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In the Literature: MEPs in Infants

Posted By W. Bryan Wilent, PhD, DABNM, FASNM, Friday, January 31, 2020
Updated: Wednesday, January 29, 2020

In the Literature: MEPs in Infants

 

IONM plays a critical role in pediatric spinal procedures. Preserving motor function is of paramount importance in any surgical procedure, but it is especially precious when the patient is an infant. There are, however, unique challenges and sensitivities associated with the IONM of infants; it is not uncommon for surgeons and surgical neurophysiologists to have questions regarding optimal MEP technique and the overall feasibility of MEPs.

 

There are three papers from this year that demonstrate the utility of MEPs in infants of less than 3 months age. Here are FOUR Key Insights from the papers and from Alier Franco, PhD, an author on the Flanders et al study and the manager of the IONM service at the Children’s Hospital of Philadelphia. 

 

1. MEPs can be safely performed and obtained at any age

  • Yi et al obtained MEPs in at least one extremity in 24 of 25 infants from 1.5 months to 3 months of age.
  • Aydinlar obtained MEPs in 15 infants from 1.5 months to under 12 months (average age 5.8 months) with at least one monitorable muscle from both upper and lower extremities in all infants.
  • Flanders et al set the bar illustrating robust MEPs in an infant at 15 days of life!

 

Thus, it has been shown that MEPs can safely and effectively be performed in infants at essentially any age.  There is no evidence to contraindicate MEPs from a safety perspective or data showing that MEPs cannot be obtained because of early age. 

 

2. The display window may need to be widened (200-300 ms) because of delayed responses

 

As illustrated in Flanders et al, the latency for lower extremity MEPs may be >100 ms, which is beyond the typical display window used for MEPs in adolescents or adults. This occurs because of the combination of pathology and a still maturing nervous system with slower conduction velocities. If responses from the lower extremities are absent at baseline using a 100 ms window, the window should be expanded to check for responses that are delayed.

 

3. TIVA and anesthesia management are critical

 

Continuous communication with anesthesia and titrating TIVA in concert with hemodynamic management ensure optimal conditions for reliable neonatal evoked potentials. The presence of any residual inhalational agents can significantly impede the reliability of MEPs throughout the procedure. High doses of propofol are often needed at induction with neonates and infants, but concentrations should be titrated to minimal safe levels throughout the course of the procedure. Awareness of decreases in core body temperature, to which infants are susceptible, is also important, as this cooling can significantly affect morphology, latency, and (in extreme cases) the monitorability of evoked potentials. 

 

 

4. Will often have to vary the stimulation parameters and use higher intensities

 

When using constant voltage technique for MEPs, intensities of >500V are often needed, and that is assuming a high train count, i.e. > 7 pulses and a pulse width up to 75 microsec. Regarding the optimal ISI, 2 ms (500 Hz) is effective and lower ISIs such as 1 ms (1000 Hz) are typically less effective, but note however, that neonates and early infants can sometimes require longer ISIs such as 5 ms (200 Hz) train and/or double train stimulation. Overall, baseline monitorability can be highly dependent on stimulus parameters and thus varying stimulus parameters is sometimes critical. 

 

References: 

 

  • Flanders TM, Franco AJ, Hines SJ, Taylor JA, Heuer GG, “Neonatal intraoperative neuromonitoring in thoracic myelocystocele: a case report.”, Child Nerv Syst, 2019, Nov 10
  • Aydinlar EI, Dikmen PY, Kocak M, Baykan N, Seymen N, Ozek MM, “Intraoperative Neuromonitoring of Motor-Evoked Potentials in Infants Undergoing Surgery of the Spine and Spinal Cord”, J Clinic Neurophys, 2019, 36 (1): 60-66
  • Yi YG, Kim K, Shin HI, Bang MS, Kim HS, Choi J, Wang KC, Kim SK, Lee JY, Phi JH, Seo HG, “Feasibility of intraoperative monitoring of motor evoked potentials obtained through transcranial electrical stimulation in infants younger than 3 months”, J Neurosurg Pediatr. 2019 Mar 15:1-9. 

 

Disclaimer: 

 

The views, thoughts, and opinions expressed in this blog post  are solely those of the author(s). Blog posts do not represent the thoughts, intentions, strategies or policies of the author’s employer or any organization, committee or other group or individual, including the ASNM. The ASNM, along with the author(s) of this post, makes no representations as to the completeness, accuracy, suitability, validity, usefulness or timeliness of any information in this blog and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. Any action you may take based upon the information on this website is strictly at your own risk.

 

Tags:  In the Literature 

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In the Literature: Technical Tips: A Checklist for Responding to Intraoperative Neuromonitoring Changes

Posted By Scott Mohr, BS, CNIM, MBA, Wednesday, January 29, 2020

Article Title: Technical Tips: A Checklist for Responding to Intraoperative Neuromonitoring Changes. 

 

The Big Question:

 

How can checklists enhance a neuromonitoring team’s response to changes in patient neurophysiologic data? The Duke Health System neurodiagnostic department recently published an article detailing their experiences coordinating the entire surgical team with an action-oriented checklist. The checklist - based off of the Vitale format - establishes defined roles and responses for each member of the surgical team, which are initiated once the neuromonitoring technologist reports a change in patient data (Vitale, et al. 2014). The Duke experiment provides the neuromonitoring community with a promising example of a neuromonitoring program effectively integrated with the surgical team.  This paper provides some evidence that working from a shared script can allow rapid and focused response to significant surgical events.

 

Background:

 

The positive impact of checklist practices in healthcare has been well documented since Dr. Atul Gawande published his landmark book The Checklist Manifesto.  When a health care team can develop uniform, standardized protocols for repeatable tasks, best practices develop which leave less room for error, omission, and confusion.  In essence, employing a checklist format can help prevent failure, which was a main tenet of Dr. Gawandes’ publication (Gawande, 2010).

 

Opportunities for failure abound when the neuromonitoring team identifies a change in data during a surgical procedure.  The oversight physician and the neuromonitoring personnel need to jointly identify the event, communicate the change to the surgical team, and work to troubleshoot possible technical causes, while maintaining timely documentation of the events.  Without education and awareness about the value of neuromonitoring data in critical situations, confusion and disregard can delay rapid interventions by the surgeon or the anesthesia team, which could negatively impact patient outcome.

