Image Guided EVD Placement

To determine if use of the Stryker Nav3 image guidance system offers superior results in external ventricular drain (EVD) placement compared to the standard free-hand technique.

Inclusion Criteria:patients requiring EVD placementpatients who can safely and reasonably be randomized to either study armpatients with available pre-procedural head CTwritten/verbal consent obtainedExclusion Criteria:patients with very small ventricles/distorted ventricular anatomy from traumatic brain injury (ie it is not reasonable to randomize the patient)scenarios where the EVD must be inserted immediately and there is not time to obtain consentscenarios where bedside image guidance system (NAV3) is unavailablesubjects medically or neurologically unstable to obtain pre-EVD CT scanEVD revisions on ipsilateral side during same admission