Transient Ischemic Attack (TIA)

Transient Ischemic Attack (TIA) refers to temporary brain dysfunction due to a shortage of blood and oxygen. It sometimes is referred to as a mini-stroke. TIA is a serious condition that serves as a warning for a stroke. The chance of suffering a stroke is greatest in the first few months after the initial TIA.

Causes

A temporary blockage of the blood supply to the brain results in a TIA. A buildup of plaque in the arteries and hardening of the arteries usually are present.
Reasons for the blockage may include:
  • A blood clot or a piece of plaque from inside the wall of an artery breaks off and blocks blood flow to a portion of the brain.
  • A blood clot dislodges from the heart and moves to the brain.
  • Temporary low blood pressure in the brain may occur due to narrowed arteries in the neck.
  • Blood and blood clotting disorders, such as:
    • Anemia
    • Polycythemia
    • Hyperviscosity
  • Vasculitis or blood vessel inflammation

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.
  • Atrial fibrillation, an irregular heart rhythm
  • Family history of stroke
  • Age: 45 or older (highest risk is in the 7th and 8th decades)
  • Diabetes
  • Heart disease
  • Smoking
  • High blood pressure
  • Excessive alcohol use
  • Sex: male
  • High cholesterol
  • Obesity
  • Sedentary lifestyle
  • Sleep apnea
  • AIDS

Symptoms

A TIA symptoms usually last less than 10 minutes, but may persist for up to 24 hours. The effects differ depending on the location of the blockage. TIA symptoms are similar to those of a stroke and warrant immediate medical care.
Symptoms include:
  • Blindness in one eye, often described as a window shade dropping
  • Other vision problems
  • Weakness, numbness, or tingling of the face, arm, leg, or one side of the body (Usually affects one side of the body, but there are exceptions)
  • Difficulty speaking or understanding words
  • Dizziness, unsteadiness, or a fall
  • Difficulty walking or unsteady gait
  • Trouble with balance or coordination
  • Loss of consciousness
  • Sudden, severe headache
  • Nausea
  • Vomiting
  • Sudden confusion or memory problems

Diagnosis

The doctor will ask about your symptoms and medial history, and perform a physical exam. A primary goal is to determine your stroke risk.
Tests may include:
Blood Tests - including a complete blood count, blood sugar, cholesterol fat levels, clotting levels, and a check of other elements in the blood
Electrocardiogram (EKG) – to measure heart rhythm and check for an irregular heart beat
Ultrasound– a test that uses sound waves to help determine if there are blockages in the arteries supplying the brain
MRI Scan – a test that uses magnetic waves to make pictures of structures inside the head
CT Scan – a type of x-ray that uses a computer to make pictures of structures inside the head
Magnetic Resonance Angiography – performed prior to carotid artery surgery to determine how much the artery has narrowed. During an arteriogram, a contrast dye is injected and images are produced to precisely locate the blockage and to determine how much of the artery is occluded. This test is usually only done to confirm the need for surgery.
Echocardiogram - an ultrasound test that looks for blood clots within the heart
Electroencephalogram (EEG) - a test that can detect seizures by measuring brain waves (used only if a seizure is suspected)

Treatment

A TIA places you at greater risk for having a stroke. Therefore, treatment aims to decrease stroke risk through lifestyle changes, medication, and surgery. Any contributing conditions such as diabetes or high blood pressure should be brought under control. Medications
Many patients receive aspirin or other drugs to decrease the risk of clot formation. However, there are situations when these drugs cannot be used. Your doctor may order medications to treat other conditions that increase the risk of stroke. If your blood cholesterol is high, drugs to lower it may be prescribed. If you have high blood pressure, work with your doctor to bring it under control. Surgery
If the carotid artery is 70% blocked or more, the doctor may recommend a carotid endarterectomy to remove the plaque deposits. Since the procedure can cause strokes, it is not routinely performed if there are no symptoms and less than 70% blockage.

Prevention

The following strategies may help reduce the chance of TIAs and stroke:
  • Exercise regularly, with your doctors approval.
  • Eat a healthful diet, one that is low in saturated fat and rich in whole grains, fruits, and vegetables.
  • Maintain a healthy weight.
  • If you smoke, quit.
  • Drink alcohol in moderation. Moderate alcohol intake is no more than 2 drinks per day for men and 1 drink per day for women.
  • Control blood pressure and diabetes.
  • Bring cholesterol levels into the normal range.