 

The Duke team was looking to establish a uniform format that assigned everyone in the operating room a role once a neuromonitoring data change was announced.  Once the checklist was initiated by the neuromonitoring technologist in the room, each person would know their role in addressing the change.  For example, if the technologist reported a loss of motor responses, the anesthesiologist would take steps to prepare for a possible wakeup test.  The surgeon could reverse any surgical manipulations (if relevant), all while the technologist would work through the listed steps to troubleshoot technical components and optimize data collection.

 

Method:

            

The authors employed the Vitale checklist, published as a best practice for neuromonitoring reporting during spinal surgery.  The Vitale checklist was published in 2014 after a research team headed up by Dr. Michael Vitale sought to establish a consensus-based set of guidelines for reporting neuromonitoring changes in a format that coordinated the response of the surgical team as as whole.  The checklist resulted from extensive literature review and surveying of over 20 neurosurgeons.  The format was initially applied to standard, low-risk spinal procedures.

 

The Vitale checklist functions by breaking the OR team up into four categories based on their role.  These are Control of Room (head circulating nurse), Anesthetic/Systemic (head anesthesiologist and primary anesthesia provider), Technical/Neurophysiologic (the neurotechnologist and their oversight physician, and finally, Surgical (the surgeon and scrubbed personnel).  The checklist provides a defined response role for each category if the technologist reports a data change.

 

The first step for the Duke program was education and awareness for the surgical teams that would participate - the checklist format was only effective with full compliance from all personnel in the operating room.  In addition to training meetings, each member of the surgical team was given a copy of the Vitale checklist.  Each neuromonitoring platform had a copy of the checklist, and a laminated copy was posted to each operating room involved in the study.  The cases involved were entirely composed of spinal procedures.

 

Once a change was announced during a procedure by the technologist, the circulator (Control of Room) would read the steps out loud to the room.  Having a central coordinator providing verbal cues reduces confusion and enhances teamwork during the tense moments of a patient status change. 

 

Most all of the steps were standardized to a point where each team member could readily anticipate the actions of others.  The technologist, for example, would know that in response to a loss of cortical amplitude, the anesthesia provider would work to treat blood pressure and raise the mean pressure.  

 

The sample size for the study was 9 surgical participants (though the study does not make clear if this number refers to surgeons, surgical teams, or neuromonitoring personnel).  After an undisclosed duration for the study, participants were surveyed for their impressions and feedback.

 

Results:

 

A post-implementation survey of the 9 participants resulted in 100% of the sample population reporting the Vitale checklist clarified their role during a neuromonitoring data change, and respondents were more confident that the practice would lead to improved safety and efficiency.  Survey reports reveal the surgical staff feel the checklist streamlined their response to critical events when every moment counts.  The Duke neuromonitoring program reported at the time of this writing that they continue to revise and customize the checklist implementation in response to the continued feedback they have received.

 

Discussion:

 

What are some key takeaways from this report for the neuromonitoring community?  Dr. Gawande wrote that checklist practices enhance consistency of care and reduces errors born from omission and confusion (Gawande, 2010).  The ability to be confident in the next practical step you take - and predict your teammates’ actions - leads to a higher rate of success when time is critical and each decision carries greater weight on the patient’s outcome.

The Duke neuromonitoring department harnessed the mechanics of the Vitale checklist with these goals in mind.  They discovered the benefits of implementing these practices; faster response times, enhanced coordination of the surgical team, and reduced technical error.  An added benefit was the checklist itself as a documentation tool; the recording of actions and data collection provide an accurate and concise report for the surgeon after the surgery.  

 

Neuromonitoring organizations must continue to drive awareness and engagement in operating room culture and surgical workflow.  What the Duke team is doing here is an excellent example for our field; they are involving their team in upstream staff education and downstream surgeon follow-up while becoming actively involved in surgical event management during a patient status change.  This level of play is neuromonitoring at its best - the Duke team is part of the patient care experience, not a backup system sitting behind the anesthesia cart with a laptop.

            

There are some questions left to be answered after this report.  A sample size of 9 is a good start, but too small to draw confident conclusions about the impact of the Vitale Checklist.  Furthermore, the paper reports that “100% [of participants] agreed that the checklist positively impacted patient safety and case efficiency” (Rendahl and Hey, 2019).  Reports of 100% success in unquantifiable reporting often reflects an element of group think  - everyone involved in the practice felt like the checklist format was a good idea and was helpful to their daily practices in the operating room.  While this sentiment is encouraging, it doesn’t give the neuromonitoring community much to learn from.  In healthcare, we learn from systems and practices when they break, where they fail.  It would be helpful to read more about where this system went wrong, and whether or not a dissenting opinion could shed light on components of the protocol that could change for the better.

 

Dr. Gawande’s book mentions a study at Johns Hopkins that ties into current Surgical Time Out practices.  The study notes that when, at the beginning of the procedure, each nurse in the room was given the chance to state their name and any concerns they had before the procedure began, the participants were more likely to note potential problems and offer up viable solutions, leading to better outcomes.  Researchers dubbed this an ‘activation phenomenon’, and the empowerment experienced by the nurses in the Johns Hopkins study is reflected in the Duke neuromonitoring department’s checklist experiment (Gawande, 2009).  The neuromonitoring community will continue to benefit from checklist best practices such as this encouraging report.

 

References:

  1. Rendahl R, Hey LA. Technical Tips: A Checklist for Responding to Intraoperative Neuromonitoring Changes. The Neurodiagnostic Journal, 2019; 59:2, 77-81.
  2.  Gawande, A. (2010). The checklist manifesto: How to get things right. New York: Metropolitan Books.
  3.  Rebecca Rendahl & Lloyd A. Hey (2019) Technical Tips: A Checklist for Responding to Intraoperative Neuromonitoring Changes, The Neurodiagnostic Journal, 59:2, 77-81,
  4.  Vitale MG, Skaggs DL, Pace GI, Wright ML, Matsumoto H, Anderson RCE, Brockmeyer DL, Domans JP, Emans JB, Erickson MA, et al. 2014. Best practices in intraoperative neuromonitoring in spinedeformity surgery: development of an intraoperative checklist to optimize response. Spine Deform.2(5):333–339.

 

Disclaimer: 

 

The views, thoughts, and opinions expressed in this blog post  are solely those of the author(s). Blog posts do not represent the thoughts, intentions, strategies or policies of the author’s employer or any organization, committee or other group or individual, including the ASNM. The ASNM, along with the author(s) of this post, makes no representations as to the completeness, accuracy, suitability, validity, usefulness or timeliness of any information in this blog and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. Any action you may take based upon the information on this website is strictly at your own risk.

