INTRACRANIAL ANEURYSMS: Frequently Asked Questions (FAQs)
Presented by Terry G. Horner, MD
Neurosurgeon with Indianapolis Neurosurgical Group, Inc.

ING Video: Strokes and Aneurysms

Frequently Asked Questions (Aneurysms): Click on the question for the answer.

• What is an intracranial aneurysm?
• Who gets aneurysms?
• What symptoms does a patient get when an aneurysm is present?
• What is a subarachnoid hemorrhage?
• How are aneurysms diagnosed?
• What is the treatment for an aneurysm?
• What other problems can occur after an aneurysm ruptures?
• What is the prognosis if one has an aneurysm rupture?

What is an intracranial aneurysm?
An aneurysm is a ballooning out of the wall of a blood vessel. In the brain, an aneurysm usually arises at a branch in the blood vessel. The reason aneurysms develop is not completely understood. There is an absence of one of the layers in the wall of the blood vessel, which may have been absent since birth. Degenerative changes in the blood vessel wall occur with aging and may also contribute to the formation of an aneurysm.
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Who gets aneurysms?
Women are affected more frequently than men are. Smoking is a risk factor. Although aneurysms may develop in young people, they most commonly occur between the ages of 40 to 70 years. People with certain diseases such as polycystic kidney disease, Marfan’s syndrome, or coarctation of the aorta are more likely to develop intracranial aneurysms.
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What symptoms does a patient get when an aneurysm is present?
The most serious symptoms occur when the aneurysm leaks (ruptures). When an aneurysm leaks, the patient experiences the abrupt onset of the worst headache of their life. This headache is usually accompanied by nausea, vomiting, neck stiffness, and light sensitivity. The headache can last up to two weeks. Hemorrhage may produce only headache or it may progress to death. Should this type of headache occur, one should call 911 and be taken immediately to a hospital emergency room.
Sometimes an aneurysm can grow and put pressure on a nerve (cranial nerve) which may cause eye pain associated with double vision, light sensitivity, and drooping of the eyelid. Other neurological symptoms such as difficulty swallowing, walking or trouble thinking may also occur. Aneurysms may also be discovered by accident during screening for other neurological problems.
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What is a subarachnoid hemorrhage?
Subarachnoid hemorrhage is the term used to describe rupture of an aneurysm into the spinal fluid surrounding the brain and spinal cord. When this occurs, the chemical effect of the blood on the brain and surrounding structures causes pain and the other symptoms described above. Other causes of subarachnoid hemorrhage include hypertension (high blood pressure), head injury, strokes, or arteriovenous malformations (AVMs).
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How are aneurysms diagnosed?
Aneurysms usually do not cause symptoms unless they rupture (leak). When an aneurysm ruptures, the symptoms described above occur. These symptoms are so characteristic for subarachnoid hemorrhage that often the diagnosis can be made on this history alone. After the patient arrives in the emergency room, a CT scan or spinal tap is done which confirms the presence of blood in the spinal fluid surrounding the brain. An arteriogram (angiogram) is performed to demonstrate the source of the hemorrhage. An arteriogram is done by placing a needle into an artery in the groin and running a catheter (a small, soft, tube) up the artery to the arteries going to the brain and injecting dye. This dye outlines the inside of the blood vessels. Up to 20% of the time, the arteriogram may fail to show the source of the hemorrhage. There is a slight risk of hemorrhage into the groin or even stroke associated with this test. A magnetic resonance angiogram (MRA) or computerized tomographic angiogram (CTA) can be done to look at the arteries and veins with less risk than a formal arteriogram but is not as accurate. The arteriogram is still the most accurate test.
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What is the treatment for an aneurysm?
The standard and most effective treatment for an aneurysm is surgical exposure and placement of a specialized metal clip across the base of the aneurysm to reform normal vessel and close off the aneurysm. Patients with a ruptured aneurysm are treated as soon as practically possible in most cases, to prevent the aneurysm from rupturing again.

A new treatment consists of placing platinum (GDC) coils into the aneurysm by an angiographic approach is available for aneurysms of certain shapes. The long-term durability is not currently known. Follow up with subsequent arteriograms is necessary to ensure that the aneurysm remains occluded.
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What other problems can occur after an aneurysm ruptures?
Blood in the spinal fluid after an aneurysm ruptures is irritating to the outside of the arteries and can cause spasm or narrowing of the arteries. This may produce a decrease in blood flow going to the brain and can result in a stroke. Normal treatment for this vasospasm is to give the patient plenty of 1V fluids and maintain a good blood pressure. Medicine (called a calcium channel blocker) is also given to reduce the effect of spasm. If this treatment fails, another type of medicine (Papaverine) can be injected directly into the arteries of the brain to relieve the spasm temporarily. Also, a tiny balloon may be inflated inside the narrowed blood vessels to expand (dilate) them back to the normal size. When hemorrhage occurs, it can also slow or stop the flow of spinal fluid around the brain. If this happens, pressure builds up in the brain. This is called hydrocephalus. This pressure may cause the patient to become sleepy or go into a coma. It is treated by placing a small hole in the skull and inserting a soft tube into the central cavities in the brain where the spinal fluid is made. This alleviates the pressure from the excess fluid.
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What is the prognosis if one has an aneurysm rupture?
Approximately 50% of patients who suffer from rupture of an aneurysm die immediately or at some time during the course of their treatment. The befter the neurological condition initially after the hemorrhage, the better the prognosis for a satisfactory recovery. Elderly patients often do worse than younger patients. Aneurysms in certain locations are treated more easily than in other locations.
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