Investigating the Changes in Somatosensory Evoked Potential Waveforms during Surgery Based on Electrical Stimulation Parameter Settings

This study examined the effects of stimulation parameters on the induced waveforms of somatosensory evoked potentials (SSEPs) during intraoperative neurophysiological monitoring and identified optimal stimulation conditions with high clinical reliability. The stimulus intensities were set to 5, 10, 15, 20, 25, and 30 mA, with a fixed averaging time of 200 and a stimulation frequency of 4.7 Hz. The averaging cycles were set to 100, 300, 500, 700, and 1,000. The stimulation intensities were 1.5 mA for the upper extremities, 25 mA for the lower extremities, and a fixed stimulation frequency of 4.7 Hz. The stimulation frequency was set to 3.7, 4.7, 5.7, 6.7, and 7.7 Hz, the stimulation intensity was fixed at 15 mA for the upper extremities and 25 mA for the lower extremities, and the averaging was set to 200 cycles for analysis. This study identified the optimal stimulation parameters applicable to SSEP testing, including stimulation intensities of 18.75 mA and 25.75 mA for the upper and lower extremities, respectively, an averaging of 100 cycles, and a stimulation frequency of 4.7 Hz, as clinically helpful in improving the accuracy of intraoperative neuromonitoring and standardizing testing.