Somatosensory- and motor-evoked potential monitoring without a wake-up test during idiopathic scoliosis surgery. An accepted standard of care.
METHODS
This was a retrospective study of 500 patients undergoing corrective surgery between 1987 and 1997 for spinal deformity caused by idiopathic scoliosis.


OBJECTIVE
To report the sensitivity and specificity of somatosensory-evoked and neurogenic motor-evoked potentials monitoring and the requirements for an intraoperative wake-up test for all idiopathic scoliosis surgeries at a single institution.


BACKGROUND
Intraoperative monitoring is recommended for use during corrective spinal surgery. Accepted monitoring standards and requirements for an intraoperative wake-up test are still debated.


METHODS
The study group consisted of 500 patients undergoing corrective surgery for idiopathic scoliosis between 1987 and 1997. All patients were monitored using somatosensory-evoked and neurogenic motor-evoked potential techniques, using a standard protocol developed at this institution.


RESULTS
The false-positive rate (significant data change without postoperative neurologic deficit) was 0.014% (n = 7). The true-positive rate (degradation of data that met warning criteria, with a corresponding postoperative neurologic deficit) was 0.004% (n = 2). No false-negative results (normal data during with a postoperative neurologic deficit) were seen. The sensitivity of combined somatosensory-evoked and neurogenic motor-evoked potential data in predicting neurologic status was 98.6%, and the specificity of normal data predicting normal findings in a neurologic examination was 100%.


CONCLUSIONS
Combined somatosensory-evoked and neurogenic motor-evoked potentials monitoring during idiopathic scoliosis surgery represents a standard of care that obviates the need for an intraoperative wake-up test when reliable data are obtained and maintained.
Padberg
A M
AM
Department of Orthopaedic Surgery, Washington University Medical Center, St. Louis, Missouri, USA.
Wilson-Holden
T J
TJ
Lenke
L G
LG
Bridwell
K H
KH
D000293:Adolescent; D000328:Adult; D002648:Child; D019054:Evoked Potentials, Motor; D005073:Evoked Potentials, Somatosensory; D005189:False Positive Reactions; D006801:Humans; D016343:Monitoring, Intraoperative / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012600:Scoliosis / Q000601:surgery*; D012680:Sensitivity and Specificity