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