Preoperative MRI, audiovisual speech perception, and mood are associated with cochlear implant outcomes in adults with postlingual deafness

Acquired severe to profound hearing loss is an increasingly challenging problem of our aging population. Cochlear implantation (CI) is the gold standard treatment for this advanced form of sensory deprivation. Despite the overall satisfactory results of CI, a substantial number of patients show unsatisfactory outcomes. This study aims to improve current predictive models of CI outcome by integrating preoperative MRI with behavioral data. We acquired a 3D T1 MRI to measure cortical thickness (CT) and volume using surface-based analysis and parcellation from the Brainnetome atlas. CI success at 6 months post-implant, as measured by audiovisual speech perception, was correlated with preoperative speech and audiovisual perception with hearing aids, and residual hearing, especially at the side of the non-implanted ear. In addition, CI outcome correlated positively with CT of the left superior temporal gyrus and sulcus, left inferior frontal region, and bilateral superior frontal regions. The volume of the left middle frontal gyrus and regions of the parietal lobe, especially at the left side, also correlated with CI outcome. Linear regression models revealed that CI outcome was best predicted by the combination of preoperative measures of audiovisual speech perception, residual hearing, depression and CT. Our results highlight the importance of preserved brain areas implicated in hearing, language, audiovisual integration, and cognitive functions for CI success. Furthermore, brain MRI in conjunction with other predictors can help to identify patients who may need more time to adjust to the CI, allowing a more tailored rehabilitation, and potentially greater efficacy.