An aneurysm is a bulge in a blood vessel, the walls of which are stretched thin and at constant risk of rupturing. When an aneurysm ruptures in the brain, it can be fatal. Brain cells die when deprived of blood. They can also be destroyed by the pressure that develops when too much blood enters the brain from a ruptured aneurysm. Because the skull prevents the brain from expanding, the extra blood can not be accommodated, which leads to compression of tissues. The brain cannot regrow cells, so lost brain functions are often lost forever. Other effects of a brain aneurysm can be just as debilitating.
Unruptured Brain Aneurysm
According to MayoClinic.com, an unruptured aneurysm can put pressure on brain tissues and on the optical nerve. This can trigger double vision or other visual disturbances, dilated pupils, a drooping eyelid, pain above and behind one eye, or a numbness or weakness on one side of the face. A headache limited to one particular spot in the head, often behind one eye, can also be an early warning sign.
Leaking Brain Aneurysm
A brain aneurysm does not always rupture catastrophically. Sometimes it develops a small tear and leaks slowly. So-called "sentinel bleeds" nearly always develop into large ruptures if untreated. A leaking aneurysm will cause a severe, sudden headache.
Ruptured Brain Aneurysm
A ruptured aneurysm will trigger a sudden headache of incredible intensity. Other symptoms may include nausea or vomiting, eyelids that droop uncontrollably, muscle weakness or loss of muscle control, seizures, and changes in vision. Patients may become confused or irritable, lethargic or be unable to speak. They may lose consciousness. Prompt medical treatment is vital. The National Institutes of Health reports that nearly a quarter of patients die within one day of a ruptured brain aneurysm, while another quarter die within three months. More than half of survivors are left with a permanent disability.
