Strokes are a major health concern worldwide, causing significant harm and disability. This article explores strokes, discussing how common they are, what factors contribute to them, and why it’s crucial to act quickly when someone has a stroke for better results.

Overview of Stroke

Stroke is a global health concern. According to the World Health Organization (WHO), an alarming 15 million people experience a stroke each year, making it one of the leading causes of death and disability globally.

A stroke occurs when blood flow to a part of the brain is interrupted, depriving brain cells of oxygen and nutrients. This can result from a blockage in an artery (ischemic stroke) or the rupture of a blood vessel (hemorrhagic stroke). The sudden deprivation of oxygen and nutrients to brain cells can result in lasting damage, leading to physical and cognitive impairments, paralysis, or even death. Symptoms of stroke include sudden weakness or numbness on one side of the body, difficulty speaking or understanding speech, vision problems, severe headache, and loss of coordination.

Strokes are a medical emergency and can cause permanent brain damage, disability, or death if not treated promptly. Stroke can strike anyone at any age, although older adults are at higher risk.

Types of stroke

Strokes can be classified into two main types: ischemic strokes and hemorrhagic strokes.

1. Ischemic Stroke: Ischemic strokes account for approximately 85% of all strokes and occur when a blood clot or plaque buildup blocks or narrows an artery, reducing blood flow to the brain. This deprivation of oxygen and nutrients leads to brain cell damage and can result in various neurological deficits. There are two subtypes of ischemic stroke:
   • Thrombotic Stroke: This type of ischemic stroke occurs when a blood clot forms within one of the arteries supplying blood to the brain, often due to atherosclerosis (hardening and narrowing of the arteries).
   • Embolic Stroke: Embolic strokes occur when a blood clot or plaque fragment (embolus) travels from another part of the body, such as the heart or a large artery, and lodges in a smaller artery within the brain, blocking blood flow.
2. Hemorrhagic Stroke: Hemorrhagic strokes, although less common, are often more severe and occur when a weakened blood vessel ruptures, causing bleeding into the brain (intracerebral hemorrhage) or around the brain’s surface (subarachnoid hemorrhage). This sudden leakage of blood can compress surrounding brain tissue and lead to neurological symptoms. Hemorrhagic strokes are typically classified into two types:
   • Intracerebral Hemorrhage: This type of hemorrhagic stroke occurs when a blood vessel within the brain ruptures and bleeds into the surrounding tissue, causing damage and swelling.
   • Subarachnoid Hemorrhage: Subarachnoid hemorrhages occur when there is bleeding into the space between the brain and the surrounding membranes (meninges), often due to the rupture of an aneurysm (weakened, bulging blood vessel) or arteriovenous malformation (AVM).

Symptoms of stroke

The symptoms of a stroke can vary depending on the type of stroke and the part of the brain affected, but common symptoms include:

1. Sudden Weakness or Numbness: Sudden weakness or numbness, especially on one side of the body, can occur in the face, arm, or leg. This may affect the ability to move or control the affected limbs.
2. Difficulty Speaking or Understanding Speech: Speech difficulties, such as slurred speech or difficulty finding the right words, may occur. Some individuals may have difficulty understanding spoken language or following conversations.
3. Vision Problems: Sudden vision changes, such as blurred or double vision, or loss of vision in one or both eyes, may occur. This may affect peripheral vision or the ability to see clearly.
4. Severe Headache: A sudden, severe headache, often described as the worst headache of one’s life, can occur with a hemorrhagic stroke, particularly in cases of subarachnoid hemorrhage.
5. Loss of Coordination or Balance: Difficulty walking or maintaining balance, sudden dizziness, or loss of coordination may occur, leading to stumbling, falling, or difficulty standing upright.
6. Confusion or Trouble Understanding: Sudden confusion, difficulty understanding what others are saying, or trouble processing information may occur. This may manifest as disorientation, memory problems, or difficulty concentrating.
7. Facial Drooping: Weakness or drooping on one side of the face, particularly when attempting to smile, may occur. This asymmetry in facial expression is a classic sign of stroke.
8. Difficulty Swallowing: Sudden difficulty swallowing or chewing, or a sensation of food getting stuck in the throat, may occur. This can lead to choking or aspiration if not addressed promptly.
9. Nausea or Vomiting: Nausea, vomiting, or a sudden onset of feeling unwell may occur, particularly in cases of severe headache or intracerebral hemorrhage.
10. Loss of Consciousness: In severe cases, a stroke may cause loss of consciousness, fainting, or coma, particularly with large or rapidly progressing strokes.

