Cochlear implant failure: diagnosis and treatment of soft failures

Objective. Early diagnosis of cochlear implant failures (CIF) is a critical part of post-im-plantation follow-up. Diagnosis is challenging and time consuming. Our study aimed to describe diagnoses of CIF with emphasis on soft failures (SF), focusing on symptoms, time from symptoms to replacement, and differences between SF and hard failures (HF). Methods. A retrospective review of medical records in a tertiary care referral paediatric medical centre including all patients who experienced CIF during 2000-2020. Results. Of 1004 CI surgeries, 72 (7.2%) cases of CIF were included, of which 60 CIF were in children (mean age 3.1 years). Twenty-five cases were due to HF, 26 SF, and 21 due to medical reasons. Patients with SF were more likely to present with headache, dizziness, or tinnitus compared with those with HF. Facial stimulation and disconnections were more common in implants from Advanced Bionics, dizziness and tinnitus in Cochlear, and poor progression in Med-El. Mean time from symptoms to implant replacement surgery was longer in cases with SF compared to HF. Conclusions. SF poses a diagnostic challenge. Symptoms such as headache, dizziness, and tinnitus are common. Diagnosis of failure should often be based on assessments of the implant and rehabilitation teams.