Pathophysiology and Etiology

Definitions

Stroke

A stroke (apoplexy) is the sudden onset of weakness, numbness, paralysis, slurred speech, aphasia, problems with vision and other manifestations of a sudden interruption of blood flow to a particular area of the brain. The ischemic area involved determines the type of focal deficit that is seen in the patient.

Transient Ischemic Attack (TIA)

A TIA is similar to a stroke, but the interruption of blood flow is temporary. The clot resolves sporadically. The symptoms are relatively the same as a stroke but last less than 24 hours, whereas stroke symptoms persist for greater than 24 hours.

Causes of Stroke

The primary pathophysiology of stoke is an underlying heart or blood vessel disease. The secondary manifestations in the brain are the result of one or more of these underlying diseases or risk factors. The primary pathologies include hypertension, atherosclerosis leading to coronary artery disease, dyslipidemia, heart disease, and hyperlipidemia. The two types of stroke that result from these disease states are ischemic and hemorrhagic strokes.

Non-reducable Risk Factors

  1. The possibilities of a stroke occurring increases with age. For every decade (10 years) over the age of 55, the possibility of a stroke occurring doubles. A patient that is 75 years of age has four times the risk of having a stroke compared to someone who is 55 years old. Of all strokes that occur in people, approximately 65% occur in those who are over the age of 65.
  2. Those who have had a stroke or TIA are more likely to have another stroke or transient ischemic attack. Approximately 60% of strokes occur in patients who have had a previous TIA.
  3. Strokes generally occur more often in males than females, until the age of 55; after age 55 the risk is the same for both men and women.
  4. The occurrence of stroke is higher in the African-American, Hispanic, and Asian-Pacific Islander population than in other ethnical backgrounds.
  5. Patients who have immediate family members (mother, father, or sibling) that have had a stroke or TIA are at greater risk for having a stroke or TIA than those who do not have a family history with these events.
  6. People who have diabetes are also at greater risk of stroke that those without diabetes.

Reducable Risk Factors

  1. Lower your high blood pressure. Hypertension (high blood pressure) is the number one most treatable risk factor for stroke. You can help prevent a TIA or stroke considerably by working to lower your blood pressure.
  2. Lowering cholesterol levels may decrease the risk of stroke. By working to lower your cholesterol, you can help prevent a TIA or stroke.
  3. Stop smoking. If you stop smoking, you can decrease your risk for stroke to that of a non-smoker within two to five years.
  4. Management of heart disease and diabetes may also help to decrease your risk of stroke.