Surgery on the vertebral column risks spinal cord, nerve root, brachial plexus and peripheral nerve injury. Spine surgery was one of the first and remains one of the most frequent indications for neurophysiology intraoperative monitoring (NIOM). This chapter outlines the anatomy, pathology, symptoms and surgery of common vertebral column disorders and then details NIOM techniques, interpretation and technical issues. It emphasizes spinal cord monitoring; nerve root protection techniques. Scoliosis consists of abnormal vertebral column curvature in the coronal plane. Some other surgical spinal disorders that may require NIOM include cervical spondylosis, spinal fractures, vertebral column tumors and ossification of the posterior longitudinal ligament (OPLL). Vertebral column tumors cause pain, radiculopathy and myelopathy when cord compression is present. Motor evoked potential (MEP) monitoring has become a regular component of spinal cord monitoring during spine surgery. Somatosensory evoked potential (SEP) monitoring halves the risk of major neurologic deficits during spine surgery.

The practice of anesthesia has historically relied on the induction of a reversible state of amnesia, analgesia and motionlessness. With the improvement of medical technology, advancement of knowledge and practice of evidence-based medicine, modern anesthesiology comprises a great deal more. It has become the role of the anesthesiologist during surgical, obstetrical and diagnostic procedures to provide anesthesia, optimize procedural conditions, maintain homeostasis and, should it be necessary, manage cardiopulmonary resuscitation. Additionally, anesthesiology has found itself branching out into chronic and acute pain treatment as well as the intensive care unit. There are four basic types of “anesthesia”: general anesthesia, regional anesthesia, local anesthesia and sedation. Intravenous anesthetic agents are generally used to induce anesthesia and afterward to supplement inhalation maintenance anesthesia. A variety of anesthetic techniques are acceptable for use during neurophysiology intraoperative monitoring (NIOM).

Neurophysiology intraoperative monitoring (NIOM) plays a vital part in patients reaching that healing destination, but arriving there is dependent on a well-thought-out and executed plan. This chapter focuses on the development of that plan and serves as a background from which one can either begin constructing policies and procedures (P&P) or revisit and edit policies already in place. The purpose of NIOM is to collaboratively work with the multidisciplinary surgical team in order to preserve, safeguard and improve neurologic function. The P&P needs to guide best practices for communicating to the team, and to back that up, it all should be documented. The patient is at the center of all that we do in health care organizations. The P&P should pay particular attention to patient safety. Continuing education is a big part of not only ensuring the best, most up-to-date practice, it also improves patient safety.

For new neurophysiologic intraoperative monitoring (NIOM) staff, the operating room can be a very intimidating environment. Becoming familiar with various operating room personnel, equipment and workflow, as well as understanding proper etiquette and safety precautions, is of upmost importance to becoming comfortable in the operating room environment. This chapter helps familiarize new NIOM staff to the operating room, thereby allowing for a successful and safe monitoring procedure. NIOM equipment that will enter the sterile field must be properly sterilized before being brought into the operating room. There are many people, such as surgical team, anesthesiology team, nursing team, and room attendant, present in the operating room, and the chapter discusses each person’s roles and how their roles relate to NIOM. Performing NIOM in the operating room requires additional knowledge beyond evoked potentials (EP), electroencephalography (EEG) and electromyography (EMG).

This chapter outlines a history of training in neurophysiology intraoperative monitoring (NIOM) for both the neuromonitorist and the interpreting physician, discusses requisite education for NIOM providers, summarizes current standards, and explores the horizons of formalized NIOM education programs. Penfield and Jasper were the first to use neurophysiology testing in the operating room (OR) in the 1930s. They employed electrocorticography to help guide the resection of epileptogenic brain tissue. Brainstem auditory evoked potential (BAEP) and cranial nerve electromyography (EMG) monitoring was refined in the 1980s. Various professional organizations have recognized the need to provide NIOM education to interpreting physicians. The past decade has seen an increase in the number of neurodiagnostic training programs, some of which are online only. Like any other health care professional, the neuromonitorist requires both didactic learning and clinical training.

