An effective intra-operative neurophysiological monitoring scheme for aneurysm clipping and spinal fusion surgeries

J Neural Eng. 2012 Apr;9(2):026021. doi: 10.1088/1741-2560/9/2/026021. Epub 2012 Mar 15.


Somatosensory-evoked potentials (SSEPs) have been widely used for intra-operative neurophysiological monitoring (IONM). Currently at least 200-300 trials are required to generate a readable SSEP signal. This study introduces a novel approach that yields accurate detection results of the SSEP signal yet with a significantly reduced number of trials, resulting in an effectual monitoring process. The analysis was performed on data recorded in seven patients undergoing surgery, where the posterior tibial nerve was stimulated and the SSEP response was recorded from scalp electroencephalography using two bipolar electrodes, C(3)-C(4) and C(Z)-F(Z). The proposed approach employs an innovative, simple yet effective algorithm based on a patient-specific Gaussian template to detect the SSEP using only 30 trials. The time latencies of the P37 and N45 peaks are detected along with the peak-to-peak amplitudes. The time latencies are detected with a mean accuracy greater than 95%. Also, the P37 and N45 peak latencies and the peak-to-peak amplitude were found to be consistent throughout the surgical procedure within the 10% and 50% acceptable clinical limits, respectively. The results obtained support the assertion that the algorithm is capable of detecting SSEPs with high accuracy and consistency throughout the entire surgical procedure using only 30 trials.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Aged
  • Algorithms
  • Artifacts
  • Child
  • Data Interpretation, Statistical
  • Electric Stimulation
  • Electroencephalography
  • Evoked Potentials, Somatosensory / physiology
  • Female
  • Humans
  • Intracranial Aneurysm / surgery*
  • Male
  • Middle Aged
  • Monitoring, Intraoperative / instrumentation*
  • Monitoring, Intraoperative / methods*
  • Monitoring, Physiologic
  • Neurophysiology / instrumentation*
  • Neurophysiology / methods*
  • Neurosurgical Procedures / instrumentation*
  • Neurosurgical Procedures / methods*
  • Normal Distribution
  • Reproducibility of Results
  • Retrospective Studies
  • Spinal Fusion / methods*
  • Tibial Nerve / physiology