[Pneumatocephalus: a clinical contribution (author's transl)].

Treatment of traumatic brain oedema leads to a decrease in raised intracranial pressure, and this may facilitate formation or progression of pneumatocephalus. Lumbar puncture or lumbar CSF drainage for treatment of CSF-rhinorrhoea/otorrhoea is occasionally responsible for the occurrence or enhancement of pneumatocephalus. Pneumatocephalus with radiological absence of fracture of the skull and absence of CSF leakage signifies communication between rhinocranium and encephalocranium: this supplies evidence of an open head injury. Post-traumatic opacification of the sphenoid sinus and presence of suprasellar air, as well as traumatic lesion of the optic chiasma are pathognomonic for the presence of a fracture of the planum sphenoidale. Computerised axial tomography is superior to plain skull x-rays in the localisation of intracerebral air.