A brain aneurysm is a bulge or ballooning in a blood vessel in the brain. It often looks like a berry hanging on a stem. A brain aneurysm can leak or rupture, causing bleeding into the brain (hemorrhagic stroke). This is called a subarachnoid hemorrhage.
A ruptured aneurysm is a medical emergency. Most cases are fatal if not treated immediately. About 40% of people who experience a ruptured brain aneurysm will die within 24 hours. The risk of death is highest in the first 2 weeks after rupture.
So in many cases, yes, a ruptured brain aneurysm can cause sudden death. But the prognosis depends on many factors, including the location, size, and shape of the aneurysm, the person’s age and health, and how quickly medical treatment is received after rupture. Many people who receive swift medical care can survive a ruptured aneurysm.
What is a Brain Aneurysm?
A brain aneurysm (cerebral aneurysm) is a weak or thin spot on an artery in the brain that balloons out and fills with blood. Typically there are no symptoms. Occasionally, aneurysms may cause headaches, numbness, changes in vision or double vision.
The bulging aneurysm can put pressure on the nerves or brain tissue. It may also leak or rupture, spilling blood into the surrounding tissue (called a hemorrhage).
A ruptured aneurysm releases blood into the subarachnoid space around the brain. This leads to a subarachnoid hemorrhage (SAH), bleeding in the area between the brain and the tissue covering the brain.
About 30,000 people in the United States suffer a brain aneurysm rupture each year. Ruptured brain aneurysms account for 3–5% of all new strokes.
Types of Brain Aneurysms
There are several types of brain aneurysms:
– Saccular aneurysm: This is the most common type of cerebral aneurysm. It has a berry-like shape with a neck and dome.
– Fusiform aneurysm: This type bulges along one side of an artery, so it’s shaped like a football rather than a berry.
– Microaneurysm: This is a small aneurysm less than 1.5 cm in diameter. The risk of rupture is lower than larger aneurysms.
– Giant aneurysm: This aneurysm is larger than 2.5 cm in diameter. The walls are usually too thin to surgically repair.
– Mycotic aneurysm: This rare, infectious aneurysm develops after a bacterial infection that spreads to the cerebral arteries.
Causes & Risk Factors
A number of factors can contribute to the formation of a brain aneurysm, although in many cases the cause is unknown. Risk factors include:
– Family history of brain aneurysms
– Existing aneurysm
– High blood pressure
– Smoking
– Drug and alcohol abuse
– Head trauma or injury
– Infection
– Blood vessel abnormalities present at birth
– Overweight and obesity
Brain aneurysms are more common in adults over age 40. Women are more likely than men to have brain aneurysms. People who have two or more relatives with SAH or unruptured aneurysms have an increased risk of developing brain aneurysms themselves.
Locations
Aneurysms can develop anywhere along the intricate arteries that supply blood to the brain. But they tend to occur in certain common locations:
– Anterior communicating artery: This is the most common site of aneurysms that rupture. It connects the two anterior cerebral arteries at the Circle of Willis.
– Internal carotid artery: The second most common location of cerebral aneurysms. The internal carotid artery supplies oxygenated blood from the heart to the front part of the brain.
– Posterior communicating artery: Located at the back of the Circle of Willis, where it branches off from the internal carotid arteries.
– Middle cerebral artery: Supplies blood to the outer surface of the brain. It branches off the internal carotid artery.
– Basilar artery: Formed from the union of the two vertebral arteries at the base of the brainstem. Aneurysms on the basilar artery are especially dangerous.
What Happens When an Aneurysm Ruptures?
A brain aneurysm that leaks or ruptures spills blood into the space between the skull and the brain. This is called a subarachnoid hemorrhage (SAH). It can cause:
– Stroke from impaired blood flow to the brain
– Increased pressure inside the skull
– Brain cell death from lack of oxygen
– Coma
– Death
The bleed and sudden increase in pressure inside the skull can damage delicate brain tissue, nerves and blood vessels. Rupture is fatal about 40% of the time. It’s an extremely dangerous medical emergency.
Symptoms of Ruptured Aneurysm
Common signs and symptoms of a ruptured aneurysm include:
– Severe, sudden headache that comes on instantly. This is typically described as the “worst headache of my life.”
– Nausea and vomiting
– Stiff neck
– Blurred or double vision
– Sensitivity to light
– Seizure
– A drooping eyelid
– Loss of consciousness or coma
– Confusion
The symptoms of a hemorrhage depend on the location, size, and damage caused. Small bleeds may cause minimal symptoms at first. Major bleeds can quickly become catastrophic.
What Happens After Rupture?
Emergency medical and surgical treatments are required after an aneurysm rupture. Anti-seizure medicine may be given to prevent seizures. Painkillers can relieve headaches and relieve the painful stiff neck.
If there are signs of increased intracranial pressure due to bleeding, lowering high blood pressure may reduce pressure inside the skull. Medication can help prevent arteries from vasospasm, a dangerous narrowing of blood vessels after hemorrhage.
Endovascular coiling or surgical clipping are used to treat the ruptured aneurysm and stop further bleeding. These procedures seal off the aneurysm from blood flow before it ruptures again.
