title: Dorsal root entry zone microcoagulation for spinal cord injury-related central pain: operative intramedullary electrophysiological guidance and clinical outcome.
abstract: OBJECTIVE
  Surgically created lesions of the spinal cord dorsal root entry zone (DREZ) to relieve central pain after spinal cord injury (SCI) have historically resulted in modest outcomes. A review of the literature indicates that fair to good relief of pain is achieved in approximately 50% of patients when an empirical procedure is performed. This study was undertaken to determine if intramedullary electrical guidance in DREZ lesioning could improve outcomes in patients with SCI-induced central pain. Additionally, electrical data were used to determine if the spinal cord could be somatotopically mapped with regard to this pain of central origin.
  
  
  METHODS
  Forty-one patients with traumatic SCI and intractable central pain underwent DREZ lesioning in which intramedullary electrical guidance was conducted. In nine patients, recording of DREZ-related spontaneous electrical hyperactivity guided the lesioning process. In 32 patients, recording of DREZ-induced evoked electrical hyperactivity during transcutaneous C-fiber stimulation (TCS) additionally guided lesioning. The follow-up period ranged from 1 to 7 years. The analyzed electrical data allowed for somatotopic mapping of the spinal cord.
  
  
  CONCLUSIONS
  Intramedullary electrical guidance of DREZ lesioning substantially improves pain outcomes in patients with traumatic SCI-induced central pain, compared with an empiric technique. The best outcome occurs when DREZ-related spontaneous electrical hyperactivity and evoked hyperactivity during TCS are both used to guide the DREZ lesioning procedure. With such guidance, 100% relief of pain was achieved in 84% of patients and 50 to 100% relief of pain in 88%. Somatotopic mapping of the electrical data led to a proposed pain mechanism for below-level pain, implicating the sympathetic nervous system.
authors.affiliation: Department of Neurosurgery, Physical Medicine and Rehabilitation, Craig Hospital, Englewood, Colorado, USA. spfalci@aol.com
authors.forename: Scott
authors.initials: S
authors.lastname: Falci
authors.forename: Lavar
authors.initials: L
authors.lastname: Best
authors.forename: Rick
authors.initials: R
authors.lastname: Bayles
authors.forename: Dan
authors.initials: D
authors.lastname: Lammertse
authors.forename: Charlotte
authors.initials: C
authors.lastname: Starnes
mesh_terms: D000328:Adult; D000368:Aged; D002422:Causalgia / Q000503:physiopathology / Q000601:surgery*; D004564:Electrocoagulation; D004568:Electrodiagnosis; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008866:Microsurgery; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010149:Postoperative Pain / Q000503:physiopathology / Q000601:surgery*; D012086:Reoperation; D012684:Sensory Thresholds / Q000502:physiology; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000601:surgery*; D013126:Spinal Nerve Roots / Q000503:physiopathology / Q000601:surgery*