Tags:  In the Literature 

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In the Literature: IONM of RLN During Thyroidectomy with Adhesive Skin Electrodes

Posted By Scott Mohr, CNIM, MBA, Friday, December 20, 2019

Article Review/Summary: Intraoperative Neuromonitoring of Recurrent Laryngeal Nerve During Thyroidectomy with Adhesive Skin Electrodes

The Big Question:

Can gel-based adhesive dermal electrodes serve as a suitable alternative to Nerve Integrity Monitor (NIM) endo-trachial (ET) tubes during Recurrent Laryngeal (RLN) monitoring for thyroidectomy procedures?  A research team based out of multiple institutes in the Republic of Korea joined forces to determine just that.  The strengths and limitations they discovered during their exploration invites further investigation into what could be a cost-effective and less-invasive alternative to standard NIM ET tube usage.

 

Background:

The IONM community can play a strong supporting role in ENT procedures such as thyroidectomies.  As cited in this paper, a former meta analysis support the position that RLN monitoring during thyroidectomies adds value to the surgical procedure; rapid and accurate identification of nerve tissue, reduction of vocal cord paralysis and overall improved surgical technique.  Monitoring of the RLN - a branch of cranial nerve X which innervates the intrinsic muscles of the larynx - is generally accomplished with electrodes either built into or adhesed to an ET tube and placed by intubation.  

However, this method offers certain complications.  Some anesthesiology programs have concerns about the size and potential esophageal damage NIM ET tubes can cause, and this concern extends to the brands of adhesive pads which are attached to the exterior of an ET tube prior to patient intubation.  Furthermore, NIM ET tubes can move during surgical manipulations or due to anesthesia team activity, leading to poor contact between the vocal folds and NIM ET tube, resulting in loss of signal (LOS).  

Finally, certain patient populations - such as difficult airway patients and certain pediatric cases - do not readily lend themselves to accurate NIM ET tube placement.  Having an alternate means of recording RLN activity during thyroid and other ENT procedures would be ideal.  Clearly, the subdermal adhesive pad recording technique warrants a closer look in this research paper. 

 

Objective:     

The research team recorded both free-run and handheld probe-triggered EMG activity from patients undergoing thyroidectomy procedures using both a NIMT ET tube with embedded recording electrodes and also dermal adhesive electrodes (referred to as ‘skin electrodes’ hence forth) to measure and compare the quality and quantity of data obtained from both techniques.  The research team wanted to ask the question, ‘could skin electrodes produce the same quality and reliability of data as a NIM ET tube?’

 

Methods:

Study participants - 39 patients in total - were intubated with a Medtronic Xomed NIM ET tube (6mm for women and 7mm for men).  Additionally, Medtronic Xomed adhesive gel pads skin electrodes were applied in the montage V1-R1 - R2 -V2  to lateralize the vocalis muscles.  During the course of the surgery, free-run EMG activity was monitored and the superior branch of the RLN was identified with a handheld stimulation probe.  Amplitude of these triggered responses were recording (in microvolts) as well as the responses’ latency (mSec). 

 

Results:

Fortunately, all 39 patients in the study awoke with no new deficits and experienced favorable outcomes.  After assessing the data collected, the researchers noted the following.  First, data was successfully collected in all 39 surgical instances from the skin electrodes.  This is in contrast to four episodes of Loss of Signal (LOS) from the NIM ET tube recording electrodes.  In essence, even when the ET tube failed to record data, the skin electrodes were able to record a triggered response during nerve stimulation.

Second, the recorded amplitude of responses was lower for the skin electrodes when compared to the NIM ET tube recording electrodes’ response amplitude - by a magnitude of four times.  Therefore, when comparing NIM ET tube recording versus skin electrode recording during nerve stimulation on the same patient, the amplitude of response was on average 4 times larger from NIM ET tube recording electrodes versus skin electrodes.  There was no difference in latency noted in any of the cases.

 

Discussion:

What does the data mean for the IONM community?  The researchers concluded that this study was an encouraging step toward establishing skin electrodes as an acceptable alternative to NIM ET tube and in situ needle recording for RLN monitoring during thyroidectomies.  With a study population of 39 patients, more data in future studies will be helpful in reinforcing the team’s conclusions.

For the neuromonitoring community, NIIM ET tube recording offers hurdles to our involvement in ENT procedures.  Many anesthesia programs and surgeons are wary of the bulk and potential for damage to the esophagus and trachea perceived as a risk of such recording devices.  Patients with difficult airways, tracheostomy patients and certain pediatric patients are often not good candidates for NIM ET tube recording.  

Most significantly, NIM ET tubes require accurate placement with a glidescope for good visualization of the vocal folds and recording electrode contact points.  Skin electrode placement offers easy visualization and accurate placement prior to prepping and draping the surgical site.  Anesthesia activity and surgical manipulations can displace NIM ET tube recording electrode contact, resulting in LOS.  This study suggests that skin electrodes do not experience the same rate of LOS as electrodes on an ET tube, a definite advantage of skin electrodes.

There are still questions that need to be answered.  Can the adhesive electrodes reliably retain good contact during prolonged procedures?  What if a patient has oily skin or other conditions precluding adhesive pad placement?  Larger incisions and retraction can displace the leads away from ideal recording locations, reducing their efficiency.  Above all, the consistent loss of recorded amplitude is a significant tradeoff when replacing NIM ET electrodes with skin electrodes.  Future inquires could provide a cost-effective and minimally invasive option for thyroidectomy patients, but until then, NIM ET tube electrodes recording of the RLN remains a best practice for the neuromonitoring community.

 

References:

Hyoung Shin Lee, Jungho Oh, Sung Won Kim, Yeong Wook Jeong, Che-Wei Wu, Feng-Yu Chiang, Kang Dae Lee. Intraoperative Neuromonitoring of Recurrent Laryngeal Nerve During Thyroidectomy with Adhesive Skin Electrodes.World J Surg. https://doi.org/10.1007/s00268-019-05208-3

 

Disclaimer: 

The views, thoughts, and opinions expressed in this blog post  are solely those of the author(s). Blog posts do not represent the thoughts, intentions, strategies or policies of the author’s employer or any organization, committee or other group or individual, including the ASNM. The ASNM, along with the author(s) of this post, makes no representations as to the completeness, accuracy, suitability, validity, usefulness or timeliness of any information in this blog and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. Any action you may take based upon the information on this website is strictly at your own risk.

