title: Comparison of Motor-Evoked Potentials Versus Somatosensory-Evoked Potentials as Early Indicators of Neural Compromise in Rat Model of Spinal Cord Compression.
abstract: METHODS
  Randomized controlled study comparing the efficacy of intraoperative somatosensory-evoked potentials (SSEPs) versus transcranial motor-evoked potentials (TcMEPs) as early indicators of neural compromise and predictors of postoperative function in a rat model of spinal cord compression.
  
  
  OBJECTIVE
  To compare the relative efficacy of SSEPs and TcMEPs to detect spinal cord compromise and predict postoperative functional deficit after spinal cord compression.
  
  
  BACKGROUND
  There is controversy regarding the efficacy of SSEPs versus TcMEPs to detect intraoperative spinal cord compromise and predict functional outcomes. Previous trials provide some guidance as to the role of each modality in spinal cord monitoring but randomized controlled trials, which are not feasible in humans, are lacking.
  
  
  METHODS
  Twenty-four adult male Wistar rats were evenly divided into three experimental groups and one control group. The experimental groups were determined according to the length of time that 100% TcMEP signal loss was maintained: 0, 5, or 15 minutes. All animals had standardized preoperative functional testing. Spinal cord compromise was initiated utilizing a validated protocol, which involved compression via a balloon catheter introduced into the thoracic sublaminar space. Both SSEPs and TcMEPs were recorded during cord compression for each experimental group. Functional behavioral testing using two validated methods (tilt and modified Tarlov) was repeated 24 hours after termination of spinal cord compression. Post hoc, animals were redistributed into two functional subgroups, noncompromised and compromised, for statistical analysis.
  
  
  RESULTS
  TcMEPs consistently detected spinal cord compromise either in advance of or at the same time as SSEPs; however, the delay in SSEP response was not significant for cases when compromised postoperative function resulted. Both SSEP and TcMEP amplitude recovery correlated well with postoperative functional scores.
  
  
  CONCLUSIONS
  TcMEPs are more sensitive to spinal cord compromise than SSEPs, but the recovery profiles of both SSEP and TcMEP amplitudes are good predictors of postoperative function.
  
  
  METHODS
  2.
authors: IWK Health Centre, Halifax, Nova Scotia.|Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada.
authors: Susan H
authors: SH
authors: Morris
authors: Division of Paediatric Orthopaedics, Sidra Medical and Research Center, Doha, Qatar.
authors: Jason J
authors: JJ
authors: Howard
authors: IWK Health Centre, Halifax, Nova Scotia.|Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada.
authors: Ron
authors: R
authors: El-Hawary
mesh_terms: D000818:Animals; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D023421:Models, Animal; D016343:Monitoring, Intraoperative / Q000379:methods; D017208:Rats, Wistar; D013116:Spinal Cord / Q000503:physiopathology* / Q000601:surgery; D013117:Spinal Cord Compression / Q000503:physiopathology* / Q000601:surgery