A new application for the sympathetic skin response: the evaluation of auditory thresholds in cochlear implant patients

Objectives: Cochlear implants (CI) are now widely used in patients with profound sensorineural deafness. Determining threshold levels for each CI electrode is required during the initial postoperative tuning session. While behavioral testing is appropriate in post-lingually deafened patients, it may be really tricky in pre-lingually deafened children. CI stimulation is responsible for auditory perception and logically induces brainstem reticular formation arousal which can be studied by sympathetic skin response (SSR). Methods: Thirteen patients (aged 3–70 years) implanted with an MXM Digisonic® were postoperatively studied. SSR as well as behavioral thresholds were recorded after electrical stimulation of CI electrodes at various intensities. Results: SSR could be recorded in all patients including the 6 studied children. There was a strong correlation between SSR threshold and subjective auditory threshold (r=0.93). Conclusions: The present data indicate that SSR could have a clinical application as a routine test in postoperative fitting procedures of CIs especially in pre-lingually deafened children.