EXPLAINED: What Is Aneurysm? All About The Brain Condition Game Of Thrones Star Emilia Clarke Suffered From

An aneurysm is a bulge in a blood vessel wall. A cerebral aneurysm will rupture and bleed into the space around the brain if the aneurysm expands and the wall of the blood vessel becomes too thin.

Game of Thrones star Emilia Clarke has opened up about two brain aneurysms she suffered in her 20s while filming the HBO series. She said she is grateful for having been able to recover after losing "quite a bit" of the brain.  ( Image Source :Getty )

Game of Thrones star Emilia Clarke has opened up about two brain aneurysms she suffered in her 20s while filming the HBO series. She said she is grateful for having been able to recover after losing "quite a bit" of the brain. 

In an interview to BBC's Sunday Morning, comments from which have been widely reported in western media, she said: "It was the most excruciating pain. It was incredibly helpful to have 'Game of Thrones' sweep me up and give me that purpose". 

The actor, famous for playing Daenerys Targaryen in Game of Thrones, suffered two life-threatening brain aneurysms while working on the show. In an essay for The New Yorker, Clarke revealed that she suffered the first aneurysm in 2011, and the second in 2013. 

During the interview to BBC's Sunday Morning, Clarke said: “The amount of my brain that is no longer usable — it’s remarkable that I am able to speak, sometimes articulately, and live my life completely normally with absolutely no repercussions,” Clarke stated. “I am in the really, really, really small minority of people that can survive that.”

What Is Aneurysm?

An aneurysm is a bulge in the wall of a blood vessel that results in an abnormal ballooning larger than 50 per cent of the vessel's normal diameter. The bulge is caused by a weakness in the blood vessel wall. Usually, weakness in a blood vessel occurs at the region where it branches. 

While any blood vessel can develop an aneurysm, it is most commonly found in an artery rather than a vein. 

Blood passing through a weakened blood vessel increases the pressure within it, causing a small area to bulge outwards like a balloon. 

The different regions in which an aneurysm may occur include blood vessels of the brain, the neck, the intestines, the spleen, the aorta, the kidney, and the vessels in the legs. An aneurysm occurring in the brain is known as cerebral aneurysm or intracranial aneurysm.

The two most common regions where aneurysms can develop are the abdominal aorta and the brain. 

A cerebral aneurysm will rupture and bleed into the space around the brain if the aneurysm expands and the wall of the blood vessel becomes too thin. This occurrence is known as a subarachnoid haemorrhage and may cause a hemorrhagic stroke, according to Johns Hopkins Medicine. 

An aneurysm can be of two shapes: fusiform and saccular. The shape of a bulge in a blood vessel helps identify a true aneurysm.

Fusiform-shaped aneurysms are more common than saccular-shaped ones. While fusiform-shaped aneurysms bulge or balloon out on all sides of the blood vessel, a saccular-shaped aneurysm bulges out on just one side. 

Most brain aneurysms result in noticeable symptoms when they rupture. 

A rupturing cerebral aneurysm and a subarachnoid haemorrhage are life-threatening events.

This is because bleeding caused by a subarachnoid haemorrhage can result in extensive brain damage.

Symptoms Of Brain Aneurysm

A person having a brain aneurysm may not be aware of the condition until the aneurysm ruptures. Most brain aneurysms are small in size and show no symptoms. Aneurysms smaller than 10 millimetres may have a decreased risk of rupture.

Sometimes, a small amount of blood may leak before an aneurysm ruptures. This leakage may result in noticeable symptoms. Such an event, in which some blood leaks before the rupturing of an aneurysm, is known as "sentinel haemorrhage" into the brain.

Since some aneurysms press on adjacent structures such as the nerves to the eyes, they show symptoms. A person with a cerebral aneurysm may suffer from loss of vision or experience diminished eye movements even if the aneurysm has not ruptured.

The most common symptoms of an unruptured brain aneurysm include pain in the eyes, changes in vision, headaches, and diminished eye movement. 

A person may also face difficulty speaking or concentrating.

A subarachnoid haemorrhage is the first evidence of a brain aneurysm because of the rupture of the bulged out blood vessel. When an aneurysm bursts, it may result in symptoms such as nausea and vomiting, a rapid onset of the "worst headache of one's life", stiff neck, changes in mental status, drowsiness, high blood pressure, sensitivity to light, dilated pupils, loss of balance or coordinator, problems with the functioning of the eyes, nose, tongue, and ears, pain in the back or legs, and pain in specific regions, especially the eyes. Sometimes, a subarachnoid haemorrhage can lead to coma, and eventually death. 

The sudden agonising headache which one experiences as a result of a burst brain aneurysm is described as a "thunderclap headache", according to the National Health Service, the healthcare system in England. 

