Stroke

Definition

A sudden circulatory disorder of the brain. The brain no longer has sufficient supplies of oxygen and nutrients, which disrupts its functioning. If this lack of oxygen and nutrients lasts for longer, brain tissue starts to die off.

A transient ischaemic attack (TIA) or “mini-stroke” involves temporary disruption to blood supply, the resulting symptoms of which usually subside after a few hours.

A disruption in blood supply to the brain (clot), which indicates an ischaemic stroke, is not the same as a bleed in the brain, which is also referred to as a haemorrhagic stroke. You cannot tell from the symptoms whether an ischaemic or haemorrhagic stroke has occurred. Massive bleeding increases blood pressure inside the skull, which can quickly become fatal.

Causes

Strokes are caused either by a blockage in an artery supplying the brain (ischaemic stroke) or bleeding in the brain. Such a blockage is more likely with arteriosclerosis (blocked blood vessels). A TIA often precedes a stroke, whereby blood flow is already temporarily disrupted but the artery in question supplying the brain is still clear. TIAs are a warning sign of an ischaemic stroke. Atrial fibrillation is a relatively common cause of strokes. This is a type of irregular heartbeat, whereby blood clots form in an atrium of the heart and then travel into the brain arteries as embolisms and cause obstruction there. Summary of causes:

  •  Arteriosclerosis (narrowing) of the carotid arteries or those supplying the brain
  • Thrombosis
  • Obstruction of the blood vessels by a clot (embolism) as a result of cardiac arrhythmia (irregular heartbeat) or cardiac abnormalities or if part of the internal wall of the carotid arteries tears
  • Brain haemorrhage
  • Acute drops in blood pressure, e.g. in the case of cardiac arrest or cardiac arrhythmia
  • In rare cases, inflammation, congenital (hereditary) deformities or injury to blood vessels in the brain

Risk factors

The risk factors include all the causes of arteriosclerosis. In rare cases, hormonal contraception can cause stroke, particularly if additional risk factors, such as smoking or obesity, are present. Summary of risk factors:

  • High blood pressure
  • Smoking
  • Diabetes
  • High cholesterol
  • Being overweight
  • Lack of exercise
  • Blood-thinners: brain haemorrhage
Symptoms

Strokes are characterised by sudden failure of brain function. This may manifest as paralysis, sensory disturbances, hearing difficulties, speech impairment or loss of consciousness. Summary of symptoms:

  • Loss of consciousness, up to coma
  • Paralysis (typically on one side), potentially with the corner of the mouth drooping down, if the nerves of the brain are affected
  • Numbness
  • Speech impairment, difficulty swallowing, disturbed vision (seeing double), hearing loss
  • Hand coordination difficulties
  • Spinning sensation
  • Sometimes sudden, severe headaches
  • Occasionally, epileptic fits may occur during or after acute strokes
Diagnosis (tests)
  • Medical history and symptoms
  • Physical examinations, particularly of the central and peripheral nervous system
  • Computed tomography (CT scan) to exclude/determine brain haemorrhage
  • Ultrasound
  • ECG to check for cardiac arrhythmia
  • Echocardiography (heart function, condition of the heart valves)
  • Blood tests to check for blood-clotting disorders

Strokes are an emergency and require immediate medical treatment, even if the symptoms subside again. The time period within which treatment is provided has a major effect on survival and regression of the paralysis. Time is brain!

Treatment

Treatment depends on the underlying causes.

  • Brain haemorrhage: neurological monitoring, potentially a surgical procedure to relieve pressure. Treatment in intensive care is generally required.
  • Thrombosis: blood-pressure monitoring, potentially drug-based lysis therapy (to dissolve blood clots), blood thinning to prevent further strokes.
  • Early rehabilitation: with the help of physiotherapy, speech therapy and occupational therapy, skills that have been lost can be relearnt. The earlier this starts, the better the results. Depending on the severity of the stroke, some patients can make a complete recovery, others take months or even years to be able to cope with everyday activities independently again.

Treatment of risk-factor conditions is also important: diabetes, high blood pressure, high cholesterol and atrial fibrillation. As many risk factors as possible need to be eliminated by: stopping smoking, losing weight exercising regularly.

Prevention
  • Balanced, low-salt diet
  • In the case of high blood pressure, consistent treatment and regular medication
  • Avoid smoking
  • In the case of diabetes, consistent treatment and regular medication
  • If overweight, weight reduction
  • Regular exercise
  • Blood-thinning drugs, if there is a likelihood of stroke occurring