Inadvertent dural puncture (IDP) is one of the complications of lumbar epidural steroid injections (ESIs). We report a case in which pneumocephalus and chemical meningitis developed at the same time after an IDP during a lumbar interlaminar ESI. A 60-year-old woman presented to the emergency room with thunderclap headache and febrile sensation 3 hours after receiving a lumbar interlaminar ESI. Brain computed tomography (CT) scan showed multiple small foci of air within the subarachnoid space and ventricle. After the admission, the patient was afebrile and reported mild improvement of headache with analgesics. However, 2 days after the admission, headache worsened and fever recurred. Follow-up brain CT scan revealed resolution of the pneumocephalus. A diagnostic lumbar puncture for cerebrospinal fluid (CSF) examination revealed the findings suggestive of aseptic (chemical) meningitis rather than bacterial meningitis. With symptomatic treatment, headache improved and there was no fever after 48 hours. No bacteria, Mycobacterium, or fungi grew in the CSF for 7 days. This case shows an IDP during a lumbar ESI can cause pneumocephalus and chemical meningitis at the same time and efforts should be made to reduce the risk of IDP during lumbar ESIs.

Objective: Decompressive craniectomy (DC) is one of the treatment modalities in severe traumatic brain injury (TBI), however, there was a lack of evidence for optimal craniectomy size. The authors aimed to investigate optimal DC size and analyze clinical outcome according to craniectomy size. Methods: We retrospectively reviewed the medical data of 87 patients with a space occupying lesion following TBI who underwent unilateral DC. Craniectomy size was measured by anterior-posterior (AP) diameter and surface estimate (SE). Mortality, clinical outcome, and complications were collected and analyzed according to craniectomy size. Results: Nineteen patients (21.8%) died and 35 patients (40.2%) had a favorable outcome at last follow-up (a mean duration, 30.3±39.4 months; range, 0.2–132.6 months). Receiver operating curve analyses identified AP diameter more than 12.5 cm (area under the curve [AUC]=0.740; p=0.002) and SE more than 98.0 cm2 (AUC=0.752;p=0.001) as cut-off values for survival, and AP diameter more than 13.4 cm (AUC=0.650; p=0.018) and SE more than 107.3 cm2 (AUC=0.685; p=0.003) for favorable outcome. Large craniectomy resulted in a significantly lower mortality rate and a higher rate of favorable outcome than small craniectomy (p=0.005 and p=0.014, respectively). However, procedure related bleeding occurred more frequently in the large craniectomy group (p=0.044). Conclusion Unilateral DC size is associated with clinical outcome of patients with a space occupying lesion following severe TBI. Large craniectomy is needed for survival and favorable outcome.