What is a Stroke: Types, Causes, Symptoms & Treatments

A stroke is a medical emergency, and it is imperative to receive prompt treatment. Therefore, every individual must have a sound knowledge about this health condition as that would help them prevent it and also make them aware of the symptoms to look out for. This particular article would act as a perfect guide in letting one know what causes a stroke and all related facts.

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Before diving into detailed facts related to stroke, one must first be aware of what is a stroke. A stroke also referred to as a cerebrovascular accident, CVA, or "brain attack," is an emergency medical condition that demands prompt treatment. If it isn’t detected early, there is a possibility of permanent brain damage taking place and the person experiencing it might even die.

Since a stroke is a cerebrovascular disease, it causes an impact on the blood vessels which feed the brain oxygen. If there isn’t a sufficient oxygen supply to the brain, the damage might start to take place.

Strokes are mainly categorised into three main categories, which are illustrated below:

Ischemic Stroke

An ischemic stroke can pose several complications for the person experiencing it. Some common medical complications include:

• Pulmonary Embolism,
• Neuropsychiatric Disturbances,
• Deep Venous Thrombosis,
• Falls, and
• Systemic Infections.

Frequent neurologic complications of an ischemic stroke include elevated intracranial pressure, haemorrhagic transformation, cerebral edema, and seizures.

Proper anticipation of these complications would help expedite the initiation of therapeutic and preventive measures. There are two major types of ischemic stroke, namely, thrombotic stroke and embolic stroke.

Haemorrhagic Stroke

A person may experience a range of complications from a haemorrhagic stroke based on the extent of the damage. This includes muscle weakness, difficulty in talking or swallowing, loss of bladder, loss of bowel control, inability to move, loss of vision, loss of hearing, and loss of the sense of touch.

Transient Ischemic Attack (TIA)

A TIA or transient ischemic attack is often referred to as a mini-stroke or a warning. The complications related to a TIA vary based on the location of artery obstruction. Most commonly, a blockage occurs in the carotid artery system.

There are two carotid arteries that supply blood to two sides of the brain, and if one is blocked, the person might experience symptoms in the eye on the side where arteries are blocked, or there may be symptoms that would affect the body’s opposite side.

The above three different types of strokes can be further classified into some more categories, which are listed down as follows:

Intracerebral Stroke

An intracerebral haemorrhage or ICH is a life-threatening kind of stroke. An ICH can take place in the deep regions of the brain or close to the surface. Deep haemorrhages can sometimes expand to the ventricles, which are the fluid-filled spaces present in the centre of the brain. If the normal cerebrospinal (CSF) circulation gets blocked, the ventricles can get enlarged, resulting in loss of consciousness, lethargy, and confusion.

Subarachnoid Stroke

Subarachnoid haemorrhage or SAH is a stroke of life threatening nature. A common complication that might occur five to ten days after SAH is vasospasm, in which by-products of blood make the walls of arteries contract and spasm. The inside diameter of an artery gets narrowed because of vasospasm. This causes a reduction in the blood flow to an area of the brain, resulting in a secondary stroke.

Embolic Stroke

An embolic stroke takes place rapidly without any warning sign and usually results from heart surgery or heart disease

Thrombotic Stroke

These strokes might be preceded by one or multiple mini-strokes or TIAs. Usually, a thrombotic stroke is seen in older human beings, especially those having high levels of cholesterol, diabetes, or atherosclerosis, which refers to a build-up of lipids and fat inside the walls of blood vessels.

Generally, the main cause of stroke is bleeding or blockage of blood vessels, which either lowers or reduces the blood supply to the brain. Due to this, a sufficient amount of nutrients and oxygen is not available to the brain, which in turn leads to the death of brain cells.

Though a stroke generally takes place in the above-mentioned manner, the causes of different types of strokes are distinct.

An ischemic stroke takes place when blood cannot flow to the brain due to a blood clot. This blood clot is usually due to atherosclerosis which refers to the build-up of fat deposits on a blood vessel’s inner lining. A part of the fat deposits can break and cause blockage to the blood flow into the brain. The entire concept is similar to what happens during a heart attack, where a blood clot blocks the blood flow to a part of the heart.

