Spontaneous pneumocephalus of an otogenic origin.

@article{Vallejo1999SpontaneousPO,
  title={Spontaneous pneumocephalus of an otogenic origin.},
  author={Luis Angel Vallejo and Luis Mar{\'i}a Gil-Carcedo and Jose Maria Borras and Jos{\'e} Ribas Milanez de Campos},
  journal={Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery},
  year={1999},
  volume={121 5},
  pages={662-5}
}