Tags:  In the Literature 

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Complete List of 2019 NASS IONM Podcasts With Links

Posted By Rich Vogel, Friday, December 20, 2019

This podcast series is about neuromonitoring and covers a range of educational topics aimed at optimizing patient care, decreasing cost and/or maximizing OR efficiency. The hosts are Drs. Rich Vogel and Adam Doan. Each episode is 5-10 mins.

 

Episode 1What information is critical to communicate to the IONM team and how far in advance of surgery?

Summary: It’s not uncommon for the IONM team to learn the details of the surgical procedure after incision, as it unfolds. This poses a number of problems. The IONM team needs to know detailed surgical plan, diagnosis and patient insurance information at least 48-hours in advance for non-emergent surgery. This will make IONM less likely to fail because the IONM team can make sure the correct equipment/electrodes/people are in the room, and the correct tests are being run with optimized anesthesia. This will also limit common issues with insurance. 

 

Episode 2Neuromonitoring in spine surgery, can’t anyone cover the case?

Summary: Did you know IONM is learned through on-the-job training, licensure does not exist, and certifications are not required for the technologist in your OR? After initial training, technologists can monitor very basic cases (e.g., PLIF), but they should spend years in training to learn more complex procedures (deformity, tumors). If a surgery isn’t booked accurately, the surgeon might get a very junior person assigned to a very complex case. Here we inform the listener of common practices around determining “competency” for performing IONM in spine surgery.

 

Episode 3Why does IONM need access to my patients and their charts before and after surgery?

Summary: It’s not uncommon for hospitals/surgeons to prohibit the IONM team from interfacing with the patient before surgery. In addition to needing informed consent, the team needs to assess the patient’s neuro status and history to interpret the IONM data. Imaging/charts help to develop an appropriate IONM plan. Facesheets are essential to reimbursement. When the IONM team is unable to access patient records, they are monitoring in the dark (and for free). 

 

Episode 4What are the anesthetic recommendations for neuromonitoring in various spine surgeries and why?

Summary: Here we discuss when and why we recommend total intravenous anesthesia (TIVA) vs 0.5 MAC. Is Ketamine really beneficial to MEPs? Why is Precedex contraindicated for MEPs? What train-of-four ratio is recommended for monitoring, when and why? We’ll answer all these questions and others.

 

Episode 5Does use of IONM necessarily add time to your surgery? 

Summary: The short answer is yes, but a closer look will show that it is negligible if the IONM team can work efficiently. We’ll discuss how setup can be optimized, and how baselines can be acquired in less than 10 seconds. We’ll also show how improved communication can reduce false positives and keep the surgery moving smoothly.

 

Episode 6How can you use neuromonitoring to guide and optimize positioning for spine surgery?

Summary: The patient is finally in position and neuromonitoring can’t get baselines. What do you do? If you elect to intervene, it’s a long process to retest baselines in a neutral position. Then, you have to reposition all over again. Here we presently a fast, efficient, systematic way to position a patient for any spine surgery to ensure the spinal cord is stable, and all peripheral nerves and plexi are not compressed or stretched. Also, we talk about positioning possibilities for all patients; not just those with unstable spines.

 

Episode 7Are there any real contraindications to MEPs.

Summary: Here we cut through the common myths associated with MEP contraindications. There are no absolute contraindications, and all of the relative contraindications have actually been shown to be quite safe. 

 

Episode 8What can you do to improve accuracy of pedicle screw stimulation?

Summary: Pedicle screw stimulation was developed and tested under very specific methods, but very few people follow these methods, and this reduces the accuracy. Here, we return to the basics and make recommendations that help even the most seasoned practitioner.

 

Episode 9Is it really an alert? Whence the criteria?

Summary: The criteria for calling an alert in IONM have evolved over the years and many people don’t know what the latest research says. This causes a lot of false positives (and some false negatives). Here we review what really constitutes an alert and how you can use IONM to improve accuracy.

 

 Episode 10Diagnostic accuracy of IONM from the neurophysiologist’s perspective.

Summary: Here we review the traditional diagnostic table (i.e., ± alert, ± deficit) and consider other factors like intervention, resolution of data, type of monitoring modality, etc. From here, we present an advanced diagnostic table that is inclusive of these factors. This has major implications for developing and interpreting research.

 

Episode 11Neuromonitoring lost their signals, now what?

Summary: Aside from checking wires and anesthesia, what else works? It turns out there is a lot one can do to restore signals. Here we review these checks and interventions.

 

 Episode 12Are wakeups always prolonged with neuromonitoring under TIVA?

Summary: It’s a common complaint: we use TIVA for MEPs, but the patients take forever to wake up from anesthesia. To combat this problem, many surgeons elect to discontinue IONM earlier in the procedure. Did you know IONM has the technology to guide the anesthesia team through a faster wakeup in most cases? It requires communication and collaboration, but it’s easy to do. Here we review these techniques.

 

Disclaimer:

The views, thoughts, and opinions expressed in this blog post  are solely those of the author(s). Blog posts do not represent the thoughts, intentions, strategies or policies of the author’s employer or any organization, committee or other group or individual, including the ASNM. The ASNM, along with the author(s) of this post, makes no representations as to the completeness, accuracy, suitability, validity, usefulness or timeliness of any information in this blog and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. Any action you may take based upon the information on this website is strictly at your own risk.

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In the Literature: Utilization of MEPs During Posterior Lumbar Procedures to Diagnose and Avoid ‘Foot Drop’ Dorsiflexion Injuries

Posted By W. Bryan Wilent, Thursday, November 7, 2019

Foot drop is a condition resulting from nerve or nerve root injury in which patients cannot properly dorsiflex the foot. While it may be a focal deficit isolated to a couple muscles, it can have a devastating impact on a patients' quality of life.  Patients may not be able to walk without assistance, are prone to further injury due to falls, and are forced to live with the distress of being unable to perform previously normal activities. 

This injury can occur during posterior lumbar fusions, but unfortunately the IONM modalities typically used during these procedures (spontaneous EMG and posterior tibial nerve SSEPs) have been historically very poor in diagnosing the injury. But, there is good news from the literature! There are two papers from ‘The Spine Journal’ this year (Wilent et al, Lieberman et al) and one from ‘Spine’ (Tamkus et al) last year that focused on the ability of MEPs to accurately diagnose foot drop dorsiflexion injuries.  

FIVE Key Points from the Papers

1. The MEP alert criterion is critical

Diagnostic accuracy is dependent on using a 50-60% amplitude attenuation as the alert criterion for MEPs when diagnosing nerve root dysfunction.

