title: Non-invasive high voltage electrical stimulation as a monitoring tool of nerve root function in lumbosacral surgery.
abstract: OBJECTIVE
  To verify the safety and clinical use of non-invasive high-voltage electrical stimulation (HVES) in patients with compressive radiculopathy. To test the feasibility of HVES to survey nerve root function during lumbosacral surgery.
  
  
  METHODS
  In 20 patients undergoing lumbosacral surgery for degenerative spinal diseases, compound muscle action potentials (CMAPs) evoked by maximal HVES were bilaterally recorded throughout surgery from L3 to S2 radicular territories. A preliminary study was performed in awake patients to rule out detrimental effects caused by HVES.
  
  
  RESULTS
  Preoperative study confirmed the safety of HVES. Unexpectedly, a transient but significant remission of pain was observed after root stimulation. Intraoperative monitoring (IOM) was accomplished in all patients. HVES never hindered surgical procedures and never caused mechanical damage within the operatory field. In 4 patients acute, highly focal and reversible conduction failure was promptly detected by HVES in radicular territories congruent with the root manipulated at that moment.
  
  
  CONCLUSIONS
  HVES is a safe and sensitive tool to monitor nerve root function in lumbosacral surgery.
  
  
  CONCLUSIONS
  The method is based on the assumption that any acute conduction failure occurring during surgery can be immediately and unambiguously detected by HVES if root stimulation is supramaximal and delivered rostral to the surgical level.
authors.affiliation: Neurology II and Laboratory of Clinical Neurophysiology, Department of Neuroscience, University of Turin, Turin, Italy. wtroni@yahoo.com
authors.forename: Walter
authors.initials: W
authors.lastname: Troni
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Benech
authors.forename: Rossella
authors.initials: R
authors.lastname: Perez
authors.forename: Stefano
authors.initials: S
authors.lastname: Tealdi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Berardino
authors.forename: Franco
authors.initials: F
authors.lastname: Benech
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D000758:Anesthesia; D004558:Electric Stimulation / Q000379:methods*; D004566:Electrodes; D004576:Electromyography; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000601:surgery; D008161:Lumbosacral Region / Q000502:physiology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009046:Motor Neurons / Q000502:physiology; D009469:Neuromuscular Junction / Q000502:physiology; D019635:Neurosurgical Procedures / Q000379:methods*; D010147:Pain Measurement; D011300:Preoperative Care; D011843:Radiculopathy / Q000473:pathology / Q000601:surgery; D012984:Software; D013117:Spinal Cord Compression / Q000601:surgery; D013126:Spinal Nerve Roots / Q000502:physiology*