Ischemic strokes account for more than 80 percent of all strokes in the United States and most often occur when an artery or vessel that supplies blood to the brain is greatly narrowed or blocked by fatty materials, such as cholesterol. Ischemic strokes also occur when small pieces of plaque or blood break off into the bloodstream and get stuck in a small blood vessel in the brain.
A Transient Ischemic Attack (TIA) is a "ministroke" that causes no permanent damage, and is an early warning sign that an ischemic stroke is coming. While the symptoms of TIAs are short-lived, the long-term damage caused by a stroke can be life-changing. People who experience symptoms of a stroke, even if only for a few minutes or on and off for a few days, should seek immediate care.
Stroke Symptoms and Warning Signs
- Sudden numbness/weakness of the face, arm or leg, especially on one side of the body
- Sudden confusion, trouble speaking or understanding
- Sudden trouble seeing in one or both eyes; double vision
- Sudden trouble walking, dizziness, loss of balance or coordination
- Sudden severe headache with no known cause
Key Risk Factors
In addition to risk factors such as age, gender, and family history, other risk factors and controlled to reduce the chances of an ischemic stroke, include:
- Hypertension: High blood pressure is the leading cause of stroke, and the most important risk that can be controlled.
- High cholesterol: Elevated total cholesterol increases the risk of stroke, while an elevated LDL cholesterol level offers some protection from stroke
- Diabetes and hyperglycemia: While many people with diabetes suffer from other risk factors like high blood pressure and obesity, the disease itself causes an increased risk
- Atrial fibrillation: Abnormal heart rhythms can cause blood to pool and form clots in the chambers of the heart, which can break free to cause a stroke.
- Carotid artery disease: When the carotid artery is more than 80 percent blocked, chance for stroke is increased.
- Sickle Cell disease: Sickle cell disease results in a decreased oxygen carrying capability and a prothrombotic state which results in ischemic stroke, particularly in younger patients.
Diagnosis
Ischemic strokes are diagnosed through clinical and diagnostic workups, neurological and physical examinations, and neuroimaging technologies such as CT scans, Magnetic Resonance Imaging (MRI) and angiography.
Treatment
Once diagnosed, treatment occurs in three levels:
Level 1: Hyperacute management – within first six hours of diagnosis the goal is to open up any blocked vessels and restore blood flow
- Administration of tPA, a clot-busting medication within first 3 hours of onset of symptoms
- Intravenous thrombolytics or intra-arterial intervention
Level 2: Acute management – within the first 24 hours of diagnosis the goal is to prevent complications associated with the stroke
- Aggressive glucose and temperature control
- Early mobilization and consultation with rehabilitation services
- Diagnostic tests aimed at identifying the cause of the stroke
Level 3: Subacute management- after the first 24 hours of diagnosis the goal is to prevent another stroke from occurring in the future and readying the patient to transition to life outside of the hospital
- Starting medications and therapies aimed at minimizing the chance of another stroke in the future
- Continuing aggressive therapy to minimize disability after the stroke
