MRI biomarkers of success of cochlear implant therapy in patients with acquired deafness

Details

Supervisors

Macq, Benoît ; Dricot, Laurence

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil biomédical, à finalité spécialisée

Abstract

enAcquired hearing loss is a major public health concern that can be partially mitigated through cochlear implantation. However, post-implantation outcomes vary greatly between individuals. This thesis aims to evaluate the predictive value of white matter microstructural integrity on auditory performance after cochlear implantation, using diffusion magnetic resonance imaging (dMRI). The study includes 65 implanted patients for whom audiometric scores, such as Auditory Word Recognition Score (AWRS) and Deggouj-Wathour test (DEWA), were collected pre-operatively, and at 6 and 12 months post-implantation. Pre-operative diffusion MRI scans were used to perform probabilistic tractography and extract diffusion tensor imaging (DTI) metrics from white matter tracts involved in speech comprehension and audiovisual integration. Significant correlations were observed between DEWA scores and specific diffusion metrics (mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD)) within the left posterior Arcuate Fasciculus (AF) and the right Inferior Fronto-Occipital Fasciculus (IFOF), particularly at the pre-operative and 6-month stages. No significant associations were found at 12 months or with score evolution over time. A cluster-based analysis identified subregions, such as external capsule and the left superior temporal region, specifically associated with performance, highlighting the relevance of localized microstructural assessment. These findings suggest that diffusion MRI may help predict cochlear implant outcomes in patients with acquired hearing loss and support more personalized clinical decision-making.