The cerebral Arteriovenous Malformation system (AVM) or fistula, is a network with large caliber vessels that yields an alternate pathway for blood flow between arteries and veins. Neurosurgical and interventional radiological techniques are the common way to treat AVM patients so that the normal capillary blood flow would be restored. Several patients who underwent this procedure had different degrees of brain swelling and subsequent hemorrhage. To understand this, Blesser et al. developed a simplified model to simulate the effect of AVM occlusion on cerebrovascular pressure and flow. Their model does not include the cerebrovascular regulatory mechanism which is an important part in cerebral pressure and flow regulation. Three different factors that may affect the hemodynamic response after AVM occlusion were investigated in this work. They are: autoregulation mechanism failure, sympathetic nervous system dysfunction and increased intracranial pressure. The revised model predicted the relationship between each of these three factors and the severity of the hemorrhage. The simulation results predicted that autoregulation mechanism dysfunction is the most important factor of all three factors, whereas increased intracranial pressure is the least important factor. Possible future study would include developing a model where autoregulation failure and sympathetic system dysfunction are considered simultaneously and the addition of other possible pathologies such as the failure of chemical regulation mechanisms, and to investigate the relationship between these factors and the potential for hemorrhage.