Monitoring of motor evoked potentials with high intensity repetitive transcranial electrical stimulation during spinal surgery.
OBJECTIVE
Clinical utility of high voltage repetitive transcranial electrical stimulation (TES) was investigated in 46 patients undergoing spine surgery.


METHODS
During spinal surgery, motor evoked potentials (MEPs) were recorded from upper or lower limb muscles following high voltage repetitive TES of motor cortex under propofol and opioid/N2O anesthesia.


RESULTS
The number of responses evoked by the double pulse stimulation was significantly higher than the single pulse stimulation. A similar finding was obtained when repetitive and single pulse stimulation was compared. Compound muscle action potentials (CMAPs) were recorded from upper and lower limbs in 4 patients with cervical spine myclopathy. The CMAP was absent on the affected side in 1 patient, which improved slightly after decompression. Radiculopathy was clinically present in 6 patients undergoing posterior lumbar decompression and fusion. No improvement of MEP was noted intraoperatively after spinal decompression and instrumentation.


CONCLUSIONS
The findings suggest that intraoperative MEP monitoring is feasible method, however, its immediate prognostic value for adequacy of neuronal decompression and improvement requires further studies with larger patient population.
Haghighi
Siavash S
SS
Clinical Neurodiagnostic Department, Sharp Memorial Hospital, San Diego, California 92123, USA. Siavash.haghighi@sharp.com
D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000368:Aged; D002675:Child, Preschool; D004558:Electric Stimulation / Q000379:methods; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009044:Motor Cortex / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D013131:Spine / Q000601:surgery*