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Guideline Summary
Guideline Title
Electrophysiological monitoring during surgery for cervical degenerative myelopathy and radiculopathy.
Bibliographic Source(s)
Resnick DK, Anderson PA, Kaiser MG, Groff MW, Heary RF, Holly LT, Mummaneni PV, Ryken TC, Choudhri TF, Vresilovic EJ, Matz PG, Joint Section on Disorders of the Spine and Peripheral Nerves [trunc]. Electrophysiological monitoring during surgery for cervical degenerative myelopathy and radiculopathy. J Neurosurg Spine. 2009 Aug;11(2):245-52. [29 references] PubMed External Web Site Policy
Guideline Status

This is the current release of the guideline.

Scope

Disease/Condition(s)

Cervical degenerative myelopathy and radiculopathy

Guideline Category
Evaluation
Management
Clinical Specialty
Chiropractic
Family Practice
Geriatrics
Internal Medicine
Neurological Surgery
Neurology
Orthopedic Surgery
Physical Medicine and Rehabilitation
Preventive Medicine
Sports Medicine
Intended Users
Physicians
Guideline Objective(s)
  • To address questions regarding the therapy, diagnosis, and prognosis of cervical degenerative disease using an evidence-based approach
  • To use evidence-based medicine to examine the diagnostic and therapeutic utility of intraoperative electrophysiological (EP) monitoring in the surgical treatment of cervical degenerative disease
Target Population

Patients undergoing surgery for cervical degenerative myelopathy or radiculopathy

Interventions and Practices Considered

Electrophysiological monitoring during spinal surgery

Major Outcomes Considered

Sensitivity and specificity of electrophysiological monitoring for detecting neurological injury during surgery

Methodology

Methods Used to Collect/Select the Evidence
Hand-searches of Published Literature (Secondary Sources)
Searches of Electronic Databases
Description of Methods Used to Collect/Select the Evidence

Search Criteria

The expert group searched the computerized database of the National Library of Medicine and the Cochrane Database (date range 1966–2007) using MeSH headings and the following keywords: "cervical myelopathy and somatosensory-evoked response," "cervical myelopathy and SSEPs," "cervical myelopathy and magnetic stimulation," "cervical myelopathy and MEPs," "cervical myelopathy and EMG," "cervical myelopathy and electromyogram," "cervical myelopathy and motor-evoked response," and "cervical myelopathy and muscle-action potential." The results were limited by the terms "decompression" or "surgery" and the search was restricted to the English language, resulting in an initial group of 868 papers. The group reviewed the title and abstract of each paper and excluded duplicates, diagnostic studies, animal studies, and case reports. They then examined reference lists of reviewed articles to cull further references. A total of 39 references were identified as providing relevant medical evidence and these provide the basis for this review. The expert group ranked evidence using previously described methodology. In this chapter, they have stratified papers into 2 groups: 1) those that examined alternations in monitoring as a diagnostic test for the development of permanent neurological deficits; and 2) those that considered the utility of monitoring to prevent neurological deficits as a therapy. The evidentiary table summarizes all papers providing relevant evidence (see Table 1 in the original guideline document).

Number of Source Documents

39 references provided relevant medical evidence and were used as the basis for this review.

Methods Used to Assess the Quality and Strength of the Evidence
Expert Consensus
Weighting According to a Rating Scheme (Scheme Given)
Rating Scheme for the Strength of the Evidence

Strength of the Evidence

Class I: Evidence evolved from well-designed randomized controlled trials (RCTs).

Class II: Evidence arose from RCTs with design problems or from well-designed cohort studies.

Class III: Evidence arose from case series or poorly designed cohort studies.

Methods Used to Analyze the Evidence
Systematic Review with Evidence Tables
Description of the Methods Used to Analyze the Evidence

Quality of Evidence

The guidelines group assembled an evidentiary table summarizing the quality of evidence.

The mainstay of any evidence-based review lies in the assessment of the quality of strength of the data. The group assessed the methodology of each manuscript carefully and assessed each study according to its relevant category—diagnosis, therapy, prognosis, or harm. The group applied a weighting scheme according to the methods delineated by Sackett and colleagues. After review of the study methods, the group determined how well each individual study met the validity requirements within its category and assigned a class to the study. In keeping with prior surgical guidelines, a 3-class system (Classes I, II, and III) was used (see the "Rating Scheme for the Strength of the Evidence" field).

