Heart Health: Surprising Facts on Stroke Everyone Must Know

A stroke strikes suddenly causing one in six people worldwide to have at least one stroke in their lifetime. The stroke happens fast especially when there is a blockage of blood flow to a part of the brain. When an individual is hit by a stroke, they may lose body functions and control (such as the drooping of their face; or the use of an arm or a leg) related with that part of the brain depending on how severe the affected area is damaged.

A Mini-stroke (TIA)

A mini-stroke or commonly called a transient ischemic attack (TIA) or “a warning stroke” does not last as long as ischemic attack or hemorrhagic stroke. However, TIA can have the same symptoms just like an ischemic stroke. Even though the symptoms of TIA may persist up to 24 hours, most of them disappear within 60 minutes. Most mini-strokes last less than 4 minutes and its symptoms can occur rapidly.

Unlike other strokes, the blockage caused by TIA is temporary (transient) and when a mini-stroke is over there is no permanent damage or injury to the brain.

The mini-stroke occurs when there is a temporal blockage to an artery supplying the brain with oxygen and blood. Other causes are due to the plaque or fatty deposits in the carotid artery of the neck causing a reduced blood flow in the brain. The ruptured plaque can create blood clots and part of them break loose and travel with the blood lodging in a brain artery and blocks blood flow temporarily. But, the brain function returns to normal once the blood flow is restored.

TIA is a minor stroke that gives one a significant warning sign of an impending major stroke. To emphasize, one must take this mini stroke seriously and seek immediate treatment. This will help you prevent a major stroke that may cause lasting damage to the affected area. If you are experiencing TIA is always advisable to get someone to drive you to a nearby hospital immediately. At the hospital, a doctor will usually ask you to be hospitalized so that they can find out where the interruption of blood flow is and how to better treat you.

The warning signs for a mini-stroke are similar for a stroke as described below:

• Trouble speaking or understanding
• Sudden trouble seeing in both eyes or even with one eye
• Sudden confusion
• Chronic, sudden headache with no known cause
• Sudden dizziness, loss of balance or coordination
• Sudden trouble in walking
• Sudden weakness or numbness in one side of the body
• Sudden weakness or numbness in the arm, leg or face

Warning: Even though TIA is not a severe stroke, you must not disregard its symptoms by denying the prompt medical treatment as it will lead to a devastating stroke that may cause death.

Generally, there are two types of stroke, namely Haemorrhagic stroke and Ischemic stroke. I will explain these two types of strokes in more detail below:

Hemorrhagic (bleeds) Stroke

Approximately 20% of the strokes are hemorrhagic in nature and the most leading cause is high blood pressure (or hypertension), occurring when a blood vessel bursts and blood accumulates. This pooled blood found primarily in the area between the skull and the brain or inside the brain can cause a great pressure on the brain, and this can kill the surrounding brain cells and even damage the distant tissue. In fact, a weakened vessel that ruptures and bleeds near the brain which can lead to blood accumulation while compressing the surrounding brain tissue. Often, hemorrhagic stroke is more devastating and even more fatal than an ischemic stroke.

There are two types of Hemorrhagic strokes: (1) Subarachnoid hemorrhage and (2) Intracerebral hemorrhage

(1):Subarachnoid Hemorrhage (SAH)

Of all strokes, Subarachnoid hemorrhage is the most severe form of a stroke, usually resulting either in a permanent disability or death. It can happen suddenly when a major blood vessel bursts upon the surface of the brain causing spilling blood into the cerebrospinal fluid surrounding the brain. Due to bleeding, the amount of fluid increases in the affected area causing enormous pressure on the whole brain and may cause the damage to the brain tissue. The damage usually depends on which part of the brain is impacted under abnormal pressure.

Subarachnoid hemorrhage can be caused by a traumatic head injury, a burst celebral aneurysm, or a defect of the circulatory system/a cluster of abnormally formed blood vessels (also called arteriovenous malformation or AVMs, usually inherited at birth). An aneurysm can cause other symptoms or headaches when there is a slight leakage of blood from the aneurysm (or a ballooning of a weakened area of an artery and when left untreated the aneurysm can continuously become weakened until it ruptures and finally bleeds into the brain), while a burst aneurysm can lead to a sudden and severe headache, usually with a description of “thunderclap” particularly in people who are usually asymptomatic prior to the incident. A CT scan or an MRI may detect the presence of subarachnoid hemorrhage.

