CREST: Cochlear Response Telemetry and Hearing Preservation
Study Details
Study Description
Brief Summary
The main purpose of this study is to monitor the response from the cochlea as the electrode is inserted during the operation to receive a cochlear implant. The Cochlear Response Telemetry tool aims to measure the response from the cells within the cochlea and may be useful in the future to help to improve the surgical technique and potentially help surgeons better preserve any natural hearing that is available. The measurements are obtained using the cochlear implant and sound processor while a sound is presented to the ear through an earphone (like an earplug) placed into the ear canal.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: Cochlear implant recipients Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. |
Device: Cochlear implant
Study involves measuring using Electrocochleography to measure the CM response in patients undergoing cochlear implant surgery
|
Outcome Measures
Primary Outcome Measures
- Change in Low-frequency Hearing Thresholds Assessed Audiometrically Pre- and Post-operatively. [Baseline measurement (pre-operatively) compared to 4 to 6 weeks post-surgery]
Average low-frequency (LF) hearing thresholds (average thresholds at 500, 750, and 1000 Hz) will be measured for the implanted ear 4 to 6 weeks following surgery and compared with average LF hearing thresholds measured relative to the pre-operative baseline measured within 90 days of CI surgery. The outcome measure of interest is the change in average LF hearing thresholds pre- to postoperative for each subject. The average change observed for individual subjects will then be compared with individual electrophysiological cochlear microphonic (CM) measures made during the surgery using the Cochlear Response Telemetry System. Of specific interest is whether or not compromised CM measures relate to pre-to-postoperative changes in low-frequency hearing. In other words, are larger changes in average LF hearing thresholds observed in subjects with compromised CM measures made intraoperative versus those with uncompromised CM response?
Secondary Outcome Measures
- Change in Low-frequency Hearing Thresholds Assessed Audiometrically Pre- and Post-operatively. [Baseline (pre-operative) compared to 3 months post cochlear implant activation]
Average low-frequency (LF) hearing thresholds (average thresholds at 500, 750, and 1000 Hz) will be measured for the implanted ear 3 months following cochlear implant activation and compared with average LF hearing thresholds measured preoperatively. The outcome measure of interest is the change in average LF hearing thresholds pre- to postoperative for each subject. The average change observed for individual subjects will then be compared with individual electrophysiological cochlear microphonic (CM) measures made during the surgery using the Cochlear Response Telemetry System. Of specific interest is whether or not compromised CM measures relate to pre-to-postoperative changes in low-frequency hearing. In other words, are larger changes in average LF hearing thresholds observed in subjects with compromised CM measures made intraoperative versus those with uncompromised CM response.
- Correlation of Preoperative High-frequency Hearing Thresholds and Cochlear Microphonic Response (Number of Electrodes Inserted When CM Detected). [Intraoperative]
The onset of the cochlear microphonic (CM) response will be measured intraoperative to determine if there is a relationship between the onset of the CM response during electrode insertion and the preoperative high-frequency acoustic hearing thresholds. The onset of the CM response will be tracked by impedance measures that are interleaved with the CM recordings. As each electrode in the array enters the perilymph in the cochlea there will be a measured reduction in impedance. CM onset will be defined in terms of the nth electrode (out of the 22 electrodes) to enter the cochlea. Preoperative high-frequency hearing will be defined as the average of preoperative thresholds at frequencies of 2 kHz, 3 kHz and 4 kHz for each individual subject.
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Candidate for cochlear implantation (with CI522, CI532, CI622, CI632 or Hybrid-L24 (US only) according to local indications
-
18 years of age or older at the time of enrolment
-
Pre-operative audiometric threshold in the implanted ear at 500 Hz of better than or equal to 80 dB HL
-
Willingness to participate in and to comply with all requirements of the protocol
Exclusion Criteria:
-
Prior cochlear implantation in the ear to be implanted
-
Ossification or any other cochlear anomaly that might prevent complete insertion of the electrode array
-
Abnormal cochlear/nerve anatomy on pre-operative CT or MRI imaging (excluding a mild Mondini malformation or Large Vestibular Aqueduct Syndrome)
-
Deafness due to lesions of the acoustic nerve or central auditory pathway
-
Diagnosis of auditory neuropathy
-
Active middle-ear infection
-
