Pseudo-aneurysms in relationship to massive cerebral haemorrhage

This paper deals with two types of small body which are found within or close to a massive intracerebral haemorrhage. These bodies have, in the past, been confused with true aneurysms (Charcot and Bouchard, 1868), and for many years it was generally accepted that they were causally related to the main haemorrhage. In 1909 Ellis examined many of these structures from 34 brains with cerebral haemorrhage and con-cluded that they were not dilatations of arteries but were in fact nothing more than perivascular collec-tions of blood clot which had escaped from small vessels by simple rupture of the wall or by a gradual dissection of the layers. Nevertheless, he believed that these blood clots or 'false ' aneurysms were