Intracranial subarachnoid fat and hemorrhage secondary to sacral fracture with spondylopelvic dissociation.

We describe a case of fat droplets and blood in the cerebral subarachnoid space secondary in a patient with a complex sacral fracture without associated cranial trauma, a few days after admission. To our knowledge, there is only one published case with similar findings and without any other underlying lesion as cause. We explain the differences in the mechanism of production between this direct fat embolism and brain fat embolism syndrome, which is an intravascular embolism with different radiological appearance. The most important features of sacral fracture with spondylopelvic dissociation are described. Finally, this entity should be taken into account in the differential diagnosis of the few causes of fat in the subarachnoid space. In the context of high-energy trauma fractures of the sacrum or spine must be ruled out as a potential cause of this uncommon intracranial finding.