Auditory Dysfunction Among Individuals With Neurofibromatosis Type 1

Key Points Question Is neurofibromatosis type 1 (NF1) associated with auditory neural dysfunction and functional hearing consequences? Findings In this case-control study of 44 individuals with NF1 and 44 matched control participants, 1 in 4 participants with NF1 showed evidence of auditory neural dysfunction, and 1 in 3 presented with abnormal functional hearing (speech perception). Diffusion-weighted magnetic resonance imaging analysis showed that participants with NF1 had significantly lower apparent fiber density within the ascending tracts of the brainstem. Meaning The findings of this study suggest that auditory dysfunction severe enough to impede developmental progress in children and restrict communication in older participants is a common neurobiological feature of NF1.
This cohort study investigates auditory neural dysfunction and its perceptual consequences in individuals with neurofibromatosis type 1.
Importance Neurofibromatosis type 1 (NF1) affects hearing through disruption of central auditory processing. The mechanisms, functional severity, and management implications are unclear. Objective To investigate auditory neural dysfunction and its perceptual consequences in individuals with NF1. Design, Setting, and Participants This case-control study included children and adults with NF1 and control participants matched on age, sex, and hearing level. Patients were recruited through specialist neurofibromatosis and neurogenetic outpatient clinics between April and September 2019. An evaluation of auditory neural activity, monaural/binaural processing, and functional hearing was conducted. Diffusion-weighted magnetic resonance imaging (MRI) data were collected from a subset of participants (10 children with NF1 and 10 matched control participants) and evaluated using a fixel-based analysis of apparent fiber density. Main Outcomes and Measures Type and severity of auditory dysfunction evaluated via laboratory testing and questionnaire data. Results A total of 44 participants (18 [41%] female individuals) with NF1 with a mean (SD) age of 16.9 (10.7) years and 44 control participants (18 [41%] female individuals) with a mean (SD) age of 17.2 (10.2) years were included in the study. Overall, 11 participants (25%) with NF1 presented with evidence of auditory neural dysfunction, including absent, delayed, or low amplitude electrophysiological responses from the auditory nerve and/or brainstem, compared with 1 participant (2%) in the control group (odds ratio [OR], 13.03; 95% CI, 1.59-106.95). Furthermore, 14 participants (32%) with NF1 showed clinically abnormal speech perception in background noise compared with 1 participant (2%) in the control group (OR, 20.07; 95% CI, 2.50-160.89). Analysis of diffusion-weighted MRI data of participants with NF1 showed significantly lower apparent fiber density within the ascending auditory brainstem pathways. The regions identified corresponded to the neural dysfunction measured using electrophysiological assessment. Conclusions and Relevance The findings of this case-control study could represent new neurobiological and clinical features of NF1. Auditory dysfunction severe enough to impede developmental progress in children and restrict communication in older participants is a common neurobiological feature of the disorder.