Cerebrovascular Event (Stroke)

Stroke is a rapid onset focal neurological deficit lasting more than 24 hours or causing death. A transient ischemic attack is fully reversible lasting between 30 minutes and 24 hours. A reversible ischemic neurological deficit is fully reversible and lasts between 24 hours and 72 hours.

• 80% of strokes are ischemic, the remaining 20% are hemorrhagic.

Epidemiology
100-200 / 100,000 / year. Of note is the fact that 12% of those cause death, making strokes the 2nd most common cause of death.

• The brain has just 2% of body weight but requires 17% of cardiac output. It normally receive 55ml / 100g brain weight / minute. Failure starts below 30ml / minute and irreversible damage starts below 10ml / minute.

Aetiology
Ischemic can be caused by atherothromboembolism (50%) or small vessel disease (25%), while haemorrhagic can be caused by anatomical factors, haemodynamic factors or coagulation problems.

Haemorrhagic is considered to be more severe and sudden, featuring nausea, vomiting, neck stiffness (and associated meningeal signs) and is more prone to complications, such as rebleeding and seizures.

Signs and symptoms
Speech problems, facial or limb palsy, movement impairment, atasia, diplopia or hemianopsia and instability or vertigo.

Diagnosis
We can use CT or MRI, though we prefer CT as it is faster. Also of use are ultrasound and angiography.

Treatment
Supportive care, recanalisation within 4.5hours with IV thrombolysis or endovascular intervention within 6 hours.

Reference: Kumran And Clark Internal Medicine Clinical Oxford Handbook