Risk Factors For Brain Aneurysm

The risk factors for brain aneurysm may be inherited or acquired. Inherited risk factors include Ehlers-Danlos syndrome, a connective tissue disorder, Klinefelter syndrome, a genetic condition in men with an additional X chromosome, and Polycystic kidney disease (PCKD), a genetic disorder that results in the growth of several fluid-filled cysts in the kidneys. 

People with a family history of aneurysms, and women are at increased risk for brain aneurysm.

The acquired risk factors for cerebral aneurysm include alcohol consumption, cigarette smoking, high blood pressure, infection, use of illicit drugs such as cocaine or amphetamine, head injury, advancing age, and atherosclerosis, among others. Atherosclerosis refers to the hardening of the arteries caused by a buildup of plaque in the inner lining of an artery.

Sometimes, a person may develop an aneurysm because there was a weakness in the walls of the blood vessels at birth.

The risk factors increase a person's risk for cerebral aneurysm, but do not necessarily cause the disease. 

How Is A Brain Aneurysm Diagnosed?

A brain aneurysm can be discovered after it has ruptured. Sometimes, the aneurysm is detected by chance during a diagnostic examination such as magnetic resonance imaging (MRI), computed tomography (CT scan), or angiography that was conducted for a different reason. 

A cerebral angiography images the blood vessels in the brain and detects a problem with vessels and blood flow. A CT scan is an imaging test that uses X rays and a computer to produce images of the body that are more detailed than general X-rays, and may be used to detect abnormalities. This helps identify the location of the aneurysm and determine whether it has burst or is leaking. 

An MRI produces detailed images of organs by using a combination of large magnets, radio frequencies, and a computer. The magnetic fields detect small changes in the brain tissue, and help Identify the location of a suspected aneurysm.

How Can A Brain Aneurysm Be Treated?

Depending on the size and location of the brain aneurysm, and whether or not it has ruptured, one or more techniques are used to treat the disease. Broadly, there are three treatment options for people with cerebral aneurysm — medical non-surgical therapy, surgical therapy or clipping, and endovascular therapy or coiling with or without adjunctive devices. 

Other methods include flow diversion with stents, artery occlusion and bypass, and observation. 

Medical Therapy

According to the American Association of Neurological Surgeons, medical therapy is usually only an option for the treatment of unruptured cerebral aneurysms. Strategies include smoking cessation and blood pressure control, because these are the only factors that have been shown to have a significant effect on aneurysm formation, growth, or rupture.

Surgical Clipping

An aneurysm is clipped through craniotomy, which is a surgical procedure in which the brain and the blood vessels are accessed through an opening in the skull, after the bulge is identified. 

The aneurysm is carefully separated from the surrounding brain tissue, following which a small metal clip, usually made from titanium, is applied to the neck of the aneurysm. 

Endovascular Coiling

Endovascular coiling is a procedure performed to block blood flow into an aneurysm, and is a minimally non-invasive technique, which means that an incision into the skull is not required to treat the aneurysm.

The process involves passing a catheter through the groin up into the artery containing the aneurysm, where platinum coils are released, to induce clotting of the aneurysm, and thus, prevent blood from getting into it. 

Flow Diversion With Stents

Flow diversion is an endovascular technique in which the device is placed in the parent blood vessel to divert blood flow away from the aneurysm itself, instead of placing a device inside the aneurysm sac. A microcatheter is navigated past the aneurysm without having to enter the aneurysm, following which the flow-diverting device is deployed across the neck of the aneurysm in the parent blood vessel where the aneurysm is present. 

Artery Occlusion And Bypass

Artery occlusion and bypass is a two-part procedure combining open microsurgery and endovascular coiling, in order to coil the entire diseased portion of the blood vessel and then bypass the blood flow to the specific location in the brain. Artery occlusion and bypass is different from endovascular coiling in the fact that the former closes down the whole vessel rather than just putting coils in the aneurysm sac. 

Flow Disruption

Intramuscular flow disruption with a WEB (Woven EndoBridge) device is one of the latest technological advancements in the management of wide-necked aneurysms, especially at the bifurcation of an artery. The WEB device, which is an innovative endovascular device used for the treatment of intracranial aneurysms, is placed within an aneurysm in contrast to the flow diversion stents which are placed in the parent artery.

Emergency Treatment

A person who may require an emergency treatment because of a ruptured brain aneurysm will initially be given a medication called nimodipine. This reduces the risk of blood supply to the brain becoming severely disrupted. 

After this, the ruptured aneurysm can be repaired by coiling or clipping. 

How Can Brain Aneurysms Be Prevented?

One can lower the risk of having a brain aneurysm by not smoking and by reducing high blood pressure. People should avoid consumption of a high-fat diet. Overweight people must exercise to reduce the risk of having a brain aneurysm.