Chronic hydrocephalus as a sequela of subarachnoid hemorrhage is a complication that neurosurgeons battle with every day. This chapter presents a case study of a 49-year-old female presented to the hospital with fever and altered mental status. Computed tomography (CT) scan of the head revealed acute hydrocephalus, with ventriculomegaly and hypodensity in the surrounding whitematter representing transependymal translocation of cerebrospinal fluid (CSF). The diagnosis of acute hydrocephalus is made based on CT scan evidence of subarachnoid hemorrhage (SAH) or intraventricular blood, with or without the presence of enlarged ventricles, as well as a declining mental status. As the popularity of endovascular treatment of ruptured cerebral aneurysms has grown, there has been speculation that this treatment modality results in a higher incidence of shunt-dependent hydrocephalus. Although necessary for the treatment of chronic hydrocephalus, ventriculoperitoneal shunt (VPS) are fraught with complications.

Normal pressure hydrocephalus (NPH) is clinical syndrome of dementia, gait disturbance, and urinary incontinence that progresses over a period of weeks to years. Urinary incontinence, a late symptom, occurs in less than 50% of patients. If untreated, NPH progresses resulting in an inability to stand, akinetic rigidity, and withdrawn behavior. The differential diagnosis includes Parkinson's disease, bifrontal brain disease due to tumor, metastases, cerebral infarction, aqueductal stenosis, metabolic encephalopathy, and Alzheimer's disease. When NPH is suspected clinically, computerized tomography (with contrast enhancement) reveals ventriculomegaly, minimal or absence of cortical atrophy, periventricular lucencies, and nearly normal-sized subarachnoid space. Magnetic resonance imaging (MRI) is the study of choice to evaluate ventriculomegaly and functional imaging of cerebrospinal fluid (CSF) flow. The role of the emergency physician is to consider the diagnosis of NPH in patients with dementia and gait disturbance and to initiate appropriate referral.