Traumatic Subdural Hygroma Due to Injury of an Ommaya Reservoir: A Case Report

68-year-old the emergency department after a passerby found him lying on the road with a bicycle. He had been diagnosed with neurolymphomatosis in and had an Ommaya reservoir targeted to the right lateral ventricle via the right Kocher’s point for chemotherapy. His initial mental status was stuporous. Brain computed tomography (CT) showed multiple traumatic injuries. Seven days after admission, bilateral subdural hygroma (SDG) developed. We performed CT cisternography. The contrast was directly injected into the Ommaya reservoir and CT images were obtained. On cisternography, contrast leakage points were identified from the Ommaya reservoir. The patient underwent surgery for Ommaya reservoir removal and occlusion of the permanent tract of the Ommaya reservoir. This case shows a rare etiology of traumatic SDG and demonstrates the usefulness of CT cisternography to determine cerebrospinal fluid leakage from an implant.