After rupture and treatment, recovery time in the hospital ICU can take from days to weeks. Rehabilitation continues after discharge from the hospital to regain skills and abilities affected by the brain bleed. Some symptoms, such as headaches and fatigue, may still persist.
Can a Brain Aneurysm Cause Sudden Death?
Yes, often a ruptured brain aneurysm leads to sudden death if no medical help is received. Of the 30,000 people who suffer a ruptured aneurysm each year in the United States, about 40% will die within the first 24 hours.
Some warning signs may precede sudden death, including:
– Sudden, severe headache
– Nausea, vomiting, dizziness
– Blurred or double vision
– Loss of balance or consciousness
– Weakness on one side of the body
– Speech problems
However, too often sudden death is the first and only symptom. This happens when a large aneurysm ruptures quickly and catastrophically, causing immediate bleeding and damage. This massive brain hemorrhage can lead to stroke, coma, and rapid death.
Risk of Early Death After Rupture
The highest risk of dying from a ruptured aneurysm comes in the first 2 weeks after bleeding begins. According to research:
– 25% of patients die before receiving medical care.
– 40% die within 24 hours.
– About half of all cases are fatal within the first month.
Studies show younger people have higher chances of survival after rupture. The mortality rate from subarachnoid hemorrhage increases with age. People over 60 have a 1-month mortality rate near 75%.
Other factors affecting survival chances include the size and location of the aneurysm, time between rupture and treatment, and other health conditions.
Preventing Rupture and Sudden Death
Because a ruptured aneurysm so often leads to sudden death or serious disability, prevention is extremely important. Steps to lower risk include:
– Quit smoking. Smoking is a major modifiable risk factor for brain aneurysms.
– Limit alcohol intake. Heavy alcohol use is linked to higher risk of aneurysms and SAH.
– Exercise regularly to keep blood pressure low. Hypertension is associated with cerebral aneurysms.
– Take medication as prescribed to control high blood pressure.
– Maintain a healthy body weight. Obesity increases risk.
– Eat a diet low in sodium to keep blood pressure down.
– Get routine screenings for heart disease and stroke risk factors.
People with a diagnosed unruptured aneurysm may need preventive treatment to avoid rupture and possibly sudden death. Options are:
Surgical Clipping
This surgery involves placing a tiny metal clip at the base of the aneurysm to block it off from blood flow through the artery. This helps prevent further growth and rupture.
Endovascular Coiling
In this minimally invasive procedure, the surgeon inserts a catheter into the femoral artery near the groin. The catheter is threaded through blood vessels into the aneurysm itself. Then platinum coils are released into the aneurysm to cause clotting and seal it off. This lowers risk of rupture.
Flow Diverters
Flow diverting stents are mesh tubes placed in the artery across the aneurysm neck. This diverts blood flow away from the aneurysm sac, which shrinks over time.
These and other treatments can greatly lower the danger of a rupture and sudden death, if an unruptured aneurysm is detected before any bleeding occurs. That’s why screening for aneurysms is so critical in those at increased risk.
Recovery and Outlook After Ruptured Aneurysm
Recovery after a ruptured aneurysm that receives proper emergency treatment can take weeks to months. Intensive care and rehabilitation are needed. With aggressive surgery and aftercare, survival rates continue to improve.
Still, consequences of a subarachnoid brain hemorrhage can be severe, including:
– Memory loss
– Speech problems
– Impaired cognition
– Muscle weakness or paralysis on one side of the body
– Vision and hearing loss
– Impaired balance and coordination
– Changes in behavior, mood, and personality
Some people may experience seizures, hydrocephalus (fluid buildup in the brain), vasospasm narrowing of arteries, or other complications that require more procedures.
Recovery is gradual, and disability after SAH may be long-term. Support groups, occupational therapy, physical rehabilitation, and follow-up care with a doctor are helpful after discharge.
Mortality After Hospital Discharge
Survivors of a ruptured aneurysm still remain at increased risk of death due to continued bleeding or complications.
– After 1 year, mortality rates are about 20%.
– After 5 years, mortality rates approach 30%.
– After 10 years, mortality rates are about 35%.
Lifelong monitoring is recommended after surviving a ruptured aneurysm. Patients should immediately report any warning signs of rebleeding or new aneurysm. With care, many can still enjoy long and active lives.
Key Takeaways
In summary, a ruptured brain aneurysm can often lead to sudden death if no medical help is received. Key points:
– About 40% of people die within 24 hours after a brain aneurysm rupture. Death rates are highest in the first 2 weeks.
– But with rapid emergency treatment, many can survive rupture, and rates continue improving.
– Preventing rupture in the first place is critical. Managing risk factors and screening those at higher risk helps avoid rupture and sudden death.
– Recovery after a ruptured brain aneurysm can be lengthy, but many patients go on to live full lives again.
– Ongoing medical monitoring is important for survivors of a ruptured aneurysm.
While ruptured brain aneurysms remain very dangerous, increased awareness, better screening, and advanced treatment options are preventing many sudden deaths. Continuing research promises to improve prevention and survival chances even more in the future.
