The grades of recommendations (standards, guidelines, and options) and classes of evidence (I–III) are defined at the end of the "Major Recommendations" field.
Diagnostic Recommendations
Standards. There is insufficient evidence to recommend a treatment standard.
Guidelines. Use of intraoperative somatosensory evoked potential (SSEP) or dermatomal sensory evoked potential (DSEP) monitoring is recommended as an adjunct in those circumstances during instrumented lumbar spinal fusion procedures in which the surgeon desires immediate intraoperative information regarding the potential of a neurological injury. The occurrence of a postoperative neurological deficit is highly correlated with intraoperative changes in these monitoring modalities. An abnormal SSEP or DSEP during surgery, however, often does not correlate with a postoperative neurological injury because of a high false-positive rate.
Use of intraoperative evoked electromyography (EMG) recordings is recommended in those circumstances in which the operating surgeon wishes to confirm the lack of a neurological injury during pedicle screw placement. A normal evoked EMG response is highly predictive of the lack of a neurological injury. An abnormal EMG response during the surgical procedure may or may not be associated with a clinically significant injury.
Options. Intraoperative evoked EMG recording is recommended as an option during lumbar spinal fusion surgery in those situations in which the operating surgeon desires immediate information regarding the integrity of the pedicle wall, as a normal evoked EMG response is correlated with an intact pedicle wall.
Therapeutic Recommendations
Standards. There is insufficient evidence to recommend a treatment standard.
Guidelines. There is insufficient evidence to recommend a treatment guideline.
Options. Intraoperative SSEP, DSEP, EMG, and/or evoked EMG monitoring are recommended only as adjunctive options during instrumented lumbosacral fusion procedures for degenerative spinal disease. The use of any of these modalities has not been convincingly demonstrated to influence patient outcome favorably.
Summary
Based on the medical evidence provided by the literature reviewed, there does not appear to be support for the hypothesis that any form of intraoperative monitoring improves patient outcomes following lumbar decompression or fusion procedures for degenerative spinal disease. Evidence does indicate that a normal evoked EMG response is predictive for intrapedicular screw placement (high negative predictive value [NPV] for breakout). The presence of an abnormal EMG response does not, however, exclude intrapedicular screw placement (low positive predictive value [PPV]). The majority of clinically apparent postoperative nerve injuries are associated with intraoperative changes in SSEP and/or DSEP monitoring. For this reason, changes in DSEP/SSEP monitoring appear to be sensitive to nerve root injury. There is a high-false positive rate, however, and changes in DSEP and SSEP recordings are frequently not related to nerve injury. A normal study has been shown to correlate with the lack of a significant postoperative nerve injury. There is no substantial evidence to indicate that the use of intraoperative monitoring of any kind provides useful information to the surgeon in terms of assessing the adequacy of nerve root decompression at the time of surgery.
Definitions:
Grades of Recommendation
Standards Recommendations of the strongest type, based on Class I evidence reflecting a high degree of clinical certainty
Guidelines Recommendations based on Class II evidence reflecting a moderate degree of clinical certainty
Options Recommendations based on Class III evidence reflecting unclear clinical certainty
Classes of Evidence
Class I Evidence from one or more well-designed, randomized controlled clinical trials, including overviews of such trials
Class II Evidence from one or more well-designed comparative clinical studies, such as nonrandomized cohort studies, case-control studies, and other comparable studies, including less well-designed randomized controlled trials
Class III Evidence from case series, comparative studies with historical controls, case reports, and expert opinion as well as significantly flawed randomized controlled trials