Headaches due to cerebrovascular disease.

Subarachnoid hemorrhage causes sudden, severe headache and requires immediate medical and surgical diagnosis and treatment. A CT scan is the first choice for correct diagnosis. In order to prevent rebleeding, delays in treatment should be avoided. Intraparenchymal cerebral hemorrhage is now often recognized by means of CT scanning and sometimes is a cause of headache. Cerebellar hemorrhage commonly causes occipital headache and is an indication for immediate surgical intervention, although small cerebellar hemorrhages can be treated conservatively. Ischemic cerebrovascular disease is frequently accompanied by headache, but its etiology remains uncertain. Thrombosis of the cerebrovenous system is a less frequent cause of head pain than that of the arterial system, but it usually shows characteristic neurologic signs. Following carotid endarterectomy or superficial temporal artery-middle cerebral artery bypass surgery, the patient may have moderate to severe unilateral headaches, probably as a result of platelet aggregation and serotonin release.