This volume contains selected works from the 25th Anniversary of the International Conference on Intracranial Pressure (ICP) held in Williamsburg, Virginia. The theme of the meeting was Intracranial Pressure and Neuromonitoring and focused on all the current state of the art brain monitoring methodologies and their application to brain injury. The brain monitoring techniques covered a wide spectrum from neurochemical monitoring of the injured brain to specialized techniques for assessing shunt function in normal pressure hydrocephalus. It also includes the most recent advances in monitoring of the brain oxygen levels using electrodes or the less invasive Near Infrared Sprectroscopy devices. Controversial issues regarding the management of ICP and CPP or both are also addressed and there are several works dealing with this topic. Of particular interest is the group of papers describing diagnosis and outcome in normal pressure hydrocephalus. It is the first compilation of papers which covers all the latest brain monitoring studies in both ischemia, trauma and hydrocephalus. The manuscripts in this volume have been selected from over 300 abstracts submitted to this international symposium. The abstracts are also published in order to provide the most comprehensive view of the progress made in brain injury research.

The small neck of the aneurysm afforded an easy surgical attack. An ordinary flat silver clip was placed over the sac and tightly compressed obliterated it completely. The clip was flush with the wall of the carotid artery. The sac, lateral to the silver clip, was then picked up with the forceps and thrombosed by the electocautery. Walter Dandy reporting his successful operation of a posterior communicating aneurysm on March 23, 1937. Walter Dandy's patient left the hospital in good health 2 weeks later, and from his report one may gain the impression that the operation was an easy task. Despite continuous developments during the following decades, it was not until the introduction of the operating microscope and microsurgical techniques that surgical treatment was generally accepted. During the microsurgical era surgical results have continued to improve due to diagnostical, neuroanaesthesi ological, and microsurgical refinements, and improved neurointensive care. Endovascular obliteration has become an important treatment alternative but this has not been included in this particular volume. The purpose of the present supplement of the ACTA NEUROCHIRURGICA is to review some of the elements in the neurosurgical management of patients with aneurysmal subarachnoid haemorrhage that are important for a successful outcome. Professor Helge Nornes has been a major force in the development of new techniques and research strategies in this area for a number of years and has recently retired from the National Hospital in Oslo."

The first international symposium on brain edema was held in Vienna/ Austria in 1965 followed by altogether eight meetings since. The most recent was organized in Y okohama by the Department of Neurosurgery of the Musashino Red Cross Hospital, Tokyo. The continuing interest of both, clinicians and experimental scientists alike may be attributable to the fact that brain edema is a common denominator of many cerebral disorders, which under acute conditions threatens life and weIl-being of afflicted patients. Although progress in understanding as weIl as treatment can be recognized since 1965 many problems remain, particularly concerning the control of brain edema under acute conditions, as in trauma or ischemia. A quantum leap was the distinction of the cytotoxic and vasogenic brain edema prototypes as advanced by Igor Klatzo, providing for transition from a morphological to functional understanding now. The recent brain edema meetings were certainly benefiting from developments of both, molecular neurobiology on the one hand side and functional brain imaging at an ever-increasing resolution on the other, such as magnetic resonance imaging orpositron emission tomography. The international symposium in San Diego 1996 may witness further breakthroughs, hopefully also of effective treatment modalities. The symposium in Y okohama was dedicated to the "Legacy of 28 Years of Brain Edema Research" as a reminder of accomplishments as weIl as remaining challenges.

25 years have passed since a small group met for the First International Symposia on Brain Edema in Vienna. Subsequent Symposia were held in Mainz, Montreal, Berlin, Groningen, Tokyo and Baltimore. During this time we have witnessed a virtual explosion of the number of publications in this field and our basic and clinical understanding of this disease process has increased tremendously. Our meetings have always been a landmark to take stock of our experience so far and to provide perspectives toward future developments. In addition, it always was a good opportunity to renew old friendship and to make new friends. This volume is a compilation of papers presented at the Eighth International Symposium on Brain Edema held on June 17-20, 1990 in Bern, Switzerland. During this Symposium 158 papers were presented as oral or poster presentations. This considerable number of papers was chosen from more than 230 abstracts that were received. The organizers wish to thank the Advisory Committee for the work done in paper selection and focus on the Symposium. Appreciation is also given to all persons, who have contributed to the success of this meeting, the Chairmen, the participants and last but not least all the staff who worked behind the scene.

The small neck of the aneurysm afforded an easy surgical attack. An ordinary flat silver clip was placed over the sac and tightly compressed obliterated it completely. The clip was flush with the wall of the carotid artery. The sac, lateral to the silver clip, was then picked up with the forceps and thrombosed by the electocautery. Walter Dandy reporting his successful operation of a posterior communicating aneurysm on March 23, 1937. Walter Dandy's patient left the hospital in good health 2 weeks later, and from his report one may gain the impression that the operation was an easy task. Despite continuous developments during the following decades, it was not until the introduction of the operating microscope and microsurgical techniques that surgical treatment was generally accepted. During the microsurgical era surgical results have continued to improve due to diagnostical, neuroanaesthesi ological, and microsurgical refinements, and improved neurointensive care. Endovascular obliteration has become an important treatment alternative but this has not been included in this particular volume. The purpose of the present supplement of the ACTA NEUROCHIRURGICA is to review some of the elements in the neurosurgical management of patients with aneurysmal subarachnoid haemorrhage that are important for a successful outcome. Professor Helge Nornes has been a major force in the development of new techniques and research strategies in this area for a number of years and has recently retired from the National Hospital in Oslo."

The control of brain edema is still one of the major problems in surgical and conservative treatment of various cerebral lesions. Many attempts have been made to develop methods for reducing the high mortality associated with brain edema. Mter many years of using hypertonic solutions it can be stated that this type of therapy has not yielded satisfactory results. During recent years increasing evidence has been accumulated on the efficacy of steroids on brain edema. Steroids were reported to result in rapid relief of signs and symptoms of increased intracranial pressure and neurological dysfunction accompanying cerebral edema. It was the aim of this workshop to evaluate the effect of corticosteroids on brain edema as an advance in therapy. It was hoped that this could be achieved by a multi disciplinary approach. Though, the volume contains the contributions of various experts - internists, neurochemists, neurologists, neuropathologists, neurosurgeons, pharmacologists, physiologists - who have added considerable experimental and clin ical evidence on the action of steroids on brain edema. New pathophysiological aspects regarding the mechanisms underlying the formation and resolution of brain The effectiveness of corticosteroid therapy in various forms edema are presented. of clinical and experimental brain edema, e. g. accompanying brain tumors, head injury, spinal cord injury, cerebrovascular lesions, etc. as well as dosage and duration of treatment are critically discussed.