This volume contains the papers presented at the First International .ijm- posium on Intracranial Pressure, held at the Neurosurgical Clinic of the Medizi- nische Hochschule Hannover (Hannover Medical School), July 27 to 29, 1972. The texts submitted have been included in their original form whenever possible. The editors have made only minor corrections and rearrangements, since rapid publication was considered to be more important than homoge- neity in style. The sessions of this book correspond to the sessions of the sym- posium. At the end of each session the reader will find a summary of the topics presented and discussed, especially prepared by the chairman and co-chairman concerned. Three main aspects ofICP were dealt with at the Symposium: Methodology (Sessions 1 and 2), Pathophysiology (Sessions 3 to 6), and Clinical Aspects (Ses- sions 7 to 10). Following the symposium a special round table was held on the major topics covered by the meeting. The participants of this round table discussed drafts prepared by T. W. LANGFITT, B. JENNETT and N. LUNDBERG. These contributions have also been included as special chapters at the end of this book, and are believed to reflect the current attitudes as to the topics discussed.