Brain Aneurysm

Brain Aneurysm:
A brain aneurysm is an abnormal outward balloon-like widening of a section of an artery or a vein in the brain. This bulging structure with a neck is also known as intracerebral aneurysm and intracranial aneurysm.

Aneurysms commonly occur in the weak areas in an artery or vein wall in the anterior region of the Circle of Willis; this is the important network loop of arteries at the base of the brain that connects with all the parts of the brain and provides them with blood and nutrition. The areas most likely to develop weak spots are at the junctions of arteries and veins.

Brain Aneurysm Causes:
There are several factors that can cause an aneurysm -

• Head Injury
• High Blood Pressure
• HighCholesterol
• Atherosclerosis
• Artery wall damage due to abnormal blood flow
• Infection of the arterial wall - mycotic aneurysms
• Congenital malformation of blood vessels
• Diseases of the vascular system
• Tumors of the head and neck
• Medical conditions like Polycystic kidney disease, Ehlers-Danlos syndrome and Marfan syndrome
• Cigarette smoking
• Drug abuse
• Binge Drinking
• Using oral contraceptives

Types of Brain Aneurysms:
Brain aneurysms are classified by size -

• Small aneurysms – less than 11mm to 15mm in diameter
• Large aneurysms – 15 to 25 mm in diameter
• Giant aneurysms – 25 to 50 mm in diameter
• Super Giant aneurysms – over 50 mm in diameter

Classification is also made by shape -

• Berry aneurysm or saccular aneurysm – aneurysm having a round saccular or berrylike pouch-like blood sac that is attached to an artery or vein with a narrow stem or neck. This is the most common type of brain aneurysm and found on Circle of Willis at the base of the brain. It can occur at any age, but is more common in adults than in children and is more frequently seen in women than in men.
• Lateral aneurysm – Grows as a bulge on one wall of the artery or vein.
• Fusiform aneurysm - Formed by the widening along all walls of the vessel.

Brain Aneurysm Dangers:

• A berry aneurysm is particularly dangerous, because it is found on one of the main arteries that supply the brain, is easily susceptible to rupture, and rupturing can lead to fatal bleeding within the brain.
• The bulging aneurysm puts pressure on a nerve or surrounding brain tissue.
• The artery or vein wall can weaken further and cause the aneurysm to rupture or leak and cause blood hemorrhage in the brain or in the subarachnoid space surrounding the brain. This is known as subarachnoid hemorrhage.
• Subarachnoid hemorrhage, depending on the severity, can cause hemorrhagic stroke, brain damage or even death.
• The larger the aneurysm the greater the risk of rupturing.
• Some aneurysms, however, if they are very small, do not rupture or cause other problems or produce any symptoms.

The risk an aneurysm poses depends on its size and location and on your age and health. Symptoms of Brain Aneurysm:

• Small aneurysm – generally will have no symptoms.
• Large aneurysm – no symptoms until very large. Pressure on surrounding brain tissue can produce headaches. before rupturing, the person will experience -
  • Unbearably severe headaches
  • Change in mental status
  • Nausea
  • Increased sensitivity to light
  • Pain above and behind the eye
  • Drooping of an eyelid
  • Dilated pupils
  • Double vision
  • Numbness
  • Weakness
  • Paralysis on one side of the face
  • Vomiting
  • Stiff neck
  • Dizziness
  • Seizures
  • Loss of consciousness

If you experience these symptoms or notice them in anyone, contact a health professional immediately. Detection of Brain Aneurysm:
Brain aneurysms can be detected by the following medical procedures -

• Computed tomography (CT)
• Computed tomography angiogram (CTA)
• Lumbar puncture (LP, or spinal tap)
• Angiography
• Magnetic resonance imaging (MRI)

Brain Aneurysm Treatment:
Treatment of brain aneurysms usually depends on -

• Extent and location of aneurysm
• Neurological condition
• Person's age
• General health

For ruptured aneurysm -
This is a medical emergency requiring immediate surgical treatment and doctors will focus on -

• Restoring deteriorating respiration
• Reducing Intracranial Pressure
• Stopping the bleeding
• Preventing any permanent brain damage
• Reducing risk of recurrence

Outcome -

• Person can die from initial bleeding
• Person can die of later complications
• Person can recover with little or no neurological deficit

For unruptured aneurysm -

• If very small, likelihood of rupturing is low and surgery is not recommended. Condition is observed and treated with medications.
• If large, possibility of rupturing is high and doctors may suggest surgery -
• Microvascular clipping - Blood supply to the aneurysm is cut off with a metal clip to the base
• Endovascular coiling - A catheter is inserted into the groin through the femoral artery and passed into the aneurysm by way of the aorta and the brain arteries. Through the catheter, platinum coils are released into the aneurysm to cause clotting and thereby eliminate the aneurysm
• Shunt surgery – This is done in case of development of hydrocephalus to drain away excess cerebrospinal fluid from the brain

Aside from this, anti-convulsant medications and calcium channel blockers are prescribed.

Brain Aneurysm Prevention:
There is no known way to prevent brain aneurysms, but the following suggestions may help -

• Give up smoking
• Don't use stimulant drugs
• Don't drink too much alcohol
• Reduce the amount of your caffeine intake
• Don't over-strain your body – go easy on the weight-lifting, for example
• Don't take aspirins, cold medicines or any other medications unless prescribed by your doctor
• Control your high blood pressure
• Check with your doctor about oral contraceptives
• Go for a regular physical examination