Updated Practice Guidelines for IOM - an important step in the right direction
Eva K.Ritzl, Director of IOM, Johns Hopkins Universityeritzl1@jhmi.edu
Eva K. Ritzl, Baltimore, MD
Submitted March 19, 2012
I read Nuwer et al. [1] as well as the comments by Drs. Ney and van der Goes [2] with interest. I applaud the AAN for endorsing an updated practice guideline that highlights the importance of intraoperative signal changes as a marker for neurologic injury during spine surgeries. Establishing that signal changes during spine surgeries reliably detect (impending) neurologic injury can only be achieved by showing that IOM correctly predicts neurologic deficit, as was done here. Randomized studies addressing the question of whether or not use of intraoperative neuromonitoring is able to prevent neurologic disability are clearly unethical. The data Nuwer et al. have compiled are therefore the logical and important first step towards evidence based guidelines for IOM:
1. A signal change predicts a neurologic deficit (see updated Practice Guidelines for IOM);
2. The signal change occurs during the surgery, in time for corrective action to be taken.
3. A permanent spinal cord injury can be avoided if the signal recovers with the corrective action. (This is the logical conclusion if 1 and 2 are correct.)
4. Permanent spinal cord injury incurs a very high cost (in dollars as well as in human suffering). Nuwer et al. did not consolidate the best but rather the most stringent evidence available on the use of evoked potentials during spinal operations. In the data compiled [1], IOM predicted an outcome that would have otherwise been revealed immediately after the surgery. But this is not the point. The point is that neurophysiologist, surgeons and all other members of the operating team need to know with confidence that a signal change implies real danger to the patient's neural structures. This review provides further important evidence that they can.
1. Nuwer MR, Emerson RG, Galloway G, et al. Evidence-based guideline update: Intraoperative spinal monitoring with somatosensory and transcranial electrical motor evoked potentials: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and the American Clinical Neurophysiology Society. Neurology 2012;78:585-589.
2. Ney JP, van der Goes DN. Updated Practice Guidelines for IOM Fall Short. Letter re Nuwer et al.[1]Available at: http://www.neurology.org/content/78/8/585/reply#neurology_el_46009. Accessed March 15, 2012.
For disclosures, contact the editorial office at journal@neurology.org.
I read Nuwer et al. [1] as well as the comments by Drs. Ney and van der Goes [2] with interest. I applaud the AAN for endorsing an updated practice guideline that highlights the importance of intraoperative signal changes as a marker for neurologic injury during spine surgeries. Establishing that signal changes during spine surgeries reliably detect (impending) neurologic injury can only be achieved by showing that IOM correctly predicts neurologic deficit, as was done here. Randomized studies addressing the question of whether or not use of intraoperative neuromonitoring is able to prevent neurologic disability are clearly unethical. The data Nuwer et al. have compiled are therefore the logical and important first step towards evidence based guidelines for IOM:
1. A signal change predicts a neurologic deficit (see updated Practice Guidelines for IOM);
2. The signal change occurs during the surgery, in time for corrective action to be taken.
3. A permanent spinal cord injury can be avoided if the signal recovers with the corrective action. (This is the logical conclusion if 1 and 2 are correct.)
4. Permanent spinal cord injury incurs a very high cost (in dollars as well as in human suffering). Nuwer et al. did not consolidate the best but rather the most stringent evidence available on the use of evoked potentials during spinal operations. In the data compiled [1], IOM predicted an outcome that would have otherwise been revealed immediately after the surgery. But this is not the point. The point is that neurophysiologist, surgeons and all other members of the operating team need to know with confidence that a signal change implies real danger to the patient's neural structures. This review provides further important evidence that they can.
1. Nuwer MR, Emerson RG, Galloway G, et al. Evidence-based guideline update: Intraoperative spinal monitoring with somatosensory and transcranial electrical motor evoked potentials: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and the American Clinical Neurophysiology Society. Neurology 2012;78:585-589.
2. Ney JP, van der Goes DN. Updated Practice Guidelines for IOM Fall Short. Letter re Nuwer et al.[1]Available at: http://www.neurology.org/content/78/8/585/reply#neurology_el_46009. Accessed March 15, 2012.
For disclosures, contact the editorial office at journal@neurology.org.