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Behavior of the electrical impedances of cochlear implants from the moment of implantation until 12 months after surgery
Behavior of the electrical impedances of cochlear implants from the moment of implantation until 12 months after surgery
Ileana S. Gutiérrez-Farfán 1 
, Ruth A. López-Gamboa 2 , Ana L. Lino-González 3 , María E. Mena-Ramírez 1 , Emilio Arch-Tirado 4
1 Servicio de Audiología Pediátrica, Subdirección de Audiología, Foniatría y Patología de Lenguaje, Ciudad de México, México; 2 Servicio de Audiología Adultos, Subdirección de Audiología, Foniatría y Patología de Lenguaje, Ciudad de México, México; 3 Clinical Neurosciences Area, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Mexico City, Mexico; 4 Neurological Center, Centro Médico ABC Santa Fe, Mexico City. Mexico
*Correspondence: Ruth A. López-Gamboa. Email: dra.rlopezgamboa@gmail.com
Abstract
Background: The cochlear implant has proven to be the first prosthesis capable of restoring a sense organ, allowing patients with severe to profound sensorineural hearing loss to obtain hearing thresholds in the acoustic components of speech and a large audible frequency range.
Objective: To describe the behavior of the electrical impedances of cochlear implants from the time of implantation to 12 months after surgery.
Method: Retrospective, descriptive and analytical study. The electrical impedances of the patients were obtained and analyzed, during surgery, and activation up to the twelfth month. Descriptive statistical tests were performed for quantitative variables. For qualitative variables, percentages and frequencies were obtained.
Results: The lowest impedances were obtained in the surgery, the highest during activation. A tendency to decrease values was observed in almost all electrodes from month 1 to 12, except for electrodes 11 and 12, which show an increase in impedance values over time. Likewise, it is evident that in the electrodes that stimulate acute frequencies more electrical energy will be necessary.
Conclusions: Having an estimated value of increase and decrease of the impedance values, at each moment of the patients’ follow-up, allows us to detect alterations in the adequate functioning of the cochlear implant and/or to suspect any complication. The older patient needs more energy in acute frequencies.
Keywords: Cochlear implant. Electrical impedances. Electrode array. Electrical stimulation.
