A stroke occurs when flow of blood to brain is interrupted. It may happen because of a broken or blocked blood vessel. Stroke may be hemorrhagic, transient ischemic attack (TIA), or ischemic. Even a little decrease in the brain’s blood supply can result in a stroke. This causes the part of the brain controls to stop working. A stroke can also be called a CVA, cerebrovascular accident, or brain attack. A person experiencing this condition must go for immediate emergency treatment.
Types of stroke
There are three main types of strokes, hemorrhagic, ischemic, and transient ischemic attack (TIA).
Hemorrhagic stroke
A hemorrhagic stroke occurs due to rupturing of a blood vessel in the brain. It allows blood to leak into the brain. According to neurosurgeons, these are usually the result of arteriovenous malformations (AVMs) or aneurysms.
Ischemic stroke
This is the most common type of stroke which makes up around 88 percent of all the cases. It occurs when a blood clot is formed in a vessel carrying blood to the brain. The blood vessel may block or restrict by blood clot or severely narrowed arteries. It prevents oxygen from reaching a part of the brain.
Transient ischemic attack (TIA)
TIA is also known as ministroke. This occurs when blood supply to a part of the brain is insufficient for a small period of time. Blood flow to its normal level may resume after a short amount of time. The major or minor symptoms may resolve without treatment.
What are the signs and symptoms of a stroke?
Signs and symptoms of stroke may depend on what part of the brain has blocked due to the loss of blood supply. The multiple symptoms include the following:
- Partial vision loss severe headache with no known cause
- Sickness of the face, arm or leg
- Acute change in the level of confusion
- Difficulty in seeing by one or both eyes
- Dizziness
- Double vision
- Difficulty in speaking or understanding speech
- Immobility of one half or part of the body
- Acute paralysis of half or area of the body
- Difficulty with vertigo
Hemorrhagic and ischemic symptoms may be the same probably, according to patients. But the patients with hemorrhagic stroke may have to deal with severe headache and vomiting.
Who is at more risk of experiencing a stroke?
According to a 2016 analysis report, African Americans are at a significantly higher risk of experiencing a first-time stroke. They are also about 60% more chances of experiencing another stroke within 2 years.
Males are at a higher risk of developing stroke than females. Even though, some studies have found that death because of this condition is more common in males than females. Another study suggests that such differences usually do not take into account regulations for age, race, the severity of the stroke, and several other risk factors.
Different types of stroke have several different sets of potential causes. But, more probably, it is more likely to affect a person with:
- Smoking
- High blood pressure
- Illicit drugs consumption
- Diabetes
- 55 years of age or older
- Overweight or obesity
- High cholesterol
- Any personal or family history of stroke
- Carotid artery disease, heart disease, or another vascular disease
- Sedentary
- Consume alcohol excessively
What Causes stroke?
A stroke can occur in two ways, either by blocking the blood flow or bleeding in the brain. The typical causes of stroke are given below:
Embolic stroke
The embolism usually occurs when a piece of atherosclerotic plaque (calcium and cholesterol accumulates on the wall of the heart or artery inside) breaks loose. It may then travel to the bloodstream and lodges in an artery in the brain.
An embolism, whether it is plaque or clot, can also deposit in a large artery, such as, the carotid artery, a large artery in the neck that delivers blood to the brain. When blood flow blocks the brain cells stop receiving the oxygen and glucose that is essential for proper functioning. Hence, a stroke occurs.
A blood clot might originally develop in the heart chamber, like, in the form of an irregular heart rhythm, such as atrial fibrillation. Usually, these clots do not detach from the inner lining of the heart. But occasionally they can break off traveling via the bloodstream (embolize). It may block a brain artery and cause a stroke.
Thrombotic stroke
This is the most common cause of a stroke. It is the blockage of an artery in the brain because of a clot. As a result, the clotted blood vessel becomes deprive of blood and oxygen. The shortage of blood and oxygen in such cells of that part of the brain may die. The part of the body that it controls may also stop working. A cholesterol plaque, typically, can rupture in one of the brain’s small blood vessels. The clotting process starts afterwards.
Cerebral hemorrhage
A cerebral hemorrhage develops when a blood vessel in the brain blocks, breaks, or bleeds into the surrounding brain tissues. The bleeding in the brain causes stroke by shortening blood and oxygen to parts of the brain in a variety of forms. This may cause loss of blood flow to several different cells. Blood can cause swelling of brain tissue which is called cerebral edema.
Edema along with the deposition of the blood from a cerebral hemorrhage results in high pressure within the skull. It can cause further disruption by compressing the brain against the bony skull. The decrease of blood flow to brain tissue and its cells may cause death.
Subarachnoid hemorrhage
When the blood deposits in a space beneath the arachnoid membrane (membrane that lines the brain), the condition is a subarachnoid hemorrhage. The blood vessels start leaking and rupturing by originating from an abnormal blood vessel. Quite often, this can be from an aneurysm which is an abnormal inflammation of the blood vessel.
Subarachnoid hemorrhages typically result in a sudden severe nausea, headache, light intolerance, vomiting, and stiff neck. If not diagnosed and treated on time, the major neurological diseases, such as coma, and brain death can occur.
Migraine headache
In people with migraine headaches, there appears to be a little bit escalated occurrence of a stroke. The blood vessels present in the brain become narrow migraine or vascular headaches. A few kinds of migraine headache can even imitate stroke. Other than the loss of function of one side of the body, there is also a loss of vision or many other speech problems. The symptoms typically get better as the headache resolves.
Vasculitis
This is another rare cause of stroke. In this condition, the blood vessels become inflamed and cause decrease in blood flow to parts of the brain.
What are the risk factors of stroke?
Risk factors may result in narrowing of blood vessels in the heart and cause cardiovascular diseases (myocardial infarction). These risk factors are:
- High blood pressure (hypertension)
- High cholesterol
- Diabetes
- Smoking
