Neurologic illness represents a major portion of clinical medicine and challenges the diagnostic and therapeutic acumen of all physicians. It is the purpose of this series to familiarize our colleagues with common clinical disorders and to emphasize not only examination techniques but also to discuss therapeutic and investigative implications. Pitfalls will also be emphasized. In this way, we hope to create a practical set of volumes that will stimulate the reader to "use" these books routinely rather than to set them on the shelf as a reference text. In the past few years, there has been a revolution in the field of neurology with the development of new techniques for brain imaging and further understanding of the role of neurotransmitters. We hope to meet the needs of our colleagues by this practical clinical series. MICHAEL I. WEINTRAUB, M.D. April,1983 ACKNOWLEDGMENTS Hysterical conversion reactions (HCR) are among the most common clinical states confronting the physician. Despite the ubiquity of this condition there has been a virtual absence of a standard text on the subject. For over twelve years I have reflected on this topic and have felt the need for a book that would instruct my medical colleagues to deal accurately and effectively with this problem. I was fortunate to work with Dr. Bernard H. Smith who introduced me to the wide spectrum of HCR. Drs. Gilbert H.