An aneurysm is a outpouching or weakness in wall of blood vessel. Aneurysms often occur in the aorta, brain, back of the knee, intestine, or spleen. A ruptured aneurysm can result in internal bleeding, stroke, and can sometimes be fatal.

Aneurysms often have no symptoms until they rupture.

Treatment varies from watchful waiting to emergency surgery. The choice depends on the location, size and condition of the aneurysm.

Lateral view of craniotomy incision with inset of cranial aneurysm clipping

Close up view of healthy blood vessel in brain vs. a brain aneurysm

Brain aneurysm facts

  • Four major blood vessel supply blood to the brain. They join together at the Circle of Willis at the base of the brain. Smaller arteries leave the circle and branch out to supply brain cells with oxygen and nutrients.

  • Artery junction points may become weak, causing a ballooning of the blood vessel wall to potentially form a small sac or aneurysm.

  • Cerebral aneurysms are common, but most are asymptomatic and are found incidentally at autopsy.

  • Aneurysms can leak or rupture causing symptoms from severe headache to stroke-like symptoms, or death.

  • The health care practitioner needs to maintain a high incidence of suspicion to make the diagnosis, since many patients may have an initial small leak of blood causing symptoms hours or days before a catastrophic bleed occurs.

  • Diagnosis of a brain aneurysm may require CT scans, lumbar puncture, or angiography.

  • Treatment to repair the aneurysm may involve neurosurgery to put a clip across the weak blood vessel wall. Instead of surgery, some patients may be treated by an intervention, where coils or stents are used to treat them.

The headache associated with a leaking aneurysm is severe. Blood is very irritating to the brain and surrounding membranes and causes significant pain. Patients may describe the “worst headache of their life,” and the health care practitioner needs to have an appreciation that a brain aneurysm may be the potential cause of this type of pain. The headache may be associated with nausea, vomiting, and change in vision. A subarachnoid hemorrhage also causes pain and stiffness of the neck because the meninges become inflamed. However, the “worst headache of their life” complaint needs to be matched with physical findings to be considered a risk factor for a leaking aneurysm.