Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
Sign up to receive an email alert when a new Case of the Week is posted.
February 3, 2014
Tension Pneumocephalus with “Mount Fuji” Sign
- Tension pneumocephalus is a neurosurgical emergency characterised by cerebral compression with a large amount of intracranial air.
- Patients typically present with headache, neurological deficits (usually weakness and altered sensation), low GCS, and altered mental status.
- Tension pneumocephalus occurs due to a valve mechanism that allows air to enter the cranium but prevents its escape.
- Most common cause: surgical evacuation of a subdural hematoma. Other etiologies: brain biopsies, PNS surgeries, head trauma and, rarely, spontaneous.
- Key Diagnostic Features: The CT scan typically shows the “Mount Fuji” sign (the name is derived from a volcanic mountain in Japan that is known for its symmetrical cone), where a large amount of air can be seen compressing and separating both frontal lobes. The symmetrical depression near the midline is due to bridging veins.
- Rx: Urgent decompression by means of a burr hole, craniotomy, or needle aspiration, and subsequent closure of the defect