Cochlear Implants Midterm Flashcards
What is a cochlear implant?
A cochlear implant is a device surgically inserted into the ear to help people with severe HL
it works by directly stimulting the auditory nerve using electrical signals, bypassing the damaged parts of the inner ear.
What part of the inner ear is damaged and how does a CI bypass that system?
The hair cells are damaged. CI bypass this by directly stimulting the auditory nerve with electrodes. The electrodes are inserted into the cochlea. They send electrical impulses that stimulate the auditory nerve fibers indirectly, through the cochlear structures. and
Who is considered the father of the cochlear implant?
William House
* spear headed the advancements in CI tech
Dr. Graeme Clark
* Motivated to develop bionic ear due to his fathers deafness
When did Dr.Graeme Clark implant his first patient?
1978 - implanted his first 3 PT’s
* mid 60’s is when he first started developing it
Why is Bilger’s report considered a landmark in the development of the cochlear implant?
- He evaluted early CI the results = the CI improved quality of life for all subjects
- lip reading & speech productions score were signifcantly better
What are the three major manufactures of CI?
Cochlear Nucleus
Advanced Biontics
MED-EL
What CI company has the first FDA approved multichannel device?
Cochlear Nucleus
Cochlear Nucleus has how many channels?
22 channels available for stimulation
Which FDA center is responsible for overseeing cochlear implant devices?
Center of Devices and Radiolgical Health
* CDRH regulates all companies that manufacture or import devices in the US
What are the different classes of medical devices?
Class I
* Devices pose the least amount of risk to PT = least amount of regulatory control
Class II
* Devices pose a moderate safety risk to PT = higher regulatory contol to “provide reasonable assurance of the device’s safety and effectivness
* Requires PMA
Class III
* Highest potential risk to the PT = highest level of regulatory contol
* Requires PMA
* Cochlear Implants
What class of medical devices do cochlear implant devices fall under?
Class III
What is premarket approval (PMA
PMA is a 4 step process
1. Adminstrative & limited review by FDA to determine completeness (acceptance & filling)
2. indepth scientific, regulartory & quality review by FDA (substantive review)
3. Review and Reccomendations by advisory committe (panel review)
4. Final Deliberations, documentaion & notification of FDA decision
what are some examples of changes that require the manufacturer to submit a PMA supplement?
- New indication for use of the device
- Labeling changes
- Changes in manufacturing facilities, methods, or quality control procedures
- Changes in sterilization procedures and packaging
- Changes in the performance or design specifications, circuits, components, ingredients, principles of operation, or physical layout of the device
What does PMA stand for?
Premarket approval
Examples of Changes that require a PMA supplement
- new indication for use of the device
- Lableing changes
- Change in manifacturing facilities, methods or quality control procedures
- Changes in sterilization procedures and packaging
- Changes in the performance or design specification, circuits, components, ingredients, principles of operation or physical layout of the device.
Who is responsible for designating the indications for cochlear implantation?
Colletive Teamwork of a multi-disciplinary group
* PT’s & family
* CI surgeon
* Audiologists
* SLP
* Deaf Educator
* Radiologists
Who is responsible for designating the audiologic criteria: who decides for cochlear implantation?
FDA doesnt set CI candidacy. Each manufacture submit a PMA app outlining indications for their device for FDA to approve or reject
* Approved = manufacturer-defined indications become the FDA criteria for device use = FDA labeled indications or FDA candidacy criteria
What is the difference between “labeled” and “off-label” indications?
Labeled: Manufacturer-defined indications listed in the physician’s package insert.
Off-labeled: Provision of a CI to a patient who does not meet the approved indications is often referred to as “off-label” use.
when would “labeled” and “off-label” indications each be considered?
Labeled: when Patient meets the criteria for CI
Off -labled: SSD for example in AB - only have label for bilateral
if a clinican recommends off-label usage what are the three conditions that must be met?
- Well informed about the product.
- Base its use on firm scientific rationale and on sound medical evidence.
- Maintain records of the product’s use and effects.
What are the FDA approved indications for traditional CI candidacy for Cochlear
- 18 +
- Bilateral SNHL
- Moderate to profound
- limited benefit from HA ampification
- < 50% in poorer ear and <60% in opposite eat for sentence recognition.
