Spontaneous extradural haematomas.

Spontaneous extradural haemorrhage may be due to neighbourhood infections, vascular malformations of the dura mater, and disorders of blood coagulation. Two cases are described here: in one, infection was present; in the other, there was a berry aneurysm of the middle meningeal artery with a small parietal dural angioma. Operation was successful in both patients.