By Dr. Dineshani Hettiarachchi Sirisena
Strokes are a leading cause of mortality and morbidity the world over. One in four people have a lifetime risk of developing a stroke. Identifying that there is a gap in stroke awareness among the public, The Sunday Morning Brunch spoke to Sri Jayewardenepura General Hospital Consultant Neurologist and the National Stroke Association of Sri Lanka President Dr. Harsha Gunesekara.
What causes an acute stroke?
An acute stroke is commonly referred to as a cerebrovascular accident and occurs as a result of a sudden disturbance of the blood supply to a specific area of the brain. This results in death or permanent changes to the brain tissue. The majority of strokes, i.e. over 85%, are ischemic; in other words, there is a blockage in a blood vessel supplying the tissues of the brain that has nerve cells or neurons. The remaining 15% result from ruptured blood vessels and are called hemorrhagic strokes.
What are the phases of an acute stroke?
Following a stroke, there is a rapid loss of brain cells (neurons) at a rate of 1.9 million per minute. Therefore, every minute counts and treatment initiated immediately can prevent this loss.
|Time lost||Brain lost (Number of nerve cells dying)|
|Every minute||1.9 million|
|Every hour||120 million|
|Every stroke||1.2 billion|
From a therapeutic perspective, acute stroke is divided into four phases by clinicians and neurologists. Each phase has its primary objectives and therapeutic focus.
The first phase is the pre-hospital phase which is from symptom onset to when the patient is brought to the hospital. If the condition is identified during this phase without much delay, it reduces the risk of death and disability through accurate suspected diagnosis, the correct choice of hospital, and due to the impact on time-to-treatment.
The second phase is referred to as the hyper-acute phase, which is the first hour from the time of bringing the patient to the hospital. This phase can aid in reducing the risk of death and disability by an absolute focus on confirming the diagnosis and restoring the blood flow by recanalisation of the artery or by reducing the swelling due to bleeding.
The next phase is the acute phase which lasts from one to 24 hours after admission. During this phase, neurological screening and close monitoring of cardiac and respiratory systems are required to reduce risk of death.
The final phase is the post-acute phase which lasts from 24 to 72 hours after admission, requiring close monitoring of the cardiac and respiratory systems. Clinicians will take measures to prevent another stroke during this phase.
Neurons are basic cellular functional units of the brain and act by transmitting electrical impulses and chemical signals within the brain and the rest of the nervous system through multiple communication channels known as synapses. A normal healthy adult brain has approximately 100 billion neurons and 100 trillion synapses.
Following a stroke, 1.9 million neurons are lost every minute and on average 1.2 billion neurons die if a stroke is left untreated. Therefore, treatment should be initiated immediately to prevent damage. The phrases ‘Every second counts’ and ‘Time is brain’ were coined owing to the urgency with which an acute stroke should be dealt with as delays can lead to missed opportunities for treatment and poor treatment outcomes resulting in death or permanent disability. Dr. Harsha Gunesekara noted that annually, 60,000 stroke patients were admitted to State hospitals, but the majority of them arrived too late.
The three main pillars of successfully managing an acute stroke include:
- Rapid diagnosis
- Rapid access to imaging (CT)
How do you identify a stroke early?
The best method is to use the FAST stroke scale, which is a simple, quick, and reliable assessment. F stands for FACE drooping, A stands for ARM weakness, S stands for SPEECH difficulty, and T stands for TIME to take immediate action. Even if the symptoms resolve, the presence of any one of these symptoms suggests a possible stroke.
If someone has any of these symptoms, they should be rushed to the nearest major hospital. The patient should be treated in a hospital equipped with a CT scanner as this helps to identify the type of stroke and initiate treatment promptly. All provincial and almost all district general hospitals in the country have CT scanners.
What are the risk factors of stroke?
The main risk factors of stroke include:
- High blood pressure – Our blood pressure changes throughout the day based on the activities we engage in. For most adults, the normal blood pressure range is less than 120 systolic and over 80 millimetres of mercury (mm Hg) diastolic pressure, which is written as – 120/80 mm Hg. Your blood pressure is considered high when you have three consistently high readings of systolic 130 mm Hg or higher or diastolic 80 mm Hg or higher.
- Diabetes – Uncontrolled high blood sugar is another major risk factor for acute stroke.
- Cardiac and vascular causes – Conditions that increase the likelihood of causing blood clots including coronary artery disease, atrial fibrillation where there is an irregular and often very rapid heart rhythm i.e. arrhythmia, valvular diseases, etc.
- High LDL cholesterol levels – When the cholesterol level in the blood is high it can cause a build-up around the arterial walls, narrowing the area available for the passage of blood. This is called atherosclerosis and these atherosclerotic plaques can block or stagnate the blood flow, causing clots that lead to ischaemic strokes.
- Smoking – Smoking tobacco increases the risk of stroke. A recent study showed that those who smoke 25 cigarettes or more daily are three times more likely to suffer from a stroke. Smoking also increases blood pressure and has over 4,000 toxic chemicals that can damage the blood vessels, leading to the formation of clots.
Other causes include viral infections such as Covid-19 and other conditions that cause inflammation such as lupus or rheumatoid arthritis. Age is also a non-modifiable risk factor; globally, 60% of strokes occur in people under 70 years and 8% are under 44 years and both types of strokes are more common in men. Even though there is a handful who get strokes at a younger age, for the majority, the risk increases with age. Our sex is also a non-modifiable risk factor and in younger years men are more likely to have a stroke than women. However, these statistics change after menopause for women.
Another important factor is family history and our genetic makeup. Certain genetic defects affect your stroke risk. Some of the modifiable risk factors can be tackled through healthy lifestyle changes.
Almost 90% of strokes can be prevented by following these 10 simple steps to control the risk factors. They are:
- Know your blood pressure and control it
- Do moderate exercise for 20-30 minutes, at least five times a week
- Eat a healthy balanced diet rich in fresh vegetables and fruit and low in processed foods
- Know your blood cholesterol level and control it
- Maintain a healthy weight with a normal body mass index and waist circumference
- Stop smoking and avoid smoky environments
- Reduce alcohol intake
- Know your blood glucose level and control diabetes
- Identify and treat irregular heart rhythm, known as atrial fibrillation
- Manage stress and depression