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Major Publication Questions Utility and Value of Neuromonitoring – ASNM Responds!

Posted By Richard W. Vogel, Friday, May 25, 2018

A recent paper published by Hadley et al1 in Neurosurgery claims that IONM has very little utility and value in spine surgery. They base this claim on a rather biased review of the literature and they call it a guideline.

It would all be a hard pill to swallow, but necessary nonetheless, if their observations were objective, if their findings were valid. Unfortunately, what we have come to call The Hadley Paper is little more than a biased repudiation of IONM in spine surgery, written by 4 neurosurgeons who don’t typically use IONM and seem to have little understanding of how it works.

You should have little doubt that this paper graced the inbox, or crossed the desk, of every spine surgeon with whom you work. Make no mistake, your surgeons are talking about it in their circles. We have already observed that some surgeons have discontinued using IONM simply based on this paper alone.

If they haven’t already, your surgeons may raise it as a topic of conversation with you. Whether that happens or not, you must be prepared to proactively educate your surgeons about the flaws in this paper and why it should be summarily dismissed.

The scale of the paper is so large, the reputation of the journal so prestigious, that this paper could have a significant impact on the future of our field. Indeed, many insurance carriers will likely use this paper to deny IONM claims and this could further drive down reimbursements and leave us in ruin.

This is a serious situation, and we want you to be aware of what is going on and what the ASNM is doing to help!

First, Drs. Bryan Wilent (Chair, Research Committee) and Rich Vogel (ASNM President-Elect) started a project last year, approved by the Board, in which the ASNM would write letters to the editor of journals in response to what we call bad literature. We loosely defined bad literature as papers invalidated by serious methodological flaws and having a high enough profile to do significant harm to our profession.

A few papers have come up for discussion, but we didn’t invest the energy because they were low profile and self-published. So, we didn’t write any letters for the first year, and then we saw The Hadley Paper.

Given the obvious and significant negative implications that come from publication of The Hadley Paper, the ASNM wrote our first Letter to the Editor2, on behalf of our membership, to point out some of the most egregious flaws. Incidentally, we weren’t the only Society to write a letter, but we were the first.

If you aren’t able to access The Hadley Paper due to limited institutional permissions, then you should at least read our Letter to the Editor of Neurosurgery. We have permission to post the original on our website.

Incidentally, Hadley and Colleagues respondedto our Letter with what can only be described as an affirmation of what we knew all along: they have little understanding of IONM and how it works. They’ve actually made matters worse by responding to us, and now we’re beginning to hear from spine surgeons around the country who contact us. They say, “[Hadley et al.] don’t speak for us and don’t represent us.”. Perhaps you'll understand why upon reading their reply.

The reader may also find amusing some of their ostentatious claims. As an example, Hadley et al. asserted that one of their authors was an expert because he studied critical appraisal of the medical literature for 5 years. Just to give you some perspective on that claim, of all the authors of the Letter to the Editor that the ASNM wrote, I’m probably one of the most junior by age, and I’ve been studying critical appraisal of the medical and scientific literature for 20 years.

More vexing than amusing is the unsubstantiated claims against the ASNM, made perhaps in an attempt to belittle our society and our profession. For example, Hadley et al. said, [the ASNM] is “perhaps unfamiliar with the rigorous, and sometimes frustrating, peer review process required before endorsement by our specialty societies, which may lead to extensive revisions and in-depth questions regarding statements and approach.” I’m sure this really irritated ASNM President, Dr. Jeff Gertsch, who recently oversaw the rewrite of our Professional Practice Guidelines. Anyway, if Hadley et al. had done a basic search of the literature, or our website, they would have found quite a few such guidelines authored by the ASNM that went through the very same process. 

