Objective To determine the influence of the presence of auditory neuropathy spectrum disorder (ANSD) on speech, language, and psycho-social development of children at three years of age. Design A population-based, longitudinal study was performed on outcomes of children with hearing impairment (LOCHI) in Australia. The demographic characteristics of the children were described, and their developmental outcomes were evaluated at three years of age. Performance of children with ANSD was compared with that of children without ANSD in the LOCHI study. Study sample There were 47 children with ANSD in the study sample. Results Sixty-four percent of children with ANSD have hearing sensitivity loss ranging from mild to severe degree, and the remaining have profound hearing loss. At three years, 27 children used hearing aids, 19 used cochlear implants, and one child did not use any hearing device. Thirty percent of children have disabilities in addition to hearing loss. On average, there were no significant differences in performance level between children with and without ANSD. Also, the variability of scores was not significantly different between the two groups. Conclusions There was no significant difference in performance levels or variability between children with and without ANSD, both for children who use hearing aids, and children who use cochlear implants.

ABBREVIATIONS ABR Auditory brainstem reflexes ANSD Auditory neuropathy spectrum disorder BVVL Brown-Vialetto-Van Laere syndrome OAE Otoacoustic emissions AIM Mutations in the genes encoding the riboflavin transporters RFVT2 and RFVT3 have been identified in Brown-Vialetto-Van Laere syndrome, a neurodegenerative disorder characterized by hearing loss and pontobulbar palsy. Treatment with riboflavin has been shown to benefit individuals with the phenotype of RFVT2 deficiency. Understanding the characteristics of hearing loss in riboflavin transporter deficiency would enable early diagnosis and therapy. METHOD We performed hearing assessments in seven children (from four families) with RFVT2 deficiency and reviewed results from previous assessments. Assessments were repeated after 12 months and 24 months of riboflavin therapy and after cochlear implantation in one individual. RESULTS Hearing loss in these individuals was due to auditory neuropathy spectrum disorder (ANSD). Hearing loss was identified between 3 years and 8 years of age and progressed rapidly. Hearing aids were not beneficial. Riboflavin therapy resulted in improvement of hearing thresholds during the first year of treatment in those with recent-onset hearing loss. Cochlear implantation resulted in a significant improvement in speech perception in one individual. INTERPRETATION Riboflavin transporter deficiency should be considered in all children presenting with an auditory neuropathy. Speech perception in children with ANSD due to RFVT2 deficiency may be significantly improved by cochlear implantation. Brown-Vialetto-Van Laere syndrome (BVVL) is a progressive neurodegenerative disorder characterized by hearing loss and pontobulbar palsy. 1 Recently, mutations in SLC52A2 and SLC52A3, encoding the riboflavin transporters RFVT2 and RFVT3 respectively, have been identified in a number of individuals with BVVL. 2,3 The phenotype of individuals with RFVT2 deficiency includes hearing loss and sensory ataxia with an onset in early childhood , followed by progressive upper limb weakness, optic atrophy, bulbar weakness, and respiratory failure. 4 While the clinical phenotype of children with BVVL due to RFVT2 deficiency has been reported in detail, the characteristics of the hearing loss have not been explored, despite it often being a presenting or early feature in affected individuals. Reports of individuals with RFVT2 deficiency and of genetically undifferentiated cohorts of individuals with BVVL classify the hearing impairment as a 'sen-sorineural hearing loss' without a clear description of its characteristics. 1,4 Functional studies have demonstrated that SLC52A2 mutations reduce riboflavin transporter expression and riboflavin uptake. 4,5 Riboflavin is critical for the biosynthe-sis of flavin mononucleotide and flavin adenine dinu-cleotide, important cofactors for carbohydrate, amino-acid, and lipid metabolism. Flavin adenine dinucleotide acts as an electron acceptor in acyl-CoA dehydrogenation reactions in mitochondrial fatty acid b-oxidation and bra...

We investigated the acceptability of electrophysiologically derived MAPs and the effect of these MAPs on speech perception in elderly adults using Nucleus 24 cochlear implants. Eight implant recipients aged 75 years or older trialed an electrophysiologically derived MAP and a behavioral MAP. The electrophysiologically derived MAP was based on the threshold and maximum comfort level for electrode 10 and evoked compound action potential thresholds measured on six electrodes using neural response telemetry (NRT). Word perception at 55 dB SPL and sentence perception in noise at 70 dB SPL were assessed after six weeks take-home experience and again after an additional two weeks of experience. During the final two weeks of take-home experience participants indicated their preferred MAP for different listening situations. The NRT derived MAP estimated behavioral T levels well, but underestimated behavioral C levels for apical electrodes in some subjects. Speech perception with NRT derived MAPs was comparable to speech perception with behaviorally measured MAPs. MAPs estimated from NRT data provided good speech perception outcomes for elderly implant recipients and were well tolerated.

Delaying amplification until VRA results were available would have led to a significant period of auditory deprivation for infants in this study group. None of the assessments could accurately determine hearing thresholds when used in isolation, however when used in combination clinicians were able to obtain sufficient information to fit hearing aids early, and identify infants requiring closer monitoring.