Intraoperative motor response monitoring
Intraoperative motor response monitoring
Surgical procedures near the spinal cord carry a risk of neurological damage. To reduce this risk, intraoperative neurophysiological monitoring (IONM) is used to assess nerve function in real time. A commonly used technique is transcranial electrical stimulation to measure muscle motor evoked potentials (Tc-mMEPs). However, these signals are highly variable, which can lead to false warnings and unnecessary surgical interruptions.
This thesis of Maria Gadella aims to improve the reliability of Tc-mMEP monitoring and reduce false positive alerts. Part I investigates optimal stimulation parameters and electrode types. Surface electrodes were found to be a safe and effective alternative to needle electrodes. Part II focuses on the influence of anesthesia. Depth of anesthesia significantly affects Tc-mMEP signals, especially in leg muscles, suggesting that current reference practices may need revision. Part III explores additional motor responses, such as H-reflexes and F-waves, which appear more stable under anesthesia and may provide complementary information.
The findings contribute to improved guidelines for neurophysiological monitoring during spinal surgeries. Future research should focus on standardizing stimulation protocols, refining anesthetic management, and integrating late motor responses into IONM.