Emerging Subspecialties in Neurology: Neurophysiologic intraoperative monitoring

Abstract

In the last 30 years, neurophysiologic intraoperative monitoring (NIOM), also referred to as surgical or operative neurophysiology, has evolved from a part-time preoccupation of a few neurologists to a subspecialty in neurology with dynamic career opportunities. NIOM uses a variety of neurophysiologic signals to warn surgeons and anesthesiologists when the nervous system is at risk of injury during a surgical procedure. Several studies have shown that these warnings often lead to modification of the surgery and consequent reduction in surgical morbidity.1,–,3 The use of intraoperative neurophysiologic techniques to aid surgery can be traced to Wilder Penfield and Herbert Jasper's use of electrocorticography for resection of epileptogenic cortex in the 1930s.4 However, it was not until the 1970s that neurophysiologic techniques began to be used during surgeries to reduce the risk of injury to the nervous system.5 During the early years, NIOM equipment was “homemade” by neurophysiologists, who served the function of not only interpreting physician but also biomedical engineer and technologist. By the 1980s and 1990s, research documented the clear utility of somatosensory and brainstem auditory evoked potentials (SEP, BAEP), EEG, and EMG in reducing morbidity of many types of surgeries.1,6 Commercial NIOM equipment became available, and academic hospitals started offering NIOM services. Technologists became available with specialized training and certification in NIOM through the American Board of Registration of Electroencephalographic and Evoked Potential Technologists. The technologists were able to help set up the monitoring and run the NIOM equipment. …