This chapter briefly reviews the relevant anatomy, pathophysiology and surgical treatment of lumbar spine disease, and then describes the techniques used for neurophysiologic intraoperative monitoring (NIOM) aimed at reducing the risk of these postoperative complications. Patients with symptomatic lumbar spine disease are usually managed conservatively with analgesic medications, physical therapy and/or spinal injections. Discectomy is the surgical removal of herniated disk material to decompress the spinal canal or nerve roots. Mixed nerve somatosensory evoked potentials (SEP) and transcranial electrical motor evoked potentials (MEP) are the NIOM techniques most often used for spinal cord monitoring, but they are not sensitive for detecting nerve root injuries. Electromyography (EMG) has become the neurophysiologic technique most often used to monitor nerve root function during lumbosacral spine surgery. A monopolar stimulating electrode is generally preferable during lumbosacral spine surgeries to avoid current shunting from fluid within the operative field.

This chapter provides legal basics and risk management concepts to provide guidance to help reduce liability risk associated with neurophysiology intraoperative monitoring (NIOM). Policies and procedures can also be used to determine the applicable standard of care for NIOM services, and their content may incorporate professional guidelines and accreditation standards as well. In cases involving NIOM, the standard of care, as in most malpractice cases, will likely be established by expert witnesses. In terms of legal liability, it is not unexpected for a hospital to be dragged into a lawsuit related to NIOM service provided at the hospital. There are three distinct components involved in NIOM: technological, interpretive and diagnostic or interventional. In general, a qualified neurophysiologist must supervise and monitor a hospital’s NIOM services. This includes credentialing, updating policies and procedures and supervising both clinical and administration NIOM services.

Motor evoked potentials (MEPs) are one of the most powerful tools in the neurophysiology intraoperative monitoring (NIOM) arsenal, particularly for spine surgeries. Surgeons are typically most concerned about preserving a patient’s ability to move, and MEPs are the modality that monitors this function directly. This chapter briefly discusses the relevant anatomy of the pathways monitored and describes the methodology for stimulation and recording of signals in a conducive environment based on optimized anesthetic parameters. It also discusses troubleshooting, mechanism of waveform changes and warning criteria. MEP responses can be recorded over the spinal cord in the epidural or subdural space or in the muscles. Myogenic responses are most frequently recorded while epidural/subdural recordings of the D-wave are typically reserved for spinal cord tumor surgeries. MEPs in general are an excellent technique for detecting injury to the corticospinal tract. MEPs are a powerful tool in the monitoring arsenal.

The neurophysiology intraoperative monitoring (NIOM) of spinal cord function has been used for spinal fusion and instrumentation surgeries by orthopedic surgeons, surgeries of thoracic and tho-racoabdominal aorta and cardiac surgeries requiring cardiopulmonary bypass by cardiothoracic surgeons, coarctation repair by vascular surgeons and surgeries of intramedullary and extramedullary tumors and arteriovenous malformations (AVMs) of the spinal cord by neurosurgeons. This chapter focuses on NIOM in the spinal cord surgeries, especially spinal cord tumors. During surgery, spinal cord injury may occur either by direct physical damage or by ischemic insult to the spinal cord. Historically, the standard for NIOM of spinal cord function has been the monitoring of somatosensory evoked potentials (SEPs). More recently, transcranial electrical motor evoked potentials (MEPs) evaluating the anterior spinal cord and motor pathways have become available. Spinal cord tumors are most often classified based on their location, namely, extradural tumors, intradural extramedullary tumors, and intramedullary tumors.

Selective dorsal rhizotomy (SDR) is a procedure used to reduce spasticity in the lower extremities in patients with bilateral spastic paresis. The surgical procedure is usually performed on patients with cerebral palsy (CP). The purpose of SDR is to reduce the excitatory input of the spinal cord in the lower limbs while preserving motor and sensory function. Children with CP often require long-term rehabilitation with physical and occupational therapy. This chapter introduces the procedure and disease with a discussion on the relative anatomy and pathophysiology. It discusses the neurophysiologic intraoperative monitoring (NIOM) paradigm and utility of NIOM in SDR, and describes technical considerations, preparation, procedure and postprocedure. The spinal cord is a central neuronal bundle with rootlets extending laterally from all spinal levels. SDR is usually performed in an inpatient operating room under general anesthesia.