Atraumatic pneumocephalus: a case report and review of the literature.

Pneumocephalus or air within the cranial vault is usually associated with disruption of the skull caused by head trauma, neoplasms, or after craniofacial surgical interventions. We report a child who presented with headache and the pathognomonic "succussion splash" and was found to have atraumatic pneumocephalus from forceful valsalva maneuvers. Pneumocephalus forms, caused by either a ball-valve mechanism that allows air to enter but not exit the cranial vault, or cerebrospinal fluid (CSF) leaks, which create a negative pressure with subsequent air entry. We review the literature for traumatic and atraumatic causes of pneumocephalus, its complications, and therapy.