This brings me to the second thing the ASNM is doing to help. Several of our members are heavily involved in the North American Spine Society (NASS). We now have a Section on Intraoperative Neurophysiological Monitoring. The Section is co-founded and co-chaired by ASNM Member Dr. Adam Doan and ASNM President-Elect Dr. Rich Vogel. Other founding members include Drs. Tony Sestokas, Bob Holdefer and John Ney, among others.

At the 2018 NASS Annual Meeting in Los Angeles, we will have our first symposium on IONM in which we have an objective review of the utility and value of IONM presented by surgeons, neurophysiologists, neurologists and a health policy economist. We will also have an abstract session in which a best paper is chosen.

Other work within NASS includes authoring a coverage policy on IONM, international speaking, and developing webinars and podcasts for 2019. All of this is being done by members of the ASNM, some of whom you elected to the Board. Inter-society cooperation is certainly the way to go!

Anyway, we thank you for taking the time to read this and we strongly recommend you take the time to read our Letter to the Editor. After all, we wrote it for you.

The ASNM is doing lots of things for you, and we hope to use our blog to be better at communicating to keep you in the know. Be sure to subscribe and keep reading!


  1. Hadley MN, Shank CD, Rozzelle CJ, Walters BC. Guidelines for the Use of Electrophysiological Monitoring for Surgery of the Human Spinal Column and Spinal Cord. Neurosurgery. 2017 Nov 1;81(5):713-732.
  2. Vogel R, Balzer J, Gertsch J, Holdefer RN, Lee GR, Moreira JJ, Wilent B, Shils JL. Letter: Guidelines for the Use of Electrophysiological Monitoring for Surgery of the Human Spinal Column and Spinal Cord. Neurosurgery. 2018 Jun 1;82(6):E190-E191.
  3. Hadley MN, Shank CD, Rozzelle CJ, Walters BC. In Reply: Guidelines for the Use of Electrophysiological Monitoring for Surgery of the Human Spinal Column and Spinal Cord. Neurosurgery. 2018 Jun 1;82(6):E192-E193.


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Comments on this post...

Jorge E. Gutierrez says...
Posted Monday, May 28, 2018
Thanks for the letter, it is very important for us. During the upcoming, IFCN sponsored, Latin American symposium of IOM in Bogota, Colombia (nov 14-16) we scheduled a round table about this “dangerous literature” moderated by Francisco Soto (ISIN President), and with the presence of several journal editors like Aatif Husain, Stanley Skinner and David MacDonald.
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Jerry Larson says...
Posted Thursday, May 31, 2018
The thing is.... I would like to think it may be different in other countries, but in the US, there are major problems with IONM. It's not so much that monitoring personnel are competent or diligent, or that
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Jerry Larson says...
Posted Thursday, May 31, 2018
the concept of monitoring is not valid; the problem is mainly with the surgeons, and sometimes anesthesia. A lot of cases are monitored that may not need to be monitored, such as microdisks; many surgeons don't understand how monitoring is supposed to work or how to use the information. For instance, they'll ask for MEP and EMG, and then paralyze for virtually the whole case. They'll rush us when we're trying to set up. They'll argue or ignore what we say. Many surgeons use monitoring for "medico-legal purposes", or because it's expected, without having any interest in the information we provide. IONM is not something that just neuophysiologists do; it requires the cooperation of surgeons and anesthesia personnel, and it's pointless if there's no real risk in the first place, or if the information isn't used appropriately.
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Jerry Larson says...
Posted Thursday, May 31, 2018
Meant to say the issue is not that personnel are NOT competent or diligent, of course.
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Anurag Tewari says...
Posted Monday, July 2, 2018
Could you please emlighten as to the authors reply to the letter when they say "Finally, in the Nuwer7 paper, we reclassified true positive to false positive because we were simply applying strict diagnostic test assessment methodology. An IOM alert followed by no postop deficit is a false positive while an alert in a patient who sustains a deficit is a true positive. We reject the idea that actions taken in response to an alert automatically equate to a deficit averted, which is the optimistic assumption that must be made to justify classifying those cases as true positives."
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