Stroke

Stroke
An interruption of blood supply (and thus oxygen) to the brain. It may result from -
- Embolism – A migrating clot causes blockage
- Thrombosis – A clot inside a vessel that causes blockage
- Haemorrhage - Bleeding
- Infarct – dead or dying tissue often resulting from diminished blood supply

- When somebody has a stroke...
o It is usually the result of one of the following 3 processes
 Embolism (usually from carotid, vertebral or basilar arteries) and subsequent brain infarction
 Thrombosis – causes occlusion in one of the main arteries, results in brain infarction
 Haemorrhage – in the brain (intracerebral or subarachnoid)
o The most common form of stroke is the Cerebral infarction

- So, Hans could have had a stroke...
o Because it is more common in males than in females
o It is uncommon before 40, but the risk increases with age (except for those on antihypertensive medication – where the risk decreases) (high blood pressure is a risk factor for stroke)
o With the limited information, it is difficult to know which stroke risk factors Hans is affected by, however some may be –
 Hypertension
 Inactivity
 Smoking
 Maintaining a healthy weight
o A cerebral infarction is associated with sudden onset – this correlates with Hans’ experience, who was fine one minute, but unconscious on the ground the next.

- However, it may not have been a stroke...
o The most common form of stroke – cerebral infarction (infarction in internal capsule which results from embolism in the middle cerebral artery branch) often results in
 Limb weakness on the opposite side of infarct (can take seconds, minutes, hours)
 Weak limbs are at first flaccid
 Facial weakness
 Slurred speech
 Consciousness is generally maintained
 This does not correlate with Hans’ intact reflexes or his apparent unconsciousness
 Reflexes usually do not return until at least a couple of days following the infarct
o Dr Perlman notes that while his pulse is steady, it’s quite slow (hypertension is a risk for stroke)
o Shortly afterwards his verbal, motor and eye responses have returned to normal – there is usually a delay in the return of response in stroke victims, particularly those afflicted with the most common form of stroke – cerebral infarction
o Quick recovery more typical of TIA (a type of stroke)
o A stroke is more common in black African populations than Caucasian (although they certainly occur in Caucasians)
- The artery which is blocked directly corresponds to a particular area of the brain being affected.
o Anterior cerebral artery – frontal, occipital and parietal lobes
o Middle cerebral artery – internal capsule
o Posterior cerebral artery – cerebellum, temporal lobe

Thanks everyone

Georgia Downing