Stroke Flashcards
Type of strokes
Ischaemic 85%
Haemorrhagic stroke 15%
TIA
Ischaemic stroke
Vascular occlusion or stenosis, leading to cell death and An episode of neurological dysfunction
Ischaemic stroke causes
Ischaemic strokes occur when large arteries (such as the extracranial carotid or vertebral arteries), intracranial arteries, or small penetrating arteries (lacunar) are occluded by:
* Thrombus (often as a complication of atherosclerosis), or
* Embolus of fatty material from an atherosclerotic plaque or a clot in a larger artery or the heart (often as a complication of atrial fibrillation or atherosclerosis of the carotid arteries).
* Other causes include intracranial or extracranial vessels disease (for example, dissection, vasculitis, venous thrombosis) or haematological conditions (for example sickle cell anaemia, antiphospholipid syndrome, or other hypercoagulable states).
- Strokes may also occur where there is no identifiable cause.
Haemorrhagic stroke
rapidly developing neurological dysfunction due to a focal collection of blood from within the brain parenchyma or ventricular system (intracerebral haemorrhage), or bleeding into the arachnoid space (subarachnoid haemorrhage) that is not caused by trauma.
Haemorrhagic stroke causes:
- Intracerebral haemorrhage (10%) — most occur in the absence of vascular malformations, aneurysms, or other structural causes, and are presumed to be due to diseases affecting small cerebral vessels. The commonest cause is high blood pressure.
- Subarachnoid haemorrhage (5%) — rupture of an intracranial saccular aneurysm accounts for 80% of cases of non-traumatic subarachnoid haemorrhage. The remaining 20% are due to arteriovenous malformations, arterial dissections, use of anticoagulants, and other rare conditions.
- Aneurysm formation may be due to structural abnormalities of cerebral vessels due to an inflammatory process. This may be influenced by smoking, hypertension, and alcohol abuse.
TIA
is a transient (less than 24 hours) neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without evidence of acute infarction.
A TIA has a sudden onset and can last from a few minutes to 24 hours. Most people have complete resolution of symptoms and signs within 1 hour.
Risk factors:
- Smoking.
- Alcohol misuse and drug abuse (for example cocaine, methamphetamine).
- Physical inactivity.
- Poor diet.
- Older age
- Male sex
- Prev Hx of TIA or stroke
- Family Hx of stroke
Established cardiovascular disease such as:
- Hypertension.
- Permanent and paroxysmal atrial fibrillation (AF) — AF causes at least 20% of ischaemic strokes.
- Infective endocarditis.
- Valvular disease.
- Carotid artery disease — atheroma and stenosis of the carotid arteries are commonly associated with stroke and TIA.
- Congestive heart failure.
- History of myocardial infarction.
- Congenital or structural heart disease
Other diseases associated with a stroke:
- Migraine — particularly in younger women and in those with migraine with aura. Brain hypoperfusion occurs in people with severe migraine with aura. Combined oral contraceptives should be avoided in women with this condition and prior ischaemic stroke.
- Hyperlipidaemia.
- Diabetes mellitus.
- Sickle cell disease.
- Chronic kidney disease.
- Ehlers-Danlos syndrome.
- Marfan syndrome.
- Polycystic kidney disease.
- Obstructive sleep apnoea
How should I manage a person with suspected acute stroke?
Arrange immediate emergency admission to an acute stroke facility for anyone with suspected acute stroke or emergent transient ischaemic attack (TIA).
Ensure the hospital receives advanced notification of arrival — this should include details of time of onset, symptom evolution, current condition, and medications (especially anticoagulants).
While awaiting transfer:
Monitor and manage any deterioration in clinical condition (airway, breathing, and circulation.
Give supplemental oxygen to people with acute stroke if oxygen saturations are less than 95% and there are no contraindications.
Risk factors relevant to the pt
Smoking (20 years)
Alcohol consumption
Older age
Family Hx
Hypertension (controlled)
