SLC26A4 p.Thr410Met homozygous mutation in a patient with a cystic cochlea and an enlarged vestibular aqueduct showing characteristic features of incomplete partition type I and II

Outcomes of Cochlear Implantation in Patients with Pendred syndrome: A Systematic Review and Narrative Synthesis

Establish outcomes following cochlear implantation (CI) in patients with Pendred syndrome. Systematic review and narrative synthesis. Databases searched: Medline, Pubmed, Embase, Web of Science, Cochrane Collection and ClinicalTrials.gov. No limits placed on language or year of publication. Review conducted in accordance with the PRISMA statement. Searches identified 251 abstracts and 242 full texts. Of these, 22 studies met inclusion criteria reporting outcomes in 231 patients with at least 234 implants. Hearing outcomes were generally good with patients experiencing useful functional improvement. A total of 46 minor complications were reported in 78 cases. The methodological quality of included studies was modest, predominantly consisting of case reports and non-controlled case series with small numbers of patients. All studies were OCEBM grade III-IV. Hearing outcomes following CI in Pendred syndrome are generally good with useful functional improvement. However, outcomes reported in published studies lack long term follow up.

Outcomes of cochlear implantation for the patients with specific genetic etiologies: a systematic literature review

CONCLUSION

Most of the cases with gene mutations of intra-cochlear etiology showed relatively good CI outcomes. To progress toward more solid evidence-based CI intervention, a greater number of reports including CI outcomes for specific gene mutations are desired.

BACKGROUND

Cochlear implantation (CI) is the most important and effective treatment for patients with profound sensorineural hearing loss. However, the outcomes of CI vary among patients. One of the reasons of this heterogeneous outcome for cochlear implantation is thought to be the heterogeneous nature of hearing loss. Indeed, genetic factors, the most common etiology in severe-to-profound hearing loss, might be one of the key determinants of outcomes for CI and electric acoustic stimulation (EAS). Patients with genetic causes involving an 'intra-cochlear' etiology show good CI/EAS outcomes.

REVIEW

This review article aimed to summarize the reports on CI/EAS outcomes in patients with special genetic causes as well as to assist in future clinical decision-making. Most of the cases were suspected of an intra-cochlear etiology, such as those with GJB2, SLC26A4, and OTOF mutations, which showed relatively good CI outcomes. However, there have only been a limited number of reports on patients with other gene mutations.

Cochlear Implantation in Inner Ear Malformations: Systematic Review of Speech Perception Outcomes and Intraoperative Findings

Objective

(1) To analyze reported speech perception outcomes in patients with inner ear malformations who undergo cochlear implantation, (2) to review the surgical complications and findings, and (3) to compare the 2 classification systems of Jackler and Sennaroglu.

Data Sources

PubMed, Scopus (including Embase), Medline, and CINAHL Plus.

Review Methods

Fifty-nine articles were included that contained speech perception and/or intraoperative data. Cases were differentiated depending on whether the Jackler or Sennaroglu malformation classification was used. A meta-analysis of proportions examined incidences of complete insertion, gusher, and facial nerve aberrancy. For speech perception data, weighted means and standard deviations were calculated for all malformations for short-, medium-, and long-term follow-up. Speech tests were grouped into 3 categories—closed-set words, open-set words, and open-set sentences—and then compared through a comparison-of-means t test.

Results

Complete insertion was seen in 81.8% of all inner ear malformations (95% CI: 72.6-89.5); gusher was reported in 39.1% of cases (95% CI: 30.3-48.2); and facial nerve anomalies were encountered in 34.4% (95% CI: 20.1-50.3). Significant improvements in average performance were seen for closed- and open-set tests across all malformation types at 12 months postoperatively.

Conclusions

Cochlear implantation outcomes are favorable for those with inner ear malformations from a surgical and speech outcome standpoint. Accurate classification of anatomic malformations, as well as standardization of postimplantation speech outcomes, is necessary to improve understanding of the impact of implantation in this difficult patient population.