Unruptured aneurysms affect about 3.2% of people worldwide. Ruptured aneurysms are less common, occurring in approximately 10 per 100,000 cases. The above statistics come from the National Library of Medicine . The average age at which they happen is 50 years.
About 2 to 3% of Americans may have or develop an aneurysm; of those, 15% have multiple aneurysms. Unruptured aneurysms are more common than ruptured (1). However, 85% of aneurysms are not diagnosed until after they bleed. Aneurysms are usually diagnosed between ages 35 to 60 and are more common in women.
Saccular, unruptured intracranial aneurysms (UIAs) are weak dilations at major bifurcating brain arteries and have a prevalence of ≈3% in the middle-aged population, which means that ≈168 000 000 persons harbor a UIA worldwide.
Absolutely. Many aneurysms cause no symptoms at all. Some people live for years without knowing they have a brain aneurysm.
Up to 6% of people living in the United States have an unruptured brain aneurysm. While still rare, they do happen to up to 30,000 Americans each year. Brain aneurysms occur in both males and females and at any age, but brain aneurysms are most common in female adults between ages 40 and 60.
“A brain aneurysm is essentially the neurological equivalent to a sudden heart attack,” said Ricardo Hanel, MD, PhD, neurosurgeon and co-director of the Baptist Stroke & Cerebrovascular Center. “It can happen to anyone, even young and healthy people. Someone can seem perfectly fine up until that singular moment.”
Not all cerebral aneurysms require treatment Some very small unruptured aneurysms that are not associated with any factors suggesting a higher risk of rupture may be safely left alone and monitored with MRA or CTA to detect any growth.
But most brain aneurysms aren't serious, especially if they're small. Most brain aneurysms don't rupture. They usually don't cause symptoms or cause health problems. In many cases, brain aneurysms are found during tests for other conditions.
“Another is that an aneurysm can disappear or heal itself. This is very rare and only happens in aneurysms that are considered benign because the flow of blood is so slow it eventually forms a clot and seals off the bulge.”
Treating unruptured brain aneurysms
A surgical clip, an endovascular coil or a flow diverter can be used to seal off an unruptured brain aneurysm. This can help prevent a future rupture. However, the risk of rupture is extremely low in some unruptured aneurysms.
With rapid, expert treatment, patients can often recover fully. An unruptured brain aneurysm may cause zero symptoms. People can live with them for years before detection. If a brain aneurysm is unruptured, no blood has broken through the blood vessel walls.
The International Study of Unruptured Intracranial Aneurysms (ISUIA) found a size greater than 7 mm and the location at the basilar tip or posterior communicating artery to be significant risk factors for rupture [2].
Unruptured brain aneurysms occasionally cause symptoms if they're particularly large or press against tissues or nerves inside the brain. Symptoms of an unruptured brain aneurysm can include: visual disturbances, such as loss of vision or double vision. pain above or around your eye.
The overall risk of rupture of untreated aneurysms in the studies with a mean follow-up <5 years was 1.2% (95% confidence interval [CI], 1.0 to 1.5), in the studies with a mean follow-up between 5 and 10 years 0.6% (0.5% to 0.7%), and in the studies with a mean follow-up time >10 years 1.3% (0.9 to 1.8).
There are three management options for unruptured cerebral aneurysms: conservative management, surgical clipping, or endovascular treatment.
Ruptured brain aneurysms are fatal in about 50% of cases. Of those who survive, about 66% suffer some permanent neurological deficit. Approximately 15% of people with a ruptured aneurysm die before reaching the hospital.
Symptoms of an unruptured brain aneurysm
If they become large enough, the bulge in your artery can put pressure on nearby nerves or brain tissue, causing the following symptoms: Headaches. Vision changes. Enlarged (dilated) pupil.
Yes, but not always. Even with treatment, around 40% of people with an unruptured brain aneurysm will experience long-term chronic headaches. Research shows similar figures for people who survive a brain aneurysm rupture.
The annual rupture rate by size was 0.8% (S; < 5 mm), 1.2% (M; 5-9.9 mm), 7.1% (L; ≥ 10 mm), and 43.1% (G; ≥ 25 mm). Of 529 aneurysms, 19 aneurysms ruptured during the follow-up period, and eight (42.1%) out of 19 aneurysms were from the S group. Six (31.6%) were < 3 mm in size.
Brain aneurysms can be diagnosed by several imaging tests, though an unruptured brain aneurysm also may be found while undergoing brain imaging — such as MRI or CT scan — or a medical evaluation for another reason, such as an evaluation for headaches or other neurological symptoms.
As seen in our study, aneurysms smaller than 2 mm can also result in an SAH and constituted 7% of ruptured aneurysms in our short experience. The incidence may have been higher in our study because some of the patients were referred after negative results on DSA or CTA.
With close follow-up, good blood pressure control and a healthy lifestyle, many patients living with aortic aneurysms can do well and may not need an intervention.
Brain aneurysms are most prevalent in people ages 35 to 60, but can occur in children as well. Most aneurysms develop after the age of 40. Women, particularly those over the age of 55, have a higher risk of brain aneurysm rupture than men (about 1.5 times the risk).
An unruptured aneurysm might not initially have any symptoms, but that usually changes as it grows larger. The warning signs that indicate a person has developed an unruptured brain aneurysm include: Pain behind or above an eye. Double vision.