Additional handicaps that would prevent participation in evaluations
-
Unrealistic expectations on the part of the subject, regarding the possible benefits, risks and limitations that are inherent to the procedure and investigational device
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Hospital Italiano de Buenos Aires | Buenos Aires | Argentina |
Sponsors and Collaborators
- Cochlear
Investigators
None specified.Study Documents (Full-Text)
More Information
Publications
None provided.- CLTD5667
Study Results
Participant Flow
| Recruitment Details | |
|---|---|
| Pre-assignment Detail |
| Arm/Group Title | Adults Implanted With CI522, CI532, CI622, CI632 or Hybrid-L24 (US Only) |
|---|---|
| Arm/Group Description | Adults (≥ 18 years of age) implanted with CI522, CI532, CI622, CI632 or Hybrid-L24 (US only) with pre-operative audiometric threshold in the ear to be implanted of better than or equal to 80 dB HL at the frequency of 500 Hz. |
| Period Title: Overall Study | |
| STARTED | 80 |
| COMPLETED | 80 |
| NOT COMPLETED | 0 |
Baseline Characteristics
| Arm/Group Title | Adults Implanted With CI522, CI532, CI622, CI632 or Hybrid-L24 (US Only) |
|---|---|
| Arm/Group Description | Adults (≥ 18 years of age) implanted with CI522, CI532, CI622, CI632 or Hybrid-L24 (US only) with pre-operative audiometric threshold in the ear to be implanted of better than or equal to 80 dB HL at the frequency of 500 Hz. |
| Overall Participants | 61 |
| Age (Count of Participants) | |
| <=18 years |
0
0%
|
| Between 18 and 65 years |
36
59%
|
| >=65 years |
25
41%
|
| Age (Years) [Mean (Full Range) ] | |
| Mean (Full Range) [Years] |
59.7
|
| Sex: Female, Male (Count of Participants) | |
| Female |
35
57.4%
|
| Male |
26
42.6%
|
| Race and Ethnicity Not Collected (Count of Participants) | |
| Device (participants) [Number] | |
| CI522/522 |
52
85.2%
|
| CI532 |
9
14.8%
|
| AETIOLOGY (participants) [Number] | |
| Unknown |
39
63.9%
|
| Otosclerosis |
2
3.3%
|
| Genetic |
8
13.1%
|
| Meniere's Disease |
1
1.6%
|
| Sudden Hearing Loss |
2
3.3%
|
| Chronic Otitis Media |
1
1.6%
|
| Usher's Syndrome |
3
4.9%
|
| DeaFNess Autosomal Dominant 9 (DFNA9) |
1
1.6%
|
| Noise Exposure |
4
6.6%
|
| EAR (Left/Right (participants) [Number] | |
| Left Ear |
31
50.8%
|
| Right Ear |
30
49.2%
|
| Nature of Hearing loss (participants) [Number] | |
| PROGRESSIVE |
47
77%
|
| CONGENITAL WITH PROGRESSION |
8
13.1%
|
| SUDDEN |
4
6.6%
|
| PROGRESSION WITH SUDDEN |
1
1.6%
|
| No Data |
1
1.6%
|
| Age of onset of hearing loss (Years) [Mean (Full Range) ] | |
| Mean (Full Range) [Years] |
30.75
|
| Age of diagnosis Severe -Profound Hearing Loss (Years) [Mean (Full Range) ] | |
| Mean (Full Range) [Years] |
46.98
|
Outcome Measures
| Title | Change in Low-frequency Hearing Thresholds Assessed Audiometrically Pre- and Post-operatively. |
|---|---|
| Description | Average low-frequency (LF) hearing thresholds (average thresholds at 500, 750, and 1000 Hz) will be measured for the implanted ear 4 to 6 weeks following surgery and compared with average LF hearing thresholds measured relative to the pre-operative baseline measured within 90 days of CI surgery. The outcome measure of interest is the change in average LF hearing thresholds pre- to postoperative for each subject. The average change observed for individual subjects will then be compared with individual electrophysiological cochlear microphonic (CM) measures made during the surgery using the Cochlear Response Telemetry System. Of specific interest is whether or not compromised CM measures relate to pre-to-postoperative changes in low-frequency hearing. In other words, are larger changes in average LF hearing thresholds observed in subjects with compromised CM measures made intraoperative versus those with uncompromised CM response? |
| Time Frame | Baseline measurement (pre-operatively) compared to 4 to 6 weeks post-surgery |
Outcome Measure Data
| Analysis Population Description |
|---|
| 19 of the 80 ECochG intro-operative responses were excluded from the analysis (reasons are outlined in the CIR). A further 18 of the remaining 61 data points were excluded due to an unclear CM response resulting in N=43 responses categorized as either preserved or compromised. Further, two subjects were excluded from the primary endpoint analysis as there were no FUV1 thresholds collected. Thereby N=41. |
| Arm/Group Title | Cochlear Implant Recipients |
|---|---|
| Arm/Group Description | Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. Cochlear implant: Study involves using Electrocochleography to measure the CM response in patients undergoing cochlear implant surgery |
| Measure Participants | 41 |
| Mean (Full Range) [dB] |
26.9
|
| Title | Change in Low-frequency Hearing Thresholds Assessed Audiometrically Pre- and Post-operatively. |
|---|---|
