​Ischemic Stroke

Stroke represents a disorder of the cerebrovascular system (brain blood vessels) which affects the blood supply of your brain. There are two major types of stroke: Ischemic and Haemorrhagic. Stroke is the leading cause of disability across the globe and can be life-threatening. The ischemic type accounts for more than 80% of all strokes and in general, both types are more common in men than women.

Let us take a look at the events leading to a stroke. Brain cells (neurons) are completely dependent on their arteries to bring them nutrients and oxygen. If this supply is cut off even for a few minutes, the brain cells are permanently injured and die. Consequently, the respective body function controlled by the damaged nerves is lost. 

Ischemia (loss of adequate blood supply) occurs due to a blockage of the brain arteries by a blood clot. The blood vessels distributing fresh oxygen to this vital organ, which controls and coordinates all your activities, are quite narrow in diameter. A blood clot can form in these tiny arteries due to build-up of fat (called a ‘thrombus’) in their walls. When a clot forms in the vascular system outside the brain, especially the heart, it can get transported to the brain and get stuck in those minute passages. This travelling clot is known as an ‘embolus’. Uncontrolled cholesterol levels raise your chances of being afflicted with an ischemic type of stroke. Atherosclerosis (cholesterol fat deposits in arterial walls) gives rise to plaques which make the respective vessel stiff and narrow.

An <arrhythmia> of your heart is another causative factor. The rate and pattern of regular heartbeats are finely tuned. If this delicate balance is disturbed your heart will not be able to pump appropriately. This is also a recognized source of an embolus to your brain. Smoking, excessive alcohol intake, uncontrolled diabetes, high blood pressure, being overweight, heart disease, diseased carotid artery, sedentary lifestyle and age above 55 years are well-known risk factors of stroke. ​

Global cerebral ischemia is decreased blood flow to the whole brain. This usually takes place due to heart attack (myocardial infarction), abnormal rhythm of the beating heart or heart failure. Once again, the lack of fresh blood necessary to maintain the brain’s metabolic demands can lead to a stroke.​​

When to seek expert advise

If you suspect a stroke by noticing any of the above mentioned symptoms, do not waste any time in rushing to the 24/7 Emergency and Acute Care Service Line at The Aga Khan University Hospital. Urgent medical attention is crucial for survival and prevention of permanent disability. Here is an easy pneumonic to help you identify the signs in yourself and others = BE FAST, which stands for:

• Balance: loss of balance suddenly while walking or even standing.

• Eyes: sudden complete loss of or blurry vision; seeing double.

• Face: drooping of one side of face when you ask the suspected person to smile.

• Arms: try to raise both of your arms (or ask the affected person to raise their arms). One arm would drift downwards involuntarily.

• Speech: slurred or strangely unrecognizable.

• Time: every minute counts. Go to the 24/7 Emergency & Acute Care Service Line immediately.

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