title: Intraoperative neurophysiological monitoring of the cortico-spinal tract in image-guided mini-invasive neurosurgery.
abstract: OBJECTIVE
  To evaluate the role of intraoperative neurophysiological monitoring in image-guided mini-invasive neurosurgery.
  
  
  METHODS
  Twenty-one patients were operated under general anaesthesia with the aid of multimodal intraoperative neurophysiological monitoring to remove supratentorials tumors closely related to the cortico-spinal tract. Pre-operative assessment included fMRI scans and tractography that were uploaded into the intraoperative neuro-navigation system. Monitoring consisted in simultaneously recording EEG, electrocorticography, transcranial and direct motor evoked potentials (tMEP and dMEP), somatosensory evoked potentials and subcortical stimulation during the whole procedures.
  
  
  RESULTS
  The recording of all the electrophysiological signals was possible in all procedures. SSEP guided the positioning of the strip electrode over the motor cortex (N20 phase inversion) that was used to evoke dMEP and monitor the lower limb motor responses; subcortical stimulation to unveil the spatial relationship between the tumors and motor fibers. Four patients had transient worsening of the symptoms, but only two had a long-term worsening, although not severe, of the pre-op clinical status.
  
  
  CONCLUSIONS
  Intraoperative neurophysiology has a great value in mini-invasive neurosurgery, especially because the motor cortex is not exposed, consequently it cannot be directly mapped. This report describes a valuable scheme making use of as many electrophysiological signals as possible to constantly monitor the motor functions.
  
  
  CONCLUSIONS
  A useful method to monitor motor functions in mini-invasive neurosurgery was described.
authors.affiliation: Dept. of Neurosurgery, Fondazione IRCCS Neurologico C. Besta, Milan, Italy. rcordella@istituto-besta.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Cordella
authors.forename: Francesco
authors.initials: F
authors.lastname: Acerbi
authors.forename: Morgan
authors.initials: M
authors.lastname: Broggi
authors.forename: Davide
authors.initials: D
authors.lastname: Vailati
authors.forename: Vittoria
authors.initials: V
authors.lastname: Nazzi
authors.forename: Marco
authors.initials: M
authors.lastname: Schiariti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Tringali
authors.forename: Paolo
authors.initials: P
authors.lastname: Ferroli
authors.forename: Angelo
authors.initials: A
authors.lastname: Franzini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Broggi
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000601:surgery; D056324:Diffusion Tensor Imaging; D004558:Electric Stimulation; D004569:Electroencephalography; D004576:Electromyography; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000294:innervation / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D016343:Monitoring, Intraoperative / Q000009:adverse effects / Q000379:methods*; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods*; D011712:Pyramidal Tracts / Q000033:anatomy & histology* / Q000502:physiology / Q000601:surgery*; D013120:Spinal Cord Neoplasms / Q000601:surgery; D025321:Surgery, Computer-Assisted / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome; D034941:Upper Extremity / Q000294:innervation / Q000502:physiology