What are the FDA approved indications for traditional CI candidacy for Advanced Bionics
- 18 +
- Severe to profound SNHL >70 db
- limited benfit from HA’s 50% or less on test of open set sentences
What are the FDA approved indications for traditional CI candidacy for MED-EL
- 18 +
- Bilateral Moderate to profound SNH
- Limited benefit from HA’s
- 50% or less in implanted ear and 60^ pr less in non implant ear.
What are the candidacy criteria for children
9 - 24 mos: Profound bilateral SNHL >90db HL at 1,00hz
2 - 17 yrs: bilateral severe to profound SNHL
* Limited benfit from binaural HA’s
* Lack of progress in development auditory skills with HA’s & aural rehab for 3 to 6 mos
* 3-6 mos HA trial
What are the candidacy criteria for SSD & AHL
- Severe to profound SNHL in inplant ear & normal or mild SNHL in other
- 5+
- Limited benefit from HA’s; score of 5% or less on CNC
SSD is defined as what
SSD is defined as profound sensorineural hearing loss in one ear and normal hearing or mild sensorineural hearing loss in the other ear.
AHL is defined as what?
AHL is defined as profound sensorineural hearing loss in one ear and mild to moderately severe sensorineural hearing loss in the other ear, with a difference of at least 15 dB inPTAs.
What are the current Medicare eligibility criteria for cochlear implant coverage?
- bilateral moderate-to-profound SNHL with limited benefit from appropriate HAs.
≤60% correct scores in the best-aided listening condition on open-set sentence cognition tests. - No ME infection, normal inner ear and auditory nerve.
- No contraindications to surgery.
- The device must be used in accordance with Food and Drug Administration (FDA)-approved labeling.
Under what circumstances would the hearing aid trial period be waived for children?
If the child has been diagnosed with Meningitis, they will implant before ossification.
What is the minimum and maximum age approved by the FDA for cochlear implantation?
Min: 9 months
Max: none, if they if they meet the criteria
Why is it important to image the auditory anatomy with CT and/or MRI prior to implantation?
Imaging of the cochlea anatomy with CT or MRI to determine:
* If it is possible to insert an electrode array
* Confirm that the auditory nerve is present and/or normal
* Which ear may be most suitable
What are some absolute (not relative) contraindications for cochlear implantation?
Anatomic
* Absent cochlea or cochlear nerve
* Neurological damage impeding aud processing
* Damaged auditory cortex
Medical
* Medical conditions preventing surgery
* Medical risks of surgery outweight benefits
Not a CI candidate
* a child who has signifant residual hearing & good HA benefit
* Absence of CN 8
* Absence of the labyrinth
* 20 + w/prelingual HL
* cognitive impairments that would prevent rehab
* active external or middle ear infection
* allergy ot intolerance to device materials
When unilateral implantation is considered, what factors are used to determine which ear should be implanted?
- Anatomy (anything abnormal; nerve/cochlea related)
- if one ear accepts eletrical stim better
- Implant worse ear OR implant better ear (will be more ready to acclimate)
- implant dominate hand side
- facial nerve too close to cochlea
- If no differnce may want right (speech & hearing on left)
what are the factors known to affect cochlear implant outcomes & how
- Duration of deafness
Longer = worse outcomes - Age of implantation
Younger = better outcomes - Motivation & support
Higher = better outcomes - Mode of communication
Listening and spoken language support better outcomes - Etiology
Some causes predict better outcomes (e.g., genetic, Meniere’s) - socioeconomic status
Higher SES = better outcomes - Preoperative residual hearing
Some hearing = better outcomes
What are the 60/60 guidelines?
60/60 guideline referal for CI eval criteria
PT’s should be referred if
* in their better ear they score 60% or less on WRS unaided
* PTA in the better eat is 60dbHL or worse unaided
How do the 60/60 guidelines help to address the under-referral of cochlea implant candidates?
Before 60/60 audiologists we’re not referring patients that needed to be referred due to the fact that they didn’t know the qualification criteria for referral.
Why is it important to include 125 Hz when evaluating CI candidacy?
