Stroke Flashcards
In simple terms, what is a stroke?
Loss of blood supply/oxygen to a brain region leading to death of neurones.
What are the two classifications of stroke?
Ischaemic and haemorrhagic
Which is more common, ischaemic or haemorrhagic stroke?
Ischaemic
Which typically has a more significant impact/threat to life, ischaemic or haemorrhagic stroke?
Haemorrhagic
Haemorrhagic strokes occur for approximately what percentage of stroke events?
20%
What percentage of people will die within one month following a stroke?
1 in 5 (20%)
What occurs in an ischaemic stroke?
An obstruction blocks blood flow to a part of the brain.
What occurs in a haemorrhagic stroke?
Weakened blood vessel ruptures, causing bleeding inside or around brain tissue.
Ischaemic stroke obstructions are usually due to either ____ or ____.
Thrombus or embolism.
A thrombus is usually associated with ____ ____.
Atherosclerotic plaque
TIA’s can be an indicator of underlying ____ ____.
Thrombotic disease.
Note: would also accept ‘cardiovascular disease’.
Haemorrhagic strokes are commonly associated with what chronic health condition?
Chronic hypertension
Aside from hypertension, what two other conditions are often associated with haemorrhagic stroke?
Aneurism or arterio-venous malformation
Why is significantly higher mortality and death associated with haemorrhagic rather than ischaemic stroke?
This type can significantly displace brain tissue and increase intracranial pressure (ICP)
Describe the neurotoxic domino effect
Loss of O2 and glucose results in rapid necrosis of the directly affected area and the damage extends beyond this area due to a neurotoxic effect; neighbouring and regional cells undergo apoptosis due to excitotoxicity.
Describe excitotoxicity
Dying cells release excessive amounts of glutamate (an NT) which hyperactivates surrounding cells and induces massive influx of calcium which triggers apoptosis (self destruction)
Aside from excessive glutamate, what other substance is produced by the excitotoxicity process that further expands the damage zone?
Reactive free radical species
What are some common conditions/lifestyle choices that lead to stroke?
- Hypertension
- Diabetes
- Smoking
i.e. leading to atherosclerosis
List some general symptoms of stroke
- Confusion
- Speech problems (dysphasia/aphasia)
- Paralysis on opposite side to damaged hemisphere
- Severe headache
- ALOC
- Visual disturbances
What is aphasia?
Loss of speech/language abilities
Aphasia is caused by damage to either or both of what two areas of the brain?
Broca’s area and Wernicke’s area
Describe the presentation of a pt with damage to Broca’s area
Unable to speak but are able to understand speech of others
Describe the presentation of a pt with damage to Wernicke’s area
Able to speak but speech is nonsensical, and unable to understand others
Describe the difference in function between Broca’s area and Wernicke’s area
Broca’s area: speech
Wernicke’s area: makes sense of speech
List six characteristics consistent with Broca’s aphasia
- Halting/no speech
- Repetition
- Disordered grammar
- Disordered syntax
- Cannot pronouce individual words (mixes letters)
- Comprehension intact
List five characteristics consistent with Wernicke’s aphasia
- Speaks fluently
- Words, syntax, grammar correct
- Makes no sense to listen to
- Uses inappropriate words
- Does not comprehend what others say
List six things that could mimic a stroke
- Hypoglycaemia
- Tumours/lesions
- Seizure
- Electrolyte imbalance
- Migraine
- Conversion disorder (psychiatric, pt feels real symptoms)
What is the purpose of the GCS?
To determine the extend of a pt’s brain dysfunction
What is a TIA?
A short (transient) depletion of O2 in a brain area with symptoms that resolve
What are the three questions when rx stroke?
- Ischaemic or haemorrhagic
- Time of event
- SPO2 value
What symptoms might suggest haemorrhagic stroke?
- N+V
- Severe headache
- ALOC
- Symptoms indicative of increased ICP
On non-contrast CT scans, what do white areas indicate?
Blood
On non-contrast CT scans, what do dark shadows indicate?
Ischaemia
What is the best method for early detection of ischaemic stroke?
Diffusion-weighted MRI (DWI) (measures diffusion of water molecules)
Fibrinolysis is given to which kind of stroke, ichaemic or haemorrhagic?
Ischaemic
Describe the action of fibrinolysis
- Gives tPA (tissue plasminogen activator)
- tPA is an enzyme that facilitates cleavage of active from inactive plasminogen
- Active plasminogen becomes plasmin
- Plasmin breaks down the fibrin clot
