Objective measures of Cochlear Implant (CI) outcome as assessed by a synergistic use of combined Electroencephalography (EEG) and Positron Emission Tomography (PET)

Introduction (background / research question) Despite decades of optimization, understanding speech with cochlear implants (CIs) remains variable, especially in complex listening scenarios. Combining electroencephalography (EEG) and positron emission tomography (PET) with O-15 water enables an objective study of neural correlates of speech perception, leveraging the high spatial resolution of the PET and the high temporal resolution of the EEG.

Material and methods This ongoing study includes patients with high (≥70%) and low (≤30%) speech discrimination ability as assessed by the performance in the Hochmair-Schulz-Moser (HSM) sentence test in noise. During the PET acquisitions, EEG data is recorded while the patients perform a sentence discrimination task with sentences containing a final word that is either semantically correct or incorrect. This task is performed with and without background noise.

Results The preliminary results show a performance rate of≥81%, indicating that the CI users were able to perform the task. The same participants revealed a distinct P1-N1-P2 complex in both conditions (with and without background noise). Furthermore, an effect of background noise can be observed, manifesting as a reduction in amplitude and an increase in latency of the P1-N1-P2 complex.

Conclusion / Discussion The preliminary results are of clinical interest because they prove the feasibility of a multimodal diagnostic approach combining PET and EEG in CI users. They also give important insights into the neural correlates of speech processing in high- and low-performing CI users, thus contributing to the better understanding of the high variability in CI outcome.

Funding information Deutsche Forschungsgemeinschaft (DFG) - SA 3615/3-1 (project number: 471410050)

 

Scroll to top

Publikationsverlauf

Artikel online veröffentlicht:
19. April 2024