STROKE Flashcards
Neurology 1
Define stroke
CVA/stroke
sudden onset of a focal neurological deficit due to a presumed local disturbance in the blood supply of the brain lasting more than 24 hours
- vascular
- blood carries essential nutrients and oxygen to the brain. Brain cells are damaged/destroyed without blood supply
- acting fast = vital
- stroke destroy 2 mill brain cells per min
stroke disablement
48% hemiparesis/hemiplegia (paralysis of muscles on one side of the body, contralateral to the side of the brain where CVA has occurred)
22% cannot walk
15 - 27% upper limb impairment
24 - 53% assistance with activities of daily living (ADL)
12 - 18% dysphasia (global, expressive or receptive).
5% residual swallow disorder (dysphagia).
32% clinically depressed
33% cognitive impairment
types of stroke
ischaemic - embolus, thrombus in blood supply to brain
Haemorrhagic - ICH - intracerebral haemorrhage -bleeding occuring with the brain itself
SAH - subarachnoid haemorrhage - bleeding within the subarachnoid spae - between arachnoid membrane and pia mater
Ischaemic 85%
Haemorrhagic 15%
Ischaemic stroke
80% of stroke
Obstruction of major cerebral artery - Anterior, Middle, Posterior cerebral arteries
Brainstem stroke - Vertebral / Basilar Arteries
Causes – atheroma (fatty plaque in vessel wall, e.g. atherosclerosis, thrombus (clot), embolus (moving clot), vessel disease (heart / neck)
cerebral artery blocked by embolism
cerebral ischaemia infarction
area of necrosis/ tissue death
Ischaemic stroke consequences depend on…
Collateral blood flow – Circle of Willis attempts to compensate for occlusion of major brain vessels, some blood can be supplied to the affected area by the opening of these collateral channels.
Vulnerability of cells in the affected area – neurones are most vulnerable to ischaemia (deprived of oxygen rich blood), followed by oligodendrocytes, astrocytes and finally endothelial cells.
Severity & Duration of ischaemia – initially autoregulation compensates. When max vasodilation fails to compensate O2 & glucose extraction fractions are increased. When cerebral blood flow drops to approx 50% of normal, electrical activity is suppressed in an attempt to conserve energy.
three cerebral vessels
anterior
middle
posterior
TACI
TACI - Total anterior circulation infarct
17% stroke
Large anterior circulation infarcts with cortical & subcortical involvement.
Poor prognosis, 50% 6month mortality.
PACI
PACI - Partial anterior circulation infarct
34% stroke
More restricted & predominantly cortical infarcts.
More likely to have an early recurrent stroke than other groups.
10% 6-month mortality
POCI
POCI - Posterior circulation infarct
24% stroke
Infarcts associated with vertebrobasilar artery.
Best chance of good functional outcome.
15% 6-month mortality
LACI
LACI - Lacunar infarct
25% CVA
Infarcts confined to deep perforating arteries.
Also infarcts are small in anatomical size, high level of disability associated
7% 6-month mortality
Intracerebral haemorrhage
15% of stroke
History of hypertension / weakening & microaneurysms arterial walls rupture haematoma
May spread to white matter & cause extensive mass lesion. Usually affects deeper structures.
Onset - severe headache / vomiting
Clinical - hemiparesis, hemisensory loss, homonymous hemianopia
Poor prognosis - 50% loss of consciousness (LOC), increased intracranial pressure (ICP)
subarachnoid haemorrhage
3 - 4% - high mortality
Bleeding into subarachnoid space
Causes:
Berry aneurysm in Circle of Willis
Congenital abnormalities - Arteriovenous malformation (AVM)
Hypertension / vascular disease
Clinical - intense headache, vomiting, neck stiffness, loss of consciousness (LOC)
actue medial management
Diagnosis
Medical assessment
Thrombolysis/Aspirin
Thrombectomy (ESCAPE trial)
Prevent complications Pneumonia, depression Post stroke pain syndrome Pressure sores, Falls Swallow assessment 24hr Physiotherapy assessment 24hr
Escape trial
ESCAPE trial Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times
Effects of stroke
A stroke causes damage to the brain, which affects how the body works
The effects will depend on the part of the brain affected
Every stroke is different, people who have a stroke are affected in different ways