Causes of stroke

Strokes occur when blood flow to a part of the brain is interrupted, leading to brain cell damage and neurological deficits. There are several underlying causes of stroke, including:

1. Ischemic Stroke: The most common type of stroke, ischemic strokes occur when a blood clot or plaque buildup blocks or narrows an artery, reducing blood flow to the brain. This can result from:
   • Atherosclerosis: Hardening and narrowing of the arteries due to the buildup of fatty deposits (plaque), reducing blood flow to the brain.
   • Embolism: Blood clots or plaque fragments (emboli) traveling from another part of the body, such as the heart or large arteries, and lodging in a smaller brain artery, blocking blood flow.
2. Hemorrhagic Stroke: Hemorrhagic strokes occur when a weakened blood vessel ruptures, causing bleeding into the brain (intracerebral hemorrhage) or around the brain’s surface (subarachnoid hemorrhage). Causes of hemorrhagic strokes include:
3. Hypertension (High Blood Pressure): Prolonged high blood pressure can weaken blood vessel walls over time, increasing the risk of rupture and bleeding.
4. Aneurysm: Weakness or bulging in a blood vessel wall (aneurysm) can rupture, leading to bleeding into the brain (intracerebral hemorrhage) or surrounding membranes (subarachnoid hemorrhage).
5. Arteriovenous Malformation (AVM): Abnormal tangles of blood vessels (AVMs) can rupture and bleed, causing hemorrhagic strokes.
6. Other Causes: Additionally, certain medical conditions and lifestyle factors can increase the risk of stroke, including:
7. Heart Disease: Conditions such as atrial fibrillation, heart valve abnormalities, or heart attacks can increase the risk of blood clots forming and traveling to the brain, causing strokes.
8. Diabetes: Diabetes increases the risk of stroke by damaging blood vessels and increasing the likelihood of atherosclerosis.
9. High Cholesterol: Elevated levels of cholesterol in the blood can contribute to the buildup of plaque in the arteries, leading to ischemic strokes.
10. Smoking: Smoking tobacco increases the risk of stroke by damaging blood vessels, promoting atherosclerosis, and increasing blood clotting.
11. Obesity: Excess body weight can contribute to hypertension, diabetes, and high cholesterol, all of which are risk factors for stroke.

Frequently asked questions

Sources

Murphy, S. J., & Werring, D. J. (2020). Stroke: Causes and clinical features. Medicine 1. (Abingdon, England : UK Ed.), 48(9), 561-566. https://doi.org/10.1016/j.mpmed.2020.06.002

Kuriakose, D., & Xiao, Z. (2020). Pathophysiology and Treatment of Stroke: Present Status and Future Perspectives. International Journal of Molecular Sciences, 21(20). https://doi.org/10.3390/ijms21207609

Fekadu, G., Chelkeba, L. & Kebede, A. Risk factors, clinical presentations and predictors of stroke among adult patients admitted to stroke unit of Jimma university medical center, south west Ethiopia: prospective observational study. BMC Neurol 19, 187 (2019). https://doi.org/10.1186/s12883-019-1409-0

Patil, S., Rossi, R., Jabrah, D., & Doyle, K. (2022). Detection, Diagnosis and Treatment of Acute Ischemic Stroke: Current and Future Perspectives. Frontiers in Medical Technology, 4, 748949. https://doi.org/10.3389/fmedt.2022.748949