Cochlear implants are electronic devices which are surgically inserted into the inner ear of individuals with severe to profound degree of hearing loss who do not benefit from the use of conventional amplification devices such as hearing aids. These implants, unlike hearing aids don’t help in sound amplification but bypass affected structures and directly stimulate (using electrical impulses)the hearing nerve via the tiny hair cells of cochlea thus the name COCHLEAR IMPLANT.
1. External Components: These components are housed outside the skull and are not inserted internally and they include,
a. Microphone: Helps pick the signal from the environment and sends it to the speech processor for further processing.
b. Speech Processor: The acoustical signal received through the microphone is directed to an electronic box i.e. Speech processor which then converts the acoustical signal into a processed electrical signal. This usually sits behind the ear.
c. Transmitter with a magnet: The magnet is attached to the skull . The transmitter transmits the processed electrical signal to the internal units .
2. Internal Components: These components are housed inside the skull and are surgically inserted . Their function is to take the signals further into the cochlea.
The internal components consists of :
a. Receiver coil: The receiver/ stimulator package picks up the radio signal from the transmitter coil.
b. Electrode array: From receiver, the signal is taken via a thin wire to the cochlea ie. inner ear. The end of the wire called the electrode array is positioned into the cochlea .
The signal from the electrodes activates the nerve of hearing (vestibulo-cochlear)which then takes the message along the usual pathway through your brainstem to the brain. At this stage, the signal may be interpreted by the brain as “a sound stimulus”
Cochlear Implants attempt in restoring the ability of the brain in perceiving sounds which they would otherwise miss. Cochlear Implants despite its best features and function might not always help hard of hearing population which places the responsibilities on the professionals to assess and select the right candidates so that its not implanted on people who might get no help from the implant especially since the procedure and device are expensive.
Cochlear Implants are useful for children, adults and geriatrics but there are certain guidelines to be followed for candidacy assessment. These guidelines are maintained by a team involving experts comprising of an ENT surgeon who specializes in cochlear implant surgery, audiologists, speech therapists and auditory verbal therapists along with a child psychologist.
The individual should not have any sort of medical condition which could possibly deteriorate post implant. Radiological evaluation has to be carried out to rule out anything which could rule out cochlear or nerve related anomalies. Radiological evaluation can include CT,HRCT and MRI. Routine blood check ups are recommended along with basic otology tests.
Before moving forward with a cochlear implant ,it is made sure that the patient is a good candidate with the use of test batteries and could not benefit from hearing aids along with provision of intensiverehabilitation therapy for at least 6 months.
Along with the degree ,age is also an important factor which has to be considered.
Psychological Evaluation is recommended in order to have an overview of patients and family state of mind and to make sure both family and patient are mentally prepared for the same. Once the candidates are chosen, following the appropriate guidelines surgery is planned.
The surgery is carried out by an ENT surgeon and the surgery can last from 2-4 hours depending upon the surgeon, approach and any expected complications.
POST-SURGERY
WHAT CAN BE THE RISKS?
Cochlear implant surgeries are relatively safe but there are always certain risk as surgery requires invasion of structures minor or major.
The risk this surgery pose are,
MORE COMMON RISKS
LESS COMMON RISKS
In absence of the risks the recovery is better and it might require for the patient to stay at hospital overnight or 2 days depending upon the overall health. Once the stitches are healed the device is ready to be switched on by an audiologist. The current level is adjusted slowly over the weeks or months by an audiologist to not overwhelm the patient with intense sound at the very beginning.
After the switch on, the patient can attend therapy which is exclusive for hard of hearing population post fitting of amplification device called Auditory Verbal Therapy which is provided by audiologists or people who are specialized on the same.Intensive therapy is recommended. For prelingual hearing impaired population, along with the AVT speech therapy is also highly recommended which is provided by the speech language pathologist.
Home training is also equally important under the guidance and help of an Audiologist and Speech Language Pathologist.
In some cases occupational therapy is also recommended.
Depending upon the total time of usage, amount of stimulation at home and therapy the outcome can vary. With appropriate therapy and efforts near normal or normal speech and language can be achieved for pre-lingual hearing impaired and for the patients with post language deafness with effort can restore their power to hear like they used to.
Overall quality of life can be improved with correct rehabilitation.
Once healed there are few do’s and don’ts which have to be taken care of by the patient and the family. Taking care of the implant increases the life of the implant. Routine follow up with the ENT and Audiologist is required to know the overall health of the implant as well as the patient.
Let’s start with an example, Joey rushes to XYZ hospital with severe stomach ache and nausea. He is attended by a general physician at first and is advised for an overnight stay at hospital where he’s taken care by the nurses, his blood samples are being collected by a pathologist to check for any issue if present, when his symptoms does not subside he’s checked upon by a Gastroenterologist and sent for an abdominal scan to a Radiologist, to get one diagnosis on what exactly went wrong with Joey ,there were more than one professional who had to get involved. Joey gets diagnosed with peptic ulcer which needs an immediate intervention before the extent of ulcer spreads and degrades his health condition and affects his overall quality of life in near future.
WHAT IS EARLY INTERVENTION ?
Early intervention is the treatment or support provided to help infants or toddlers(from birth to 3 years mostly) who are in need of it due to certain disabilities or developmental delays as it can have a significant amount of impact on a child’s ability to learn new skills and reach milestones.
Intervention can include Speech and Language therapy, Physical therapy, Occupational therapy, Psychological therapy, Special education programmes etc.
WHY IS IT IMPORTANT?
“Earlier the Better”
Intervention and its outcomes are more likely to be effective if provided early in life due to numerous reasons.
In early years of life, especially till the age of 3, the brain is like a plastic which means it is malleable and adapts to new things which later becomes the foundation to learn skills and behaviours. The adaptable brain if left unstimulated can have negative impact on development of the child which becomes tougher to mould.
Acting early on a child’s diagnosis gives a chance to receive appropriate therapies or other cures which can change developmental path and improves the outcomes for children and family thus helps the child and family to have normal lives by improving his/her quality of life.
WHO NEEDS TO BE INVOLVED ?
A centre providing early intervention for developmental delays should consist of an Audiologist, Speech Language Pathologist, Special Educators, Occupational Therapist, Psychologist and others if required.
The team members need to work alongside each other to provide the best care for the patient and each of them have their unique role which makes each of them vital part of the team.
An audiologist can help evaluate and rehabilitate hearing related issues, a speech language pathologist can provide help to assess and innervate speech and language problems, special educators are trained to deal with children with special needs, occupational therapist can assess and help patients across things they want and need through therapeutic use of occupations and a psychologist can assess and provide psychological therapies to patients is required.
All these professionals also need to counsel patients and family to make sure they understand the need and importance of individual intervention.
Acting early on developmental concerns can make a huge difference for your child and you. If you are concerned about your child’s development, do not wait long.
Every day of therapy and approach counts and treatment of every team counts. You know what is best for your child and every professional on the team will help you reach the best.