Each year, cerebral aneurysms cause
death and permanent damage
to millions around the world.
Here’s what you should know about
the causes of hemorrhagic stroke,
and what to do when a stroke occurs.
It’s difficult to overstate the magnitude of the global threat: According to the World Stroke Organization (WSO), nearly 15 million people worldwide suffered a stroke last year, and half of them didn’t survive. Stroke and other types of cerebrovascular disease continue to rank at or near the top of the world’s leading causes of death and disability.
Most people have a basic understanding of strokes, and many have lost loved ones to stroke. Fortunately, significant progress has been made in stroke diagnosis, treatment and prevention; patients now have a better chance of surviving a stroke, and there are better ways to limits its damaging effects.
Unlike the more common ischemic stroke, which involves a clot or blockage, hemorrhagic stroke – one cause is cerebral aneurysm or brain aneurysm – results from the dilation or thinning of the wall of an artery or blood vessel in the brain that eventually tears or ruptures, allowing blood to flow into the brain.
The nature of the threat
Cerebral aneurysms are caused by an abnormal thinning of the wall of a blood vessel or artery carrying blood to the brain. The normal flow of blood through the body’s circulatory system exerts constant pressure on blood vessels – even more so when the patient has high blood pressure or hypertension. A blood vessel already weakened by thinning of its wall is at risk of developing a balloon-like bulge susceptible to tearing or rupturing, an event that can cause severe brain damage or even death.
“We can try to identity a probable cause for a cerebral aneurysm, but it’s difficult to know precisely why some areas of the arterial wall are thinner than others,” explains Dr. Somkiet Siriwimonmas, a neuroradiologist at Bumrungrad. “It can be due to a congenital abnormality or the consequence of another disease. While Thailand doesn’t compile statistics on cerebral aneurysm, it is estimated that the condition is present in about two percent of the population.”
“It’s impossible to determine when the aneurysm
might rupture; there won’t be any symptoms
to alert the patient of the potential threat.”
Dr. Somkiet Siriwimonmas
According to Dr. Somkiet, there are a number of aspects that add to the medical challenges of dealing with cerebral aneurysm: It’s impossible to determine when the aneurysm might rupture; most patients don’t know that they have an aneurysm; and so long as the blood vessel or artery doesn’t rupture, there won’t be any symptoms to alert the patient of the potential threat.
“If ever you get a headache unlike
any you’ve had before,
get to a doctor immediately.”
Dr. Roekchai Tulyapronchote
The threat of cerebral aneurysm can feel especially ominous due to the reality that it cannot be prevented. Dr. Somkiet points out that while the danger has been described as a time bomb ticking away inside the head, “there’s no widely-used screening test to detect the condition, and the methods that are capable of aneurysm detection require expensive equipment, making their widespread use impractical. Even with advanced testing, it’s not possible to predict if or when an aneurysm will eventually rupture,” Dr. Somkiet notes. “But not all aneurysms end up causing strokes.”
Detecting the presence of an aneurysm is often a case of coincidence or chance. “Detection tends to occur in one of three scenarios,” notes Dr. Somkiet. “The aneurysm may be spotted by coincidence when a patient undergoes a CT scan or MRI while being diagnosed for an unrelated condition; sometimes it’s found after a patient experiences symptoms resulting from the aneurysm causing compression of certain areas of the brain; or it is discovered when the patient has been admitted after suffering an actual stroke.”
When to treat?
Dr. Somkiet notes the distinction between patients who have suffered a ruptured cerebral aneurysm and those whose aneurysm has not yet ruptured. “If a cerebral aneurysm ruptures, it’s critical for the patient to get medical attention as quickly as possible,” he explains. “For patients who have an aneurysm that has been detected by coincidence but hasn’t ruptured, doctors must determine if there is a high risk of rupture, and whether the aneurysm is located in an area prone to more severe damage if a rupture occurred.”
Dr. Somkiet continues: “The size of the aneurysm also must be considered; those larger than seven millimeters are classified as high risk. We typically recommend treatment for high-risk situations, while low-risk patients would typically be monitored frequently for changes in the shape or size of the aneurysm. In deciding whether to proceed with treatment, patients should thoroughly consider and compare the risks of having the treatment versus the inherent risk of not receiving any type of treatment.”
There are several treatment methods that doctors consider for patients with cerebral aneurysms. One method employs a surgical technique to locate the aneurysm and attach a clip to the affected area. Another surgical treatment option involves the insertion of a catheter through the femoral artery into the aneurysm, followed by the packing of coils onto the affected site. Both methods share the same objective: to prevent the weakened area of the arterial wall from growing larger in size, thereby reducing the risk of a dangerous rupture.
The suitability of each treatment depends on a number of factors that can vary from one patient to another. Every aneurysm has a unique set of disease characteristics. “Treatment recommendations must consider the aneurysm’s size and location, and the patient’s overall physical health must be factored into the decision,” says Dr. Somkiet. “Doctors must carefully consider each situation on a case-by-case basis.”
Whether or not to treat
One of the more vexing questions that arises after detection of a cerebral aneurysm is: If no one can know with certainty whether the aneurysm will actually rupture or not, is treatment truly necessary?
To help find an answer, turned to Dr. Roekchai Tulyapronchote, a neurologist specializing in neurovascular diseases. “The treatment of cerebral aneurysm aims to reduce the chances of a future rupture because there is no way of knowing exactly when a stroke will occur, or what its effects will be,” says Dr. Roekchai. “Data from clinical research indicates that aneurysms larger than 7mm have a high probability of rupturing at any time, while those smaller than 7mm have a less than or equal to one percent chance of rupture per year – a very insignificant risk.
But doctors must be mindful of the fact that when aneurysms rupture, patient mortality rates are as high as 50 percent. Even if they survive, they may face severe neurological deficit. Personally, I think those patients who know they have a cerebral aneurysm are fortunate and should seriously weigh the risks before deciding whether to undergo treatment or not.”
Final points to ponder
When an aneurysm ruptures, time is critical. “If patients get medical attention quickly, the potential damage to the brain can be minimized,” Dr. Roekchai explains, “and the risk of a re-rupture can be reduced.”
Dr. Roekchai stresses the critical lesson that his many years’ as a doctor has taught him about stroke: “If ever you get a headache unlike any you’ve had before, get to a doctor immediately. We still see too many stroke patients who, because they looked and acted normally, neglected to seek medical treatment. Without being properly assessed by a doctor, these patients have put themselves in greater danger of a second stroke, which is more deadly.” While that severe headache may turn out to be a harmless event and not a sign of stroke, the danger of a severe headache signifying stroke is too great to dismiss without having a doctor take a look just to be sure.
These symptoms require urgent medical attention
- Severe headache unlike any before: Everyone has headaches from time to time. But the onset of a sudden severe headache unlike previous headaches requires urgent medical help.
- Other signs and symptoms: The simultaneous onset of a headache together with weakness of the limbs is a sign of a possible stroke. Urgent medical attention is necessary, even if the patient appears fine and is able to walk and talk normally.