Stroke

• What happens during a stroke?
• Causes of strokes
• Risk factors
• Early symptoms
• Examination and diagnosis
• Treatment following a stroke
• Prevention
• Emergency first aid

What happens during a stroke?

During a stroke, the brain does not receive sufficient oxygen and nutrients. The cause of this is either vascular occlusion or cerebral haemorrhage. Both will cause damage to the affected brain tissue.

When a stroke is suspected, it is vital to take immediate action. If first aid is given, this will help to minimise the extent of long-term damage following a stroke.

Causes of strokes

Stroke due to vascular occlusion

A stroke is characterised by a sudden circulatory disorder in the brain. The cause of this disorder is usually occlusion in a cerebral artery as a result ofarteriosclerosis or an embolism. This is known as an ischaemic stroke.

Stroke due to cerebral haemorrhage

However, a circulatory disorder can also be the result of cerebral haemorrhage. For example, if a brain aneurysm bursts. This is known as a haemorrhagic stroke.

Risk factors

The risk factors for a stroke are generally the same as for a heart attack:

• High blood pressure
• High cholesterol
• Overweight
• Diabetes
• Smoking and lack of exercise

Another significant risk factor is atrial fibrillation. If cardiac arrhythmia occurs , blood clots may form in the heart. They are then transported to the brain, where they cause an embolism.

Early symptoms

The symptoms of a stroke occur suddenly. The following symptoms sometimes occur beforehand :

• Dizziness
• Temporary vision problems
• Speech problems
• Loss of sensation or difficulty walking

Such temporary episodes are known as transitory ischaemic attacks and constitute warning signs of a stroke. A stroke can cause different symptoms, depending on which region of the brain is affected.

Characteristic symptoms of cerebral infarction include the following:

• One-sided paralysis
• Vision, speech and hearing problems
• Severe dizziness
• Sudden headache
• Loss of consciousness

Symptoms of this type which occur suddenly should be immediately checked by a doctor, even if they disappear again after a short time. Time is the most important factor to prevent permanent damage from a stroke.

Examination and diagnosis

Ischaemic and haemorrhagic stroke cannot be differentiated solely on the basis of the symptoms. Both lead to the death of brain cells and the loss of brain functions.

It is only possible to identify whether a stroke stems from a haemorrhage or the occlusion of a cerebral artery with the help of computed tomography(CT) and magnetic resonance imaging (MRI).

Treatment following a stroke

The treatment depends on the severity of the stroke. If a cerebral haemorrhage is the cause, the source of the bleeding must usually be stopped with surgery. If vascular occlusion exists, there are medical and surgical options to deal with it.

Find out more about the different treatment options in the endarterectomy and brain aneurysm surgerysections.

Prevention

If there is a known risk of stroke (atrial fibrillation, transitory ischaemic attacks), blood thinners can be used as a preventative measure.

Emergency first aid

On average, someone in Switzerland suffers a stroke (or apoplexy) every 30 minutes. 16 000 people are affected in Switzerland each year. What are the symptoms of a stroke and how should I respond?