Understanding Strokes: Meaning, Causes, And Effects

A stroke, or brain attack, is a life-threatening medical emergency that occurs when there is an issue with blood flow to the brain. This can be due to blocked blood vessels or bleeding in the brain. Without a steady supply of blood, brain cells are starved of oxygen and begin to die within minutes, causing brain damage, long-term disability, or even death. Recognising the signs of a stroke and seeking immediate medical attention is critical to prevent permanent damage.

What are the symptoms of a stroke?

A stroke is a life-threatening medical emergency that requires immediate attention. It occurs when there is an issue with blood flow to the brain, either due to blocked blood vessels or bleeding in the brain. The quicker a stroke is treated, the more likely a person will recover without disability.

To recognise the warning signs of a stroke, remember the acronym BE FAST or F.A.S.T:

• Balance: Look out for a sudden loss of balance.
• Eyes: Check for a sudden loss of vision in one or both eyes, or double vision.
• Face: Ask the person to smile and look for a droop on one or both sides of their face, indicating muscle weakness or paralysis.
• Arms: Ask the person to raise both arms. If one arm is weak or numb, it will drift downward.
• Speech: Strokes often cause a loss of the ability to speak. Speech may be slurred or strange, or the person may have trouble choosing the right words.
• Time: Time is critical. If you observe any of the above signs, call the emergency services immediately. Make a note of the time the symptoms first appeared, as this will help healthcare providers determine the best treatment.

Other symptoms of a stroke include:

• One-sided weakness or paralysis.
• Loss of muscle control on one side of the face.
• Blurred or double vision.
• Loss of coordination or clumsiness.
• Dizziness or vertigo.
• Nausea and vomiting.
• Emotional instability and personality changes.
• Confusion or agitation.
• Memory loss.
• Severe headaches.
• Passing out or fainting.

What are the different types of strokes?

Strokes occur when there is a sudden disruption to the blood and oxygen supply to a part of the brain. This can happen in several ways, and doctors classify strokes into several types.

Firstly, doctors classify strokes according to their cause. The two main types of stroke are ischemic and hemorrhagic. Ischemic strokes are caused by a blockage in a blood vessel and account for 87% of all strokes. Hemorrhagic strokes are caused by bleeding in or around the brain and account for 13% of all strokes.

Ischemic strokes are further divided into thrombotic and embolic strokes. Thrombotic strokes are caused by a blood clot that develops in the blood vessels inside the brain. Embolic strokes are caused by a blood clot or plaque debris that develops elsewhere in the body and then travels to one of the blood vessels in the brain through the bloodstream. Embolic strokes often result from heart disease or heart surgery and occur rapidly and without warning signs.

Hemorrhagic strokes are divided into intracerebral hemorrhage and subarachnoid hemorrhage. Intracerebral hemorrhage occurs when there is bleeding from the blood vessels within the brain. Subarachnoid hemorrhage occurs when there is bleeding in the subarachnoid space, which is the space between the brain and the membranes that cover it.

Doctors can also classify strokes according to their location. For example, a stroke in the brain stem is not a specific type of stroke but can be either ischemic or hemorrhagic. However, it can cause complex symptoms and be difficult to diagnose. A stroke in the brain stem can affect both sides of the body and may lead to paralysis.

Another type of stroke is the transient ischemic attack (TIA), also known as a "mini-stroke." This is a temporary blockage of blood flow to the brain that lasts a short time and does not cause long-term damage. However, it is a warning sign that a more severe stroke may occur in the future.

In some cases, the cause of a stroke cannot be determined. These are called cryptogenic strokes.

What are the risk factors for a stroke?

A stroke is a life-threatening medical emergency that occurs when there is an issue with blood flow to the brain. This can be due to blocked blood vessels (ischemic stroke) or bleeding in the brain (hemorrhagic stroke). Ischemic strokes account for about 87% of strokes and are usually caused by a blood clot or plaque blocking an artery in the brain. Hemorrhagic strokes occur when a blood vessel in the brain breaks open and leaks blood, causing swelling and pressure that damages brain cells.

