Unilateral tinnitus resulting from single-sided deafness can be treated with electrical stimulation via a CI. The outcomes of this pilot study demonstrate a new method for treatment of tinnitus in select subjects, perhaps an important new indication for cochlear implantation.

Background: While hearing aids for a contralateral routing of signals (CROS-HA) and bone conduction devices have been the traditional treatment for single-sided deafness (SSD) and asymmetric hearing loss (AHL), in recent years, cochlear implants (CIs) have increasingly become a viable treatment choice, particularly in countries where regulatory approval and reimbursement schemes are in place. Part of the reason for this shift is that the CI is the only device capable of restoring bilateral input to the auditory system and hence of possibly reinstating binaural hearing. Although several studies have independently shown that the CI is a safe and effective treatment for SSD and AHL, clinical outcome measures in those studies and across CI centers vary greatly. Only with a consistent use of defined and agreed-upon outcome measures across centers can high-level evidence be generated to assess the safety and efficacy of CIs and alternative treatments in recipients with SSD and AHL. Methods: This paper presents a comparative study design and minimum outcome measures for the assessment of current treatment options in patients with SSD/AHL. The protocol was developed, discussed, and eventually agreed upon by expert panels that convened at the 2015 APSCI conference in Beijing, China, and at the CI 2016 conference in Toronto, Canada. Results: A longitudinal study design comparing CROS-HA, BCD, and CI treatments is proposed. The recommended outcome measures include (1) speech in noise testing, using the same set of 3 spatial configurations to compare binaural benefits such as summation, squelch, and head shadow across devices; (2) localization testing, using stimuli that rove in both level and spectral content; (3) questionnaires to collect quality of life measures and the frequency of device use; and (4) questionnaires for assessing the impact of tinnitus before and after treatment, if applicable. Conclusion: A protocol for the assessment of treatment options and outcomes in recipients with SSD and AHL is presented. The proposed set of minimum outcome measures aims at harmonizing assessment methods across centers and thus at generating a growing body of high-level evidence for those treatment options.

The present large-scale clinical survey revealed current epidemiological trends for idiopathic sudden sensorineural hearing loss (SSNHL) and various factors associated with the severity of hearing impairment and prognosis.

In our cohort of congenital/early-onset SSD (n = 210), the most prevalent cause in children was cochlear nerve deficiency (43.7%; 87 of 199 patients undergoing CT and/or MRI), followed by CMV infection, mumps infection, anomalies of the inner ear, ANSD, and other rare etiologies. In contrast, half of the adult SSD patients presented with idiopathic sensorineural hearing loss, followed by various types of otitis media, cerebellopontine angle tumor and other rare etiologies.

Mutations in the CDH23 gene are known to be responsible for both Usher syndrome type ID (USH1D) and non-syndromic hearing loss (DFNB12), and the molecular confirmation of the CDH23 gene has become important in the diagnosis of these conditions. The present study was performed to find whether the CDH23 mutations are also responsible for non-syndromic hearing loss in patients in the Japanese population. A total of 51 sequence variants were found in 64 Japanese probands with non-syndromic sensorineural hearing impairment from autosomal recessive families. Among them, at least four missense mutations in six patients from five families were confirmed to be responsible for deafness by segregation study. All mutations detected were missense mutations, corroborating the previous reports regarding DFNB12. The present data confirmed that CDH23 mutations are frequently found and significantly responsible in Japanese. Interestingly, the CDH23 mutation spectrum in Japanese is very different from that found in Caucasians. This Japanese spectrum may be representative of those in Eastern Asian populations and its elucidation is expected to facilitate the molecular diagnosis of DFNB12 and USH1D.