[Cochlear implants reduce tinnitus in older patients in the long term]. / Eine Cochlea-Implantat-Versorgung reduziert langfristig die Tinnitusbelastung bei älteren Patienten.

BACKGROUND: Tinnitus is one of the most common otologic comorbidities, particularly in older patients with severe hearing loss or deafness. Cochlear implants (CI) have been used for hearing rehabilitation more and more successfully in elderly patients and CI treatment is performed in Germany without an age limit. The aim of this follow-up study was to assess the tinnitus burden in the long-term follow-up of elderly patients with hearing rehabilitation using CI. MATERIAL AND METHODS: This prospective longitudinal study included 15 patients between 72 and 92 years of age with preoperative tinnitus who had been treated unilaterally with a CI for the first time about six years ago. Monosyllabic speech understanding and tinnitus burden were assessed using the Mini-Tinnitus Questionnaire. The results were compared with our previous study 24, focusing on the first six months. RESULTS: Six years postoperatively, there was a nonsignificant increase in monosyllabic understanding to 61.7 ± 26.3%, compared with the results six months postoperatively (p = 0.069). The burden of tinnitus showed a stable low mean of 3.9 ± 3.6 points six years postoperatively, compared with the six-month control (p = 0.689) and significantly reduced compared to the preoperative status with 6.9 ± 6.5 points (p = 0.016). CONCLUSION: Hearing rehabilitation by using CI leads to a stable improvement of monosyllabic discrimination in elderly people as well as to a stable reduction of tinnitus burden over years.

Evaluation of a bone groove geometry for fixation of a cochlear implant electrode.

PURPOSE: Electrode migration is a rare, but relevant complication in cochlear implant (CI) surgery. An effective countermeasure is to create a bone groove in the facial recess to secure the electrode lead. We use this method routinely since 2013, but still experienced sporadic electrode migration events most likely due to an improper surgical execution. The aim of this study was to determine the optimum groove geometry. METHODS: Grooves of defined geometry were created in specimens of fresh porcine femur compacta by use of a CNC milling machine. Electrode dummies were fixed in the groove and then exposed to tensile stress. Force measurements were carried out to examine the effect of groove diameter and opening width on the holding force. The mechanical impact on the electrode cable during insertion into the groove was recorded and the electrode lead was examined under microscopic magnification to assess potential structural damage. RESULTS: Optimum groove geometry (diameter 1.10 mm, opening width 0.90 mm) ensured an average holding force of 830 mN which is equivalent to the established fixation by use of a titanium clip. None of the microscopic inspections revealed any morphological deterioration of the electrode lead. CONCLUSION: The fixation of a CI electrode in a bone groove in the facial recess appears to be effective and safe. Furthermore, this method does not require additional costs or foreign material. The optimum geometry defined in this study helped us to refine our surgical standard produce and to generate more consistent results.