The Outcomes of Cochlear Implantation in Usher Syndrome: A Systematic Review

Abstract

Objective: To systematically appraise the implementation of cochlear implantation (CI) in Usher Syndrome (USH) Types 1, 2, and 3 patients, and analyze who would benefit from CI. Data Sources: A comprehensive search of PubMed, Embase, CINAHL, and Cochrane Library electronic databases from inception through June 2020 was performed. There were no language restrictions. Study Selection: The PRISMA strategy was followed. Included studies discuss USH patients who underwent CI regardless of age, nationality, or clinical subtype. All included studies report post-implantation functional, cognitive, or quality of life outcomes. Only reviews were excluded. Results: Fifteen studies met the inclusion criteria. USH patients experienced improvements in PTA and speech perception and expression outcomes after CI, as well as improvements in phonological memory and quality of life measures. Overall, patients implanted at younger ages outperformed older patients in audiological testing. Similarly, patients with prolonged auditory deprivation had relatively poor performance outcomes in sentence recognition and speech detection following CI. Conclusions: Most USH patients benefit from CI. USH patients who undergo CI at younger ages generally achieve better hearing, speech, and cognitive outcomes. CI at older ages can still prove beneficial if appropriate auditory amplification is started at the right time. Further research is warranted to fill the gap in understanding regarding the gene mutations underlying the pathophysiology of USH that have favorable CI outcomes as well as the optimal time to perform CI.

The Enigmatic Genetic Landscape of Hereditary Hearing Loss: A Multistep Diagnostic Strategy in the Italian Population

“…In these cases, the identification of the correct molecular diagnosis before the onset of vision loss is fundamental to prompt a specific clinical follow-up. For instance, periodic ophthalmological evaluations should be planned and, whenever patients develop severe progressive HL with poor speech discrimination and communication difficulties even with hearing aids, making these children excellent cochlear implant candidates, surgery should be performed before the onset of ocular problems to maximise communication skills [ 41 ]. In the SHL group, Patient 41 came to the geneticist’s attention at 48 years of age and had already developed vision loss together with HL: in this case, the clinical diagnosis was straightforward and thus confirmed by the molecular one.…”

Usher Syndrome

“…For example, it has been reported that patients with DFNB2 have been subsequently investigated and diagnosed for mild RP. Nevertheless, “age at surgery” is the most important prognostic factor [ 58 , 59 , 60 ]. Ineligible cases till surgery or poor outcomes of CIs may benefit from tactile and sign language [ 61 ].…”

The genetic and phenotypic landscapes of Usher syndrome: from disease mechanisms to a new classification

“…Patients with Usher syndrome may benefit from the fitting of hearing aids or cochlear implants, which can partially alleviate auditory sensory deprivation (for review see Davies et al 2021). Gene replacement with AAVs of various serotypes has been successfully used to replace four Usher genes in mouse models; USH1C (Landegger et al 2017;Pan et al 2017), USH1G (Emptoz et al 2017), USH2D (Chien et al 2016;Isgrig et al 2017) and USH3A (Dulon et al 2018;Geng et al 2017;Gyorgy et al 2019).…”