In Lieberman et al, the average change in amplitude was 65% in the Tibialis Anterior (TA) muscle and 60% in Extensor Hallucis Longus (EHL) muscle. Tamkus et al found an average decrease of 59.5% (they linked TA and EHL in the recording channel). Wilent et al emphasized that it was typically a greater than 50% decrease in amplitude of TA MEPs that prompted an alert. 

It should be noted that while amplitude is most common MEP response characteristic assessed intraoperatively, Tamkus et al found that the area under the curve (AUC) of the response was slightly more reliable in diagnosing nerve root dysfunction. 

2. MEPs > sEMG in diagnosing nerve root dysfunction

HISTORICAL BELIEF: During spine procedures, sEMG monitors nerve root function and MEPs monitor cord function.

DATA SAYS: During spine procedures, sEMG (with subdermal needles) provides information about proximity to nerve roots or if mechanically manipulated but this modality does NOT reliably diagnose dysfunction; in contrast, MEPs do reliably diagnose spinal cord motor dysfunction & motor nerve root dysfunction.

From Lieberman et al, “Our study further challenges the fidelity of EMG monitoring for detecting a nerve root injury. Out of 25 injured patients, only 10 (40%) had an episode of tonic EMG that occurred concurrently with acute changes in the MEPs. Moreover, no patients had any significant EMG activity that suggested motor nerve injury without also having MEP amplitude changes.”

Tamkus et al found that 40% of the patients with foot drop also had free-run EMG alerts that were reported. However, free-run EMG alerts were also reported in 56.9% of the procedures in which the patients had NO deficit. Thus, 56.9% of the time, sEMG did not portend dysfunction 100% of the time.

In Wilent et al, 100% of patients with nerve root injuries had unresolved MEPs, but only 14% of those procedures had an EMG alert called.

3. Contrary to what is commonly thought, MEPs do NOT have many false positives

Of the 4,382 procedures in Wilent et in which patients had no new deficit, only 15 had a false positive unresolved TA MEP alert. That’s it. Just 0.3% of procedure had false positive isolated TA MEP alerts.  The overall specificity of MEPs was 97.9%, which was higher than the specificity of sEMG.  

Lieberman et al reported, “For detecting any injury, a 50% threshold represents a desirable balance between sensitivity (96%) and specificity (97%)”.

Using an alert criterion of a >50% decrease in amplitude, Tamkus et al found that the sensitivity was 100% and the specificity was 87.9%. This specificity was lower than the other two studies; however, as Tamkus et al notes in their conclusion, a total intravenous regimen (TIVA) should be considered to reduce the number of false positives. In their study, a balanced anesthesia regimen with inhalational agents at 0.5 MAC was employed; in contrast, in Lieberman et al, a propofol and opioid TIVA regimen was primarily used and inhalational agents were used only occasionally and if so always limited to 0.3 MAC and were always removed if signals were initially weak or fading.

4. The precipitating event is most likely related to stretch after vertebral displacement and NOT pedicle screw insertion

Neuromonitoring during posterior lumbar fusion is often focused on the safe insertion of pedicle screws, but that surgical maneuver does not typically correlate with the intraoperative diagnosis of foot drop dysfunction. 

Tamkus et al stated “No pedicle bone violation was reported in any of the patients with the foot drop.”

Liberman et al stated, “Injury rates were highest among patients who underwent reduction of high-grade L5-S1 spondylolisthesis or had a PSO. All seven injured high-grade spondylolisthesis patients had MEP amplitude changes between 14 and 55 minutes after reduction of the spondylolisthesis. Seven of the nine injuries in the PSO group occurred after closure of the osteotomy (five after L5 PSO; two after L4 PSO).”

Wilent et al provides an example where the MEPs were reduced in amplitude after L4-5 distraction. 

Thus, the precipitating event is typically vertebral distraction/displacement likely resulting in a stretch of the neve root.

5. If MEPs are resolved, deficits are avoided.   #Therapeutic impact

Lieberman et al stated, “Many of our subjects sustained large reductions in MEP amplitude (e.g., >50%) during their surgical procedures. These transient changes resolved and these subjects did not develop new weakness. We were not able to measure the frequency of these events nor correlate them to the patient’s risk of developing an injury.”

 Wilent et al reported 100% of the patients which TA MEPs were resolved by closure had no new deficits postoperatively. Most procedures in which TA MEPs were resolved involved a clear surgical intervention, as shown in the aforementioned example on which a prompt intervention to release distraction resulted in the resolution of the MEPs and the patient had no postoperative dysfunction.  

CAVEAT: For IONM to have a therapeutic impact, you not only need an accurate diagnosis (correct MEP alert criterion), you need a timely diagnosis and a proper intervention. This is only accomplished via relatively continuous MEP acquisition and immediate communication so an alert has context within the sequence of surgical events. This facilitates clinical decision making and impacts the therapeutic benefit of interventions.

References:

  • Wilent, WB, Tesdahl, EA, Harrop JS, Welch WC, Cannestra AF, Poelstra KA, Epplin-Zapf T, Stivali T, Cohen J, Sestokas AK, “Utility of motor evoked potentials to diagnose and reduce lower extremity motor nerve root injuries during 4,386 extradural posterior lumbosacral spine procedures”, The Spine Journal, 2019
  • Lieberman JA, Lyon R, Jasiukaitis P, Berven SH, Burch S, Feiner J The reliability of motor evoked potentials to predict dorsiflexion injuries during lumbosacral deformity surgery: the importance of multiple myotomal monitoring”, The Spine Journal, 19: 377-385, 2019
  • Tamkus A, Rice KS, Hoffman G, “Transcranial motor evoked potential alarm criteria to predict foot drop injury during lumbosacral surgery”, Spine, 15;43(4):E227-E233, 2018

Disclaimer:

The views, thoughts, and opinions expressed in this blog post  are solely those of the author(s). Blog posts do not represent the thoughts, intentions, strategies or policies of the author’s employer or any organization, committee or other group or individual, including the ASNM. The ASNM, along with the author(s) of this post, makes no representations as to the completeness, accuracy, suitability, validity, usefulness or timeliness of any information in this blog and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. Any action you may take based upon the information on this website is strictly at your own risk.

