Subarachnoid Fat Deposition After Lumber and Sacral Fractures: Case Imaging.

A 28-year-old man suffered multiple injuries, including a burst fracture of the L2 vertebra and bilateral sacral fractures, after a fall from a height. On day 5 of hospitalization, head computed tomography unexpectedly revealed fat deposition in the basal cistern, which was not observed on admission. Magnetic resonance imaging later showed thickened meninges and a subdural hematoma, suggesting low intracranial pressure. Although computed tomography myelography did not reveal cerebrospinal fluid leakage, imaging findings suggested a minor dural injury, likely allowing fat to migrate from the fracture site into the subarachnoid space. The patient remained asymptomatic throughout hospitalization, and a follow-up magnetic resonance imaging two months later confirmed persistent intracranial fat. This rare case illustrates that fat embolism into the subarachnoid space, though uncommon, can occur after spinal trauma and dural injury. It emphasizes the importance of sequential evaluation of imaging findings in understanding and managing complex trauma cases.