Neurophysiological Monitoring during Intensive Care and Surgery. By N. Jollyon Smith, M.A., F.R.C.P., Mark van Gils, Ph.D., and Pamela Prior, M.D., F.R.C.P. Amsterdam, Mosby/Elsevier, 2006. Pages: 390. Price: $69.95.

Permanent damage to the nervous system resulting from injury sustained during neurosurgical, orthopedic, or vascular procedures is often devastating. Prevention of this much feared complication depends on proper surgical technique and on early detection of untoward events to ensure prompt corrective action. Early detection depends almost exclusively on the use of neurophysiological techniques to monitor the integrity of neural pathways during the surgical procedure. Despite remarkable technological advances, the practice of neuromonitoring remains a complex endeavor because it relies on small bioelectric signals that must be recorded rapidly and reliably in electrically hostile environments during complicated, often challenging clinical situations. This book offers a comprehensive review of this complex and fascinating field. The editors have recruited expert European neurophysiologists to provide in-depth coverage of all relevant topics. Although the emphasis clearly is on monitoring the integrity of neural pathways, depth of anesthesia monitoring and the detection of unintentional intraoperative awareness are also well covered. A variety of anesthesia monitors (cerebral function analyzing monitor [CFAM; RDM Consultants, Uckfield, Sussex, United Kingdom], advanced depth of anesthesia monitor, Bispectral Index [Aspect Medical Systems, Norwood, MA], Patient State Index [Hospira, Lake Forest, IL], Narcotrend [Arbeitsgruppe Informatik/Biometrie Anästhesie Klinikum, Hannover, Germany], entropy measures [GE Health Care, Helsinki, Finland], AEP Index [Danmeter A/S, Odense, Denmark]) are presented along with a very interesting historical review of the early use of the electroencephalogram during chloroform anesthesia by the neurologist Hans Berger, M.D. (University of Jena, Jena, Thuringia, Germany) (1873-1941) (who in the 1920s made the first recordings of the electroencephalogram in humans) and of the early attempts to develop automated monitors.

The book covers all aspects of neurophysiological monitoring: the physiologic bases of biologic potentials (electroencephalogram, sensory and motor evoked potentials, electromyogram/nerve conduction), the methodological principles for recording these responses, the effects of pathological and pharmacological factors. Attention is also given to the critical issue of interpretation of the findings, with a detailed section of how to assess the results of monitoring efforts (sensitivity, specificity, predictive value). The neurophysiological instrumentation required for recording biopotentials is described clearly for each application (electroencephalogram, sensory and motor evoked potentials, electromyogram) with explanations of the technical aspects involved (electrode placement, process of amplification, signal acquisition and processing), including safety considerations. A chapter is devoted to normal and pathologic phenomena in electroencephalogram, evoked potentials, and electromyogram/nerve conduction studies. This information, which is rarely found in anesthesia-oriented monitoring books, is elegantly presented and provides a gentle introduction to the topic. There is abundant information on neurophysiological monitoring during sedation and anesthesia, as well as on the clinical conditions observed in intensive care units. The chapter on neurophysiological monitoring during surgical operations (scoliosis correction, interventions on or near cranial nerves) is admittedly the most important for the nonspecialist. It offers clear and concise descriptions of the current techniques with a fairly balanced view of their performance. I would, however, have liked a more elaborate coverage of the techniques generally considered the most useful, such as sensory and motor evoked potentials during scoliosis surgery or facial nerve electromyogram during posterior fossa surgery (as opposed to, for example, the use of electroencephalogram or evoked potentials to decrease neurologic deficit after cerebral aneurysm surgery or carotid surgery). The chapter on advanced signal processing (filtering, artifact detection/exclusion, and wavelet analysis, among others) and statistical methods (pattern matching, process control, decision assistance, and others) shows what developments to expect in the future. The last chapter concerns the legal implications of monitoring and includes practical advice on good practice.

This is an attractive book that will primarily interest those already familiar with the field. It will not replace basic textbooks devoted to the electroencephalogram and evoked potentials, but it provides a broad, contextual overview of this critical field along with a detailed description of the relevant physiologic, technological, pharmacological, and pathologic factors involved. It will also be of great value as a comprehensive reference in departmental libraries, where it may also well attract the attention of keen students and residents interested in monitoring the nervous system during anesthesia and surgery.

Montreal Neurological Hospital, McGill University, Montreal, Quebec, Canada.