This volume of Advances in Neurosurgery 7 presents the papers held at the Joint Meeting of the American Academy of Neurological Surgery and the "Deutsche Gesellschaft fUr Neurochirurgie" in October 1978 in Munich. This exchange of thoughts on scientific methods in neurosurgery on both sides of the globe, i.e., both in the United States and in Germany, covered a number of different topics in the field of neurosurgery, with special emphasis on the following subjects: Intracranial vascular surgery and specialized neurosurgical techniques used for different operative approaches to the skull, brain, pituitary gland, and peripheral nerves. Contributions to the field of computer tomography, traumatology, functional and experimental neurosurgey, as well as chemotherapy rounded off the broad exchange of thoughts. In particular, the variety of the problems discussed, gives insight into the present state of our special field and shows progress and new points of departure. Special gratitude is expressed to the Springer-\Tedag for its help in editing the Ad vances in Neurosurgery, Volume 7. Miinchen, September 1979 EMARGUTH v Opening Oration F. MARGUTH I should like to welcome all of you wholeheartedly to the Joint Meeting of the American Academy of Neurological Surgery and the Deutsche Gesellschaft fUr N eurochirurgie. I welcome especially our collegues from the United States and the ladies."

This volume is dedicated to the Third International Symposium on Microneurosurgical Anastomoses for Cerebral Ischemia, which took place in Rottach-Egern, June 2&-30, 1976, under the sponsorship of Professor F. Marguth, Director of the Depart- ment of Neurosurgery, Ludwig-Maximilians-University of Munich (West Germany). It contains the continuing devel- opments of the extra- intracranial arterial bypass (EIAB) for cerebrovascular occlusive disease since the First International Symposium in Lorna Linda, California, in June, 1973, and the Second International Symposium in Chicago, Illinois, in June, 1974. The EIAB was developed by Donaghy and Yasargil, and it consists of a microsurgical anastomosis of the superficial tem- poral artery or the occipi tal branch of the external carotid artery to the middle cerebral artery on the surface of the brain and, very recently, the anastomosis of the occipital artery to the posterior-inferior cerebellar artery for the treatment of verte- brobasilar insufficiency. From the presentations at the sym- posium it became evident that the greatest potential in the pre- vention of a stroke in a susceptible patient is the presence of an adequate collateral cerebral blood flow. The basic diagnostic procedure is cerebral angiography in- cluding both carotid and vertebral arteries. Regional cerebral blood flow (rCBF) studies and computerized tomography add further diagnostic information and are particularly important in the selection of potential surgical candidates.