External Ventricular Drain Placement Stealth Study

External ventricular drain (EVD) placement is performed very often in neurosurgical practices. EVD's are most commonly placed at the bedside using external anatomical landmarks to guide the catheter into the frontal horn of the ipsilateral lateral ventricle. EVDs are often placed due to acute neurological compromise and require timely insertion. Accurate catheter placement is essential to achieving effective external CSF drainage without complications or occlusion/failure of the catheter. Catheter placement is most commonly performed via a freehand approach using external anatomical landmarks to help identify the location of the lateral ventricle within the brain without the aid of imaging. Proper identification of the ventricles on pre-procedure imaging, surgeon skill, and estimation of pathologic perturbations to the normal location of the ventricles all factor into the success of catheter placement. Multiple passes are often required. The accuracy rate from the freehand technique has been reported to range from 40 to 98 percent. Current methods for EVD placement do not compensate for superficial brain vessels or pathology that may alter the intracranial anatomy such as trauma, hemorrhage, or mass lesions. Some studies have attempted to use CTA imaging to identify intracranial vessels in an attempt to avoid them during placement. Image guidance is a tool used very commonly for placement of EVD's and shunts in the operating room. AxiEM Stealth is a noninvasive image localization modality that registers a CT or MRI to the individual patients facial and scalp anatomy. This study will compare the current standard of care of freehand placement of bedside external ventricular catheters to the placement of EVD catheters with AxiEM Stealth image guidance.