Symptomatic air trapped in the spine after lumbar epidural corticosteroid injection. Case report.

The authors report the first case involving trapped epidural air in the spine that mimicked a mass lesion and caused neurological symptoms after epidural corticosteroid injection in the lumbar region. New neurological symptoms developed immediately after injection, and magnetic resonance (MR) imaging demonstrated trapped air displacing the dural sac. After the patient underwent conservative treatment, the new symptoms resolved, and follow-up MR imaging and computed tomography demonstrated resorption of the epidural air in the lumbar region. To limit this problem, the clinician should decrease the amount of air injected in the epidural space or substitute nitrous oxide for air when injecting steroid agents epidurally.