Aneurysm in the brain Health Article

Definition

An aneurysm is an abnormal widening or ballooning of a section of a blood vessel. When an aneurysm occurs in the brain, it is called a cerebral aneurysm.

Alternative Names

Aneurysm - cerebral; Cerebral aneurysm

Causes, incidence, and risk factors

Aneurysms in the brain occur when there is a weakened area in the wall of a blood vessel. An aneurysm may be present from birth (congenital) or it may develop later in life. (For example, after a blood vessel is injured.)

There are many different types of aneurysms. A berry aneurysm can vary in size from a few millimeters to over a centimeter. Giant berry aneurysms can reach well over 2 centimeters. These are more common in adults. Multiple berry aneurysms are inherited more often than other types of aneurysms.

Other types of cerebral aneurysm involve widening of an entire blood vessel, or they may appear as a "ballooning out" of part of a blood vessel. Such aneurysms can occur in any blood vessel that supplies the brain. Trauma and infection, which can injure the blood vessel wall, can cause such aneurysms.

About 5% of the population has some type of aneurysm in the brain. Risk factors include a family history of cerebral aneurysms, and certain medical problems such as polycystic kidney disease and coarctation of the aorta.

Symptoms

Aneurysms usually cause no symptoms unless they rupture and cause bleeding into the brain. Often, an aneurysm is found when a CT scan or MRI is performed for another reason. Symptoms occur if the aneurysm pushes on nearby structures in the brain.

Symptoms depend on what structure the aneurysm pushes on, but may include:

• Double vision
• Loss of vision
• Headaches
• Eye pain
• Neck pain

A sudden, severe headache (often described as "the worst headache of your life") is one symptom that an aneurysm has ruptured. Other symptoms of an aneurysm rupture may include:

• Confusion, lethargy, sleepiness, or stupor
• Eyelid drooping
• Headaches with nausea or vomiting
• Muscle weakness or difficulty moving any part of the body
• Numbness or decreased sensation in any part of the body
• Seizures
• Slow, sluggish, lethargic movement
• Speech impairment
• Stiff neck (occasionally)
• Sudden onset of irritability, impulsivity, or poor temper control
• Vision changes (double vision, loss of vision)

NOTE: A ruptured aneurysm is a medical emergency. Seek immediate medical help.