It was the group's conclusion that expert opinion and case reports did not add significantly to the evidence used for the formulation of recommendations and should not be separately classified.

When disagreement arose as to the strength of evidence (that is, determining how well the methods conformed to the weighting scheme), the group resolved said disagreement by expert consensus within itself. To avoid the undue influence of a single individual, each member had the opportunity to list the reason(s) why a study should be downgraded or upgraded. Group members then prioritized each reason. If a reason had low priority, it was eliminated. Ultimately, there was convergence of opinion within the group. The result was unanimity to support publicly the assessment of the quality of evidence and the strength of the guidelines despite potential individual reservations regarding specific details.

Methods Used to Formulate the Recommendations
Expert Consensus (Consensus Development Conference)
Description of Methods Used to Formulate the Recommendations

In March 2006, the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons/Congress of Neurological Surgeons compiled an expert group to perform an evidence-based review of the clinical literature on the management of cervical degenerative spine disease. Comprising the group were spinal neurosurgeons and orthopedic surgeons active in the Joint Section and/or the North American Spine Society. This combination of specialties ensured the comprehensive participation of both surgical specialties. At least half of the group had participated in prior guidelines development, and several had completed the evidence-based course developed by the North American Spine Society. The multiple recommendations represent the product of this group with input from the Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.

Formulation and Strength of Recommendations

The group formulated recommendations using expert consensus in a consensus development conference. After assessment of the quality and strength of evidence, the assigned subgroup summarized the studies leading to the basis of the Scientific Foundation section of each chapter. In general, if high-quality (Class I or II) data were available on a particular topic, poorer quality evidence was only briefly summarized. If no high-quality evidence existed, Class III data formed the basis of the scientific foundation. Based on the quality and strength of data, each subgroup formulated initial treatment recommendations. Each subgroup presented these to the entire group whose membership included active members of the Congress of Neurological Surgeons, the American Association of Neurological Surgeons, the North American Spine Society, and the American Academy of Orthopedic Surgery. The presentation was a plenary session acting as a consensus development conference from which final recommendations arose.

The group gave each recommendation a grade for strength based on the quality of the underlying studies. Grading was based on the methods of the Scottish Intercollegiate Guidelines Network and also mirrored that used by the Oxford Centre for Evidence-Based Medicine (www.cebm.net External Web Site Policy) (see the "Rating Scheme for the Strength of the Recommendation" field).

Rating Scheme for the Strength of the Recommendations

Strength of the Recommendations

Grade A: Recommendations based on consistent Class I studies.

Grade B: Recommendations based on a single Class I study or consistent Class II studies.

Grade C: Recommendations based on a single Class II study.

Grade D: Recommendations based on Class III or weaker data, or based on inconsistent data.

Cost Analysis

A formal cost analysis was not performed and published cost analyses were not reviewed.

Method of Guideline Validation
External Peer Review
Internal Peer Review
Description of Method of Guideline Validation

Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons and through external peer review prior to publication.

Recommendations

Major Recommendations

The rating schemes used for the strength of the evidence (Class I-III) and the grades of recommendations (A-D) are defined at the end of the "Major Recommendations" field.

Recommendations

  • The reliance on changes in electrophysiological (EP) monitoring as an indication to alter a surgical plan or administer steroids has not been observed to reduce the incidence of neurological injury during routine surgery for cervical spondylotic myelopathy (CSM) or cervical radiculopathy. Accordingly, its routine use in these circumstances is not recommended (Quality of evidence, Class III; Strength of recommendation, D). However, there may be circumstances in which the surgeon desires the added intraoperative diagnostic information that EP monitoring may confer.
  • Although the use of EP monitoring, including transcranial motor-evoked potentials (Tc-MEPs), may serve as a sensitive means of diagnosing potential neurological injury during anterior spinal surgery for CSM, the practitioner must understand that intraoperative EP worsening is not specific—it may not represent clinical worsening and its recognition does not necessarily prevent neurological injury, nor does it result in improved outcome (Quality of evidence, Class II; Strength of recommendation, C).
  • No recommendation may be given for the use of intraoperative improvement on EP parameters/indices as a means to forecast outcome with reliability because conflicting Class I data exist on this matter.

