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.
