Medical Student Research Fellowship for Summer 2009

Mentor: Daniel J. Sucato, MD MS
Department: TSRH Orthopaedics
Room number:2222 Welborn Street, Dallas, TX 75219
Mail Code:
Phone number: 214-559-8471
E-mail: dan.sucato@tsrh.org
Project title: Combination Learning Curve for the Use of Transcranial Motor Evoked Potentials and Combination Motor Monitoring

Human subjects IRB approved project number (where applicable): Has not been submitted yet.

Animal subjects IRB approved project number (where applicable): n/a

Project Type (patient-based research, animal-based research, or basic research; this characterization is only to permit a general classification for grouping similar types of projects) Chart review (retrospective)

Brief Description of Project:

The goal of spine deformity surgery is to correct and maintain the correction of the deformity over time. It is often necessary to distract a spine which places stress on the spinal cord. Spinal cord monitoring is imperative for the safety of spinal deformity surgery to prevent permanent neurologic deficit. Although the likelihood of developing neurologic deficit intraoperatively and postoperatively is uncommon, the neurologic deficit is our most feared and devastating complication when performing this type of surgery. The original intraoperative neuromonitoring (IONM) utilized somatosensory evoked potentials which monitored the sensory tracks of the spinal cord. The development of neurogenic or mixed motor evoked potentials (MEP) utilized stimulation in the cervical region of the spine and evaluation in the lower extremities. The criticism of this monitoring, however, is that it is not a pure motor track monitoring since stimulation does not start in the motor cortices of the brain. Despite this theoretical disadvantage, there has been great experience with this particular technique in monitoring spinal deformity.

Transcranial MEP was developed to be in more pure motor track evaluation. This, however, requires intravenous anesthetic using propofol, which is somewhat challenging and has a high learning curve. In addition, muscle relaxation cannot be performed in makes surgical treatment more challenging since more muscle forces are present during the surgical procedure. Although most academic centers have moved towards transcranial MEPs, there are some, such as TSRH, who have very good success with neurogenic MEP and have moved toward transcranial more cautiously.

The objective of this study would be to evaluate the learning curve of utilizing transcranial motor evoked potentials which have been in place for three years at TSRH. In addition, many procedures have utilized both neurogenic MEP as well as transcranial MEP and understanding their roles in a dual monitoring situation is important and is part of this project.

Previous Research Activities or Publications with Medical Students:
Long Term Follow Up of Surgically Treated Congenital Spine Deformities

Prospective evaluation of pulmonary functions in pediatric spinal deformity comparing video-assisted thoracoscopic surgery (VATS) with other approaches