surgery? Child needs CT scan brain and temporal bones to see the anatomy of the cochlea and also the maturity of the bone. Any malformation of the nerve and brain can be visualised by MRI scan.
What are the risks of cochlear implantation surgery? There are no major risks associated with the cochlear implantation surgery apart from regular anesthesia risks.
Can you explain about the surgery? After thorough evaluation, a child will be taken up for surgery. It's a three-hour surgery conducted under general anesthesia. The child is discharged within a day. Sutures are removed after a week. Wound gets healed in one month and mapping done after one month of surgery. Mapping means starting the implant and sending the appropriate sounds to the brain.
How about the follow up after surgery? After one month of the surgery, mapping will be done and has to be followed up with the audiologist and speech therapist almost every three months till he gets the good speech. Later on, the visits can be reduced. Cochlear implantation surgery is only a part of the treatment. The Audiologist and speech therapist will take care of remaining most of the rehabilitation.
What are the post-op precautions? They cannot undergo MRI scan in future because they have the implant in their body. Child should take precaution not to get hurt on the implant during sports and fighting with other kids.
Can they swim, shower and participate in sports? Yes, they can swim, take shower and participate in sports. The only restriction is skydiving and scuba diving because it involves significant changes in the air pressure which is not advisable for them.