Abstract
Introduction: In patients who have had meningitis, application of cochlear implants can be difficult due to fibrosis or ossification of the inner ear. Insertion of an electrode may be complicated by a non-patent cochlear lumen due to new bone formation.
Objective: The purposes of this study were to identify the outcomes of cochlear implantation in patients with profound hearing loss caused by meningitis and to compare the outcomes in those with and without cochlear osteogenesis.
Methods: Among 390 adult patients who received cochlear implants between 1985 and 2013, 27 patients with a history of meningitis received 30 cochlear implants. The backgrounds of the patients and the outcomes during and after the operation were investigated. Speech performance was evaluated with threshold and Japanese speech perception tests.
Results: The age at which the patients contracted meningitis ranged from 0.9 to 66 years, and the age at implantation ranged from 23 to 68 years. The causative factors were bacterial in 14 cases, abacterial in one case, viral in two cases, and unknown in 10 cases. The cochleae were ossified in five cases, fibrotic in five cases, and normal in 20 cases. The electrodes were fully inserted in all but two cases. The average threshold with a cochlear implant was 36.5dB, and speech perception of Japanese words and sentences was 32.0% and 46.1%, respectively.
Conclusions: Patients with postmeningitic deafness benefit significantly from cochlear implantation. However, the audiologic outcomes are difficult to predict in some cases, particularly in the presence of ossification.
