Question
Regarding implant of this stucture as shown image , which of the following is true:
A. Not contraindicated in cochlear malformation
B. Contraindicated in < 5 yrs
C. Indicated in mild to moderate hearing loss
D. Implanted through oval window
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Correct Answer » A Explanation |
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Ans : A. Not contraindicated in cochlear malformation .
This structure is cochlea
COCHLEAR IMPLANT
Cochlear implants are neural prostheses that convert sound energy to electrical signals and can be used to stimulate the auditory division of the eighth nerve directly.
General criteria for cochler implant candidacy
- B/L severe to profound sensorineural hearing loss(with non-functional Cochlear Hair Cells).Little or no benefit from hearing aids.
- PTA of 70 dB or more
- No medical contraindication for surgery.
- An intact and functional auditory processing pathway, from Spiral ganglion cells to –
- Auditory Nerve to -Auditory cortex.
- Realistic expectation
- Good family and social support
- Adequate cognitive function to be able to use the disease.
Contraindications for Cochlear Implants:
- Deafness caused by lesions of the acoustic nerve or the central auditory pathway
- Active middle ear infections
- Cochlear ossification that prevents electrode insertion
- Tympanic membrane perforation
- Cochlear malformation is not a contraindication for cochlear implantation.
Pre-op investigation before a Cochlear Implant is placed:
- HRCT Temporal Bone and Complete Audiological Examination.
- MRI may be needed.
Parts of Cochlear Implant:
- Microphone, Speech-processor and Transmitter are the part of external component of cochlear implant, which remain outside the body.
- Receiver/Stimulator (Implanted under the skin) and Electrode array (implanted in the scala tympani of the cochlea) are the part of internal component of cochlear implant, which are fitted inside the body.
Candidates are defined as pre-lingual or post-lingual depending on whether they were deafened before or after the acquisition of speech & language.
- In children with pre-lingual deafness (at birth or in early child hood) implantation at an early age ensures better results and children can be implanted at 12 months of age.Post lingual patients with shorter duration of deafness have better outcome.
- Minimum age for Cochlear Implant Surgery is 1 year.
- In cochlear implant surgery the electrode array is placed within the scala tympani of the cochlea(at Round window).
