Detection of intracochlear damage during cochlear implant electrode insertion using extracochlear measurements in the gerbil.
Laryngoscope
; 122(3): 636-44, 2012 Mar.
Article
em En
| MEDLINE
| ID: mdl-22252968
ABSTRACT
OBJECTIVES/HYPOTHESIS:
An intraoperative monitoring algorithm during cochlear implant electrode insertion could be used to detect trauma and guide electrode placement relative to surviving hair cells. The aim of this report was to assess the feasibility of using extracochlear recording sites to monitor acoustically evoked responses from surviving hair cells and neural elements during implantation in an animal model. STUDYDESIGN:
Animal experiments.METHODS:
The normal-hearing gerbil was used. Two recording methods, one using a lock-in amplifier and another using Fourier analysis of recorded signals, were used to obtain frequency-specific information about the responses to tones. Amplitude and threshold determinations were made at the round window and at three extracochlear sites. To induce intracochlear damage, a platinum-iridium wire was inserted through the round window. The wire was advanced, and changes in the potentials were correlated with cochlear contact. Anatomic integrity was assessed using cochlea whole mount preparations.RESULTS:
In general, the lock-in amplifier showed greater sensitivity and lower thresholds at higher frequencies relative to the Fourier method. Also, the lock-in amplifier was more resistant to masking effects. Both systems were able to detect loss of cochlear potentials secondary to intracochlear trauma. Histologic damage was seen in all cases and corresponded to electrophysiologic changes.CONCLUSIONS:
Impact of electrodes on cochlear structures affecting cochlear performance could be detected from several extracochlear sites. The lock-in amplifier demonstrated greater sensitivity and resistance to noise when compared to the fast Fourier transform recording paradigm. The latter showed greater flexibility of detecting and separating hair cell and neural potentials.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Limiar Auditivo
/
Monitorização Intraoperatória
/
Implantes Cocleares
/
Células Ciliadas Auditivas
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
Laryngoscope
Assunto da revista:
OTORRINOLARINGOLOGIA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos