Motor evoked potentials during brain surgery.
In order to obtain a robust method for intraoperative monitoring of motor pathways, different stimulation patterns to elicit muscle motor evoked potentials (MEPs) were studied during neurosurgical procedures in 3 patients. MEPs were recorded by a catheter electrode in the subdural space and/or by needle electrodes in limb muscles. For stimulation single pulses and trains consisting of two to five pulses were used. Muscle MEPs were only obtained after trains of at least 3 stimuli while single/double stimuli were inefficient. Simultaneous subdural recordings showed that single and double stimuli only elicited D-waves, whereas trains of 3 or more stimuli generated I-waves, as well. We propose that train stimulation can overcome the depressive effects of anesthesia on cortical motoneurons.
Rodi
Z
Z
University Institute of Clinical Neurophysiology, Ljubljana University Medical Centre, Slovenia.
Deletis
V
V
Morota
N
N
Vodusek
D B
DB
D001921:Brain / Q000601:surgery*; D004558:Electric Stimulation; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D006801:Humans; D009044:Motor Cortex / Q000502:physiology*; D009132:Muscles / Q000294:innervation / Q000502:physiology