Lumbar Subdural Hemorrhage
Findings:
Multiple MR images demonstrate abnormal T1 hyperintensity and relative T2 hypointensity within the ventral margin of the lumbar thecal sac. Changes of lower lumbar degenerative disc disease are incidentally noted.
Discussion:
This patient underwent an epidural blood patch procedure for treatment of potential CSF leak. The blood patch was inadvertently placed in the ventral subdural space and not epidural.
Non-iatrogenic lumbar subdural hematomas may have a more irregular appearance and could be caused by trauma or coagulopathy. The hemorrhage is thought to accumulate between dural layers due to rupture of radiculomedullary veins that cross the subdural/subarachnoid space. Rupture of extraarachnoidal vessels on the inner dural surface could also cause this.