A haemorrhagic stroke occurs when blood is spilled into the surrounding tissues due to the breaking of or rupturing of a blood vessel in the brain. Haemorrhagic strokes are further classified into three major types. The first one is an aneurysm, which leads to a part of the weakened blood vessel ballooning outward and rupturing sometimes.

The second one is an arteriovenous malformation in which the blood vessels are formed in an abnormal manner. If a rupture occurs in such an abnormally formed blood vessel, a hemorrhagic stroke can take place. Thirdly, substantially high blood pressure can weaken the small blood vessels in the brain, thereby resulting in bleeding into the brain.

TIA occurs when anything causes a temporary blockage to the blood flow to the brain. The blood clot and the symptoms of TIA last for a short period.

An ICH is caused because of bleeding within the brain tissue. It is commonly caused due to hypertension, arteriovenous malformations, or head trauma.

Subarachnoid haemorrhage is caused due to bleeding in the surrounding spaces of the brain. A ruptured aneurysm, AVM, or head injury are some of the reasons which can cause SAH.

A blood clot that is formed somewhere else in the body and travels through the bloodstream into the brain bears the potential to cause an embolic stroke. It is found that around 15% of all embolic strokes occur in humans having atrial fibrillation, which is a kind of abnormal heart rhythm characterised by an ineffective beating of the heart’s upper chambers.

A thrombus or blood clots developed in the arteries which supply blood to the brain possess the capability of causing a thrombotic stroke.

A majority of the stroke symptoms in men and women are common, and these include the following:

• Weakness or numbness in arm, face, or leg
• Difficulty in speaking
• Facing troubles in understanding speech
• Vision problems
• Difficulty while walking or a lack of coordination
• Extreme headache without any known cause
• Face drooping

However, in addition to these, there are additional subtle stroke symptoms in women. These are as follows:

• General weakness
• Confusion or disorientation or memory problems
• Vomiting
• Nausea
• Fatigue

Having mentioned these, one must note that several people are aware of these symptoms but what many are unaware of is that there are silent stroke symptoms as well. This implies that there is a complete possibility that a person can experience a stroke without even noticing it. Given below are all the symptoms of a silent stroke:

• Sudden lack of balance
• Slight memory loss
• Sudden changes in personality or mood
• Temporary loss of basic muscle movement, which includes the bladder
• Issues with cognitive ability and skills

At any point in time, if any of the above silent symptoms are noticed, one must immediately call an ambulance. Medical help should be sought as early as possible, even if the person claims that the symptoms are no longer visible.

Though the symptoms of stroke make a sudden appearance, some individuals experience symptoms before a stroke. Signs like numbness, headache, or tingling are sometimes observed several days before a serious stroke.

A stroke originates rapidly. To get the best outcome, an individual must get treated at a hospital within three hours of the first appearance of symptoms.

A doctor can make use of several different diagnostic tests for stroke to determine the stroke type. These tests to determine stroke include:

• Blood tests: A doctor might prescribe to get the individual’s blood tested to determine if a high risk of bleeding or blood clot is present. For this determination, the levels of some specific substances in the blood, like clotting factors, are measured. Besides this, there might be tests to check whether an infection is present in the blood or not.
• CT scan: These include a series of scans that bear the potential of showing haemorrhages, tumours, strokes and other conditions within the brain.
• MRI scan: These scans utilise radio waves and magnets to create a brain’s image, proving useful to a doctor for detecting damaged brain tissues.
• Physical examination: A doctor will be interested in looking into the symptoms and medical history of the individual. They would conduct checks on the reflexes, sensation, vision, muscle strength and coordination. Additionally, doctors might also look into the blood pressure of the concerned person, inspect the blood vessels located at the back of the eyes and listen to the carotid arteries present in the neck.’
• Cerebral angiogram: This involves the doctor injecting a dye into the blood vessels of an individual’s brain to make them visible under MRI or X-ray. This enables the doctor to obtain a detailed view of the blood vessels presenting the neck and brain.
• Echocardiogram: An echocardiogram generates a detailed image of the heart, which the doctors can use to check sources of clots.
• Carotid ultrasound: An ultrasound scan is done to check the flow of blood in the carotid arteries and see if there is any plaque or narrowing present.

The stroke type can only be confirmed through a brain scan conducted in a hospital.

A stroke can occur to any individual irrespective of age. The chances of having a stroke increase if an individual faces certain risk factors. Some can be changed or managed out of all of these risk factors, while some cannot be managed.

