A 62-year-old man presents with low Back Pain and lethargy. Imaging reveals a surprising finding of gas within the lumbar spine. What’s the diagnosis?
A 62-year-old man presented with a 5-day history of low back pain and a 1-day history of lethargy. Physical examination was notable for tenderness over the lumbar spine and a normal neurologic examination. Radiographs of the lumbar spine showed gas within L4. Computed tomography of the lumbar spine confirmed the presence of intramedullary gas within L4, and also showed that the gas extended into the surrounding soft tissue, epidural space, and psoas muscles. What is the most likely etiology of this skeletal finding?