This is a blood vessel ballooning with blood because the vein is blocked or obstructed higher up. If this bulge (aneurysm) bursts, blood enters and damages the brain. When this happens, it is referred to as a hemorrhagic stroke. While brain aneurysms are less frequent than ischemic strokes, they are more deadly.
An aneurysm is the result of a weakened artery wall that can bulge and rupture. Aneurysms can occur in the brain (cerebral aneurysm) or in other parts of the body, such as the abdomen or the heart. A brain aneurysm can cause a hemorrhagic stroke. Most people will not notice symptoms of aneurysm until the vessel bursts.
Aneurysms and stroke are not the same, but a ruptured aneurysm can lead to a hemorrhagic stroke and bleeding in or around the brain. Symptoms of an aneurysm that has burst or is likely to burst include a thunderclap headache. This is also a sign of a hemorrhagic stroke.
Ruptured brain aneurysms are fatal in about 50% of cases. Of those who survive, about 66% suffer some permanent neurological deficit. Approximately 15% of people with a ruptured aneurysm die before reaching the hospital. Most of the deaths are due to rapid and massive brain injury from the initial bleeding.
With rapid, expert treatment, patients can often recover fully.
While brain aneurysms are less frequent than ischemic strokes, they are more deadly. Most aneurysms happen between the brain itself and the tissues separating it from your skull; this is called the subarachnoid space.
An unruptured aneurysm might not initially have any symptoms, but that usually changes as it grows larger. The warning signs that indicate a person has developed an unruptured brain aneurysm include: Pain behind or above an eye. Double vision.
The weakness in the wall of a vessel leads to ballooning or bulging, which can eventually lead to a rupture of the wall. “When it ruptures,” Dr. Shekhtman says, “the blood comes out of the artery and damages whatever brain structures are near.” An aneurysm can lead to a stroke, but a stroke won't lead to an aneurysm.
Survivors face the potential for physical, emotional, and cognitive changes that can be minor or significant, short-term or long-lasting. Recovery for patients who suffered a ruptured aneurysm tends to be longer and more difficult than it is for patients whose aneurysm did not rupture.
Signs of stroke include sudden weakness or drooping in the arms, legs, or face, especially on one side of the body. The person may also be confused, have difficulty speaking, have changes in vision, or have a sudden headache. An aneurysm may not cause any symptoms at all until it ruptures.
Experts think brain aneurysms form and grow because blood flowing through the blood vessel puts pressure on a weak area of the vessel wall. This can increase the size of the brain aneurysm. If the brain aneurysm leaks or ruptures, it causes bleeding in the brain, known as a hemorrhagic stroke.
An aneurysm is different from a blood clot in that it is a defect in the wall of a blood vessel that can bleed. If an aneurysm in the brain bleeds, it usually causes a subarachnoid hemorrhage, which results in a blood clot in the subarachnoid space surrounding the brain.
Some of the causes of aneurysms include: a weakness in the blood vessel wall that is present from birth (congenital aneurysm) high blood pressure (hypertension) over many years resulting in damage and weakening of blood vessels. fatty plaques (atherosclerosis) resulting in a weakness of the blood vessel wall.
“An aneurysm usually grows slowly, around 1–2mm per year. Once it reaches a certain size, the risk of it rupturing (bursting) becomes too high and surgery is needed to repair it.” An aneurysm is usually classed as large once it reaches 5.5cm.
High blood pressure is the leading cause of subarachnoid hemorrhage. Heavy lifting or straining can cause pressure to rise in the brain and may lead to an aneurysm rupture. Strong emotions, such as being upset or angry, can raise blood pressure and can subsequently cause aneurysms to rupture.
Hemorrhagic strokes are particularly dangerous because they cause severe symptoms that get worse quickly. Without fast medical attention, these strokes often cause permanent brain damage or even death.
The most severe embolic strokes are due to a clot that travels from the heart to the brain. Large blood clots are especially dangerous because they can completely stop blood from flowing through the largest, and thus most important, blood vessels in the brain.
Cognitive dysfunction is a frequent complication of an aneurysm or the surgery to repair it. The aneurysm and the surgery may cause physical changes to brain tissue and can lead to diffuse cognitive deficits, including problems with attention, memory, executive functioning, and information processing.
Most people with brain aneurysms do not have close family members with this condition. But a landmark study found that 1 in 5 people with a brain aneurysm has a family history of them.
According to a 2021 case report , an unruptured brain aneurysm may cause psychological changes similar to schizophrenia or bipolar disorder. The researchers note that mental conditions are common with unruptured brain aneurysms.