Thrombotic Diseases Flashcards
Define what a stroke is?
- Rapid death of brain tissue due to a disturbance in blood supply
- Persists for beyond 24 hours or results in death
Define what a TIA is?
- Transient Ischaemic Attack (TIA)
2. A mini stroke that is completely resolved within 24 hours
Give examples of risk factors for stroke?
- Inactivity
- High blood pressure
- Heart disease
- Previous stroke or TIA
- Obesity: unhealthy eating
- smoking
- Diabetes
What are main arteries that supply blood to the brain?
- Carotid arteries: Anterior: supply front and back part of brain
- Vertebral arteries: Posterior: Brain stem and rear regions of brain
- Basilar arteries: two vertebral arteries
- Communicating arteries: Posterior and anterior
Describe how a thrombosis can cause an ischaemic attack?
- Affects large arteries: Carotid (blockage in here, clog in cerebral artery), Vertebral, Basilar
- Larger branches: anterior, middle and posterior cerebral arteries
- Small branches of the larger branches
- Atherosclerotic plaque rupture leads to thrombosis
- Interrupts blood supply (oxygen and other nutrients) to neurones
- Rapid death of brain tissue leads to loss of brain function
- Changes observed within 2 to 3 hours of ischemia
Describe how a embolism can cause an ischaemic attack?
- This is clots from other main stream arteries such as the heart is a common source to the brain
- Congestive heart failure and MI (common causes of clots to left ventricle)
- Low ejection fraction for left side of the heart leads to emboli forming
- Blood stasis leads to thrombosis: clot
- Emboli can break up to pieces and block arteries which results in stroke
Describe what a haemorrhagic stroke is in relation to intercerebral?
- Intercerebral (within brain)
- Caused by: Hypertension, trauma, bleeding disorders and vascular effects
- Mechanism:
- NIDUS group of smaller blood vessel bursts, spilling blood onto brain, less nourishment
- Haematoma is formed which does irreversible damage to neurons
Describe what a haemorrhagic stroke is in relation to subarachnoid (surface of brain)?
- Weak spot in tissue wall called aneurysm bursts mainly in circle of willis (bottom mid section of brain)
- Risks: smoking, alcohol, hypertension, genetic, drug abuse
- Anterior communicating and cerebral arteries
- Two types: saccular (berry) and fusiform
- Damage: compression of tissue from expanding haematoma
- Direct toxic effect to the blood cells (free iron)
- Interrupting blood supply to neurones
- Surgical intervention necessary
Describe what occurs in a TIA stroke?
- Temporary small blockage of blood supply due to small blood clots
- Overcome in 30 to 60 minutes or 24 hours
- Can occur repeatedly or in multiple regions
- Major ischemic stroke can occur
Describe what an ABCD2 is able to identify?
- A score assessment that identifies people at high risk of a stroke
- Based on: Age, blood pressure, clinical features and duration of symptoms
- 300mg aspirin immediately: cannot assess someone like this if they’re already on anti-coagulant
Describe the specific symptoms of a stroke?
- Loss of consciousness or coma
- Worst headache
- Loss of vision or double vision
- Slurred speech
- Numbness in right side of face or arms and legs
- Weakness of face, arm or leg
- Loss of balance and co-ordination
Define how you simply recognise a stroke with the term: FAST?
F: Falling and drooping of face, can they smile
A: Arm weakness, can they lift them up and keep it there
S: Slurred speech, can they speak clearly?
T: Time to call 999
How do you manage a stroke?
- Rapid recognition of stroke symptoms
- Rapid action to ensure patient survival
- Risk of stroke in TIA patients
- Acute stroke: brain scans of MRI
- Existing treatment to prevent further strokes
- Neurological loss (neuroprotection)
- Neurorestoration (replace damaged neurons)
How do you pharmacological manage a patient after they’ve had TIA?
High score
- Aspirin 300mg daily
- Specialist assessment and management
- Measures for secondary prevention- assessment of individual risk factors
- Crescendo TIA (treated for high risk)
Low risk
- Assessment within one week following onset of symptoms
- Refer to brain imaging if necessary
How do you pharmacological manage a ischemic stroke?
- Thrombolytic agents:
- Tissue plasminogen activator (tPa)
- Alteplase (900 micrograms for 1 hour) - Promotes breakdown of fibrin (lysis of blood clot)
- IV administration within 4.5 hours of stroke, improves clinical outcome (decrease mortality)
- Carotid angioplasty (stent) (cannot be used in haemorrhage stroke)
- Carotid endartectomy: treatment to remove the plaques