| Description | Average low-frequency (LF) hearing thresholds (average thresholds at 500, 750, and 1000 Hz) will be measured for the implanted ear 3 months following cochlear implant activation and compared with average LF hearing thresholds measured preoperatively. The outcome measure of interest is the change in average LF hearing thresholds pre- to postoperative for each subject. The average change observed for individual subjects will then be compared with individual electrophysiological cochlear microphonic (CM) measures made during the surgery using the Cochlear Response Telemetry System. Of specific interest is whether or not compromised CM measures relate to pre-to-postoperative changes in low-frequency hearing. In other words, are larger changes in average LF hearing thresholds observed in subjects with compromised CM measures made intraoperative versus those with uncompromised CM response. |
| Time Frame | Baseline (pre-operative) compared to 3 months post cochlear implant activation |
Outcome Measure Data
| Analysis Population Description |
|---|
| 5 data points were excluded from this analysis due to post-operative thresholds not being measured at FUV2 (43 - 5 = 38). |
| Arm/Group Title | Cochlear Implant Recipients |
|---|---|
| Arm/Group Description | Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. Cochlear implant: Study involves using Electrocochleography to measure the CM response in patients undergoing cochlear implant surgery |
| Measure Participants | 38 |
| Mean (Full Range) [dB] |
31.52
|
| Title | Correlation of Preoperative High-frequency Hearing Thresholds and Cochlear Microphonic Response (Number of Electrodes Inserted When CM Detected). |
|---|---|
| Description | The onset of the cochlear microphonic (CM) response will be measured intraoperative to determine if there is a relationship between the onset of the CM response during electrode insertion and the preoperative high-frequency acoustic hearing thresholds. The onset of the CM response will be tracked by impedance measures that are interleaved with the CM recordings. As each electrode in the array enters the perilymph in the cochlea there will be a measured reduction in impedance. CM onset will be defined in terms of the nth electrode (out of the 22 electrodes) to enter the cochlea. Preoperative high-frequency hearing will be defined as the average of preoperative thresholds at frequencies of 2 kHz, 3 kHz and 4 kHz for each individual subject. |
| Time Frame | Intraoperative |
Outcome Measure Data
| Analysis Population Description |
|---|
| 40 data points with a CM response were eligible to be analysed for this outcome. Those excluded were due to an absence of CM under visual inspection (n =16), an absence of the impedance measurement used to calculate depth (n = 4), or an array that was withdrawn or reinserted at any time (n = 5). |
| Arm/Group Title | Cochlear Implant Recipients |
|---|---|
| Arm/Group Description | Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. Cochlear implant: Study involves Electrocochleography to measure the CM response in patients undergoing cochlear implant surgery |
| Measure Participants | 40 |
| Number [Pearson correlation coefficient] |
0.78
|
Adverse Events
| Time Frame | 5 months | |
|---|---|---|
| Adverse Event Reporting Description | Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months | |
| Arm/Group Title | Cochlear Implant Recipients | |
| Arm/Group Description | Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. Cochlear implant: Study involves measuring cochlear response electrophysiologically during surgery to place a cochlear implant in patients already identified as candidates. | |
All Cause Mortality |
||
| Cochlear Implant Recipients | ||
| Affected / at Risk (%) | # Events | |
| Total | 0/61 (0%) | |
Serious Adverse Events |
||
| Cochlear Implant Recipients | ||
| Affected / at Risk (%) | # Events | |
| Total | 2/61 (3.3%) | |
| Surgical and medical procedures | ||
| SUDDEN ONSET ROTARY VERTIGO | 2/61 (3.3%) | |
Other (Not Including Serious) Adverse Events |
||
| Cochlear Implant Recipients | ||
| Affected / at Risk (%) | # Events | |
| Total | 15/61 (24.6%) | |
| Ear and labyrinth disorders | ||
| OTITIS MEDIA WITH EFFUSION | 1/61 (1.6%) | 1 |
| OTITIS EXTERNA DURING SURGERY | 1/61 (1.6%) | 1 |
| PULSATILE TINNITUS | 1/61 (1.6%) | 1 |
| PAIN AND INFLAMATION POST SURGERY | 1/61 (1.6%) | 1 |
| EXACERBATION MENIERE'S DISEASE | 1/61 (1.6%) | 1 |
| BLOOD/FLUID STILL BEHIND EAR; NO PAIN REPORTED BY PATIENT | 1/61 (1.6%) | 1 |
| General disorders | ||
| COLD | 1/61 (1.6%) | 1 |
| VERTIGO AND NAUSEA | 4/61 (6.6%) | 4 |
| INTRAOPERATIVE HORIZONTAL CANAL DEFECT resulted in 'SEVERE VERTIGO EXPERIENCED DURING AUDIOMETRY, TY | 1/61 (1.6%) | 1 |
| Musculoskeletal and connective tissue disorders | ||
| UNDISPLACED FRACTURE OF THE MEDIAL FEMORAL CONDYLE | 1/61 (1.6%) | 1 |
| DELAYED FACIAL PARALYSIS | 1/61 (1.6%) | 1 |
| Respiratory, thoracic and mediastinal disorders | ||
| BRONCHITIS | 1/61 (1.6%) | 1 |
Limitations/Caveats
More Information
Certain Agreements
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.
Results Point of Contact
| Name/Title | Ruth English |
|---|---|
| Organization | Cochlear |
| Phone | 0386633105 |
| REnglish@cochlear.com |
- CLTD5667