Although most textbooks of neurology contain a certain amount of pathological information, neuropathology has often been treated in isolation. However, neuropathology has a close relationship to clinical neurology, neurosurgery and neuroradiology. Thus, advances in the rapidity and accuracy of pathological diagnosis have often led to changes in clinical management and, recently, improvements in clinical diagnosis, particularly CT scanning, have brought about a change in emphasis in the practice of neuropathology. In this textbook we have sought to present a widely based account of neuropathology in combination with information from clinical experience. We chose this approach in order to emphasize the close interrelation between clinician and pathologist. The book grew out of a course organised jointly by two neurologists and two neuropathologists from the Depart­ ments of Neuropathology and Neurology of The London Hospital and The University of Southampton. It is hoped that the book will be useful not only to pathologists, neurologists, neurosurgeons, and neuroradiologists, but also to general physicians. In a period of rapid advance in knowledge it is important to recognise how changes in the clinical and laboratory disciplines overlap. In order to make the most of consultations with pathologist colleagues the clinician must know what skills and techniques are available in the laboratory, and similarly, the pathologist must keep abreast of changes in clinical practice. In the past the clinician and pathologist have often been slow to appreciate advances in each other's fields.