Influence of Tonotopic Cochlear Stimulation on Subjective Visual Vertical – A Pilot Study

Introduction Vestibular dysfunction causes a major socioeconomic burden, and to date, there is no established device for functional vestibular rehabilitation. Cochlear implants (CI) may be able to address this issue through targeted stimulation, as they are known to have vestibular effects. This pilot study aimed to evaluate the effect of tonotopic (basal) stimulation on the Subjective Visual Vertical (SVV) in patients unilaterally treated with a CI.

Materials and Methods Ten adult subjects with profound sensorineural hearing loss, who are implanted with a CI from Advanced Bionics, model HiRes 90KTM or newer, were included in this prospective pilot study in 2020. A specific CI processor (Naída CI Q90) was used to generate five different stimulation modes: simulation of either basal, medial, or apical electrodes, all electrodes on and all electrodes off. The examination of the verticality was carried out using SVV goggles both in the upright body position (head position 0 degrees) and with the head tilted sideways (−30°, −15°, +15°, +30°).

Results In each stimulation mode, there was a significant difference (p-value  < 0.05) in SVV between the straight head orientation and the tilted head position. There were, however, no significant differences between the five CI settings in any given head position. No significant differences could be found regarding the direction of SVV deviation relative to the operated ear.

Conclusions SVV could not be influenced by tonotopic CI stimulation. Different stimulation settings, patterns, and intensity other than the auditory strategy may have to be developed to provide an adequate stimulus to the otolith organs.

Conflict of Interest Der Erstautor weist auf folgenden Interessenkonflikt hin Die Studie wurde von der Firma Advance Bionics unterstützt.

Publikationsverlauf

Artikel online veröffentlicht:
24. Mai 2022