The book discusses the application of evoked potentials recording in comatose patients admitted to Intensive Care Units and in patients undergoing surgical procedures that require direct monitoring of central nervous system function. In particular, it addresses patients undergoing neurosurgical operations, such as posterior fossa surgery, operative treatment of intracranial aneurysms, spinal cord surgery, cerebrovascular surgery, and operations on the descending aorta. Evoked potentials have been widely employed in neurology since the computer-assisted averaging technique became readily accessible to neurologists. More recent applications are discussed in this book. These require a different approach for monitoring the unconscious patient, often in a rapidly changing clinical situation. Applications of the different stimulus modalities are discussed in relation to the clinical situation of individual patients. SEPs and BAEPs find the widest application in the operating theatre and in evaluating comatose patients.