It’s a terrifying thought hut at least 100 000 Australians are walking around with little time bombs in their brains.
These bombs can go off at any time but usually detonate between the ages of 20 and 50. When this happens there is a 50 per cent chance they will kill or seriously disable their host.
Brain bombs look like small balls of string and are made up of bundles of vessels wrapped around each other. Neurosurgeons call them arteriovenous malformations, or AVMs.
People are born with AVMs, and while it is possible to live a healthy life and die of old age with an AVM still intact, it is also possible to detect it and remove it before it causes damage.
In a normal brain, veins and arteries are separate vessels that travel on their own pathways, circulating blood through brain tissue. In an AVM, the vessels are tangled together.
These little bombs usually sit in the brain in absolute silence. Most people wouldn’t know il they had one. In some they cause migraines and epilepsy but in most cases they are discovered only alter a dramatic event like a collapse or a stroke.
With age, the little vessels in these clusters become thickened and more susceptible to leaking or bursting. When this occurs, a range of symptoms may follow, from sudden and severe headaches with vomiting to unconsciousness and death.
When an AVM in 21-year-old D.W.’s brain burst, his first symptom didn’t seem too serious. His parents remember him coining home from university, where he was studying naval architecture, with a ‘lousy headache’. He went directly to bed and the next morning woke to find he had no association with the left side of his body. A tangle of vessels in the left side of his brain had ruptured and he was haemorrhaging.
While his anguished parents waited outside the operating theatre, surgeons spent 17 hours repairing the vessels in his brain. Six days later he spoke quite normally to his parents. But that night a main artery in his brain burst, leaving him in a vegetative state. Intensive attempts to rehabilitate him failed and he died two years later.
AVMs are usually treated with surgery, but radiotherapy alone can be used if they are very small. About 99 out of 100 people will survive surgery to remove an AVM, but there is a risk of paralysis or loss of memory, speech or vision.
To eliminate such devastation, more research is needed into the causes of AVMs, the triggers of a haemorrhage and how predictions can be made about which patients will run into problems because of treatment.
Central to research into AVMs is the role of pressure in the vessels in the brain.
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