There are several risk factors for stroke, some of which can be controlled or treated to help prevent a stroke or future strokes. Here are the key risk factors:

Medical Conditions

• High blood pressure (hypertension): This is a significant risk factor for all types of strokes as it can contribute to blood vessel damage and increase the likelihood of bleeding.
• High cholesterol (hyperlipidemia): High cholesterol levels can increase the risk of ischemic strokes by contributing to plaque buildup in the arteries.
• Type 2 diabetes: Diabetes can increase the risk of ischemic stroke, especially when coupled with high blood pressure and high cholesterol.
• Heart conditions: Atrial fibrillation, heart valve disease, and coronary heart disease can increase the risk of blood clots, a common cause of ischemic strokes.
• Sickle cell disease: This condition has been linked to blood clots and ischemic strokes, particularly in children.
• Sleep apnea: Obstructive sleep apnea has been associated with an increased risk of stroke, especially when untreated or poorly managed.
• Kidney disease: Kidney-related conditions can impact blood flow and increase the risk of stroke.
• Migraine headaches: People who experience migraines, especially with auras, have a higher risk of stroke.
• History of stroke or heart attack: Individuals who have previously experienced a stroke or heart attack are at a higher risk of having another one.

Lifestyle Factors

• Smoking and tobacco use: Smoking cigarettes, vaping, and using smokeless tobacco products can increase the likelihood of stroke.
• Alcohol consumption: Excessive alcohol intake can elevate blood pressure and contribute to stroke risk.
• Drug use: Recreational drug use, including the use of illegal substances such as cocaine, can increase the risk of stroke.
• Diet and physical activity: An unhealthy diet, lack of exercise, and obesity can contribute to high blood pressure, high cholesterol, and diabetes, all of which are risk factors for stroke.
• Sleep: Getting too much sleep (more than 9 hours) has been associated with an increased risk of stroke.
• Stress and mental health: High levels of stress, anxiety, and depression, as well as a lack of social connections, may raise the risk of stroke.

Demographic Factors

• Age: While a stroke can occur at any age, the risk increases with advancing age, especially for adults over 65.
• Sex: Men are more likely to experience a stroke at younger ages, while women tend to have a higher lifetime risk due to their longer life expectancy. Additionally, hormonal factors such as the use of birth control pills or hormone replacement therapy can further increase the risk for women.
• Race and ethnicity: In the United States, stroke occurs more frequently in Black, Alaska Native, American Indian, and Hispanic adults compared to white adults.
• Family history and genetics: Individuals with a parent or close relative who has had a stroke, particularly at a younger age, are at a higher risk. Certain genetic factors, such as blood type, also play a role in stroke risk.
• Social determinants of health: Research suggests that social factors such as living in a poor or rural area, low education or income level, and lack of access to quality healthcare can influence stroke risk.

How is a stroke diagnosed?

A stroke is a life-threatening medical emergency that requires immediate attention. Tests for stroke usually begin in the ambulance, on the way to the hospital, which is why it is crucial to call emergency services instead of driving to the hospital. The tests aim to determine whether an individual has had a stroke, what type of stroke it was, and what caused it. This information will help doctors plan the treatment.

Upon calling emergency services, an ambulance worker will arrive and start the stroke exam, which a doctor will continue at the hospital. The exam includes asking the patient or a family member about their symptoms and medical history, as well as performing a physical exam. The physical exam involves checking the patient's blood pressure and assessing their mental alertness, numbness or weakness, and ability to speak, see, or walk.

A neurological exam is also conducted to test how well the nervous system is functioning and determine whether the patient has had a stroke. This involves the doctor asking the patient questions, testing their reflexes, and asking them to perform simple actions. Each part of the exam tests a different part of the brain, helping to identify the severity and location of the stroke.

Imaging tests are also used to visualise the inside of the brain and assess the extent of the damage and the location of the stroke. These tests include:

• Computed tomography (CT) scan: This uses X-rays to take pictures of the brain and can detect bleeding, damage to brain cells, and other issues that may be causing stroke symptoms.
• Magnetic resonance imaging (MRI): MRI uses a strong magnet and radio waves to create detailed images of the brain, showing changes caused by the stroke, bleeding, and blood flow problems. It can also rule out other problems like tumours.
• CT or MR angiogram: An angiogram is an X-ray movie of the blood vessels and blood flow, created by injecting a dye into the veins.
• Carotid ultrasound: This test uses sound waves to visualise the carotid arteries, which supply blood to the brain, and check for plaque buildup that may be blocking blood flow.
• Trans-cranial Doppler (TCD) ultrasound: The TCD helps identify which artery in the brain is blocked by measuring blood flow using sound waves.