(2): Intracerebral Hemorrhage (ICH)

Intracerebral hemorrhage happens when there is a burst of a blood vessel in the brain, resulting in leaking blood into the brain. This condition may cause a sharp, sudden headache and vomiting as well. Intracerebral haemorrhage sometimes causes coma, death and loss of consciousness.

This type of a stroke is more common among people aged above 60 and can be most commonly caused by high blood pressure (or hypertension). However, it can also be a result of infections, a burst aneurysm (an abnormal bulge in the wall of a blood vessel that results in a weak spot), tumors or head injuries.

Ischemic (clots) Stroke

Approximately 80% of strokes are ischemic in nature, and it occurs when there is a blockage inside the carotid arteries (the blood vessels supplying blood to the brain) or in the vertebral arteries. A fatty deposit (a plaque) or mass of blood cells (a clot) travelling in the blood can get trapped in a narrowed or small artery which will obstruct blood flow and cause the occurrence of a stroke. The other underlying cause of this stroke is due to the formation of fatty deposits lining the vessel walls. Bleeding of a blood vessel in the brain can also cause a stroke.

An Ischemic stroke is a sudden loss of brain function and can be caused by partial or complete obstruction of a blood vessel supplying the brain. The fatty deposits of the carotid artery in a neck can reduce the amount of blood flowing into the brain. Blood clots are formed when there is a rupture in the plaque and the clots break off and travel to a blood vessel inside the brain blocking blood flow, causing permanent damage in parts of the brain.

There are three types of Ischemic stroke: (1) Lacunar stroke and (2) Thrombotic stroke and (3) Embolic stroke.

(1): Lacunar Stroke

Lacunar stoke contributes to 25% of ischemic strokes and occurs when there is a blockage in one of the smaller blood vessels found inside the brain. A “hole” of scar tissue is due to that the blockage starves a small part of the brain. As only small portion of the brain is affected, lucunar stroke is usually hard to be diagnosed. Due to the smaller part being involved and damage being to a lesser extent, people with lacunar stroke have better odds of regaining neurological function.

(2): Thrombotic Stroke

Thrombotic stroke is responsible for 15% of ischemic strokes and happens when the artery is clogged by plaque and hardens, or most exactly when a cholesterol-filled plaque of atherosclerosis especially in a brain (cerebral), carotid or vertebral artery breaks open. This in turn causes the formation of a blood clot over the plaque obstructing blood flow. A term of a thrombus (blood clot) is a condition where the blockage seals off the blood vessel. This thrombotic stroke always is preceded by mini-stroke (s).

(3): Embolic Stroke

Atrial fibrillation (AF) is reported to be responsible for about a quarter of the cases of embolic strokes. The clots coming from plaque created by atherosclerosis in the body’s largest artery (or in the ascending aorta), or from inside a heart that is not beating efficiently as in a case of AF (or an irregular heartbeat that creates a situation where clots form in the heart, dislodge and move to the brain), or from below the start of the carotid arteries can travel together with the blood lodge in a brain artery causing blockage to blood flow is during which embolic stroke strikes one’s lifetime.

An embolus refers to a piece that breaks off. The embolus can block a blood vessel supplying the brain causing the occurrence of am embolic stroke which contributes 60% of ischemic strokes. Unless the source is found and treated immediately, people with embolic strokes are at potential risk of another stroke/s.

Embolic strokes hit fast and sudden and are normally severe. One may have a repeated stroke as the symptoms may come and for minutes or even hours, and they may disappear for a while or may become progressively worst.

Final remark:

Any type of a stroke may cause brain damage and death depending on the amount of pressure incurred inside the skull and the entire brain. Therefore, it is advisable for you to seek immediate medical assistance even though your stroke appears to be mild.

A minor stroke is often a warning sign of an impending major stroke or recurrent stroke attacks. If you have a stroke, please do not delay treatment! Remember: Strokes and even mini strokes are a medical emergency and can be life threatening!

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As always, stay well and healthy!