Cerebrovascular Neurosurgery - Stroke
What is stroke?

Stroke occurs when there is an interruption of normal blood flow to the brain, causing brain cells to die and a subsequent impairment of functions such as speech, vision, and movement. Severe cases of stroke may also cause coma and death.

Knowing the factors that increase the risk of stroke and recognizing the symptoms of stroke may help you to seek the early diagnosis and treatment that will improve your chances for complete recovery

How common are strokes?

Deaths

  • Stroke is the fourth leading cause of death in Canada.
  • Each year, about 16,000 Canadians die from stroke.
  • Each year, more women than men die from stroke.

Prevalence

  • There are between 40,000 to 50,000 strokes in Canada each year.
  • For every 10,000 Canadian children under the age of 19, there are 6.7 strokes.
  • About 300,000 Canadians are living with the effects of stroke.
  • After age 55, the risk of stroke doubles every 10 years.
  • A stroke survivor has a 20% chance of having another stroke within 2 years.

Effects

Of every 100 people who are hospitalized for stroke:
  • 20 die before leaving the hospital
  • 50 return home
  • 10 go to an inpatient rehabilitation program
  • 15 require long-term care
What causes a stroke?

A stroke occurs when an artery within or leading to the brain becomes obstructed or ruptures. These arteries can become blocked by blood clots that have formed in the carotid artery or heart or by the gradual build-up of fatty plaques or deposits—a process known as atherosclerosis. A brain artery ruptures when a weak spot on the blood vessel wall breaks, as in aneurysms. When the blood supply to a portion of the brain is stopped, even for a few minutes, the cells within the brain rapidly begin to die.

The carotid artery, a large artery in the neck, is one of the major sources of blood flow to the brain. This artery may gradually become clogged by the build-up of fatty deposits or plaques secondary to a variety of causes, including high blood pressure, smoking, high cholesterol and fat levels in the blood, and hereditary factors. Blood clots usually develop in the heart secondary to an abnormal beating pattern known as atrial fibrillation. Blood thinning medications help prevent the formation of these clots.

A hemorrhagic stroke occurs when there is bleeding into the brain tissue. This may lead to irreversible damage to the delicate structures of the brain. Brain hemorrhages, or hemorrhagic strokes, occur for a variety of reasons and may be related to a systemic problem, such as uncontrolled hypertension, or an underlying structural abnormality, such as a vascular malformation or tumour. Hemorrhagic strokes usually come on suddenly, with little or no warning, and their results can be devastating.

What are the risk factors for stroke?
  • high blood pressure (hypertension)
  • cigarette smoking
  • high blood cholesterol level
  • obesity
  • heart disease
  • diabetes
  • transient ischemic attacks (TIAs)
  • family history of stroke
  • African-American heritage
What are the signs of a stroke?
  • numbness of the face, arm or leg on one side of the body
  • weakness of the face, arm or leg on one side of the body
  • sudden and severe headache with no apparent cause
  • difficulty speaking or understanding language
  • dizziness, loss of balance, or loss in coordination
  • visual loss

About 30 percent of stroke patients have a history of transient ischemic attacks, or TIA's. These "small strokes" basically have the same symptoms, but they usually subside quickly (often within a few minutes, and nearly always within 24 hours).

What should I do if I have these symptoms?

If you recognize these symptoms in yourself or someone else, call 911 immediately. Early treatment ensures the best chance of recovery from a stroke.

What are the treatment options?

Carotid endarterectomy:  One method for relieving the obstruction of blood flow in the carotid arteries is to surgically remove the fatty deposits causing the blockage. Surgery has been shown to dramatically reduce the risk of stroke for patients who have had TIA's and who have severe blockage of the corresponding carotid artery, as compared to the benefit of medicine alone.

Thrombolytic therapy:  One method of removing a blood clot obstructing a brain artery is to advance a tiny catheter through the affected blood vessel to the site of obstruction. Through this catheter a clot busting medicine (thrombolytic agent / TPA / urokinase) can be directly applied to the clot to dissolve it. Once the clot is dissolved, normal blood flow to the brain can be re-established, thus avoiding permanent brain injury. This form of therapy needs to be instituted within 6 hours of the onset of stroke symptoms.

Blood clot removal:  In some carefully selected patients, timely removal of blood clots within the brain can be life-saving and may result in improvement of neurological impairment.

Medical treatment:  Antiplatelet medicines, such as ASA and blood thinners, are used routinely in the prevention of stroke. There are many studies which show that good control of blood pressure, cholesterol, and blood sugar lowers the risk of stroke.

Balloon angioplastyIn this procedure a plastic tube or catheter with a balloon is advanced over a guidewire to the site of carotid artery narrowing. The balloon is then inflated, thus widening the flow channel through the area of plaque.

Carotid stenting:  When an angiography is being conducted, a metallic stent can be placed into the carotid artery in order to keep it open.