An aneurysm occurs when a weak area of a blood vessel’s wall bulges or balloons. Brain aneurysms generally form where arteries fork because those areas are weaker from the start. They may appear anywhere in the brain but most commonly form at the brain’s base. As an aneurysm expands, the arterial wall thins. When the wall becomes too thin, the aneurysm can leak or rupture, bleeding into the brain. This is called a hemorrhagic stroke. A ruptured brain aneurysm is life threatening and requires immediate treatment. The majority of brain aneurysms, however, don’t rupture or even cause symptoms. These are usually detected by chance while checking for other issues. Unruptured brain aneurysms may or may not be treated, depending on the likelihood of a future rupture.
Causes of Symptoms
Unruptured brain aneurysms are often asymptomatic, particularly when they are small. Headaches are possible but are often not a direct result of the aneurysm. Large unruptured aneurysms typically cause symptoms based on the pressure they put on surrounding structures, including brain tissue and nerves. According to the Colorado Neurological Institute, only about 40 percent of people with unruptured aneurysms will experience cerebral aneurysm symptoms.
Obvious Physical Signs and Symptoms
Symptoms of an unruptured brain aneurysm may include a localized headache, centered above and behind an eye. Also common are vision problems, such as double vision, blurred vision, a deficit of peripheral vision and photosensitivity. One of your pupils may become dilated or an eyelid might droop. Additionally, one side of the face may become numb, weak or even paralyzed.
Signs and Symptoms that Are Easy to Overlook
Some symptoms of an unruptured brain aneurysm can be written off as the results of stress or exhaustion, particularly when they are seemingly not accompanied by any physical effects. These include problems with perception and difficulty concentrating. Short-term memory and the ability to process information often suffer. Fatigue, another possible symptom, may actually make it easier for you to ignore the signs of an unruptured cerebral aneurysm, as it can cause you to assume you're just run down.
Risk Factors and Screening
Because unruptured aneurysms frequently provide little or no warning, it is important to determine your level of risk. Screening for unruptured brain aneurysms is usually not advisable, but people with certain risk factors may be benefit from screening even if not symptoms have been detected. Any person with a parent or sibling who has had a ruptured brain aneurysm faces an increased chance of having a cerebral aneurysm of their own. Multiple close family members who have had ruptured brain aneurysms make it more likely that screening is right for you. Some congenital disorders increase your risk of brain aneurysm, so they should also be taken into account when you discuss possible screening with your doctor.
Diagnosis and Treatment
If you have symptoms of an unruptured brain aneurysm you will likely undergo the same tests as someone with symptoms of a ruptured brain aneurysm. These include imaging tests like an MRI or a CT scan, which can confirm the existence of an aneurysm. At this point, treatment may be called for. The most common treatment for unruptured brain aneurysm is a procedure called “clipping.” Your neurosurgeon will put a metal clip over the aneurysm so that no more blood can flow to it, which will prevent it from breaking. Endovascular coiling is performed when small coils are put in the aneurysm to seal it off from blood flow and keep it from bursting. These procedures come with serious risks, though, which must be carefully weighed against potential benefits when deciding whether or not to treat an unruptured cerebral aneurysm.