Epidural Steroid Injection Complicated by Intrathecal Entry, Pneumocephalus, and Chemical Meningitis

BackgroundEpidural steroid injections are frequently used to treat back and extremity pain. The procedure is generally safe, with a low rate of adverse events, including intrathecal entry, pneumocephalus, and chemical meningitis.Case ReportWe report a case of a 45-year-old woman who presented to the emergency department (ED) with headache, nausea, vomiting, and photophobia after a lumbar epidural steroid injection. She was afebrile and had an elevated white blood cell count. A non-contrast computed tomography scan of the head revealed pneumocephalus within the subarachnoid space and lateral ventricles. The patient was admitted to the ED observation unit for pain control and subsequently developed a marked leukocytosis and worsening meningismus. A lumbar puncture was performed yielding cerebrospinal fluid (CSF) consistent with meningitis (1,000 total nucleated cells, 89% neutrophils, 85 mg/dL total protein, and no red blood cells). Gram stain revealed no bacteria. The patient was admitted on empiric vancomycin and ceftriaxone. Antibiotics were discontinued at 48 h when CSF cultures remained negative and the patient was clinically asymptomatic.Why Should an Emergency Physician Be Aware of This?Emergency physicians should consider intrathecal entry and pneumocephalus in patients who present with a headache after an epidural intervention. The management of pneumocephalus includes supportive therapies, appropriate positioning, and supplemental oxygen. These symptoms can be accompanied by fever, leukocytosis, and markedly inflammatory CSF findings consistent with bacterial or chemical meningitis. Empiric treatment with broad-spectrum antibiotics should be initiated until CSF culture results are available.