Summary

Currently, there is no Class I evidence that demonstrates the ability of EP monitoring to improve safety and functional outcome. Conversely, there have been no studies appropriately designed to demonstrate that EP monitoring does not improve outcome or safety. The use of intraoperative somatosensory evoked potential (SSEP) monitoring does not appear to provide useful diagnostic or therapeutic information during anterior surgery for CSM, and the role of SSEP monitoring in posterior procedures is not well defined. Transcranial MEP monitoring may be more useful in the diagnosis of neurological injury during anterior decompression; however, there is no evidence to suggest that the use of such monitoring substantially improves the safety of surgery in the majority of patients with CSM. There is some evidence to suggest that exclusive reliance on Tc-MEP monitoring may lead to surgeon behavior that may be detrimental to patient welfare. Spinal cord–evoked potentials may be helpful for the localization of the level of neurological compromise in cases of multiple levels of compression on magnetic resonance (MR) imaging; however, the utility of this monitoring technique for altering surgical strategy is unclear. Preoperative electromyography (EMG) may be useful for the identification of patients at high risk for C-5 root palsy after laminoplasty, but the data to support this are of relatively poor quality.

Definitions:

Strength of the Evidence

Class I: Evidence evolved from well-designed randomized controlled trials (RCTs).

Class II: Evidence arose from RCTs with design problems or from well-designed cohort studies.

Class III: Evidence arose from case series or poorly designed cohort studies.

Strength of the Recommendations

Grade A: Recommendations based on consistent Class I studies.

Grade B: Recommendations based on a single Class I study or consistent Class II studies.

Grade C: Recommendations based on a single Class II study.

Grade D: Recommendations based on Class III or weaker data, or based on inconsistent data.

Clinical Algorithm(s)

None provided

Evidence Supporting the Recommendations

Type of Evidence Supporting the Recommendations

The type of supporting evidence is identified and graded for each recommendation (see "Major Recommendations").

Benefits/Harms of Implementing the Guideline Recommendations

Potential Benefits

Appropriate use of electrophysiological (EP) monitoring during surgery for cervical degenerative myelopathy and radiculopathy

Potential Harms

There is some evidence to suggest that exclusive reliance on transcranial motor-evoked potential (Tc-MEP) monitoring may lead to surgeon behavior that may be detrimental to patient welfare.

Qualifying Statements

Qualifying Statements
  • During guideline development, the group commonly encountered unsophisticated or poorly designed comparative methods in clinical trials. The most common flaw was the lack of a control group or the utilization of historical controls. Other common flaws were invalid outcome measures, and the lack either of randomization or blinding of outcome assessors. Specific examples are provided in the text of each topic. At the conclusion of each chapter are suggestions for future areas of study and ideas to improve the quality of clinical research.
  • With each recommendation comes the risk of conformational bias. The recommendation of a therapeutic option presumes that functional and economic preferences have been determined. Reliable and valid outcome measures help in this respect. It is hoped that such functional and economic outcome measures represent the values important to the patient and society and less the practitioner. By focusing attention on outcome measures in each study, the values of the patient and society are represented in these guidelines.
  • To minimize any specialty bias, spinal surgeons from both orthopedic and neurosurgery departments participated in the creation of these guidelines. However, although invited, nonsurgical stakeholders did not participate—a circumstance that some might argue would predispose to conformational bias toward strong surgical recommendations. It is hoped in the future that nonsurgical stakeholders will participate. During this process, the entire group made a concerted effort to be unprejudiced. Many authors acknowledged that poor quality or controversial data often formed the basis of their predetermined ideas regarding standard treatment. It is expected that certain practitioners may disagree with the recommendations. However, with careful review of the scientific foundation, the critically thoughtful reader should find the recommendations warranted.

Implementation of the Guideline

Description of Implementation Strategy

An implementation strategy was not provided.

