Stroke

Definition

A stroke affects the arteries leading to and within the brain. When a stroke occurs, the blood supply to a part of the brain is either blocked by a clot or ruptures, which deprives the brain of oxygen and nutrients, and causes brain cells to die.

Symptoms

If the following signs occur, seek immediate medical health and note when the symptoms started:

• Trouble speaking and understanding or confusion
• Paralysis or numbness of the face, arm or leg
• Trouble with seeing in one or both eyes
• Headache which is sudden and severe, followed by vomiting and dizziness
• Trouble walking

Causes

High blood pressure (hypertension) is the most important known risk factor for stroke. High blood pressure can damage blood vessel walls and overtime, this may lead to a stroke.

The other major lifestyle risk factors that can be controlled include:

• High blood cholesterol
• Smoking
• Obesity or being overweight
• Poor diet and lack of exercise
• High alcohol consumption

A stroke can occur in two main ways. It can either be caused by a blocked artery or the bursting of a blood vessel.

Ischaemic stroke

Approximately four out of five strokes are ischaemic. This occurs when the arteries to the brain become narrowed or blocked, severely reducing blood flow to the brain. The two common ischaemic strokes are:

• Thrombotic stroke which occurs when a blood clot forms in one of the arteries that supplies blood to the brain. A clot may form by fatty deposits or plaque, which builds up in the arteries, also known as atherosclerosis, and cause reduced blood flow.
• Embolic stroke which occurs when a blood clot forms outside of the brain and is then carried through the bloodstream and lodges in a narrower brain artery. These clots are commonly formed in the heart.

Haemorrhagic stroke

Around one in every five strokes is haemorrhagic. A haemorrhagic stroke occurs when a blood vessel in the brain ruptures, causing blood to leak into the brain. The two common types of haemorrhagic stroke include:

• Intracerebral haemorrhage which can be caused by longstanding high blood pressure, trauma, vascular malformations or use of blood-thinning medications.
• Subarachnoid haemorrhage, commonly caused by an aneurysm, which is a weak or thin spot on a blood vessel wall.

Transient ischaemic attack

A transient ischaemic attack (TIA) or “mini stroke” has the same symptoms as a stroke but these disappear within 24 hours. The causes are similar to that of a stroke and a TIA should be regarded as a warning sign, as approximately one in five people who have a TIA will have a major stroke within the next three months.

Diagnosis 

To determine the possible type of stroke, and the area of the brain most affected, doctors may need to run the following tests:

• Physical examination
• Blood tests
• CT scan
• MRI
• Carotid ultrasound
• Cerebral angiogram
• Echocardiogram

Treatment

Treatment will depend on the type of stroke experienced.

Ischaemic stroke 

To treat an ischaemic stroke, doctors need to restore blood flow to the brain quickly. Doctors may do this through:

• Medication e.g. aspirin, intravenous injection of tissue plasminogen activator
• Medications delivered directly to the brain
• Mechanical clot removal
• Carotid endarterectomy
• Angioplasty and stents

Haemorrhagic stroke

Treatment of a haemorrhagic stroke focuses on controlling the bleeding and reducing pressure in the brain. Doctors may need to do the following:

• Surgical blood vessel repair
• Surgical clipping
• Coiling (endovascular embolization)
• Surgical AVM removal
• Intracranial bypass
• Stereotactic radiosurgery

Stroke recovery and rehabilitation

Every patient’s recovery differs and depends on the condition. Treatment may include:

• Seeing a neurologist (doctor trained in brain conditions)
• Seeing a rehabilitation doctor 
• Nurse
• Dietician
• Physical therapist
• Occupational therapist
• Recreational therapist
• Speech therapist
• Social worker
• Case manager
• Psychologist 

Prevention

A stroke can happen to anyone. Certain unchangeable factors like age, gender and family history can lead to an increased risk of stroke, however lifestyle modifications can prevent the likelihood of stroke from occurring. These include:

• Manage high blood pressure
• Manage high blood cholesterol
• Quit smoking
• Manage weight
• Eat a healthy diet
• Exercise regularly
• Drink alcohol in moderation

Research into Strokes