Pneumocephalus

PNEUMOCEPHALUS (from Greek pneuma-air and kephale-skull), penetration of air into the cranial cavity. Synonyms of P.: pneumocrania, pneumocele, pneumocystacerebri, pneumocephalus, Pneumoventrikel, emphysema cerebral. Observed mainly in head injuries, especially during wartime, as well as in pathological processes (e.g., in tumors) that lead to the development of communications between the cranial cavity and the external environment. The communication may not be direct, for example, it may pass through the accessory nasal cavities. Depending on the location of the air, one speaks of p. extracerebralis (air outside the brain, i.e., in the meninges), of p. intracerebralis (air in the brain substance) and of p. combinata (Guttmann).