Cerebral aneurysms are caused by thinning of the walls of the arteries. Aneurysms usually occur at the bifurcations or branches of the arteries because the blood vessels are weaker in these areas. Although aneurysms can occur anywhere in the brain, they are usually seen most often in the arteries at the base of the brain.
Risk factors
Many factors can cause weakness in the artery walls and increase the risk of brain aneurysms. Brain aneurysms are more common in adults than in children, and more common in women than in men. Some risk factors appear over time; others are congenital.
Risk factors that develop over time include.
1. advanced age.
2. smoking.
3. hypertension.
4. hardening of the arteries (atherosclerosis).
5. drug abuse, especially cocaine.
6, head trauma.
7, heavy alcohol consumption.
8, certain bloodstream infections.
9. low estrogen levels after menopause.
Out congenital risk factors include.
1, hereditary connective tissue disorders, such as Love-Tang syndrome, which causes thinning of blood vessels.
2. polycystic kidney disease, an inherited disorder that causes fluid-filled sacs in the kidneys and usually raises blood pressure.
3. abnormal narrowing of the aorta (aortic stenosis), the large artery that carries oxygen-rich blood from the heart to the body
4. arteriovenous malformation of the brain (cerebral AVM), in which an abnormal connection between the arteries and veins of the brain prevents normal blood flow.
5. a family history of cerebral aneurysm, especially first-degree relatives such as parents, siblings, etc.
Complications
When a cerebral aneurysm ruptures, the bleeding usually lasts only a few seconds. The blood can cause direct damage to surrounding cells, and the bleeding can damage or kill other cells. At the same time it will cause an increase in intracranial pressure. If the intracranial pressure is too high, the blood and oxygen supply to the brain may be disrupted until loss of consciousness or even death occurs.
Complications that occur after a ruptured aneurysm include
1. rebleeding. Ruptured or leaking aneurysms are at risk of rebleeding. Rebleeding can lead to further brain cell damage.
2. vasospasm. After a ruptured cerebral aneurysm, the blood vessels in the brain may constrict erratically (vasospasm). This condition can restrict blood flow to brain cells (ischemic stroke) and cause additional cellular damage and death.
3. hydrocephalus. When a ruptured aneurysm causes blood to flow into the gap between the brain and its encapsulated tissue (subarachnoid hemorrhage) – which is the most common condition – the blood can block the circulation of cerebrospinal fluid. This disease can lead to an excess of cerebrospinal fluid that increases the pressure on brain tissue and causes brain tissue damage (hydrocephalus).
4. Hyponatremia. Subarachnoid hemorrhage caused by a ruptured cerebral aneurysm can disrupt the sodium balance in the blood. This can be caused by damage to the hypothalamus, an area near the base of the brain. A decrease in the level of sodium in the blood (hyponatremia) can lead to edema of brain cells as well as permanent damage.