Spontaneous otogenic pneumocephalus.

A very rare case of otogenic pneumocephalus in a healthy 24-year-old man with a widely pneumatized right mastoid, precipitated by forceful Valsalva's maneuver, is reported. When a pneumocephalus is suspected, computed tomography scans are mandatory. The pertinent literature is discussed and the potential mechanisms causing spontaneous pneumocephalus are described. To the best of our knowledge, only two other similar cases have been reported up to now.