Clinical Reasoning: Pneumocephalus and pneumorrhachis in a 67-year-old man.

SECTION 1 A 67-year-old man was admitted to the medical intensive care unit at a hospital in eastern Bavaria. The patient presented with back pain, fever (38.7°C, 101.7°F), disorientation regarding time, place, and his own identity, and drowsiness, all of which had developed in recent weeks. Apart from these findings, the neurologic examination was unremarkable. One day before admission, the patient had been placed on an IV broad-spectrum antibiotic regimen of ceftriaxone and combined piperacillin and tazobactam in response to increased infection parameters. In addition to the man’s febrile temperature, his leukocyte count was elevated to 12,500/mL; however, examinations of urea, electrolytes, blood sugar, and liver and thyroid functions yielded unremarkable findings. In the absence of a specific focus from the internal medicine perspective, the possibility of meningoencephalitis was considered. A cranial CT study detected diffuse subarachnoid pneumocephalus with generalized accumulation of gas in the cranial cavities (figure 1). There was no recognizable point of entry for the gas.