An unruptured aneurysm may go unnoticed throughout a person's lifetime. A burst aneurysm, however, may be fatal or could lead to hemorrhagic stroke, vasospasm (the leading cause of disability or death following a burst aneurysm), hydrocephalus, coma, or short-term and/or permanent brain damage.
The prognosis for persons whose aneurysm has burst is largely dependent on the age and general health of the individual, other pre-existing neurological conditions, location of the aneurysm, extent of bleeding (and re-bleeding), and time between rupture and medical attention. It is estimated that about forty percent of individuals whose aneurysm has ruptured do not survive the first 24 hours; another twenty five percent die from complications within six months. People who experience subarachnoid hemorrhage may have permanent neurological damage. However, other individuals may recover with little or no neurological deficit. Delayed complications from a burst aneurysm may include hydrocephalus and vasospasm. Early diagnosis and treatment of the disorder are important.
Individuals receiving treatment for an unruptured aneurysm require less rehabilitative therapy and recover more quickly than persons whose aneurysm has burst. Recovery from treatment or rupture may take weeks to months.
Results of the International Subarachnoid Aneurysm Trial (ISAT), sponsored by health ministries in the United Kingdom, France, and Canada, and announced in October 2002, found that the outcome for individuals treated with endovascular coiling may be superior in the short-term (1 one year) as compared to those whose aneurysm was treated with surgical clipping. Long-term results of coiling procedures are unknown and more research is required on this topic, since some aneurysms can recur after coiling. Individuals may want to consult a specialist in both endovascular and surgical repair of aneurysms, to provide greater understanding of treatment options.
This answer from the National Institute of Neurological Disorders and Stroke has been reviewed and/or edited by Dr. William D. Knopf.