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President's Message - November 2019

Posted By Rich Vogel, Thursday, October 31, 2019

Dear Members,

 

Just a few announcements this month:

 

ASNM elections open this coming Monday (November 4th). Please look for an email from the ASNM with a link to access information about the candidates, and a link to access the ballot. We have 2 people running for one open position as ASNM President, and 9 running for 4 open positions on the ASNM Board of Directors. Once ballots open, you will have 2 weeks to vote. We’ll announce the winning candidates in December. Winning candidates will take office at the ASNM Annual Meeting in May of 2021.

 

Our new industry prospectus is out, on time, as promised. I’d like to thank our Exhibitor Taskforce, Executive Committee and the team at Affinity for all the hard work that went into developing this prospectus. As our society grows and experiments with new educational platforms, we’ve elected to offer our industry partners a variety of new options to tailor their support of the ASNM to their individual needs.

 

We finally have a date for the ASNM 2020 Winter Symposium. It will be held Feb 22-23. As I said previously, this will be a (mostly) virtual meeting, consisting of a live, interactive, world-wide internet broadcast. We’ll plan to air commercials from our sponsors between talks. 

 

Symposium attendees will be able to attend via an internet portal without the expenses associated with travel. Virtual attendees will be able to purchase individual sessions or the entire symposium. The fee structure will significantly reduce member’s cost unit of CME and CEU. Limited in-person audience attendance is available.

 

Why are we doing this? Because you asked for it! Last year, we conducted a membership survey which indicated that members wanted, 1) more innovative speakers and formats, 2) effective utilization of their time, and 3) lower cost CME/CEU options. Ask and you shall receive! This is a big experiment for us, and I certainly hope you will join us in February. I’d like to thank the Representation and Advocacy Committee for coordinating the membership survey, and many thanks to Dr. Gene Balzer for his vision and hard work in developing this virtual meeting program.

            

Finally, I have a very big and exciting announcement to make. I’m bringing in a very special guest as my Presidential Speaker at the 2020 ASNM Annual Meeting. This meeting will be held May 15-17, 2020 in St. Louis, Missouri. If you want to know who it is and why I’m bringing this person in, you’ll have to watch my November President’s video

 

If you want to go back and watch my previous monthly video messages, just search for “ASNM President” on youtube.

 

I hope you all have a very happy Thanksgiving. I’ll be back in December with another update from the front lines. Thanks for being a valued member!

 

Disclaimer:

The views, thoughts, and opinions expressed in this blog post are solely those of the author(s). Blog posts do not represent the thoughts, intentions, strategies or policies of the author’s employer or any organization, committee or other group or individual, including the ASNM. The ASNM, along with the author(s) of this post, makes no representations as to the completeness, accuracy, suitability, validity, usefulness or timeliness of any information in this blog and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. Any action you may take based upon the information on this website is strictly at your own risk.

 

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ASNM Committee Updates

Posted By Rich Vogel, Thursday, October 10, 2019

Members,

 

In an effort to keep you informed of what the ASNM is doing for you, each Committee’s ongoing work will be summarized for you on a semi-annual basis (or more frequent if needed). This update is current as of the 2019 Fall Board Meeting.

 

Education Committee (Chair: Dr. Jeff Balzer):

This committee was very pleased with the success of all our educational offerings. Our Fall Symposium was a resounding success, as is our new, bi-annual online, interactive CNIM Prep course taught by James Watt. Our fall course is in progress and we have more than 40 people registered. One great thing about this course is it is free to members. So, you can actually sign up to become an ASNM member (and get all the benefits of membership) for a small fraction of what it would cost to register for the CNIM prep! 

 

Ethics Committee (Chair: Dr. Bob Sclabassi):

You don’t hear much from this committee on purpose because they operate independent of the Board to maintain autonomy and remain free of any actual or apparent influence. This committee is presently reviewing our Conflict of Interest Policy and is expected to make recommendations for potential changes. The goal is to ensure ASNM Leaders can't influence topics of discussion or vote on motions where a conflict may exist. That's not to say that we're experiencing a problem. We just don't want there to be any potential for that problem to occur. Better to be proactive, right? The review of our COI policy is not done, potential changes are not approved, but we will update you as things unfold.

 

Finance Committee (Chair: Willy Boucharel):

This committee just makes sure our finances are in good shape and we can operate as a society. There is no ongoing work, and we’re very stable financially. 

 

Guidelines and Standards of Care Committee (Chair: Dr. Gene Balzer):

This committee is working on a Facial Nerve Monitoring Guideline which is almost done.

 

Membership Committee (Chair: Clare Gale):

The Membership Committee is busy as always. Dr. Faisal Jahangiri completed his term as Chair (Thank you!!!). The new Chair is now Clare Gale. Our membership continues to increase as we expand and improve our membership benefits. One new announcement is that the ASNM is rolling out new awards to recognize the hard work of our members. It would be a lot to write, but you can learn more about these awards in the October President’s Message video. Frequencies and descriptions of these awards are subject to change as we finalize them in prep for our 2020 Annual Meeting. 

 

Nominations Committee (Chair: Dr. Jay Shils):

This is a new ad-hoc committee which is being written into the updated Bylaws. This committee will oversee nominations and elections. Moving forward, all nominees for ASNM Board or elected leadership positions will be required to disclose financial relationships so our membership has a better idea of who they are voting for and what factors may influence how they perform as a leader in the ASNM. Elections for Board and President will open very soon. Stay tuned for that!

 

Representation & Advocacy Committee (Chair: Dr. Gene Balzer):

This committee is working to develop videos for patient education. They are also working to revise/expand our Position Statement on Business Practices in IONM. Stay tuned for a new version to be released in the weeks ahead.

 

Research Committee (Chair: Dr. Miriam Donohue):

The Research Committee is now called the “Research & Technology Committee”. Dr. Bryan Wilent completed his term as Chair (Thank you!!). The new Chair is now Dr. Miriam Donohue. This committee recently submitted a Letter to the Editor in response to a high profile and low quality paper published in the literature. This Committee is also charged with periodically posting article summaries on our Blog. Recently, ASNM Member, Chris Halford, summarized an article, which you can read here. Thank you, Chris!!

 

So, that’s our Committee Update for the second half of 2019. We’ll update you again sometime in the first half of 2020. 

 

Are you interested in getting involved in Committee work? Contact one of the committee chairs and ask if there is an opening.

 

Disclaimer:

The views, thoughts, and opinions expressed in this blog post are solely those of the author(s). Blog posts do not represent the thoughts, intentions, strategies or policies of the author’s employer or any organization, committee or other group or individual, including the ASNM. The ASNM, along with the author(s) of this post, makes no representations as to the completeness, accuracy, suitability, validity, usefulness or timeliness of any information in this blog and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. Any action you may take based upon the information on this website is strictly at your own risk.

