This is an application for funds to arrange and conduct the Thirteenth Princeton Conference on Cerebrovascular Disease to be held February 28, March 1-2, 1982 in Williamsburg, VA. This conference over the years has brought together the leading investigators in the field from this country and abroad to present new information, explore avenues for future research, and stimulate their colleagues in other disciplines. The resulting publication has allowed the information to be widely disseminated. The new format proposed in this application we feel will further improve the quality and timeliness of the topics to be discussed at this conference and will provide for stimulating and active discussion by all participants. The resulting publication will be a definitive statement encompassing the state of the art of knowledge on the topics addressed.