Hemorrhage into the substance of the brain is one of the commonest lesions of the human body, being eclipsed, insofar as the central nervous system is concerned, only by occlusion of a major arterial channel. In the great majority of cases such hemorrhages are the result of rupture of an arteriosclerotic vessel, being precipitated by an elevated blood pressure. Other essential causes of intracerebral arterial rupture, such as trauma, embolism, ruptured aneurysm or vascular anomaly, blood dyscrasias, and syphilis, are relatively rare.1 Occasionally one encounters a case in which no cause for the hemorrhage can be found. In general, cerebral effusions may be subdivided into traumatic and "spontaneous" groups.
The onset of cerebral symptoms following hemorrhage is usually acute and immediately consequent to rupture of the diseased or injured artery. However, in many instances, particularly those consequent to trauma, evidence of hemorrhage may be delayed for hours or even