While the symptoms of cerebral hemorrhage and of cerebral embolism are well understood, the differentiation between a more or less slowly progressive degeneration of the brain secondary to thrombosis of larger or smaller cerebral arteries and some forms of infiltrating tumors is not so clearly defined, and the differential diagnosis between these two pathologic states and cerebral degeneration due to an infiltrating new-growth which has involved a large brain artery is often difficult.
When this study was undertaken, it was planned to consider the diagnosis between cerebral degeneration from thrombosis, and cerebral neoplasm, and we studied the records of our cases in which gross cortical softening and other degenerative changes had been found at the operating table. We then discovered a number of records of patients in whom a degenerated cortex had been exposed and a diagnosis of a vascular lesion had been made at the time of the operation.