Audiometric evaluation short and medium term in cochlear implants.

OBJECTIVE

Our purpose is report the results of cochlear implant program in this Institute, since our first surgery from November 2007, until December 2012.

MATERIAL AND METHODS

A cross-sectional study, observational, descriptive, analyzing the information about thresholds before and after implantation, using patients files (diagnosis, onset of hearing loss, brainstem auditory evoked potential (BAEP), computed tomography (CT), magnetic resonance imaging (MRI), implanted ear, brand and model of cochlear implants (CI) and audiometric studies before and after the CI.

RESULTS

We report the evolution of 68 patients, age ranged 1 year 8 months to 39 years 3 months old. 94% patients (n = 64) had pre-lingual hearing loss being hereditary non-syndromic hearing loss the most common etiology (29.4%). 100% patients had auditory brainstem responses showing bilateral profound hearing loss, in the 77.9% type A tympanograms were obtained (Jerger's classification), and 100% had absence of stapedial reflexes and otoacoustic emissions with low reproducibility. CT reported as normal in 85.2% of patients, the findings: 5.8% had chronic mastoiditis changes, other findings reported in 1.4% of patients were: digastric right facial nerve, facial nerve canal dehiscence, enlarged vestibular aqueduct, occupation and poor pneumatization of mastoid air cells, lateral semicircular canals agenesis, incomplete partition of the cochlea with wide vestibular and vestibular aqueduct dilatation. Most frequent MR findings of skull with cerebellopontine angle approach were vascular loops of internal auditory canals unilaterally. In 10.2%, 55.8% of patients (n = 38) were implanted in the right ear, 56 (82.3%) with a CI from Advanced Bionics, HiRes 90K model, the remaining with Cochlear, Freedom and Nucleus 5 models. Developments in CI results by audiometric tests: prior to placement was 106.2 dB averages at frequencies assessed, one month later 62.4 dB, at 6 months 44 dB, and with satisfactory threshold 32.9 dB. 55.8% of patients (n = 38) with P + HiRes Fidelity 120 strategy, the remaining with Hires S + Fidelity 120, Hires S and ACE RE.

DISCUSSION

Audiology service proposed to place the CI in the worst ear by threshold in audiometric tests, the otolaryngology service proposed the best ear from anatomical point view. Implanted in the INR more Advanced Bionics CI faq frequently due to the donation by the insurance for a new generation. Hearing thresholds using CI have improved since activation.