There are four main types of brain aneurysms. Most aneurysms occur where an artery branches, often at the base of the brain. The treatment options depend on the type of aneurysm, its size and its location.
1. Saccular (berry) aneurysm bulges from one side of an artery.
2. Giant aneurysm can involve more than one artery and can be over 2.5 centimeters wide.
3. Fusiform aneurysm bulges from all sides of an artery.
4. Mycotic aneurysm is caused by an infected artery wall. This type of aneurysm is fairly rare.
Aneurysms are also classified by size: small, large and giant.
- Small aneurysms are less than 11 millimeters in diameter (about the size of a large pencil eraser).
- Large aneurysms measure 11 to 25 millimeters (about the width of a dime).
- Giant aneurysms are more than 25 millimeters in diameter (more than the width of a quarter).
It is still unclear what exactly causes the wall of affected blood vessels to weaken, although risk factors have been identified.
These include:
- smoking
- high blood pressure
- a family history of brain aneurysms
In some cases, an aneurysm may develop because there was a weakness in the walls of the blood vessels at birth.
It’s difficult to estimate exactly how many people are affected by brain aneurysms because they usually cause no symptoms and pass undetected. Brain aneurysms can develop in anyone at any age, but are more common in people over the age of 40. Women tend to be affected more commonly than men.
Symptoms of a burst brain aneurysm include:
- a sudden agonising headache – it’s been described as a “thunderclap headache”, similar to a sudden hit on the head, resulting in a blinding pain unlike anything experienced before
- a stiff neck
- sickness and vomiting
- pain on looking at light
Several types of scans and tests can be used to figure out whether you have a brain aneurysm. They include:
- CT scan: This exam creates images of your brain. You will lie on a table that slides into a CT scanner. A technician will inject contrast dye into one of your veins to make it easier to see the blood flow and spot aneurysms in your brain.
- MRI: This exam is similar in that you lie on a table that slides into a scanner. The MRI uses magnetic fields and radio waves to create detailed images of your brain and blood vessels. MRIs and CT scans can detect aneurysms larger than 3 to 5 millimeters.
The following tests are more invasive than CT or MRI scans. But they could give a more complete picture of what’s going on:
- Angiogram: This test, considered the most reliable way to detect aneurysms, shows the weak spots in your blood vessels. During the test, you lie on an X-ray table, and you will be given something to numb any pain. Your doctor will insert a small flexible tube through a blood vessel in the leg. They’ll guide that tube, called a catheter, into the blood vessels in your neck that reach the brain. Then they’ll inject a contrast dye into you, and X-rays will be taken that show all the blood vessels in the brain. This gives your doctor a map of your blood vessels, pinpointing the aneurysm.
- Cerebrospinal fluid test: Your doctor may order this test if they think an aneurysm may have ruptured. You’ll be given something to block any pain. A technician will put a needle into you to draw spinal fluid. That fluid is tested to see whether it contains blood, which could mean an aneurysm has ruptured.
Scientists are actively working on a groundbreaking model for diagnosing brain aneurysms. This innovative approach relies on the detection of specific molecules that can indicate a heightened risk of an aneurysm rupture. Remarkably, this diagnostic procedure can be conducted through brain imaging without the necessity of skull opening. Beyond its less invasive nature, this cutting-edge tool holds the potential to enable proactive treatment before an aneurysm reaches the critical point of bursting.
Most people with a brain aneurysm live without problems without even knowing it. Since many aneurysms do not cause health problems or cause symptoms, people can live for many years without being aware of having a brain aneurysm.
The severity of a brain aneurysm depends on whether it ruptures and/or whether the aneurysm causes symptoms. Most aneurysms do not rupture and cause no symptoms, but when they do rupture, they can become life-threatening and require immediate medical attention.
After an aneurysm ruptures, it can cause serious complications such as:
- Rebleeding. Once ruptured, an aneurysm can rupture again before being treated, causing further bleeding in the brain and resulting in further damage or death.
- Change in sodium level. Bleeding in the brain can alter the balance of sodium in the bloodstream and cause swelling in brain cells. This can cause permanent brain damage.
- Hydrocephalus. Subarachnoid hemorrhage can cause hydrocephalus. Hydrocephalus is a buildup of too much cerebrospinal fluid in the brain, causing pressure that can lead to permanent brain damage or death. Hydrocephalus frequently occurs after a subarachnoid hemorrhage because blood blocks the normal flow of cerebrospinal fluid. If left untreated, the increased pressure inside the head can cause a coma or death.
- Vasospasm. This frequently occurs after a subarachnoid hemorrhage when the bleeding causes the brain’s arteries to contract and limits blood flow to vital areas of the brain. This can cause strokes due to lack of adequate blood flow to certain parts of the brain.
- Convulsions. Bleeding from the aneurysm can cause seizures (convulsions), both at the time of the hemorrhage and in the immediate aftermath. Although most seizures are obvious, they can sometimes only be detected using sophisticated brain tests. Untreated seizures or those that do not respond to treatment can cause brain damage.
Certain risk factors for brain aneurysms, such as age and genetic conditions, may be beyond one’s control. However, there are proactive measures individuals can take to reduce the risk of developing a brain aneurysm. These include:
1. Maintaining Healthy Blood Pressure:
This can be achieved through the use of medications and/or lifestyle changes.
2. Avoiding Smoking or Quitting Smoking:
Smoking is a known risk factor for the development of aneurysms, and quitting can contribute to reducing this risk.
3. Addressing Alcohol and Substance Use Disorders:
Seeking help for alcohol use disorder and/or substance use disorder is important.
Avoiding the use of cocaine or other stimulants is also recommended, as these substances can contribute to an increased risk of brain aneurysms.
By adopting these lifestyle changes and seeking appropriate medical interventions, individuals can actively work towards lowering their risk of developing a brain aneurysm.
