Cerebral Aneurysm, Brain Aneurysm
Cerebral aneurysm is a common disorder caused by a weakness in the wall of a brain artery. It may be congenital, or come from pre-existing conditions like hypertension or atherosclerosis (fatty deposits in the arteries), or very rarely from head injury. Aneurysms are present in probably 2% or more of adults, and multiple aneurysms occur in more than 10% of these.
Cerebral aneurysms are much more common in adults than in children and more common in women than in men, but can occur at any age. Before an aneurysm ruptures there may be a minor “warning” haemorrhage with a sudden headache, often not very severe but different from one’s usual headaches; more often the individual is asymptomatic, with no complaints at all. Onset is usually explosively sudden and without warning, with very severe headache, nausea and vomiting, and temporary loss of consciousness. Rupture of a cerebral aneurysm is very dangerous, leading as it does to bleeding around or in the brain, often resulting in an intracranial haematoma (a mass of blood—usually clotted—within the skull). Sudden death, recurrent bleeding, hydrocephalus (excessive accumulation in the brain of cerebrospinal fluid), or vasospasm (delayed narrowing of the arteries) may occur.
Emergency treatment for individuals with a ruptured cerebral aneurysm includes strict bedrest and painkillers. Unconscious patients may need treatment to restore deteriorating breathing and to reduce raised pressure in the head. Surgery is usually performed within the first 3 days to clip the ruptured aneurysm and thus eliminate the risk of rebleeding. Emergency operation may be needed if there is a large blood clot. Other treatments include drugs or hypertensive-hypervolaemic therapy (artificially increasing blood volume and blood pressure) to control vasospasm. In patients for whom surgery is considered too risky, and in an increasing proportion overall, microcoil thrombosis or balloon embolisation may be performed.
The outlook after rupture of a cerebral aneurysm depends on the size and location of the aneurysm, the person's age, general health, and neurological condition after haemorrhage. Many patients (probably over 40%) die from the initial bleeding or later complications, and others eventually recover with little or no permanent disability. Early diagnosis and treatment are vital, to reduce the risk of further bleeding.
Aneurysms are increasingly being discovered by accident or because of a family history. Depending on the circumstances a procedure to clip or coil the aneurysm may be recommended, to prevent future rupture.
Further Information and Support
Aetna InteliHealth (Harvard Medical School)
http://www.intelihealth.com (Go to Look It Up - Health A-Z)
National Brain Aneurysm Foundation USA
British Brain and Spine Foundation
Reviewed by Associate Professor Nicholas Dorsch, Neurosurgeon, Westmead Hospital, Australia