Introduction: Resection of motor eloquent lesion has become safer due to intraoperative neuromapping and -monitoring (IOM). Subcortical MEP stimulation (scMEP) is been increasingly used to increase patients´ safety even further. So far, scMEP is been performed intermittently during the resection of motor eloquent lesions
Methods: An ultrasonic aspirator was connected to the IOM stimulator and was used as a monopolar subcortical stimulation probe during the resection of subcortical lesions in the near vicinity of the corticospinal tract (CST) in 12 consecutive cases. During resection, the stimulation current at which an MEP response was still elicitable with scMEP using the surgical aspirator was compared to the corresponding stimulation current needed using a standard monopolar probe at the same position of stimulation.
Results: scMEP using the surgical aspirator or standard monopolar probe was successful in all cases. Motor mapping and MEP threshold was identical for both modalities. There were no new permanent postoperative motor deficits. A transient new postoperative motor deficit was observed in 17% (2/12) of cases
Conclusions: Continuous motor tract mapping using the ultrasonic aspirator as a monopolar subcortical stimulation probe is a feasible and safe method for localizing the location and distance to the CST. This method of continuous stimulation provides better temporal and spatial mapping capabilities compared to a standard subcortical stimulation using a separate stimulation probe and the necessity to change instruments between resection and mapping.
Patient Care: Can improve patient safety during the resection of motor eloquent lesions.
Learning Objectives: The participant will be introduced to a novel use of intraoperative monitoring, that might increse patient's safety during the resection of motor eloquent lesions