The preoperative measurements of auditory nerve diameters from MRT predict postoperative speech perception in adult patients with cochlear implantation (CI)

Introduction Previous studies have shown that implantation age, history of hearing aid use, cognitive ability, preoperative speech perception, the status of auditory nerve affect the postoperative speech perception. Of which, the status of auditory nerve is one of the crucial factors. The current MRT imaging can clearly display the auditory nerve from modiolus to cerebellopontine angle and thus might allow to detect tiny pathological changes. This study test whether objective measurements of the auditory nerve based on preoperative MRI images correlate with the postoperative speech perception in patients with CI.

Methods In total, 48 patients were recruited into this study. The auditory nerve area (FNC) and the volume of the modiolus (VM) were measured from preoperative MRI images. Postoperatively, speech perception, word recognition scores (WRS) and speech recognition thresholds (SRT) were obtained at four different time points i.e., on 2-day, 1 month, 3 months and 6 months after the first activation of CI processor.

Results A statistical positive correlation between the FNC and WRS on the 2-day after first activation of CI processor were detected (R=0,39, p<0,020). This correlation disappeared in the follow-ups. In addition, a similar trend was also found between VW and WRS, but without statistical significance. Last but not least, there is no difference between the ears with CI and the opposite ears in terms of FNC and VM.

Conclusion The preoperative FNC correlated with postoperative WRS on the 2-day after first activation of CI processor in patients with CI. However, the FNC and VM cannot be used to predict the auditory nerve status mainly because there are no differences between the ear with CI and the opposite ears from the same patients.

Publication History

Article published online:
19 April 2024