- to assess hearing preservation and guide post - op amplification strategy
- to support counseling by setting expectation about potential HL
According to MSTB-3, what are the four key steps in the cochlear implant candidacy assessment process recommended for best clinical practice?
- Comprehensive Audiological Evaluation
- Hearing Aid Verification
- Aided Speech Recognition Testing
- Outcome Measures
what is the first key step in the MSTB-3 process and what is involved?
Comprehensive Audiological Evaluation
* Otoscopy
* Acoustic Immittance
* Air conduction
* 125 - 8,000hz w/inserts
what is the second key step in the MSTB-3 process and what is involved?
Hearing Aid Verification
* Choose and fit HA’s to optimize WRS performance
* Listening check and or electroacoustic test for internal noise or distortion
* REM to verify output matches targets
* Verify output with a calibrated speech signal at 60/65 dbSPL matching the level used in candidacy speech recognition
* If PT’s HA’s do not pass
1. adjust PT’s HA’s to be appropropriate or
2. Loaner HA’s programmed to ensure accuarte aided results
what is the third key step in the MSTB-3 process and what is involved?
Aided Speech Recognition Testing
* Speech discrimination score are key for candidacy
* Calibrate - very important
* Aided Speech recohnition is evaluted w/ the minimum speech test battery (MSTB)
* CNC & AzBio (RE only,LE only & bilateral if needed)
what is the fourth key step in the MSTB-3 process and what is involved?
Outcome measures
* Patient reported outcome measures.
* Questionnaires.
What is the purpose of a hearing aid evaluation prior to beginning aided speech assessment?
- Hearing aids should be fit appropriately to maximize aided speech performance.
What is the purpose of calibration prior to aided speech assessment?
Calibration ensures speech stimuli are presented at consistent, clinically relevant levels.
* Enables reliable tracking of PT’s Progress
* Outcome measures remain valid & compariable
* inaccurate calibration = inappropriate CI referrals (under or over qualified)
Free-field calibration of speech stimuli requires what?
SF calibration uses speech simuli
Input calibration
&
Output Calibration
For free field calibration what does input calibration do?
Input calibration – prevents distortion or clipping of the input signal
For free field calibration what does output calibration do?
Output calibration – ensures that speech materials are presented in the SF at the intended level
what happens if calibration is not done?
could result in inaccurate presentations = inappropriate CI refferals
* either under or over qualifiying PT’s
What is the main purpose of postoperative CI assessment,
To ensure that a patients amplification is appropriate and is maximizing auditory potential.
what are the main components of the Postopertive CI assessment.
Behavioral & Subjective
Behavioral measuremnts after implantation are used to what?
- program the CI
- Monitor the developemnt of speech perception
- provide an indication of auditoy function or how child is usng CI to hear
what is involoved in the behavioral assessment for the post opertive protocol?
MSTB-3 provides a structured protocol for postoperative testing
* Unaided audiometric thresholds (125 to 8000 Hz) in the implanted ear; this includes AC & BC
* Unaided thresholds for the non-implanted ear (for bimodal listeners)
* Aided soundfield thresholds for the implanted ear(s)
* Aided speech assessment
* Speech Recognition Testing
CNC and AzBio tests under aided conditions
* May include comparison between CI alone and CI + HA (for bimodal benefit)
what is involoved in the subjective assessment for the post opertive protocol?
Questionaires to evalute percived benfit and/or quality of life
* CIQOL-10, SSQ-12, THI, GAD-7, PHQ-9 (as needed)
* Assess QOL, communication, mental health, and patient perception
What is the recommended MSTB-3 follow-up schedule after implantation, and when should additional visits be considered within that timeline?
Postoperative testing at 3 months & 12 months following implantation for all patients
* If performance is suboptimal at 3 mos consider additional testing before 12 mos
How are the benefits of bimodal hearing determined?
If the patient performs well on CNC words with the CI alone, compare performance on AzBio sentence scores at +10 SNR (S₀N₀) using the CI-alone and CI + hearing aid in non implanted ear (bimodal).
* Improvement in performance w/ CI + HA = bimodal benefit
* Minimal or no improvement = limited benefit from bimodal use
What are the main speech tests used in the MSTB-3 battery?