In addition to these imaging tests, an electroencephalogram (EEG) may be used to rule out seizures or related problems as a cause of the symptoms. An electrocardiogram (ECG or EKG) is also performed to check the heart and determine if atrial fibrillation caused the stroke.

While there is no specific blood test to diagnose a stroke, a series of blood tests may be conducted in the hospital to determine the underlying cause of the stroke symptoms. These include:

• Complete blood count (CBC): This measures overall blood health and helps diagnose issues such as infection, anaemia, clotting problems, or other blood disorders.
• Serum electrolytes: This test assesses substances in the blood that carry an electric charge to detect issues like electrolyte imbalances, dehydration, or kidney problems, which can cause stroke-like symptoms.
• Blood clotting tests: These tests measure how quickly the blood clots to determine if the stroke was caused by a clot (ischemic stroke) or bleeding (haemorrhagic stroke).
• Heart attack tests: Some individuals with stroke symptoms may also exhibit signs of a heart attack, as certain heart problems can lead to a stroke.
• Thyroid tests: Hyperthyroidism increases the risk of atrial fibrillation, which is a risk factor for stroke.
• Blood glucose: Low blood sugar can be a complication of diabetes treatments and can cause stroke-like symptoms.
• Cholesterol tests: High blood cholesterol is a risk factor for stroke.
• C-reactive protein test and blood protein test: These tests assess substances in the blood that indicate swelling or inflammation, which may be caused by damage to arteries.

How is a stroke treated?

A stroke is a life-threatening medical emergency, and immediate treatment is critical to prevent permanent damage or death. Treatment for a stroke depends on the type of stroke and how soon the patient receives treatment.

Ischemic Stroke Treatment

Ischemic strokes are the most common type of stroke, accounting for about 80%-87% of all strokes. They occur when blood flow to the brain is blocked, usually by a blood clot, causing brain cells to die from a lack of oxygen. The urgent treatment for ischemic strokes is clot removal, which can be done through medication or mechanical treatments.

Medication

Doctors can use thrombolytic drugs, such as Alteplase IV r-tPA, to dissolve clots and improve blood flow to the brain. These medications must be administered within three to four and a half hours of the onset of stroke symptoms to be effective and safe.

Mechanical Treatments

Mechanical thrombectomy is a procedure that uses a catheter (tube-like) device inserted into a major blood vessel to reach the clot in the brain. A wire-cage device called a stent retriever is then used to grab and remove the clot. Special suction tubes may also be used to remove the clot. Mechanical thrombectomy is typically done within 24 hours of the onset of symptoms, but it is most effective if performed within six hours.

Hemorrhagic Stroke Treatment

Hemorrhagic strokes occur when there is bleeding in or around the brain, causing damage to surrounding brain tissue. Treatment for hemorrhagic strokes depends on the location and severity of the bleeding.

Reducing Blood Pressure

Lowering blood pressure is often a priority in treating hemorrhagic strokes to reduce bleeding and allow for clotting to seal the damaged blood vessel.

Improving Clotting

In some cases, treatments may be used to improve clotting and stop the bleeding. This can include vitamin K therapy or prothrombin or clotting factor infusions.

Surgery

Surgery may be necessary to relieve pressure on the brain caused by accumulated blood, especially in subarachnoid hemorrhages, which occur on the outer surface of the brain.

Hospital Care and Additional Treatments

During hospitalisation, a healthcare team of doctors, specialists, and therapists will assist in the patient's recovery. This includes monitoring to detect and prevent complications, finding the cause of the stroke, initiating preventive measures for future strokes, and determining rehabilitation needs.

Medicines

Long-term treatments for stroke may include anticoagulants to prevent blood clots, medications to lower blood pressure, and statins to reduce cholesterol levels.

Rehabilitation

Rehabilitation is a crucial part of stroke recovery, helping individuals regain abilities and adapt to changes in their brain. This may include:

• Speech therapy to improve language, speaking abilities, and control of muscles related to breathing, eating, drinking, and swallowing.
• Physical therapy to improve or regain movement and function in the hands, arms, feet, and legs, as well as address balance issues and muscle weakness.
• Occupational therapy to retrain the brain for daily activities and improve hand movements and muscle control.
• Cognitive therapy to address memory problems, concentration, and focus issues.

Frequently asked questions