 

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President's Message - October 2019

Posted By Rich Vogel, Thursday, October 10, 2019

Dear Members,

 

We just finished our 2019 Fall Symposium in Boston. I was excited to hear from attendees and exhibitors alike that this was one of the best meetings they ever attended. Attendees liked the variety of speakers/topics and the practical advice for all levels of practitioner. Exhibitors liked the attendance, room setup, foot traffic and engagement. I’d like to extend my congratulations to our Program Chairs, Drs. Joe Moreira and Faisal Jahangiri, who developed the educational content. I’d like to thank all of our speakers, and a very special thank you to our industry partners for sponsoring the event. We couldn’t have done it without you!!

 

I think the success of our 2019 Fall Symposium foreshadows what is to come from future ASNM meetings. In taking office as ASNM President, I promised to double down on education, experiment with new technologies, expand our annual meeting and make the ASNM the best place in the world to learn about IONM. At this moment, today, there is no question in my mind that the ASNM has emerged as the nation’s premier resource for IONM education, we’re just getting started.

 

I’m happy to announce that the 2020 ASNM Winter Symposium will be a (mostly) virtual meeting to be held in early 2020. In a major departure from our traditional symposia, we will be offering a live, interactive, world-wide broadcast of the meeting. This allows attendees to get the same premier education they’ve come to expect from the ASNM, and without having to pay additional cost of travel and hotel. So, you can get your CMEs/CEUs in your pajamas! Of course, we still expect to offer in-person attendance to a limited number of participants. We’re still working out the specifics/logistics and finalizing the dates, but we expect to make formal announcements very soon. So, stay tuned. 

 

This leads me to the 2020 ASNM Annual Meeting. This will be our biggest and best meeting that we’ve ever hosted. We’re incorporating new formats, new technologies, new topics and new speakers. I won’t say any more right now, but I will say this: if you’re going to travel to one meeting in 2020, you will definitely want to make sure it is the ASNM Annual Meeting May 15-17 in St. Louis, MO.

 

Finally, if you have been a speaker at a recent ASNM meeting, or are a frequent audience attendee, you may have noticed that we’ve been changing our requirements for what speakers need to disclose, as well as what can/can’t appear on slides. We do this for two reasons, 1) because some of it is required by our CME provider, and 2) so the audience can readily detect any bias in a presentation.

 

When I say “bias”, I’m talking about bias driven by economic influence, not individual opinions about how to practice. So, someone saying that you should do BCR on all spine cases is certainly free to present evidence to support that argument; however, someone whose company sells the latest “BCR electrode” stands to make financial gain from that statement, and the audience has the right to know that. Also, we’re learning new things from our CME provider. For example, if you work for an academic institution, you can put your institution name and symbol on you slides, but you cannot do that if you work for a private company. So, we’re making changes to our rules over time to maintain transparency for the audience, as well as compliance to rules set forth by our CME and CEU providers. We hope you will understand and bear with us while we hone our technique.

 

Happy Halloween everyone. No matter where you live, I hope you get to enjoy some of the beautiful fall foliage that we see in the north. It’s a wonderful time to travel. I’ll be back in November with another update from the front lines. Thanks for being a valued member!

 

Disclaimer:

The views, thoughts, and opinions expressed in this blog post  are solely those of the author(s). Blog posts do not represent the thoughts, intentions, strategies or policies of the author’s employer or any organization, committee or other group or individual, including the ASNM. The ASNM, along with the author(s) of this post, makes no representations as to the completeness, accuracy, suitability, validity, usefulness or timeliness of any information in this blog and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. Any action you may take based upon the information on this website is strictly at your own risk.

 

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President's Message - September 2019

Posted By Administration, Thursday, September 5, 2019

Dear Members,

 

Summer is winding down and the cool winds of fall are beginning to make their way to my home state of Pennsylvania. This is my favorite time of year, but right now my thoughts are with the people affected by hurricane Dorian. I hope all of our members, as well as their loved ones, in affected areas are somewhere safe.

 

Over the past month, we’ve been busy getting ready for the upcoming Board Meeting, which will be held on Friday September 13th, just before our Fall Symposium in Boston, Massachusetts. More on the symposium in a few minutes. 

 

If you’ve ever wondered what goes on at our Board Meetings, you can always attend one as they are open to all members. In general, we discuss the business of running a society and shaping a profession. Each Committee gives reports to update us on their projects. We discuss various topics and takes votes on proposals that will shape the direction of the ASNM. I think it is excellent experience to serve on a board, and I’d encourage everyone to run for office at some point in their career. If you’re looking for a good entry point to get some experience, I’d strongly encourage you to start by serving on one of our Standing Committees. Feel free to contact me if you’d like to get involved. 

 

One big project we’ve been working on in August is a major update to our 2019 Industry Prospectus for 2020. You may remember from my Incoming President’s Addressthat I wanted to work more closely with our industry partners. In doing so, I created an Industry Partner Taskforceto advise us on certain topics that impact our partners. In developing our 2020 Industry Prospectus, we’ve worked closely with this Taskforce to ensure it works well for the ASNM and our partners who support our Society. The Board still needs to vote on the 2020 Prospectus, so it won’t be available for a few weeks. Stay tuned!

 

In the middle of August, I traveled to Kansas City to attend ASET’s Annual Meeting. The Neurodiagnostic Society celebrated its 60thyear. I had the opportunity to meet with ASET leadership to continue our close collaboration. As usual, I had a wonderful and productive conversation with ASET Immediate Past President Susan Agostini and the new ASET President, Connie Kubiac. I look forward to our continued collaboration. 

 

In late August, neuromonitoring was again in the national spotlightand, sadly, not in a positive light. I think we are on the verge of seeing more national news stories related to out of network (OON) billing for neuromonitoring. While the OON status of many companies is mostly the fault of the insurance industry refusing to allow us to be in-network, the news stories will sensationalize this and blame the IONM profession as a whole. Those of you who are engaged in business practices of questionable ethics (you know who you are), you’re not helping matters because stories that break about you will only make the rest of us look bad. 

 

Anyway, I’m sure you’re all aware of the NPR story about IONM that broke on June 17th. Well, a different version of this story also aired on NBC Nightly News with Lester Holton August 18th. In this segment, Ms. Cannon’s story was reported by Catie Beck in the Your Money Your Lifesegment. This particular story did not use quotes or comments from me, but it did talk about surprise bills and paint IONM in a negative light. 

