The aim of this study is to measure eCAPs intraoperatively (and perform electrocochleography [ECochG] in case of any residual hearing) and to estimate cochlear health in these patients by applying insights gained from our guinea pig experiments.
ID
Source
Brief title
Condition
- Inner ear and VIIIth cranial nerve disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Primary outcome measures: amplitudes and latencies of the electrically evoked
compound action potential (eCAP); secondary outcome measures: amplitudes and
latencies of electrocochleography.
Secondary outcome
In order to assess the clinical applicability/usefulness of the aforementioned
measurements, these experimental measurements will be compared to routinely
(clinically) obtained data such as etiology, degree, and duration of hearing
loss, and speech intelligibility scores.
Background summary
In case of substantial to complete loss of cochlear hair cells, cochlear
implants (CIs) can partially restore hearing. While most CI users benefit
significantly, some hardly experience any improved functional hearing. It is
largely unclear why such variability in hearing improvement exists among CI
users, although factors such as age at implant, duration of deafness, etiology
of deafness, and degree of hearing loss prior to implantation appear to be
predictive of measurements of hearing performance with a CI. such as word
recognition in noise. In particular, the chances of good CI performance tend to
be higher for young people with a short duration of non-profound deafness. To
some extent, this optimistic prognosis can be attributed to the plasticity of
the central nervous system, but the state of the neural auditory periphery
(also called "cochlear health") plays an important role as well.
In an effort to find functional objective measures indicative of this cochlear
health, we have conducted several studies in recent years focusing on measuring
the compound action potential (eCAP) in guinea pigs. For example, we identified
several eCAP measures that seem to change as the auditory nerve degenerates.
For example, with increasing inter-phase gap (IPG) in the biphasic stimulus
current pulse, eCAP latency is unchanged in normal-hearing guinea pigs, but
becomes longer in deaf animals (Ramekers et al., 2014, J Assoc Res Otolaryngol
15). Conversely, the overall excitability of the population ("level50%")
increases in normal-hearing animals, but not in deaf animals, with greater IPG
(Ramekers et al., 2014, J Assoc Res Otolaryngol 15).
Study objective
The aim of this study is to measure eCAPs intraoperatively (and perform
electrocochleography [ECochG] in case of any residual hearing) and to estimate
cochlear health in these patients by applying insights gained from our guinea
pig experiments.
Study design
This study is observational. The treatment that the participating patients
receive (cochlear implantation) is no different from those who choose not to
participate. In addition, for the participating patients, measurements will be
taken at two moments (once immediately after implantation intra-operatively,
and once 3-6 months post-operatively), which have no influence on the
treatment.
Study burden and risks
Only during the postoperative measurements (3-6 months after implantation) the
patient may experience some discomfort, because the eCAP measurements require a
relatively loud hearing sensation to be generated electrically. Additional
burden comes from the time the patient spends participating in the
post-operative measurements. If possible, the moment of these measurements will
be scheduled simultaneously with other regular (clinical) appointments, so that
the patient does not have to come to the UMC more often than necessary.
Heidelberglaan 100
Utrecht 3584 CX
NL
Heidelberglaan 100
Utrecht 3584 CX
NL
Listed location countries
Age
Inclusion criteria
Age >= 16 years.
Capable of providing informed consent.
Dutch as native language.
The chosen type of cochlear implant must be supported by the available test
equipment.
Exclusion criteria
Neurological or mental disorders.
Use of anticonvulsant medication or psychotherapeutic drugs.
No measurable eCAPs on any of the available electrodes.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL76131.041.21 |