VESTIBULAR STIMULATION BY MULTICHANNEL COCHLEAR IMPLANTS

The recipient of a Nucleus 22 multichannel cochlear implant began to e xperience severe vestibular stimulation related to the implant, This p atient's experience initiated a study with the objective of determinin g the frequency of implant-related vestibuloocular stimulation, Subjec ts consisted of 17 randomly selected patients who use cochlear implant s, Included in the study were 14 Nucleus 22 and three Med-El Combi 40- devices. Stimulation of the implants was performed both by individual channel and with sound field broad-band 80-dB noise using the users' n ormal device settings, Eye movements were monitored with infrared vide onystagmography. Only one subject, who used a Med-El Combi 40, showed a consistent and strong ocular response to cochlear stimulation but ha d no subjective symptoms, The authors conclude that vestibulo ocular a ctivation is possible with multichannel cochlear implants but is infre quent and may not be clinically significant.