This online course awards 20 ACE credits for successful completion and passing grade of 80% or better. Course completion requires reading these assignment listed below. You need not purchase the books if you can access them from a library or borrow them from other staff, such as the neurologist interpreter or technologist supervisor.

First reading assignment:

Text: Intraoperative Neurophysiological Monitoring: Gloria M Galloway, Marc Nuwer, Jamie Lopez, and Khaled Zamel

Read Chapters: 9, 11

Second reading assignment:

Text: Intraoperative Monitoring of Neural Function edited by Marc Nuwer.

Read Section III, Chapters: 37, 38, 39, 40, 41, 42

IONM 109: Skull Base Surgery and

Cranial Nerve Monitoring

(Contains: Detailed Brainstem Anatomy, BAER, Cranial nerve monitoring

including Facial Nerve and Layngeal Nerve Monitoring)

by Jack Kartush, MD and Ilka Naumann, MD,

with special lectures by:

  • Sarah Chandler, AuD
  • Mark Ryland, MGR, AuD, R.NCS T., RPSGT, R. EP T.
  • E. Tracy Mishler, AuD
  • Alan Legatt, MD, PhD
  • Emily Murphy, R. EEG T.
  • Joshua Castle, R. EEG/EP T., CNM

Learning Goals:
The goals of the course are to provide training in the basics of intraoperative neuromonitoring in surgeries of the skull base, brainstem, and auditory pathway, as well as those requiring monitoring of any of the cranial nerves, including the facial and recurrent laryngeal nerves.

Learning Objectives:

Lesson 1: Reading Assignments: (obtain, borrow or check out from a library)

First reading assignment:

Text: Intraoperative Neurophysiological Monitoring: Gloria M Galloway, Marc Nuwer, Jamie Lopez, and Khaled Zamel

Read Chapters: 9, 11

Second reading assignment:

Text: Intraoperative Monitoring of Neural Function edited by Marc Nuwer. Go to, search for the text and click "View inside this book"

Read Section III, Chapters: 37, 38, 39, 40, 41, 42

Lesson 2: Quiz on Reading Assignments 5% of grade

Lesson 3: Foundations of Monitoring
by Jack Kartush, MD and Ilka Naumann, MD

  • Identify elements in an overview of the foundations of IONM
  • Identify the importance of monitoring in Acoustic Neuroma surgeries
  • Relate the importance of training for IONM professionals with clear understanding of instruments and monitoring
  • Identify the integrated team work needed between the technologist, the set up and instrumentation, and the surgeon and interpreter.
  • Recognize the different responsibilities of technologists, the surgeon and interpreting neurophysiologist
  • Recognize the differences between intramuscular needle electrodes (subdermal needles) and surface electrodes
  • Identify appropriate stimulating electrodes, and their use
  • Identify patterns of responses and their interpretation
  • Identify sources of errors
  • Differentiate passive and active monitoring
  • Identify current flow issues
  • Identify items that should be on the IONM Checklist
  • Identify patterns of responses and their interpretation
  • Identify sources or errors in IONM
  • During the procedure realize the importance of artifact recognition, limitations of iONM during cautery, and using the stimulator to help locate the nerve
  • Identify safety measures and risks for monitoring cranial nerves including:
  • Identify the risk of subdermal needle burns due to capacitive coupling with Bovie Cautery in the OR (Watch free ASET eLearning Portal Lecture by Brett Netherton)
  • Identify risks of injury using Endotracheal tube monitoring devices such as the unfurling of a tube’s internal wire which may be life threatening and an airway obstruction.

Lesson 4: Basic Audiometric Interpretation
by Sarah Chandler, AuD

  • Identify the peripheral hearing system anatomy
  • Identify the basics of Brainstem Auditory Evoked Potential Recordings (BAER, BAEP, ABR)
  • Recognize the basic types of hearing loss including:
  • Recognize basic audiometric tests
  • Identify examples of clinical test results and the expected impact on BAER (ABR)
  • Conductive loss is outer or middle ear dysfunction
  • Sensoryneural hearing loss is inner ear loss

Lesson 5: Detailed Brainstem Anatomy: Brainstem Auditory Evoked Response Waves Generators: more than just relay points

by Mark Gl Ryland, Au.D, R.EP T., R.NCST, RPSGT

  • Define in the simplest form what is a BAER - series of waves generated and recorded when the auditory mechanism is stimulated
  • Identify human speech as the signal to which our auditory system is most essentially designed to respond
  • Define the terms and describe how they relate to BAER, Hearing Testing and Brainstem anatomy:
  • Define the BAER Generators or “Relay Stations”
  • Recognize the Outer/Middle Ear & Cochlear Mechanism
  • Recognize that although not inside the brainstem, the auditory nerve is where the neural potion of the BAER begins
  • Recognize the BAER: AN summary
  • Recognize the contribution to the BAER of the Cochlear Nucleus and Pons, Superior Olivary complex, Decussation of fibers, Trapezoid bodies, Generators of wave III, Lateral Lemniscus, Reticular formation and Inferior colliculus (Midbrain)

