[A case of cerebral fat embolism with unfavorable outcome demonstrated by temporal changes on serial brain MRI].

A 74-year-old man sustained a left femoral neck fracture following a fall on day X. Approximately four hours after the injury, he developed impaired consciousness, which persisted even after osteosynthesis was performed on day X+1. Brain MRI on day X+2 revealed multiple hyperintense lesions scattered in the bilateral cerebral hemispheres on diffusion-weighted imaging (DWI), leading to a diagnosis of cerebral fat embolism (CFE). Despite treatment with methylprednisolone and protirelin, his condition did not improve. Nonconvulsive status epilepticus was treated with levetiracetam; however, consciousness remained impaired. Serial brain MRI revealed progressive confluence of white matter lesions. Hyperintense areas on DWI in the cerebral white matter persisted into the subacute and chronic phases. Together with previous reports, this case highlights the potential association between persistence of DWI hyperintensity approximately one month after onset and poor neurological outcomes in patients with CFE.