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Recently, my aunt suffered cerebral aneurysm and she was called home a week after operation. This article by Dr Alex Tang is a real eye opener for me. Hopefully this can help others who are facing the same predicament.
MK, a 45-year-old executive, suffered a seizure and collapsed in the washroom early in the morning. He had been complaining of dizziness and excruciating headache, the worst of his life, ever since midnight. He had also complained that he was sensitive to bright light.
When he was found in the washroom, he was rushed to a nearby hospital and an emergency brain scan was done. The doctor said he had a burst artery in the brain and the chances of survival was 50-50.
MK was put to sleep with a tube down his wind pipe, helping him to breath. He underwent an emergency procedure using tiny platinum coils to fix the burst artery, a new technique called endovascular coiling. He was ventilated in the intensive care unit for a few days and was discharged after two weeks with mild weakness on one side of his body. He had a successful and full recovery after three months of intensive physiotherapy.
MK suffered a condition called subarachnoid haemorrhage (SAH), a highly dangerous type of stroke with bleeding into the surface of the brain from a ruptured cerebral aneurysm, commonly encountered in both the young and elderly. He was lucky to survive the ordeal.
In general, up to 30% of such victims would have died before reaching the hospital, and for the remaining, half will live with varying degrees of neurological deficits.
What is a cerebral aneurysm?
Cerebral aneurysm (also known as an intracranial or intracerebral aneurysm) is a weak or thin spot on a blood vessel in the brain that balloons out and fills with blood. The bulging aneurysm can put pressure on a nerve or surrounding brain tissue. It may also leak or burst, spilling blood into the surrounding tissue (called a haemorrhage).
The majority of cerebral aneurysms, particularly those that are very small, do not bleed or cause other problems. Cerebral aneurysms can occur anywhere in the brain, but most are located along a loop of arteries that run between the underside of the brain and the base of the skull.
How common are aneurysms?
Brain aneurysms can occur in anyone, at any age. It is estimated that 0.3% to 1% of the general population has or will develop a cerebral aneurysm. They are more common in adults than in children, and slightly more common in women than in men, most commonly in people between ages 30 and 60 years. In Malaysia
How do aneurysms form?
Aneurysms usually develop at branching points of arteries and are caused by constant flow stress and pressure from blood flow. They often enlarge slowly and become weaker as they grow, just as a balloon becomes weaker as it stretches.
Aneurysms may be associated with other types of blood vessel disorders, but these are very rare. They may run in families. Some aneurysms develop as the result of infection, trauma, and drugs such as amphetamines and cocaine that damage the brain’s blood vessels.
What are the symptoms of an aneurysm?
Most cerebral aneurysms do not show symptoms until they burst or grow larger. Small, unchanging aneurysms commonly are asymptomatic, whereas a larger one that is steadily growing may produce symptoms by pressing on tissues and nerves.
Some symptoms may include pain behind or above the eye; numbness, weakness, or paralysis on one side of the face; dilated pupils or drooping of eyelids; and vision changes. These symptoms are due to the local mass effect of the aneurysm.
When an aneurysm bursts, an individual may experience a sudden and extremely severe headache, dizziness, nausea/vomiting, double vision, stiff neck, sensitivity to light, change in mental status or loss of consciousness. The patients usually describe the headache as “the worst headache of my life” and it is generally different in severity and intensity from other headaches the patients may have experienced.
“Sentinel” or warning headaches may result from an aneurysm that leaks for days to weeks prior to rupture. Only a minority of patients have a sentinel headache prior to aneurysm rupture. Prolonged coma or a marked change in the level of consciousness are ominous signs. Some individuals may have seizures.
People experiencing this “worst headache”, especially when it is combined with any other symptoms, or complains of recent onset of “migraine”, should seek immediate medical attention.
How is an aneurysm diagnosed?
A brain aneurysm needs to be detected by special imaging tests. Two non-invasive tests show the blood vessels in the brain. In the first, called CTA (Computed Tomographic Angiography), patients are placed on a table that slides into a CT scanner. A special contrast material (dye) is injected into a vein, and images are taken of the blood vessels to look for abnormalities such as an aneurysm.
In the second test, called MRA (Magnetic Resonance Angiography), patients are placed on a table that slides into a magnetic resonance scanner, and the blood vessels are imaged to detect a cerebral aneurysm. Both of these screening tests are useful to detect most cerebral aneurysms larger than 3–5mm.
