Any patients suspected of having a brain hemorrhage should have an immediate CT scan. This gives precise information about the location of the hemorrhage, its size and configuration, the degree of edema in the adjacent brain tissue, and whether there is hydrocephalus. When the clinical syndrome and CT scan indicate a typical hypertensive hemorrhage, angiography is rarely indicated. If hypertension is unlikely to be the cause, angiography is needed to look for a vascular malformation or tumor. Lobar hemorrhage may be related to hypertension but can also occur with other pathology.
Fibrinoid necrosis is usually the etiology of the weakness in the arterial wall.
The final triggering mechanism for the hemorrhage is unknown, but a sudden increase in blood pressure has been suggested since hemorrhage usually occurs during activity, and only infrequently during sleep. Pathologic studies demonstrate tracking of blood along tissue planes and displacement of tissue more often than gross destruction. Because of this the ultimate outcome for the patient may be considerably better than indicated by the acute deficit. The clinical syndrome usually comes on over minutes to hours. Hemorrhage probably lasts only a few seconds and then stops.