This 16th volume of Advances in Neurosurgery contains a selection of pa pers presented at the 38th Annual Meeting of the German Society of Neurosurgery, held in Munster on 3-6 May 1987. The program committee had to choose these contributions from a total of 161 presentations. I am very much obliged to the members of the committee who contributed their experience and effort to the organization of the scientific pro gram: Prof. Dr. R.A. Frowein, Prof. Dr. W.J. Bock, Prof. Dr. E. Kazner, Prof. Dr. G. Lausberg, Prof. Dr. M. Klinger, and Prof. Dr. M. Brandt. The aim of the Meeting was to exchange...