Institute of Medicine (IOM) National Healthcare Quality Report Categories

IOM Care Need
Getting Better
Living with Illness
IOM Domain
Effectiveness
Safety

Identifying Information and Availability

Bibliographic Source(s)
Resnick DK, Anderson PA, Kaiser MG, Groff MW, Heary RF, Holly LT, Mummaneni PV, Ryken TC, Choudhri TF, Vresilovic EJ, Matz PG, Joint Section on Disorders of the Spine and Peripheral Nerves [trunc]. Electrophysiological monitoring during surgery for cervical degenerative myelopathy and radiculopathy. J Neurosurg Spine. 2009 Aug;11(2):245-52. [29 references] PubMed External Web Site Policy
Adaptation

Not applicable: The guideline was not adapted from another source.

Date Released
2009 Aug
Guideline Developer(s)
American Association of Neurological Surgeons - Medical Specialty Society
Congress of Neurological Surgeons - Professional Association
Source(s) of Funding

Administrative costs of this project were funded by the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons and Congress of Neurological Surgeons.

Guideline Committee

The Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons and Congress of Neurological Surgeons Expert Group

Composition of Group That Authored the Guideline

Authors: Daniel K. Resnick, M.D., Department of Neurological Surgery, University of Wisconsin, Madison, Wisconsin; Paul A. Anderson, M.D., Department of Orthopedic Surgery, University of Wisconsin, Madison, Wisconsin; Michael G. Kaiser, M.D., Department of Neurological Surgery, Neurological Institute, Columbia University, New York, New York; Michael W. Groff, M.D., Department of Neurosurgery, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, Massachusetts; Robert F. Heary, M.D., Department of Neurosurgery, University of Medicine and Dentistry of New Jersey—New Jersey Medical School, Newark, New Jersey; Langston T. Holly, M.D., Division of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles, California; Praveen V. Mummaneni, M.D., Department of Neurosurgery, University of California at San Francisco, California; Timothy C. Ryken, M.D., Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa; Tanvir F. Choudhri, M.D., Department of Neurosurgery, Mount Sinai School of Medicine, New York, New York; Edward J. Vresilovic, M.D., Ph.D., Department of Orthopedic Surgery, Milton S. Hershey Medical Center, Pennsylvania State College of Medicine, Hershey, Pennsylvania; Paul G. Matz, M.D., Division of Neurological Surgery, University of Alabama, Birmingham, Alabama

Financial Disclosures/Conflicts of Interest

No author received payment or honorarium for time devoted to this project. Dr. Resnick owns stock in Orthovita. Dr. Matz receives support from the Kyphon Grant for Thoracolumbar Fracture Study, and an advisory honorarium from Synthes for the cadaver laboratory. Dr. Heary receives support from DePuy Spine and Biomet Spine, and receives royalties from DePuy Spine and Zimmer Spine. Dr. Groff is a consultant for DePuy Spine. Dr. Mummaneni is a consultant for and receives university grants from DePuy Spine and Medtronic, Inc., and is a patent holder in DePuy Spine. Dr. Anderson is an owner of, consultant for, and stockholder of Pioneer Surgical Technology; a consultant for and receives non–study related support from Medtronic, Inc., and is a patent holder in Stryker. The authors report no other conflicts of interest concerning the materials or methods used in this study or the findings specified in this paper.

Guideline Status

This is the current release of the guideline.

Guideline Availability

Electronic copies: Available from the Journal of Neurosurgery Web site External Web Site Policy.

Print copies: Available from the Journal of Neurosurgery Publishing Group, 1224 Jefferson Park Avenue, Suite 450, Charlottesville, Virginia 22903, USA. Telephone: 434-924-5503

Availability of Companion Documents

The following is available:

  • Introduction and methodology: guidelines for the surgical management of cervical degenerative disease. J Neurosurg Spine. 2009 Aug;11(2):101-3. Electronic copies: Available from the Journal of Neurosurgery Web site External Web Site Policy.
Patient Resources

None available

NGC Status

This NGC summary was completed by ECRI Institute on February 15, 2011. The information was verified by the guideline developer on March 20, 2011.

Copyright Statement

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.

Disclaimer

NGC Disclaimer

The National Guideline Clearinghouse™ (NGC) does not develop, produce, approve, or endorse the guidelines represented on this site.

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