Data will be collected that reflects the duration of the patient's hospitalization at Duke University through chart abstraction. The study period will be defined as admission to discharge. The attending physician has, and will continue to, determine the appropriateness of the duration of ICP monitoring, NCCU discharge criteria and hospital discharge criteria. Chart abstraction will be completed daily to obtain the ICP values and CSF volumes during that period of time for which the patient has a ventriculostomy.