A brain aneurysm is a bulge in an artery in the brain that has the potential to burst or rupture. A ruptured aneurysm can cause a type of stroke called a subarachnoid hemorrhage.
An estimated 5 percent of Americans may have or develop a brain aneurysm each year, according to the Mayfield Clinic.
Not all aneurysms cause stroke, and vice-versa. However, if a person is at risk for a burst aneurysm, treatment is often required to prevent this potentially life-threatening occurrence.
Doctors don’t detect an estimated 85 percent of aneurysms until they burst. Fortunately, if a person can seek them quickly enough, there are treatments available for both stroke and aneurysm.
There are different forms of stroke and aneurysm. The treatment that a doctor gives will depend on what type occurs.
Two stroke types exist: hemorrhagic and ischemic.
Hemorrhagic strokes account for an estimated 13 percent of all stroke types, according to the American Heart Association. This stroke type occurs when a vessel in the brain bursts.
As a result, blood spills into the brain. The added blood can compress the brain, which can keep life-saving oxygen and blood from getting to the brain tissue.
Hemorrhagic strokes are usually the result of one of two causes: an aneurysm or a collection of abnormal blood vessels in the brain that can rupture.
Ischemic strokes are those that result from a blockage in an artery in the brain. When a blood clot breaks free from its place in an artery, it can lodge in a portion of the brain. This keeps blood from flowing freely to the brain.
Without the oxygen and nutrients that the blood brings to the brain tissue, the tissue dies. The result can be impaired body functioning or death.
An aneurysm is a weakened area of an artery in the brain. This area of weakness can result in bulging as blood flows through it. If enough pressure is generated against this weak area, it can burst and blood will flow out.
Doctors may classify an aneurysm by the symptoms it causes. These include:
Aneurysm that hasn’t burst
An aneurysm that hasn’t burst can range in size from large to small. Some people may have a small brain aneurysm and go their entire lives without knowing it.
If an aneurysm gets bigger, it can start to press on areas around the brain. This can cause symptoms such as:
- Pain behind the eye
- Dilated pupil
- Drooping eyelid
- Numbness or weakness on one side of the face
- Pain behind the eye
- Visual changes, such as seeing double
Some people have a family history of brain aneurysms, and they may undergo imaging studies to help a doctor identify if the person may have one that hasn’t burst. Most will largely go undiagnosed until a person starts experiencing symptoms or the aneurysm bursts.
Doctors may classify aneurysms that haven’t burst by their location or size in the brain. These include:
- Fusiform: An aneurysm that has no distinct “neck” and bulges in every direction
- Giant: An aneurysm that is larger than 2.5 centimeters in diameter
- Saccular: Also known as a “berry” aneurysm, this aneurysm type has a distinct neck and typically bulges to one side of an artery
‘Leaking’ aneurysm
A leaking aneurysm is one that may have enough of a weak area to allow a small amount of blood through. This leak can lead to a sudden, severe headache that indicates the extra pressure on the brain.
A leaking aneurysm is dangerous because it is often a precursor to a burst aneurysm.
Burst aneurysm
A burst aneurysm occurs when the weakened area of an aneurysm ruptures, leaking a significant amount of blood.
The symptoms associated with a burst aneurysm are severe, and the side effects can be deadly. They include:
- Confusion
- Nausea and vomiting
- Neck stiffness
- Passing out
- Sudden, severe headache
- Visual changes, such as blurred or double vision
A burst aneurysm is a type of subarachnoid hemorrhage. This is because the bleeding occurs between the brain and the membrane that covers the brain. A subarachnoid hemorrhage is a cause of a hemorrhagic stroke.
According to Johns Hopkins Medicine, an estimated 3 percent of all strokes are subarachnoid hemorrhage strokes.
If a person has a burst aneurysm and seeks emergency medical attention, medications are often given to prevent symptoms and damage from getting worse.
Examples of immediate medical treatments include:
- Anti-seizure medications to prevent seizures that can occur
- Pain medications to relieve the very intense headache a ruptured aneurysm can cause
- Vasodilators, which are medicines that cause blood vessels to expand
Vasodilators keep the affected vessel from tightening too much and stopping important blood flow. These medications also keep a person’s blood pressure from getting too high, which could lead to increased pressure in the skull and bleeding.
Doctors will take into account many factors when determining a potential surgical approach to aneurysm treatment.
Doctors don’t always treat an aneurysm that hasn’t burst, but usually will when it is causing symptoms. Burst aneurysms require fast treatment. Examples of considerations are the patient’s symptoms, health history, and the aneurysm’s size and location.
Several treatment approaches exist for brain aneurysms.
Surgical clipping
This involves accessing the area in the brain where the aneurysm occurred, placing a metal clip at the “neck” of the aneurysm. This keeps blood from flowing into and out of the aneurysm.
The surgical clipping approach involves removing a piece of the skull to access this portion of the brain.
Endovascular coiling
Endovascular coiling is a less invasive approach to aneurysm treatment. It involves accessing a large artery in the body, usually the femoral artery in the groin. A small tube is threaded through this artery up to the area where the aneurysm is.
A doctor will then introduce a special kind of metal coil or glue that fills the aneurysm and blocks blood flow. Clipping and coiling are both known as endovascular treatments.
Flow diversion with stents
This approach involves inserting a special device to re-route blood flow past the aneurysm. The flow diversion procedure can only be performed on an aneurysm that hasn’t burst.
The ability to do this reduces one of the greatest risks associated with surgery, which is accessing the aneurysm itself. With time, the aneurysm should close because it doesn’t receive blood flow that causes it to bulge.
Artery occlusion or bypass
An approach to use if an aneurysm can’t be coiled or clipped. This involves a surgeon removing a portion of the skull to access the area of the aneurysm. An artery from the patient or a donor artery is sewn to the damaged artery, re-routing blood.
If a person experiences a burst aneurysm and subarachnoid hemorrhage, they are at increased risk for an occurrence known as a vasospasm.
A vasospasm is when an artery in the brain tightens or narrows. This limits blood flow and causes symptoms like confusion, restlessness, and muscle weakness.
Treatments for stroke depend upon the stroke type. Doctors can treat an ischemic stroke with a medication called tissue plasminogen activator (tPA). If given within several hours of the first symptoms, this medicine can help to break up a clot and improve blood flow.
If a person cannot receive tPA, another option is retrieving a clot through a procedure known as a mechanical thrombectomy. This involves using a special device to remove the clot and insert a stent to keep the artery open.
A doctor will usually access the clot in a similar method to endovascular coiling, which is through an artery in the groin.
Hemorrhagic stroke treatments due to a subarachnoid hemorrhage are the same as those listed above for an aneurysm. Treatments for a hemorrhagic stroke caused by a collection of abnormal blood vessels may also involve clipping or bypass surgery to prevent bleeding.
According to University Hospital in Newark, NJ, the fatality rates for hemorrhagic stroke are higher than ischemic stroke. The effects of the massive bleeding associated with a hemorrhagic stroke are often difficult to combat, even with today’s technological advancements.
As a result, it’s important that people who have any symptoms of an aneurysm seek immediate medical treatment.