Abstract
Causes of subarachnoid hemorrhage It is not the purpose of this chapter to go into great depth about the variety of vascular lesions that may cause subarachnoid hemorrhage (SAH). We shall limit ourselves to hemorrhages occurring at the base of the brain, because extravasation at the convexity of the brain is associated with few symptoms and signs, if any at all. The vast majority (85%) of spontaneous hemorrhages in the subarachnoid space at the base of the brain are caused by aneurysms. Other potential causes are listed in Table 47.1; certain elements of the history or the physical examination may point to one or other of these unusual causes. Sudden headache The key feature in diagnosing SAH is the history of sudden, severe, and unusual headache. Classically, it comes on in seconds (“a flash”, “ just like that”, “ a bolt from a blue sky”, “ as if I was hit on the head”), or in a few minutes at most. A potential pitfall is that patients may sometimes use the word “sudden” to describe an episode of headache that came on in half an hour or longer, depending on the interval after which the history is given. Even if the headache really comes on within seconds or minutes, such a history is not specific for ruptured aneurysms or for SAH in general. Sudden onset headache may also occur with other intracranial hemorrhages, with non-hemorrhagic brain disease, and especially with innocuous forms of thunderclap headache: variants of vascular headache, migrainous or not, or of muscle contraction headache. Sexual activity may precipitate not only SAH [1], but also either type of the relatively harmless headaches [2].
Original language | English |
---|---|
Title of host publication | Stroke Syndromes |
Subtitle of host publication | Third Edition |
Editors | J. Bogousslavsky, L. Caplan |
Place of Publication | Cambridge |
Publisher | Cambridge University Press |
Pages | 534-541 |
Number of pages | 8 |
ISBN (Electronic) | 9781139093286 |
ISBN (Print) | 9781107018860 |
DOIs | |
Publication status | Published - 1 Jan 2012 |