1

Case 1

A 52-year old female patient was referred to our clinic with the diagnosis of NF2 and deafness. Medical history revealed that, first diagnosis of NF2 was accomplished 18 years ago in another clinic. Left sided tumor had been surgically removed on that time, resulting with the total hearing loss on left side. Furthermore, partial surgical excision of VS at right side had been performed 6 years after this surgery with preserving hearing on that side. Due to growing of residual tumor on right side stereotactic radio therapy has been given to patient 4 years ago. After radiotherapy, hearing status had been deteriorated and patient had been started to wear hearing aid. Although tumor size became stable, her hearing loss continue to deteriorate progressively. Sudden total hearing loss had been occurred in her only hearing ear 6 months ago and couldn’t be improved despite system steroid therapy. Then, patient was referred to our clinic for hearing rehabilitation.

Audiologic work-up revealed that patient has bilateral profound hearing loss. Temporal MRI showed that there was a VS completely filling CP angle and extending into the internal acoustic canal on right side. Tumor size was 23×28 mm. VS removal from right side via retrosigmoid approach was accomplished 15 months ago. We achieved to remove tumor totally and to preserve facial nerve, but we couldn’t preserve cochlear nerve. We had no additional difficulty due to prior radiation therapy while dissecting the tumor from surrounding tissues. MED-EL Concerto (MED-EL Company, Innsbruck, Austria) ABI electrode was placed to Foramen Luscha simultaneously. We checked the ABI place by computed tomography scan in postoperative 1st day. We observed facial nerve paralysis in postoperative period and it improved to House-Brackmann Grade IV level on postoperative 15th months. No additional complication was observed either intra or postoperatively.

First fitting process was accomplished at post-operative 2nd month and all electrodes were activated. In first stimulation, comfort and threshold levels were determined. Auditory and non-auditory perceptions were recorded by applying monopolar stimulations with each electrode. No non-auditory side effect was observed. At 3rd month setting of device, 8th and 10th electrodes were turned off due to patient discomfort. Audiologic outcome of patient at postoperative 15th month is quite well. With the free-field audiometry test of the patient, 25 dB hearing threshold at speaking frequencies, 87.5% word discrimination score, and 70% sentence discrimination score were obtained. The patient reported that there is a significant increase in quality of life after ABI, she is using the device daily and she can even make phone calls with non-relative people whose voices are unfamiliar with her.

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Case 2

A 57-year-old woman with a complaint of bilateral deafness was referred to our clinic. Medical history revealed that she had deafness on the left ear since childhood due to an unknown reason. Since 2010, hearing loss has begun on right ear and increased progressively. Complete audiologic and radiologic work-up was performed in another clinic 1 year ago. Magnetic Resonance Imaging (MRI) of the temporal bone showed VS in the right internal acoustic canal. No surgical attempt had been considered due to presence of VS in only hearing ear and hearing aid had been advised to patient on that time. Unfortunately, sudden hearing loss in only hearing right ear had been occurred in 4 months ago. Systemic steroid therapy had been tried, but no recovery in hearing loss had been occurred, and patient became bilaterally deaf since last 4 months. Then patient was referred to our clinic.

The audiologic test battery demonstrated a bilateral profound sensorineural hearing loss. Bilateral speech discrimination scores were 0%. No recognizable ABR waves were obtained at a stimulation level of 100 dB HL (hearing level) with clicks, on both sides. MRI identified a 10×12 mm sized VS in the right internal auditory canal.

After detailed discussion of the management options with the patient, surgical removal of the VS was decided. It was explained to patient that cochlear implantation would be performed if we achieved to preserve cochlear nerve anatomically; otherwise ABI placement would be the only choice.

