Define Stroke
Stroke is defined as an acute neurological deficit lasting more than 24 hours and caused by cerebrovascular aetiology.
It is also referred to as a cerebrovascular accident
Epidemiology of Stroke
Aetiology of Ischaemic stroke
Aetiology of Haemorrhagic stroke
RF for Stroke
Pathophysiology of Stroke
Patients typically have a focal neurological deficit which corresponds to the region of the brain that’s affected e.g.
Both motor and sensory fibres may be affected:
Both motor and sensory symptoms usually happen on the side that’s contralateral from the stroke, except in rare cases of brain stem stroke, where both sides are affected.1
General stroke symptoms
Usually sudden onset followed by gradual decline
Specific symptoms depends on anatomical site of stroke
S/S of Anterior cerebral artery stroke
S/S of Middle cerebral artery stroke
S/S of Posterior cerebral artery Stroke
S/S of Vertebrobasilar artery stroke
S/S of Weber’s syndrome (midbrain infarct)
Oculomotor palsy and contralateral hemiplegia
S/S of Lateral medullary syndrome (Posterior inferior cerebellar artery occlusion)
Assessment using ROSIER scale
Recognition of Stroke in the Emergency Room (ROSIER) scale is a variation of FAST (Face, Arm, Speech, Time) and is used to differentiate acute stroke from stroke-mimics
A stroke is possible if the score is > 0 and requires an urgent non-contrast CT head. Once hypoglycaemia has been excluded, assess the following:
Loss of consciousness or syncope: -1
Seizure activity: -1
Asymmetric facial weakness: +1
Asymmetric arm weakness: +1
Asymmetric leg weakness: +1
Speech disturbance: +1
Visual field defect: +1
Primary investigations for stroke
Differentials for stroke
Management of Ischaemic stroke
Maintain stable blood glucose levels, hydration status and temperature
Blood pressure should not be lowered too much during a stroke because this risks reducing the perfusion to the brain.
Prevention of stroke
Management of Haemorrhagic stroke
The exact management of haemorrhagic stroke depends on the subtype (refer to haemorrhage topics)
Complications of Stroke
Prognosis of stroke
For ischaemic stroke, the prognosis depends on the severity. A total anterior circulation stroke confers the poorest prognosis. Regarding thrombolysis, if administered within 3 hours, patients are 30% more likely to have minimal or no disability.
In general, mortality for haemorrhagic stroke is significantly higher than for ischaemic stroke and can be as high as 40%.
What are the common types of ischaemic stroke
Large vessel disease (50%), Small vessel disease (25%), Cardioembolic (20%), Cryptogenic/rarities (5%)
Notes on neuronal transmission in relation to epilepsy
Neuronal communication is controlled through neurotransmitters and receptors.
Neurotransmitters bind to the receptors and tell the cell to either open up the ion channels and relay the electrical message, called excitatory neurotransmitters, or close the ion channels and stop the electrical message, called inhibitory neurotransmitters.
The main excitatory neurotransmitter in the brain is glutamate, and NMDA is the primary receptor that responds to glutamate by opening ion channels that let calcium in.
The main inhibitory neurotransmitter in the brain is GABA, which binds to GABA receptors that tell the cell to inhibit the signal by opening channels that let in chloride ions.
Define epilepsy
Epilepsy is an umbrella term for a condition where there is a tendency to have seizures. Seizures are transient episodes of abnormal electrical activity in the brain.
There are many different types of seizures.