LAUSR

The purpose of this study was to see if the rate of usage of each modality was the same between geographic regions. Demographic information (age, gender, and region within the United States) as well as clinical information (type of intraoperative neuromonitoring and rates of alerts) were assessed. A total of 841 patients with an average age of 61 yr (range 12-88 yr) had intraoperative neuromonitoring during minimally invasive spine surgery (MIS) LLIF/XLIF procedures. A total of 314 were from the Southeast and 527 from the Northeast. Overall, alerts for each modality occurred at different rates (P < .05). Between regions, there was no difference in motor evoked potential (MEP) alerts (P = .83) but electromyography (EMG) and somatosensory evoked potential (SSEP) alerts occurred at different rates, with both alerts seen more frequently in the Northeast, (P < .05). Four cases had an alert occur in 2 modalities, 2 cases had SSEP and EMG alerts, and 2 other cases had SSEP and MEP alerts. No common cause was found to trigger any of the alerts. The rate of usage for all 3 monitoring modalities was different between regions as MEP and SSEP were used more often in the Northeast and EMG was used more often in the Southeast. This regional variation indicates potential opportunity for standardization of monitoring indications. Although the alerts for each modality were seen at different rates, an alert from one modality was rarely seen in the same case as an alert from a different modality. In the few instances with alerts from more than one modality within the same case, the alerts did not seem to have the same cause. Because of this, utilizing different intraoperative neuromonitoring modalities has the potential to increase detection of potential neurologic injury.