what is Stroke

 

What is a stroke?

A stroke occurs when a blood vessel in the brain ruptures and bleeds, or when there’s a blockage in the blood supply to the brain. The rupture or blockage prevents blood and oxygen from reaching the brain’s tissues.

A stroke occurs when a blockage or bleed of the blood vessels either interrupts or reduces the supply of blood to the brain. When this happens, the brain does not receive enough oxygen or nutrients, and brain cells start to die.

Stroke is a cerebrovascular disease. This means that it affects the blood vessels that feed the brain oxygen. If the brain does not receive enough oxygen, damage may start to occur.

This is a medical emergency. Although many strokes are treatable, some can lead to disability or death.

There are three primary types of strokes:

• Transient ischemic attack (TIA) involves a blood clot that typically reverses on its own.
• Ischemic stroke involves a blockage caused by either a clot or plaque in the artery. The symptoms and complications of ischemic stroke can last longer than those of a TIA, or may become permanent.
• Hemorrhagic stroke is caused by either a burst or leaking blood vessel that seeps into the brain.

 

 

Symptoms of a stroke

The main symptoms of stroke can be remembered with the word FAST:

• Face – the face may have dropped on 1 side, the person may not be able to smile, or their mouth or eye may have dropped.
• Arms – the person with suspected stroke may not be able to lift both arms and keep them there because of weakness or numbness in 1 arm.
• Speech – their speech may be slurred or garbled, or the person may not be able to talk at all despite appearing to be awake; they may also have problems understanding what you're saying to them.
• Sudden numbness or weakness in the face, arm, or leg, especially on one side of the body.
• Sudden confusion, trouble speaking, or difficulty understanding speech.
• Sudden trouble seeing in one or both eyes.
• Sudden trouble walking, dizziness, loss of balance, or lack of coordination.
• Sudden severe headache with no known cause.

Causes of a stroke

Like all organs, the brain needs the oxygen and nutrients provided by blood to function properly.

If the supply of blood is restricted or stopped, brain cells begin to die. This can lead to brain injury, disability and possibly death.

There are 2 main causes of strokes:

• ischaemic – where the blood supply is stopped because of a blood clot accounting for 85% of all cases
• haemorrhagic – where a weakened blood vessel supplying the brain bursts

There's also a related condition called a transient ischaemic attack (TIA),  where the blood supply to the brain is temporarily interrupted.

This causes what's known as a mini-stroke. It can last a few minutes or persist up to 24 hours.

TIAs should be treated urgently, as they're often a warning sign you're at risk of having a full stroke in the near future.

Get medical advice as soon as possible, even if your symptoms get better.

Certain conditions increase the risk of having a stroke, including:

• high blood pressure (hypertension)
• high cholesterol
• Irregular heartbeats (atrial fibrillation)
• Diabetes

 

Treatment stroke

Because ischemic and hemorrhagic strokes have different causes and effects on the body, both require different treatments.

Rapid diagnosis is important for reducing brain damage and enabling the doctor to treat the stroke using a suitable method for the type.

The sections below cover the treatment options for ischemic stroke and hemorrhagic stroke, as well as some general rehabilitation tips for both types.

Ischemic stroke

Ischemic stroke occurs due to blocked or narrowed arteries. Treatment tends to focus on restoring an adequate flow of blood to the brain.

Treatment starts with taking drugs that break down clots and prevent others from forming. A doctor may administer blood thinners such as Aspirin or an injection of tissue plasminogen activator (TPA).

TPA is very effective at dissolving clots. However, the injection needs to take place within 4.5 hours of the stroke symptoms starting.

Emergency procedures include administering TPA directly into an artery in the brain or using a catheter to physically remove the clot. Research is ongoing as to the benefits of these procedures.

There are other procedures that surgeons can perform to reduce the risk of strokes or TIAs. A carotid endarterectomy, for example, involves opening the carotid artery and removing plaque that could break and travel to the brain.

Another option is angioplasty. This involves a surgeon inflating a small balloon inside a narrowed artery using a catheter. Afterward, they will insert a mesh tube, or a stent, into the opening. This prevents the artery from narrowing again.

Hemorrhagic stroke

Blood leaking into the brain can cause a hemorrhagic stroke. Treatment focuses on controlling the bleeding and reducing the pressure on the brain.

Treatment often begins with taking drugs that reduce pressure in the brain and control overall blood pressure, as well as preventing seizures and any sudden constrictions of blood vessels.

If a person is taking blood-thinning anticoagulants or antiplatelet medication, such as warfarin or clopidogrel, they can receive medications to counter the effects of the blood thinners.

Surgeons can repair some of the problems with blood vessels that have led or could lead to hemorrhagic strokes.

When an aneurysm — or a bulge in a blood vessel that may burst — causes a hemorrhagic stroke, a surgeon can place small clamps at the base of the a aneurysm or fill it with detachable coils to stop the blood flow and shrink the aneurysm.

If the hemorrhage occurs due to an AVM, a surgeon can remove it. AVMs are connections between arteries and veins that can be at risk of bleeding.

Rehabilitation

Stroke is a potentially life changing event that can have lasting physical and emotional effects.

Successful recovery from a stroke will often involve specific therapies and support systems, including:

• Speech therapy: This helps with problems producing or understanding speech. Practice, relaxation, and changing communication style can all make communicating easier.
• Physical therapy: This can help a person relearn movement and coordination. It is important to stay active, even though this may be difficult at first.
• Occupational therapy: This can help a person improve their ability to carry out daily activities, such as bathing, cooking, dressing, eating, reading, and writing.
• Support groups: Joining a support group can help a person cope with common mental health   issues that can occur after a stroke, such as depression. Many find it useful to share common experiences and exchange information.
• Support from friends and family: Close friends and relatives should try to offer practical support and comfort after a stroke. Letting friends and family know what they can do to help is very important.

Rehabilitation is an important and ongoing part of stroke treatment. With the right assistance and the support of loved ones, regaining a normal quality of life is usually possible, depending on the severity of the stroke.