Spontaneous otogenic pneumocephalus. Case report and review of the literature.

Pneumocephalus is commonly seen in clinical neurosurgical practice. Typical causes include trauma, tumor, and infection. Pneumocephalus may also occur iatrogenically at the time of intracranial surgery; it is not pathological and may be seen routinely on postoperative neuroimaging. Pneumocephalus is rarely encountered in the absence of the aforementioned entities. The authors report on an elderly woman in whom spontaneous intraventricular pneumocephalus occurred because of a congenital defect in the left tegmen tympani. Eustachian tube closure and middle ear exclusion were used to obliterate the fistulous connection. This case illustrates both an unusual cause and a unique treatment for spontaneous otogenic pneumocephalus.