IONM 107:

IONM in Spine Surgery

Jay Shils, PhD, D ABNM, FASNM

Course Goals:

The purpose of this online self paced course is to provide IONM technologists with skills for performing neurophysiological monitoring during spine surgery. The course includes somatosensory evoked potential monitoring, transcranial motor evoked potentials, free run and triggered EMG, and Pedicle screw testing. Also included in the course is a review of terminology used in spine surgery, an overview of various spinal procedures and review of the spinal anatomy and neuroanatomy relating to spinal surgery. The course also includes guest lectures on Selective Dorsal Rhizotomy and Brachial Plexus surgery by Judi Berry, BS, CNIM and Comprehensive Motor Exams in IONM by Ryan lau, MS, R. EEG/EP T, CNIM, CLTM, and a lecture recording by Gayle Hicks, PhD, DABNM, FASNM on the use of H-Reflex in IONM.

The course consists of nine lectures in video format, one as an audio file with PDF handout and some additional reading assignments. There are ten quizzes, a practice exam review and a final exam. The quizzes allow you to have three tries to achieve the correct answer. The
quizzes count as 45% of your final grade. The final exam counts 55% of your final grade and is made up of 92 questions and covers all the content and a short exam on vertebral anatomy. 12 ACE Credits are awarded for successful completion

The final is structured differently than the quizzes, and you will receive only one try at the exam for full credit. You will be given one second chance on questions, but if you answer correctly on the second try, you will receive only partial credit for the question. In other words there is a penalty for not getting it right the first time, but the penalty is only slight. Please make use of the review practice exam to insure a passing grade on the final exam.

A lot of important information is covered in this course. Listen to the lectures additional times if needed, and take notes. Review your notes before quizzes and study in depth before the final exam.

Course Outline and Objectives:

  • Define terms used in spinal surgical procedures, and in IONM Explain what is monitored during Spinal Surgery
  • Explain what is monitored during Spinal Surgery IONM and Identify causes of changes in Neural system integrity and function
  • Recognize that the monitoring method must actually test the neural structure at risk
  • Recognize that the monitoring method must be physiologically sensitive to the process that causes the deficit
  • Recognize the need to localize the problem if there is one
  • Identify the method or “How” that the Motor System is is stimulated and the pathway it takes
  • Recognize problems that can arise from patient positioning
  • Compare and contrast prone positioning for lumbar and cervical surgeries
  • Compare and contrast supine positioning for ACDF (Anterior cervical discectomy and fusion)
  • Compare and contrast lateral and anterior thoracic spine positioning and possible problems

Somatosensory Evoked Potentials During Spine Surgery

  • Identify Spinal Cord Procedures
  • Identify peripheral procedures where SSEP may be useful in monitoringRecognize the history and early progress in monitoring human potentials.
  • Recognize appropriate monitoring procedures for spine and peripheral nerve surgeries
  • Identify Somstosensory pathways
  • Recognize the parameters of an artificial stimulus used in IONM
  • Recognize what we are monitoring in IONN
  • Demonstrate recognition of stimulating electrode application techniques
  • Recognize physiological Effects on SSEPs
  • Apply measurements to SSEP data using appropriate criteria
  • Monitoring the Motor Tracts during Spinal and Cranial Surgery
  • Recognize historical landmarks in the development of neurophysiology


  • Recognize elements of stimulating and recording from the Corticospinal tract
  • Recognize Monitoring Methodologies and Criteria
  • Recognize Safety Issues and respond appropriately

Troubleshooting and Decision Making

  • Recognize artifacts and technical problems and take appropriate actions
  • Define and use appropriate “ISI” - Inter stimulus Interval
  • Recognize examples, Review of literature, outcomes and Case Studies
  • Recognize the usefulness and positive findings when monitoring Free Run and Triggered EMG during IONM Methods
  • Recognize the Intra-operative Physiology of the Sacral System
  • Recognize why monitoring upper SSEPs for Cauda Equina surgeries is valuable
  • Identify that sometimes SSEPs produce a false negative Define the impact of various Anesthesia on the monitored potentials including:
  • Recognize standard and compare and contrast anesthesia agents CMAPS amplitude reduction by boluses
  • Recognize the impact of Physiology changes and Evoked Potentials
  • Recognize interventional neuroradiology methods used in spinal cord embolization
  • Identify decision making criteria in IONM and reasons to use and not use IONMWhile the CNIM cannot “Interpret” data they can give a technical description and relay information from the neurophysiologist. and call on the neurophysiologist when changes approach alarm criteria so the neurophysiologist can interpret the data for the surgeon.
  • Recognize examples of statistics on outcomes of monitored surgeries and limitations of IONM
  • Review of utility of IONM

