A subdural hygroma is characterized by an accumulation of cerebrospinal fluid (lacking blood) within a separation of the dura-arachnoid space. A hygroma can develop following traumatic head injury, meningitis, ventriculoperitoneal shunting (secondary to the sudden decrease in intracranial pressure), or, infrequently, as a result of a tearing of an arachnoid cyst. Generally, hygroma can be differentiated from hematoma using CT scan although chronic subdural hematomas may more closely resemble hygroma via CT, in which case MRI scans are utilized. Clinically, hygromas produce similar symptoms as hematomas. These include drowsiness, confusion, irritability, and low-grade fever, which dissipate when the CSF is drained (Victor and Ropper 2001). Most subdural hygromas resolve with adequate reexpansion of the brain (Lee 1998).