Causative factors of CM-associated hemorrhage are currently under investigation and remain poorly understood, though many potential mechanisms have been suggested. The current data, including original studies, meta-analyses, and literature review suggest that only prior hemorrhage prognosticated significant bleeding risk [2,11-12,20,22,25-26]. To date, no studies have directly investigated the relationship between ICP, transmural pressure, or CSF flow dynamics and CM hemorrhage. Some have suggested a correlation with hydrocephalus in general, though establishing causality in these cases is difficult as intracranial hemorrhage in general can pre-dispose to hydrocephalus [5,7]. In the present case, the patient presented with hemorrhage-related hydrocephalus from a known periventricular cavernous malformation; VPS placement on the contralateral side resulted in CM hemorrhage, which stabilized once CSF diversion, and therefore transmural pressure gradient, were decreased. This case suggests that placement of the VPS and lowering the ICP increased transmural pressure differential, which disturbed the internal flow dynamics of the CM leading to hemorrhage; increasing the valve setting, and by proxy the ICP around the CM, stabilized the hemorrhage. The apparent fragility of these pseudo-vascular lesions, and thereby their susceptibility to relatively small changes in transmural pressure differential, may be suggested by the finding that they are composed of immature, disorganized proto-endothelium. 20 This hypothesis is further corroborated by cerebral and aortic aneurysm and arteriovenous malformation data, which suggests that alterations in transmural pressure, such as by CSF drainage, blood pressure changes, and even atmospheric pressure, increases the risk of hemorrhage from these lesions [3,9,13,21]. While one may not anticipate that a CM is subject to these same factors given that they are low-flow “vascular” lesions without truly differentiated vascular elements [20,23], the temporal correlation of interventions, imaging findings, and symptoms in this case suggests possible causality. It is also of note that the peri-ventricular location of this CM may have pre-disposed to greater risk of hemorrhage from alterations in CSF flow dynamics and ICP. The present case suggests correlation between alteration in CSF flow dynamics or ICP and cavernous malformation hemorrhage, strengthened by the fact that current data supports a causal link between CSF flow dynamics, transmural pressure, and hemorrhage in other intracranial vascular lesions, and that changes in these parameters resulted in hemorrhage and subsequent stabilization. Future directions include prospective studies to establish causality between ICP changes via CSF drainage and CM hemorrhaging, and studies of vascular flow dynamics of cavernous malformations in relation to transmural pressure.