An aneurysm is a bulge in the wall of an artery. Aneurysms may result from congenital defects, preexisting conditions such as high blood pressure and atherosclerosis (the buildup of fatty deposits in the arteries), or head trauma. Aneurysms most commonly occur in arteries at the base of the brain and in the aorta. Aneurysms may involve arteries or veins and have various causes. They are commonly further classified by shape, structure and location. Cerebral aneurysms occur more commonly in adults than in children but they may occur at any age. They are slightly more common in women than in men. Cerebral aneurysms are also more common in people with certain genetic diseases, such as connective tissue disorders and polycystic kidney disease, and certain circulatory disorders, such as arteriovenous malformations. Some investigators have speculated that oral contraceptives may increase the risk of developing aneurysms. Aneurysms are dangerous because they may burst. Pain in the area of an aneurysm is a common symptom. The larger an aneurysm becomes, the more likely it is to burst.
Aneurysms that result from an infection in the arterial wall are called mycotic aneurysms. Cancer-related aneurysms are often associated with primary or metastatic tumors of the head and neck. It is known that men over the age of 60, and younger men with a brother or father who has had an aneurysm, are at risk. It is unclear why a person develops a brain aneurysm. It appears that aneurysms are related to an absence of a muscular layer that makes up part of the blood vessels that over time stretches and thins. An aneurysm may be small and not cause symptoms. An ultrasound examination of the abdomen is a very good way of finding an aneurysm. This is a painless procedure involving a lubricated probe pressing gently on the abdominal skin (over the aneurysm). Many cases of ruptured aneurysm can be prevented with early diagnosis and medical treatment. Because aneurysms can develop and become large before causing any symptoms, it is important to look for them in people who are at the highest risk.
Causes of Aneurysm
It is not clear exactly what causes aneurysms. Defects in some of the parts of the artery wall may be responsible. An aneurysm can result from atherosclerosis. Cerebral aneurysms occur more commonly in adults than in children but they may occur at any age. They are slightly more common in women than in men. Cerebral aneurysms are also more common in people with certain genetic diseases, such as connective tissue disorders and polycystic kidney disease, and certain circulatory disorders, such as arteriovenous malformations. Other causes include trauma or injury to the head, high blood pressure, infection, tumors. Some investigators have speculated that oral contraceptives may increase the risk of developing aneurysms.
Symptoms of Aneurysm
There are many symptoms of a brain aneurysm and each person with an aneurysm may not experience the same symptoms. Small, unchanging aneurysms generally will not produce symptoms, whereas a larger aneurysm that is steadily growing may press on tissues and nerves. Before a larger aneurysm ruptures, the individual may experience such symptoms as a sudden and unusually severe headache, nausea, vision impairment, vomiting, and loss of consciousness, or the individual may be asymptomatic, experiencing no symptoms at all. Rupture of a cerebral aneurysm is dangerous and usually results in bleeding into the meninges or the brain itself, leading to a subarachnoid hemorrhage or intracranial hematoma, either of which constitutes a stroke.
Treatment of Aneurysm
Treatment depends on the size and location of the aneurysm and your overall health. Aneurysms in the upper chest (the ascending aorta) are usually operated on right away. Anticonvulsant medications can prevent seizures, analgesics may relieve headache symptoms, and calcium channel blockers can help widen narrowed blood vessels. Surgery is also usually required for aneurysms as introducing foreign material in the low flow veins can produce a high risk blood clotting environment. Patients who have suffered a subarachnoid hemorrhage often need rehabilitative, speech, and occupational therapy to regain lost function and learn to cope with any permanent disability.