[Subdural tension pneumocephalus after trephination for chronic subdural hematoma]

Symptomatic tension pneumocephalus developed after an evacuation of chronic subdural hematoma is reported. In this 71 year-old man, a rapid deterioration of consciousness was noted 5 days after a trephination for bilateral chronic subdural hematomas. An evacuation of hematoma was performed under a local anesthesia, and the preoperative and immediate postoperative course was uneventful. Subdural tension pneumocephalus was confirmed by typical CT findings and treated by re-trephination and drainage. The literature on the tension subdural pneumocephalus was reviewed, and the mechanism of its development was briefly discussed.