Letter: Guidelines for the Use of Electrophysiological Monitoring for Surgery of the Human Spinal Column and Spinal Cord

To the Editor: We were eager to read the review article by Hadley et al1 “Guidelines for the Use of Electrophysiological Monitoring for Surgery of the Human Spinal Column and Spinal Cord.” However, we were quite disappointed. The authors failed to follow their own inclusion and exclusion criteria, so no systematic review was conducted. Without meeting the research bar that the authors set for themselves, their product was highly misleading and not actual research. The article can only be properly appreciated in that light and should have been classified as an opinion or viewpoint rather than original research. Case in point is where the authors cite a Letter to the Editor2 that we wrote expressing some of our concerns regarding the 2012 American Academy of Neurology evidence-based guidelines for Intraoperative Neurophysiological Monitoring (IOM): “Ney and van der Goes, prominent electrophysiologists, do not agree with Nuwer et al on this issue and proposed randomized clinical trials to assess for the therapeutic value of IOM during spinal cord surgery.” First, Hadley et al1 indicate in their methods that letters and commentaries were excluded from the review, but they in fact include this letter. Second, we were misquoted as proposing “randomized clinical trials to assess for the therapeutic value of IOM,” when we actually stated that we were interested in outcomes research by evaluating large observational datasets. Third, we were identified as “prominent electrophysiologists,” when Dr van der Goes is a health economist and Dr Ney is a neurologist and health services researcher. Neither one of us would be considered to be a “prominent electrophysiologist.” Beyond this small point, we noted that our work on cost-effectiveness and outcomes (all referenced in MEDLINE) was ignored in this analysis, when these articles should have been found according to the authors’ search terminology. Included in Hadley et al1 was Traynelis et al,3 which is best referred to as a case series rather than a study, wherein the surgeons did not use IOM, and because no patients had neurological deficits lasting greater than a year, indicated that the medical center saved more than a million dollars in IOM costs. That Traynelis et al3 had no comparator, did not explain by what rationale IOM was not utilized, nor was the study sample adequately powered to detect changes given published cervical spine neurological deficit rates,4 were also not mentioned. Hadley et al1 did not include our published cost-consequences model of IOM in spine surgery,5 wherein we conclude that IOM costs $63 387 (95% confidence interval $61 939, $64 836) per neurological deficit avoided, nor our cost-benefit analysis which demonstrates that IOM is cost-saving over the patient's lifetime for surgeries with a baseline risk of neurological injury of 0.3% or greater.6 Furthermore, Hadley et al1 reference the paper by James et al7 which looked at the very rare incidence of ICD-9 coding for iatrogenic nerve root injury (20/400 000) in spine surgeries with and without IOM to state that IOM should not be used with “simpler surgeries.” In this, Hadley et al1 ignored our analysis of IOM in noncomplex spinal surgeries showing a benefit to IOM in reduced neurological complications (odds ratio = 0.60, 95% confidence interval) in the same nationally representative administrative database used by James et al.8 The cited literature demonstrates a substantial and unacknowledged bias which could mislead surgeons to follow purported “Guidelines” from their leading journals. Much uncertainty remains in the effectiveness of a therapy which is dependent not only on the neurophysiologist to detect abnormalities but also the operative team to appropriately act on the information the neurophysiologist provides. But that lack of evidence should not be construed as evidence of lack of effect. Both neurophysiologists and spinal surgeons should have great interest in future research to reduce this uncertainty and provide unbiased and accurate evidence-based guidelines for use of IOM in spinal surgery. The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.