My object in this paper is to show that sclerotic blood vessels in the brain at times so press on and actually excavate the adjacent parenchymatous tissue that clinical pictures are produced resembling those of focal lesions. In the course of study of the pathologic changes in many cases of cerebral arteriosclerosis my colleagues and I were struck by the fact that in a small number the blood vessels acted as minute expansile lesions. We saw in some instances actual erosion of brain tissue, so that eventually a small groove was formed by the sclerotic, tortuous and frequently enlarged blood vessel at the expense of the functioning structure of the brain.
This condition has not been entirely overlooked in the literature, since reference to it has been made particularly in conjunction with pressure on cranial nerves. Pappenheim,1 in 1926, claimed that trigeminal neuralgia can be caused by pressure of