Intracranial aneurysm
An intracranial aneurysm, also known as a cerebral aneurysm, is a cerebrovascular disorder in which weakness in the wall of a cerebral artery or vein causes a localized dilation or ballooning of the blood vessel.
Intracranial aneurysm
Cerebral aneurysm, brain aneurysm
30–60 years old
old age, family history, smoking, alcoholism, cocaine use[1]
Endovascular coiling, surgical clipping, cerebral bypass surgery, pipeline embolization
Aneurysms in the posterior circulation (basilar artery, vertebral arteries and posterior communicating artery) have a higher risk of rupture. Basilar artery aneurysms represent only 3–5% of all intracranial aneurysms but are the most common aneurysms in the posterior circulation.
Prognosis[edit]
Outcomes depend on the size of the aneurysm.[44] Small aneurysms (less than 7 mm) have a low risk of rupture and increase in size slowly.[44] The risk of rupture is less than one percent for aneurysms of this size.[44]
The prognosis for a ruptured cerebral aneurysm depends on the extent and location of the aneurysm, the person's age, general health, and neurological condition. Some individuals with a ruptured cerebral aneurysm die from the initial bleeding. Other individuals with cerebral aneurysm recover with little or no neurological deficit. The most significant factors in determining outcome are the Hunt and Hess grade, and age. Generally patients with Hunt and Hess grade I and II hemorrhage on admission to the emergency room and patients who are younger within the typical age range of vulnerability can anticipate a good outcome, without death or permanent disability. Older patients and those with poorer Hunt and Hess grades on admission have a poor prognosis. Generally, about two-thirds of patients have a poor outcome, death, or permanent disability.[20][45][46]
Increased availability and greater access to medical imaging has caused a rising number of asymptomatic, unruptured cerebral aneurysms to be discovered incidentally during medical imaging investigations.[47] Unruptured aneurysms may be managed by endovascular clipping or stenting. For those subjects that underwent follow-up for the unruptured aneurysm, computed tomography angiography (CTA) or magnetic resonance angiography (MRA) of the brain can be done yearly.[48] Recently, an increasing number of aneurysm features have been evaluated in their ability to predict aneurysm rupture status, including aneurysm height, aspect ratio, height-to-width ratio, inflow angle, deviations from ideal spherical or elliptical forms, and radiomics morphological features.[49]
Epidemiology[edit]
The prevalence of intracranial aneurysm is about 1–5% (10 million to 12 million persons in the United States) and the incidence is 1 per 10,000 persons per year in the United States (approximately 27,000), with 30- to 60-year-olds being the age group most affected.[10][20] Intracranial aneurysms occur more in women, by a ratio of 3 to 2, and are rarely seen in pediatric populations.[10][17]