 

On a more positive note, there was also a recent story about IONM published in Neurosurgery Market Watch. Among those interviewed for the story include myself, Dr. Faisal Jahangiri (ASNM President-Elect), Dr. Jay Shils (ASNM Secretary) and Dr. Marc Nuwer (longtime ASNM member and Fellow).

 

Turning to the future, the ASNM Fall Symposium will be held September 13-15at the Hyatt Regency Boston. You can view the program online and register here . There will be three pre-conference workshops covering the 10-20 system, TCD and electrode safety. As usual, the main conference will feature a variety of new speakers covering a variety of new topics. If you’re one of those people who continues to think of that ASNM as presenting stale topics with the same old speakers, I’d encourage you to set aside your prejudice and check out our program. Also, if you can’t make the fall symposium, I’d strongly encourage you to plan to attend our 2020 Annual Meeting in St. Louis, MO. We’re planning a bunch of new activities that will transform your meeting experience.

 

So, that’s my President’s Message for September 2019. In my October President’s Message, I’ll tell you about how our Fall Symposium went, and give you important updates from our Board Meeting. I hope you’re all enjoying the closing days of summer. I’ll be back in October with another update from the front lines. Thanks for being a valued member!

 

Rich Vogel, PhD

ASNM President

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In the Literature: Predicting Motor Recovery After Surgery of Tumors in Motor Eloquent Areas

Posted By Rich Vogel, Thursday, September 5, 2019

In this blog post, one of our members stepped up to the challenge of helping us review recent papers from the literature. Many thanks to Christopher Halford! If any readers would like help by writing summaries of recent papers, please contact me (ASNM President Rich Vogel). The post below was written by Christopher D. Halford BA, R. EEG/EP T., CNIM.

 

 In the article "Postoperative navigated transcranial magnetic stimulation to predict motor recovery after surgery of tumors in motor eloquent areas" by Seidel, et al., published in the June 2019 edition of Clinical Neurophysiology, the authors approach a very interesting topic. As the title says, they attempted to use post-operative transcranial magnetic stimulation (TMS) on patients to see if a present MEP could predict patient recovery following an intraoperative change in dcMEPs and/or tcMEPs that resulted in a post-operative motor deficit.

 Throughout the article the authors explain their methodology in great detail. They included essential information like the majority of the standards they used for establishing their criteria for changes in intraoperative MEP testing, the time frame used in the study to test the patient post-op, and a detailed chart showing the important information for each patient in the study including pre- and post-op strength changes, individual intraoperative MEP change (with recovery of signal or a lack thereof), recovery of strength from day one, one week, and one month post-op, etc. The authors make educating the reader of their testing and results, along with prior research done in this area (with many citations of pertinent scholarly articles to support each statement of fact or claim that guided their methods) a very high priority of their publication.

 Results:

 All of the 13 patients included in this study presented with a decrease in post-operative motor function compared to their pre-op exam. Within one week post-op (average=3.8 days) the researchers tested each patient and were able to record an MEP through navigated transcranial magnetic stimulation in 11 of the 13 patients. Ten of the 11 that had had a recordable MEP after TMS demonstrated a positive functional recovery by 30 days post-op, demonstrating this method has a positive predictive value (PPV) of 90.9%. Of the remaining two that did not have a post-op MEP after navigated TMS both had minimal to no recovery of function after one month post-op while one patient that had a post-op MEP from magnetic stimulation did not show improvement (based off of their progress criteria).

 Conclusion:

 In this article Seidel et al. show the reader the basis for his study done by other researchers (whose evidence and findings are stated and cited in this article) but they also expand these conclusions as well. As they point out, they extend their testing and results to lower limb motor function (as well as including upper limb) and propose the value of this technique for possible determination of patients that might benefit from aggressive post-op therapy that may have otherwise been seen as candidates that would benefit little from it. Also, the authors offer the prospective benefit of TMS for assessing more secondary and/or associative motor areas of the brain in a way not possible using only intraoperative tc or dcMEPs, which was also one of the key focuses of their testing.

 Limitations:

 The authors are very good about citing the sample size as the biggest limitation of their study. However with the solid outcomes of this limited sample size the authors have demonstrated that additional research will likely have merit. They also acknowledge that though the tumor locations for each resection were in different eloquent areas, each did have a limit of 3 to 8-cms distance from motor eloquent areas. Although the authors did inform the reader of most of their intraoperative criteria for evaluating and reporting change, it is still somewhat incomplete given that they didn’t list what specific surgical maneuvers were/could have been used to respond to intraoperative MEP changes, once an alarm criteria had been met. Also, more detailed stim parameters, anesthesia regimen/changes, and individual alarm criteria for each intraoperative change would be valuable for study reproduction. As mentioned they did provide much of these aspects but these key components would be crucial for complete replication.

 The IONM Big Picture Perspective:

 The article offers a potential technique of great value: a method that might indeed help determine the likelihood that a post-operative deficit is either going to be transient or permanent. Although this is an incredibly valuable determination (both to surgeons and patients/families), adaptation of this into the clinical setting could be a difficult task considering the cost of magnetic stimulators to those hospitals and facilities that don’t have preexisting needs for this technology. However, for those that do have this technology onsite, this could be a tremendous opportunity to consider research opportunities. If larger, repeated studies could further support the preliminarily data shown in this current article, then it could serve as evidential support for convincing hospitals to invest the necessary funds to acquire this technology and implement this type of monitoring. The development of a neuromonitoring test that would allow a surgeon to tell a patient, with confidence, that their new deficit will be only temporary has the potential to be a critical area where neuromonitoring could directly contribute to improving patient care. I encourage those that have the interest and the means to help to contact the authors, compile all information needed to replicate the study and move this research forward. 

 References:

Seidel, K., Hani, L., Lutz, K., Zbinden, C., Redmann, A., Consuegra, A., . . . Schucht, P. (2019). Postoperative navigated transcranial magnetic stimulation to predict motor recovery after surgery of tumors in motor eloquent areas. Clinical Neurophysiology,130(6), 952-959.

 Disclaimer:

 The views, thoughts, and opinions expressed in this blog post  are solely those of the author(s). Blog posts do not represent the thoughts, intentions, strategies or policies of the author’s employer or any organization, committee or other group or individual, including the ASNM. The ASNM, along with the author(s) of this post, makes no representations as to the completeness, accuracy, suitability, validity, usefulness or timeliness of any information in this blog and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. Any action you may take based upon the information on this website is strictly at your own risk.

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