Lesson 6: Cranial Nerves and ABR in IONM
by E. Tracy Mishler, Au.D

  • Recognize that the goal of cranial nerve monitoring is to preserve integrity of cranial nerve function and to perform functional mapping or identification of the nerves during surgery
  • Differentiate passive recording of EMG from muscles innervated by cranial nerves of interest and Direct stimulation of cranial nerves for identification and testing integrity.
  • Define Compound Muscle Action Potentials
  • Identify anesthesia requirements for cranial nerve monitoring
  • Recognize the extraocular muscles
  • Identify electrode placements for CN III through CN VI
  • Identify uses for monitoring CN V “Trigeminal” nerve
  • Recognize characteristics of CN V “Trigeminal” nerve
  • Recognize usefulness of CN VII “Facial” monitoring
  • Recognize characteristics of CN VII “Facial” nerve
  • Recognize characteristics of CN IX: Glossopharyngeal
  • Identify procedures where monitoring CN X “Vagus” is needed
  • Recognize characteristics of CN X: Vagus
  • Recognize characteristics of Cranial Nerve XI “Spinal Accessory Nerve” monitoring
  • Recognize characteristics of Cranial Nerve XII “Hypoglossal Nerve” monitoring
  • Identify general considerations for monitoring cranial nerves
  • Identify appropriate instrument parameters for cranial nerve monitoring
  • Define current shunting with direct stimulation
  • Identify Anesthetic considerations during CN monitoring
  • Recognize cranial nerve responses by latency, morphology and amplitude
  • Identify spontaneous EMG
  • Differentiate significant EMG response by waveform recognition
  • Recognize the monitoring required for microvascular decompression for hemifacial spasm
  • Identify responsibilities of monitoring technologist to report to surgeon and document
  • Identify appropriate documentation for surgical monitoring
  • Recognize sample data and categorize responses and significance

Lesson 7: Laryngeal Nerve Monitoring
by Jack Kartush, MD
and Ilka C. Naumann, MD

  • Identify the need for monitoring cranial nerves
  • Recognize that the NIH has stated Facial Nerve monitoring is an effective and essential adjunct to reduce risk of facial palsy (Standard of Care)
  • Recognize that RLN monitoring is still evolving and efficacy is modality dependent (Caution required)
  • Identify the Laryngeal nerves
  • Differentiate Vocal Cord anatomy and function
  • Identify some anatomical variations
  • Identify mechanisms of Nerve Injury
  • Recognize complications of Vocal Cord Paralysis
  • Recognize the importance of monitoring in helping prevent malpractice litigation
  • Identify methods of RLN Recording
  • Recognize some of the historical developments in endoscopic electrode placement
  • Recognize that the benefits to monitoring are marginal and not considered standard of care, with some false positives and negative errors
  • Recognize the need to use continuous stimulation and proper placement and location of the recording and stimulating electrodes
  • Recognize the need for policies and procedures for all modalities and surgical procedures
  • Identify some of the problems with current methods and electrodes
  • Recognize the responses of RLN (Burst, Train)
  • Define a “Tap Test”
  • Recognize the importance of impedance and good electrode contact
  • Identify troubleshooting questions
  • Recognize that the RLN is less likely to display train potentials from mechanical stretch injury like un-myelinated facial nerves in the CPA
  • Define current shunting and current jump
  • Recognize dangers and risks to the patient from electrode unraveling of wire, kinked tube, risk of obstruction, need for bite blocks, and faulty adhesive loosening in long cases, need to not leave the electrode tube in post op, must replace.
  • Recognize importance of constant review of literature, FDA safety database, Manufacturer and User Facility Device Experience Database (MAUDE) and staying current with new developments in products and procedures.

Lesson 8: BAEP in IONM
By Alan Legatt, MD, PhD

  • Define BAEP testing and its usefulness
  • Identify recording parameters
  • Recognize elements of evaluation of BAEP results
  • Recognize what BAEP testing does not measure and the limitations of recording during periods of time when other instruments are in use such as drilling, cautery and CUSA

Lesson 9: Use of an Infrared Camera to Improve the Outcome of
Facial Nerve Monitoring
by Emily Murphy, R. EEG T., BA

  • Recognize basic traditional Facial nerve monitoring techniques
  • Realize that during periods of cautery use, IONM is ineffective
  • Identify use of infrared camera techniques to visually monitor the patient’s face for twitches during cautery therefore identifying activation of the facial nerve

Lesson 10: Intraoperative Neuromonitoring During Skull Based Surgeries
by joshua R. Castle, R. EEG/EP T, CNIM

  • Recognize Anatomy and Physiology of the Brainstem and Cranial Nerves
  • Identify Surgical Procedures and:
  • Identify monitoring and mapping techniques
  • Recognize some of the historical developments involving monitoring of skull base surgery
  • Recognize the basic anatomical division of the Brainstem including:
  • Identify the 12 Cranial Nerves including:
  • Identify the pneumonic device or remembering the Cranial Nerves and their sensory/motor/mixed nerve status
  • Identify how to monitor each of the cranial nerves
  • Recognize Surgical Procedures requiring Cranial Nerve Monitoring and IONM
  • Identify most common procedures involving the middle/posterior fossa


  • Quiz: Lesson 2 Reading assignments 5% of grade
  • Quiz: Lesson 3 Foundations of IONM 7% of grade
  • Quiz: Lesson 4 Basic Audiometric Interpretation 5% of grade
  • Quiz: Circle of Willis 3% of grade
  • Quiz: Lesson 5 Brainstem Anatomy 5% of grade
  • Quiz: Lesson 6 Cranial Nerves and ABR in IONM 5% of grade
  • Quiz: Lesson 7 Laryngeal Nerve Monitoring 5% of grade
  • Quiz: Lesson 8 BAEP in IONM 5% of grade
  • Quiz: Lesson 10 IONM During Skull Based Surgery 5% of grade
  • Practice exam 0% of grade
  • Final Exam 55% of grade