Hearing Rehabilitation in Patients with SERAC1 Related MEGD(H)EL Syndrome

Abstract

Background SERAC1 related MEGD(H)EL syndrome is a rare but regularly severely disabling and progressive inborn metabolic disease characterized by 3-methylglutaconic aciduria, dystonia and deafness, encephalopathy, (hepatopathy) and a Leigh syndrome-like presentation. Knowledge on hearing rehabilitation in affected individuals is scarce but important for being a possible therapeutic intervention in many cases. We investigated the details of hearing impairment and response to hearing rehabilitations in 35 MEGD(H)EL patients. Methods Retrospective, cross-sectional study. Results A total of 35 patients from sixteen international centres were included for analysis. Bilateral hearing loss was reported in 30 patients (30/35, 85%). In patients, representing the mild end of the spectrum of MEGD(H)EL syndrome with juvenile onset of symptoms, hearing impairment appeared not to be a compellent symptom. Both cochlear and retro-cochlear hearing loss was diagnosed. Fifteen patients, all with pre-lingual hearing loss, were treated with conventional hearing aids, five patients with cochlear implants. None of the patients with hearing rehabilitation, neither hearing aids, nor cochlear implant, developed spoken language. The only benefit reported, independent from type of rehabilitation, was an improved awareness to environmental sounds. Conclusion Valid audiometric data in patients with MEGD(H)EL syndrome was limited, therefore, definite characterization of type of hearing loss in the whole group was not possible. However, hearing rehabilitation with conventional hearing aids was possible and should be offered to all patients, knowing that spoken language seems not to be achievable. Likewise, cochlear implants seem to offer limited additional benefit.