title: Transcranial motor evoked potential monitoring outcome in the high-risk brain and spine surgeries: Correlation of clinical and neurophysiological data - An Indian perspective.
abstract: OBJECTIVE
  The objective of this study is to assess the safety, feasibility and clinical value of transcranial motor evoked potential (MEP) monitoring by electrical stimulation.
  
  
  METHODS
  Clinical neurophysiology department of tertiary reach hospital.
  
  
  METHODS
  MEP monitoring was attempted in 44 "high risk" patients. Intraoperative surgical, anesthesia and neurophysiological findings were documented prospectively. MEP monitoring results were correlated with motor outcome.
  
  
  RESULTS
  The success for reliable MEP recording from the lower limbs was 75%. Incidence of new permanent post-operative motor deficit was zero. Nearly, 76.5% of the cases (13 out of 17 cases) who showed unobtainable and unstable MEP outcome had lesion location in the spine as compared with 23.5% (4 out of 17 cases) that had lesion location in the brain. Chi-square test demonstrated a statistically significant difference between these two groups (P = 0.0020). Out of these 13 spine surgery cases, 8 (62%) were operated for deformity. Seven out of 12 (60%) patients less than 12 years of age had a poor MEP monitoring outcome suggesting that extremes of age and presence of a spine deformity may be associated with a lesser incidence of successful MEP monitoring. No complications related to the repetitive transcranial electrical stimulation for eliciting MEP were observed.
  
  
  CONCLUSIONS
  MEP monitoring is safe. The protocol used in this study is simple, feasible for use and has a fairly high success rate form the lower limbs. Pediatric age group and spine lesions, particularly deformities have an adverse effect on stable MEP recording.
authors: Department of Clinical Neurophysiology, Centre for Brain and Nervous System, Kokilaben Dhirubhai Ambani Hospital and Medical Research Centre, Mumbai, Maharashtra, India.
authors: Poornima Amit
authors: PA
authors: Shah
keywords: Clinical and neurophysiological correlation; high-risk cases; motor evoked potential