Some common risk factors for stroke which can be treated, changed or medically managed include:

• High Blood Pressure: A blood pressure of 140/90 or more can cause damage to the arteries or blood vessels that supply blood to the brain.
• Diabetes: Individuals with diabetes stay at a higher risk for a stroke than those who don’t have diabetes.
• Smoking: The risk of an ischemic stroke gets almost doubled with smoking
• High RBC Count: The blood of an individual gets thickened if there is a substantial increase in the number of RBCs. This makes it more favourable to form clots, thereby increasing the risk factor for a stroke.

Besides these major risk factors for stroke, some risk factors cannot be changed. These include:

• Gender
• History of a prior stroke
• Old age
• Race
• Genetics or heredity

In addition to the above, given below are the causes of a stroke in a woman. These factors are associated with an increased risk of stroke in a woman:

• Contraceptive pill
• Pregnancy
• Obesity
• Migraines with visual aura

The best treatment for stroke depends on whether the stroke is an ischemic or haemorrhagic one.

Ischemic stroke

For ischemic stroke treatment, blood flow must be rapidly restored to the brain of the individual. This can be carried out with:

• Emergency IV Medication: Therapy with drugs that bear the potential for breaking up a clot must be given intravenously within 4.5 hours from the first appearance of the symptoms. These drugs must be given as early as possible as a quick treatment reduces complications and improves survival chances.
• Emergency Endovascular Processes: There are some instances where doctors treat ischemic strokes directly inside the blood vessel, which is blocked. Endovascular therapy significantly improves outcomes and lowers long-term disability after an ischemic stroke, and these processes should be performed as early as possible. The processes are:
  • Medications being delivered directly to the brain
  • Removing the clot with the help of a stent retriever

Some other procedures are used to decrease the risk of another stroke or transient ischemic attack taking place. These include:

• Carotid Endarterectomy
• Angioplasty and Stents

Haemorrhagic Stroke

Emergency treatment of haemorrhagic stroke aims to control bleeding and lowers the pressure in the brain caused because of excessive fluid. The various treatment options for this include:

• Surgical Clipping: In this process, a surgeon puts a small clamp at the base of the aneurysm to stop the flow of blood to it. This clamp keeps an aneurysm from bursting, and it can also prevent an aneurysm that has recently haemorrhaged from bleeding.
• Stereotactic Radiosurgery: This is an advanced minimally invasive treatment that makes use of multiple beams of highly focused radiations for repairing blood vessel malformations.

Besides these, there are some other options like surgical AVM removal, coiling or endovascular embolization, and surgery.

Apart from these, mild stroke treatment or partial stroke treatment options, which basically imply treatment for TIA, include antiplatelet drugs, anticoagulants, minimally invasive carotid intervention, lifestyle changes and surgery.

The prevention and control of stroke can be done through the following ways:

• Reducing Blood Pressure: If one has high blood pressure, one must work with a doctor to maintain it in a healthy range. Medications, regular exercise to prevent stroke, a healthy diet and lifestyle can be helpful.
• Staying Away from Smoking: One must consult a doctor for ways to quit smoking. Counselling sessions and using nicotine patches can be helpful. In addition to first-hand smoke, one must keep in mind that breathing second hand smoke also increases the chances of a stroke.
• Cutting Down on Alcohol: Excessive consumption of alcohol can increase blood pressure and triglycerides. Hence, one must cut down on alcohol intake if it's irregular.
• Controlling Diabetes: Individuals having diabetes must check their blood sugar on a regular basis and medicines as prescribed. Seeing a doctor every few months helps to keep the levels in check.
• Managing Your Heart: Atrial fibrillation or AFib or simply the condition of irregular heartbeat is the reason for strokes caused due to blood clots. One must see a doctor if one is unsure whether or not one has this condition but feels heart flutters or shortness of breath.
• Keeping a Check on Cholesterol: Excessive cholesterol can clog the arteries and lead to a stroke. If exercise and diet aren’t sufficient, doctors might recommend medicines.

In addition to these best ways to prevent stroke, one must exercise on a regular basis and eat healthy food to prevent strokes.

Now that you are aware of what causes a stroke and all related facts, note the symptoms regarding your close ones. Accordingly, take the necessary steps if you notice any signs of stroke.