This book contains articles presented at the 12th International Conference on Cerebral Vasospasm, held in Lucerne, Switzerland, in July 2013. The included papers represent a balanced cross-section of the enormous progress achieved in basic and clinical research on aneurysmal subarachnoid hemorrhage and its sequelae, including early neurovascular events and delayed cerebral vasospasm. The section on basic research covers a broad range of aspects, from pathophysiology and neuroprotection in early brain injury through to macro- and microcirculatory disturbances, inflammation and blood-brain barrier disruption, spreading depolarization, and the role of nitric oxide. There is a special focus on animal models for the study of acute events after experimental subarachnoid hemorrhage. The section on clinical topics encompasses imaging and endovascular management, surgical innovations and techniques, management and monitoring in neurocritical care, the status of clinical trials, and factors involved in aneurysm formation. This edition is of interest not only for basic researchers but also for clinicians who wish to apply state-of-the-art knowledge to the research and management of this devastating condition.