CNC
&
AzBio
Previously, AzBio sentences were used to determine implant candidacy. In the current MSTB-3, CNC word testing is the clinical basis for determining candidacy. What are the rationales for this change?
- The CNC offers a more objective and consistent metric for evaluating CI candidacy compared to AzBio, which may vary more due to sentence-level context.
- Minimization of Contextual Cues:
- CNC consists of monosyllabic words = less contextual support, offering a truer measure of speech perception at the phoneme level.
- AzBio Still Used for Insurance purposes
What approaches are used to isolate the non-test ear (NTE)?
- Plug and muff approach, ideal for patients who struggle to process signal from masking noise.
- Masking noise delivered via insert earphones to the better ear.
- Insert earphone + circumaural headphones; combines acoustic sealing with masking for enhanced isolation
How is ANSD diagnosed in children?
Normal OAE & Abnormal ABR
Why is determining the site of lesion important?
ANSD involves disrupted neural synchrony, often at the inner hair cells, auditory nerve, or brainstem.
Identifying the site of lesion is critical to:
* Predict CI outcomes
* Guide appropriate intervention strategies
* Rule out non-cochlear causes that may not benefit from implantation
The presence of ANSD may influence CI candidacy decisions and postoperative expectations
Pediatric Minimum Speech Test Battery (PMSTB)
- It is modeled after the MSTB developed for adults
- The PMSTB provides a structured protocol to assess speech recognition in children who are:
- Being considered for cochlear implantation
- Already using cochlear implants
parental questionnaires
Functioning After Pediatric Cochlear Implantation (FAPCI)
Age range
2-5 yrs
parental questionnaires
Meaningful Auditory Integration scale (MAIS)
Age range
3 - 5 years
parental questionnaires
LittleEARS
Age range
0 -24 mos
parental questionnaires
Auditory Skills Checklist
Age range
0 -36 mos
parental questionnaires
Early Language Milestones (ELM)
Age range
0-36
parental questionnaires
Parents Evaluaton of Aural/oral Performace of Children (PEACH)
Age range
3 - 7
what are parental questionnaires used for?
parental questionnaires used to track postoperative development of auditory skills in children
What are the External components of a CI?
- Microphone
- Digital Speech Processor
- Cord, Coil/antenna
- Magnet
- Power source
What are the External components of a CI and the function of each?
- Microphone picks up the acoustical signal and converts it to an electrical signal for input to the speech processor.
- Speech Processor converts a microphone input into electrical stimulation.
- Cord for delivery of electrical data.
- External transmitter to deliver data to the internal receiver (antenna) via radio frequency.
- Magnet to locate and maintain connectivity between internal and external components.
- Power source: Rechargeable or disposable batteries
Identify Image
- Microphone
- Speech Processor
- Cord
- External transmitter
- Magnet
- Power source
What are the Internal components of a CI ?
Magnet
Receiving/transmitting coil
Digital signal processor:
Stimulator for electric pulse generation
Electrode leads
Electrode array
What are the Internal components of a CI and the function of each?
- Magnet: Maintain connectivity with external hardware
- Receiving/transmitting coil: Receives data delivered by external transmitter via radio frequency
- Digital signal processor: Receives signals from the speech processor and converts them into electric impulses.
- Stimulator for electric pulse generation: Decodes, analyzes, and delivers data to electrode array
- Electrode leads: Deliver the electric current from the stimulator to the electrode array that is housed within the cochlea.
- Electrode array:Stimulate the auditory nerve fibers in the cochlea
In general, how does a cochlear implant convert sound into electrical stimulation, step-by-step, from sound pickup to nerve stimulation?
- A microphone picks up sound from the environment, amplifies it, and converts it into an electrical signal.
- The electrical signal is transmitted to the speech processor. The amplitude, duration, and rate of these pulses are controlled by the speech processor.
- The speech processor analyzes incoming speech and converts it into digital information
- The speech processor sends this digital information to the external transmitting coil.
- The external coil transmits both power and digital information through a RF link to the internal receiver/stimulator.
- The receiver decodes the digital signal and delivers electrical stimulation pulses to the electrode array implanted inside the cochlea.
- The electrodes stimulate the auditory nerve terminals using a series of biphasic current pulses.
Label internal components of implant