Selective Dorsal Rhizotomy by Judi Berry, BS, CNIM

  • Recognize uses for Selective Dorsal Rhizotomy including reduction of spasticity in conditions such as cerebral palsy
  • Identify current trends in Selective Dorsal Rhizotomy (SDR)
  • Recognize the patients who would benefit and the criteria for selection for the procedure
  • Recognize the procedural steps in surgery and IONM monitoring procedure
  • Identify the anesthesia requirements for recording IONM during SDR and patient set up in the OR
  • Identify the monitoring methods require for quality IONM during SDR
  • Recognize case studies and possible outcomes of IONM during SDR

Comprehensive Pre and Post-Op Motor Exams in IONM
by Ryan Lau, MS, R. EEG/EP T., CNIM,CLTM and MeChelle Vance, R. EEG/EP T., CNIM, CLTM

  • Recognize the usefulness of performing pre-and post operative motor exams to define the baseline of function immediately prior to the exam/test/surgery, and immediately post operatively.
  • Identify the ACNS Guidelines and ABRET EP Practice Analysis that included assessment of visual, auditory and twitch intensity adequate to perform testing, and the similarity of motor evaluations in pre and post-op setting.
  • Outline the elements of a basic motor exam including:
  • Identify reasons why a motor exam just per-operatively and post-operatively would be useful
  • Recognize examples of motor exams
  • Recognize also that evaluating the patient allows us to know the patient on a personal level and establish that we care, also skills in evaluation are valued by staff involved in the patient’s care.
  • Identify the nerve root and muscle innervations
  • Become familiar with a standardized form for testing motor skills in patients
  • Identify best posture of patients for testing each muscle group (lying down, sitting up)
  • Recognize specific examples of (in pictures or diagrams) of testing each muscle or muscle group.

Monitoring the Brachial Plexus During Reconstructive/Exploratory Surgery
by Judi Berry, BS, CNIM

  • Recognize the basic anatomy of the brachial plexus including elements of the lateral, posterior, and medial cords and nerve roots entering the cervical and thoracic spine
  • Recognize clinically relevant gross motor function of the cervical nerve roots
  • Identify types of Injuries to the Brachial Plexus
  • Identify the types of injuries in different types of patients
  • Recognize that 6 months is the usual waiting period for spontaneous healing and surgical intervention is not considered until that time
  • Identify the advantages of using IONM during Brachial Plexus surgery
  • Select appropriate modalities for IONM including and list usefulness
  • Recognize special considerations in Brachial Plexus surgeries
  • Set up a Monitoring Strategy

H-Reflex in Surgery by Gayle Hicks, PhD, DABNM, FASNM

  • Recognize the basics of reflex physiology
  • Determine the relationship between reflex behavior and Hoffmann’s Reflex
  • Recognize the differences in TCeMEP and H-Reflex
  • Provide recording standards for successful acquisition of Haffmann’s Reflex
  • Recognize the non-pathological and pathological factors affecting Hoffman’s Reflex
  • Recognize waveform morphology, latency and relative amplitude of normal H-Reflex responses Recognize the usefulness of Hoffman’s reflex as an adjunct to IONM protocol
  • Identify accessible Muscles of the Upper Extremity
  • Identify accessible Muscles of the Lower Extremity
  • Identify electrode placements including or montage including placements
  • Identify recording and stimulating parameters
  • Recognize anesthetic requirements for H-Reflex recording including problems with Nitrus and Halogenated agents
  • Recognize the need to perform pre-operative studies in patients without normal reflexes clinically in their History and Physical exam and how abnormal responses (Upper Motor Neuron Disease) may impact the usefulness of monitoring H-Reflex in surgery
  • Recognize the importance of Hematocrit on H-Reflexes (25% lowest acceptable level)

Course grade:

  • Test your knowledge of Vertebral Anatomy (Review only 0% of grade)
  • Lesson 1 Introduction to IONM in Spine Monitoring 5%
  • Lesson 2 Somatosensory Evoked Potentials 5%
  • Lesson 3 Monitoring Motor Tracts in Spinal/Cranial Surg 5%
  • Lesson 4 EMG 5%
  • Lesson 5 Anesthesia 5%
  • Lesson 6 Decision Making in IONM 5%
  • Lesson 7 Selective Dorsal Rhyzotomy 5%
  • Lesson 8 Comprehensive Motor Exams in IONM 5%
  • Lesson 9 Brachial Plexus Surgery 5%
  • Lesson 10 H-Reflex in IONM 5%
  • Practice exam to prepare for the final exam 0%
  • Vertebral Anatomy Exam (part of final exam) 5%
  • Final Exam (2 attempts with slight penalty for missing on first attempt) 45%
  • Passing score for course - 80% or higher

Click here for a detailed 37 page course outline, goals, objectives document.