The last twenty years have witnessed a remarkable development in neurology. Investigation of the effects of war injuries of the spinal cord has greatly increased our knowledge of reflex action in man. The appearance of encephalitis lethargica and the multiplication of forms of acute disseminated encephalitis have added a new field to clinical neurology and brought it into relationship with the new branch of bacteriology which studies the filterable viruses. The discovery of important metabolic centres in the hypothalamus has enhanced the importance of neurology to general medicine. Advances in the technique of neurological surgery have aroused fresh interest in the symptoms and in the pathology of intracranial tumours. Other developments, scarcely less important, have occurred.
Much of this new knowledge is physiological, and in one respect I have departed from the traditional arrangement of a textbook of nervous diseases. Neurology is more dependent than many other branches of medicine upon anatomy and physiology. These subjects, the essential basis of neurological diagnosis, are usually dismissed in a few introductory pages, with the result that much clinical neurology is apt to be both unintelligible and uninteresting to the student. In the first part of this book, as an introduction to the subject, I have discussed—at greater length than usual—the application of anatomy and physiology to the interpretation of the physical signs of nervous disease. Elsewhere will be found sections dealing with anatomy and physiology as introductions to clinical sections. In planning the clinical sections I have used what seemed the most practical, if not always the most logical, arrangement, for there is no entirely satisfactory way of arranging subjects, many of which might be placed in more than one group.
Limitations of space restrict the number of references which it is possible to quote. I have, therefore, chosen only those of special interest and those which form the best introduction to a subject, or are themselves useful sources of references. To the many other writers upon whose work I have freely drawn I express my indebtedness. I am indebted also to a number of my colleagues for the loan of illustrations.
Finally, I welcome this opportunity of expressing my gratitude to my colleagues at the London Hospital for their teaching, encouragement, and help, especially to Dr Charles Miller, Professor Arthur Ellis, and Dr George Riddoch, under whom I had the privilege of working on the Medical Unit, and to Mr Hugh Cairns, Dr Dorothy Russell, and Dr S. Phillips Bedson.
W. Russell Brain