Chapter 3 Flashcards
How does a Cochlear Implant work?
external speech processor that uses battery
nternal receiver stimulator that communicates with electrodes implanted in the cochlea
Operates by converting sound into electrical signals that stimulate the auditory nerve.
What components are in a BTE Speech Processor?
Includes:
* Microphone
* Speech Processor
* Battery
* connected via Transmitter Coil or antenna-magnet that adheres to head over receiver stimulator. Sends info through skin via fm radio waves to internal receiver timulator
The microphone picks up sound and converts it to an electrical signal.
What is the function of the internal receiver in a CI?
Surgically implanted in the mastoid bone
it sends information to the implanted electrodes
What are the criteria for adult candidates for Cochlear Implants?
Includes:
* Moderate to profound HL in low frequencies
* Severe/profound HL in mid to high frequencies
* <50% Aided WRS in the ear to be implanted, <60% in good ear
* Desire to be part of the hearing world
* No medical contraindications
-MRI/CT scan
-3-6 month HA trial
What is the MAP in the context of Cochlear Implants?
The CI activation program that encodes the acoustic signal and translates it into electrical stimulation levels
2-3 weeks after surgery
## Footnote
This involves adjusting T (softest 100% of the time) and C (loudest-over a long period of time) levels for the patient.
Testing similar to pure tone audiometry
What factors affect the performance of Cochlear Implants?
Includes:
* Age of onset
* Length of Deafness
* Age of implantation
* Length of CI use
* Etiology of the HL
* Nerve survival
* Mode of communication
* CI technology
* Surgical issues
* Audiologic rehab techniques
* Motivation
Each factor can significantly influence the outcome and effectiveness of the implant.
What is Electroacoustic Stimulation?
CI/HA combination where the HA and CI are enclosed in a behind-the-ear case
Used for patients with usable hearing in the low to mid frequencies but no hearing in the high frequencies.
CI electrode is only in basal to mid portions of cochlea
Low to mid frequencies are amplified with HA technology
ONLY FOR ADULT USE
What is the FDA clearance for the Nucleus Hybrid Implant System?
Adults over 18
Normal to moderate HL through 500 Hz
Severe to profound SNHL <70 at 2-4k Hz
WRS <60% in implanted ear, <80% in good ear
-concern over losing residual hearing
How does bilateral hearing with CI improve quality of life?
Provides improved localization, better hearing in noise, and overall enhanced quality of life
Particularly beneficial for children, considering lifespan and potential new technology.
Electrodes
Threaded through middle ear into cochlea
Sends sound info to the auditory. Nerve fibers
Auditory nerve send info to brain for perception of sound
Current CI systems
Cochlear
Advanced Bionics
Med-El
CI Criteria for children
Bilateral profound HL >90 12-24 months and lack of dev in simple auditory skills over a 3-6 month period
Severe to profound >70 24 mos-18 years with <30% aided WRS
3 month HA trial <24 mos
6 months HA trial for older children
Therapy program with emphasis on dev auditory skills
No medical contraindications
Highly motivated
Poor prognosis for prelingugal children 6 and older
Nottinghma children’s implant profile (NChIP)
Summarizes evaluation process:
-age
Duration of deafness
Med and radiologic conditions
Audiology assessment data
Speech/language assessment data
Multiple handicaps/disabilities
Family structure and support
Ed environment
Availability of services
What does pretraining consist of
Adults:
Speech reading
Communication strategies
Communication breakdown
children:
Conditioning for play audiometry using tactile or visual stimulation
Surgery
Electrode inserted into the scala tympani through round window
Telemetry - used to ensure proper device function before surgical closure
Follow up programming
1 week after initial programming to adjust MAP
Weekly for first 2 months
Again at 3 months
6 months then yearly
Test results guid treatment plan
Bilateral hearing with CI
Improved localization
Better hearing in noise
Improved quality of life
Consider lifespan and possible changes in technology for children
Bi modal hearing
CI in one hear, HA in the other
Recommended for all patients with unilateral CI
HA provides prosody info, rhythm, stress, intonation
Helps speech understanding in noise
Music sound quality improves
Bilateral vs bimodal
Similar results in one study
Improved hearing in noise with bilateral
Auditory brainstem implant
For individuals with neurofibromastosis
Bilateral tumors along VIIIth CN
Implant on the cochlear nucleus of the brain stem during removal of the tumor
Beneficial for those that cannot use CI because lack of functioning VIII CN