The most reliable test is called a diagnostic cerebral angiogram. In this test, the patient lies on an x-ray table. A small tube (catheter) is inserted through a blood vessel in the leg and guided into each of the blood vessels in the neck that go to the brain. Contrast is then injected, and pictures are taken of all the blood vessels in the brain.
This test is slightly more invasive and less comfortable, but it is the most reliable way to detect all types and sizes of cerebral aneurysms.
Before any treatment is considered, a diagnostic cerebral angiogram is usually performed in order to fully map a plan for therapy.
What is the usual damage to the brain after an aneurysm bleeds?
Once an aneurysm bursts, there is a 30% to 40% chance of death, and a 20% to 35% chance of moderate to severe stroke or brain damage, even if the aneurysm is successfully treated.
A good outcome is only found in patients, having mild difficulties or almost no difficulties (5% to 30%).
Another bleed may occur from the already ruptured aneurysm if it is not treated promptly. In 15% to 20% of patients, severe spasm of the arteries from the irritation by the leaked blood may occur. This can lead to further brain damage.
Hydrocephalus (swelling of the cavities within the brain that produce cerebrospinal fluid), difficulty in breathing that requires a mechanical ventilator, and infection are common co-morbid problems. Heart and lung problems may result due to extensive brain damage that can affect the body’s normal functions.
Will treating a ruptured aneurysm reverse or improve brain damage?
Once an aneurysm bleeds and brain damage occurs, treating the aneurysm will not reverse the damage. Treatment is necessary, but is aimed at preventing more bleeding, which can cause more damage to the brain and, consequently, to the body’s functions.
Supportive treatment with medications to reduce brain swelling, prevent vasospasm, ensure adequate brain circulation and control of infection is essential in helping the patients through this critical time.
How is a treatment method for an aneurysm chosen?
Each aneurysm is unique and different. Your doctors must weigh the risk factors that favour treatment vs non-treatment and must decide which technique may be best.
It is important to consult with experts in this field. This should include a discussion with a cerebrovascular neurosurgeon who specialises in surgical clipping of aneurysms and an interventional radiologist who specialises in the less invasive treatment of cerebral aneurysms by coiling. These two types of medical specialists are usually different, and have different expertise and training backgrounds. It is highly recommended that you consult with both types of physicians.
What are the treatments options available?
Medical therapy.
Small, unruptured aneurysms are usually symptomless and may not need treatment unless they grow, trigger symptoms, or rupture. Regular check-ups in these cases is essential to monitor the progress and any secondary complications.
Microsurgical clipping.
Microsurgical clipping involves cutting off the flow of blood to the aneurysm. Under general anaesthesia, a section of the skull is removed, the aneurysm is located using an operating microscope, and a small, metal, clothespin-like clip is placed across the aneurysm’s neck, halting its blood supply.
Endovascular coiling.
Depending upon the aneurysm’s size, location and shape, it may be possible to treat the aneurysm from inside the blood vessel. This minimally invasive procedure is similar to the cerebral angiogram.
However, in addition to taking pictures, a catheter is directed through the blood vessels into the aneurysm itself. Then, under x-ray guidance, soft platinum micro-coils are carefully inserted into the aneurysm. The coils stay within the aneurysm and act as a mechanical barrier to blood flow, thus sealing it off. Sometimes, a stent (metal mesh) may be placed across a wide neck aneurysm to preserve the parent artery.
What are the potential complications of aneurysm treatment?
Until the aneurysm is safely and completely treated, there is always the risk that it may re-bleed and cause more brain damage. The risk of re-growth is low in small neck aneurysms, but may be as high as 20% in the wide neck variety.
The use of intracranial stents has significantly reduced the chances of recurrence. Both open surgical and endovascular treatment options carry a risk of stroke. In general, it is quoted as 10% in coiling and the percentages vary for open clippings.
If normal blood vessels are damaged, it could also result in more brain damage. This could cause weakness or paralysis of the arm or leg, difficulty with speech or understanding, vision loss, confusion, loss of memory and/or seizures.
There is also the risk of the anaesthesia itself, infection, bleeding, damage to the kidneys from the x-ray dye and other potential problems. All these risks need to be carefully considered when deciding upon a course of treatment.
Note: Dr Alex Tang is a consultant vascular & interventional radiologist. He is also honorary secretary of the College of Radiology, Academy of Medicine of Malaysia
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