Ischemic and hemorrhagic stroke occur 15-20 million times a year and form a major cause of maternal mortality and morbidity. X-ray angiography is one of the most important modalities to image the cerebral circulation and diagnose stroke related symptoms. In a previous study we used a 1D wave propagation model and 3D CFD to simulate blood flow in the cerebral circulation and support the interpretation of diagnostic measurements performed in the cinic (PhD thesis: Gwen Mulder 2011). In a current study (Wouter Donders) we extend the model with an autoregulation model and develop tools to analyze sensitivity for model parameters and uncertainty due to variability in input data.