VS was completely removed from the right internal auditory canal via translabyrinthine approach. Preservation of cochlear and facial nerves was accomplished. No electrophysiologic measurement such as promontorium stimulation test was performed to measure the functional integrity of the cochlear nerve. During the same surgical session a MED-EL-Sonata (MED-EL Company, Innsbruck, Austria) cochlear implant electrode array was inserted successfully in the cochlea, via posterior tympanotomy. The electrodes’ array insertion was complete. All the electrodes had a regular telemetry of impedance. The operative cavity was then filled with autologous fat from the abdomen. Surgical procedure was completed without any complication. The post-operative course was uneventful.

The patient’s speech processor was switched on and the map fitted 1 month after implantation. All the 22 electrodes were active and retained good impedance values.

The verbo-acoustic rehabilitation sessions were done monthly. She improved her speech understanding scores at 3 months, reaching 25% in the disyllabic words recognition task (close set). Narrow band audiometric thresholds via CI were set at 30 dB on all frequencies. After 6 months surgery the disyllabic words recognition task (close set) reached score of 67% and sentence recognition score was still 0%. After 18 months use of the CI, the patient retained score of 67% the disyllabic words recognition (close set) and speech discrimination performances was still 0%. Although audiometric pure tone thresholds were quite well, patient didn’t improve open set speech discrimination. However, she is very happy with CI. She is daily user, and CI improves lip reading. She has good communication with lip reading with the help of CI.

2

Case 2

A 57-year-old woman with a complaint of bilateral deafness was referred to our clinic. Medical history revealed that she had deafness on the left ear since childhood due to an unknown reason. Since 2010, hearing loss has begun on right ear and increased progressively. Complete audiologic and radiologic work-up was performed in another clinic 1 year ago. Magnetic Resonance Imaging (MRI) of the temporal bone showed VS in the right internal acoustic canal. No surgical attempt had been considered due to presence of VS in only hearing ear and hearing aid had been advised to patient on that time. Unfortunately, sudden hearing loss in only hearing right ear had been occurred in 4 months ago. Systemic steroid therapy had been tried, but no recovery in hearing loss had been occurred, and patient became bilaterally deaf since last 4 months. Then patient was referred to our clinic.

The audiologic test battery demonstrated a bilateral profound sensorineural hearing loss. Bilateral speech discrimination scores were 0%. No recognizable ABR waves were obtained at a stimulation level of 100 dB HL (hearing level) with clicks, on both sides. MRI identified a 10×12 mm sized VS in the right internal auditory canal.

After detailed discussion of the management options with the patient, surgical removal of the VS was decided. It was explained to patient that cochlear implantation would be performed if we achieved to preserve cochlear nerve anatomically; otherwise ABI placement would be the only choice.

VS was completely removed from the right internal auditory canal via translabyrinthine approach. Preservation of cochlear and facial nerves was accomplished. No electrophysiologic measurement such as promontorium stimulation test was performed to measure the functional integrity of the cochlear nerve. During the same surgical session a MED-EL-Sonata (MED-EL Company, Innsbruck, Austria) cochlear implant electrode array was inserted successfully in the cochlea, via posterior tympanotomy. The electrodes’ array insertion was complete. All the electrodes had a regular telemetry of impedance. The operative cavity was then filled with autologous fat from the abdomen. Surgical procedure was completed without any complication. The post-operative course was uneventful.

The patient’s speech processor was switched on and the map fitted 1 month after implantation. All the 22 electrodes were active and retained good impedance values.

The verbo-acoustic rehabilitation sessions were done monthly. She improved her speech understanding scores at 3 months, reaching 25% in the disyllabic words recognition task (close set). Narrow band audiometric thresholds via CI were set at 30 dB on all frequencies. After 6 months surgery the disyllabic words recognition task (close set) reached score of 67% and sentence recognition score was still 0%. After 18 months use of the CI, the patient retained score of 67% the disyllabic words recognition (close set) and speech discrimination performances was still 0%. Although audiometric pure tone thresholds were quite well, patient didn’t improve open set speech discrimination. However, she is very happy with CI. She is daily user, and CI improves lip reading. She has good communication with lip reading with the help of CI.