Chapter 30 - Intraoperative neurophysiology of the peripheral nervous system

Abstract

The surgical management of peripheral nerve pathology is facilitated with the addition of information describing the functional status of the nerve at the region of pathology and at the time of surgery. Intraoperative recordings of compound nerve action potentials (CNAPs) can provide quick, reliable information on the functional status of peripheral nerves at the time of surgery. The technique is straightforward and can be easily used by those without a lot of previous experience monitoring peripheral nerves. It requires no unusual instrumentation and is very cost-effective. It does not compromise routine surgical exploration of a peripheral nerve injury. The information provided by these studies is very useful in determining the best course of action to deal with a particular peripheral nerve injury. The indications of early, successful peripheral nerve regeneration observed in these studies cannot be obtained in any other way. Thus the method should not be viewed as a “monitor” of peripheral nerve activity—the information is diagnostic and essential. We will not consider peripheral nerve “monitoring” in this chapter but rather focus on the operative evaluation of peripheral nerve function. We encourage the use of this technique as a means of evaluating a peripheral nerve injury and deciding the best way to deal with it. To facilitate the application of intraoperative recordings, this chapter will include a description of the methodology, an interpretation of the findings of intraoperative recordings, some background in the pathophysiology of nerve injury and regeneration, and a practical section on troubleshooting to assist those who are just beginning to use this technique.