Stroke and TIA Flashcards
What is a stroke?
- Rapid development of symptoms/signs
- Focal loss of cerebral function
- Global loss with coma or SAH
- Lasts > 24 hours
- Presumed vascular origin
What are the types of stroke (and explain)?
Explain intra-cerebral haemorrhage
- Bleed from a blood vessel
- Variable prognosis
- Occasionally from an AVM or tumour
How does an infarction occur?
-
Thrombosis in situ
- A blood clot (thrombus) forms at the site of a hardened patch of artery within the brain
- Usually affects the small blood vessels in the brain
- Main RF: Hypertension, diabetes, smoking, lipids
Explain embolic stroke
- A thrombus forms outside the brain and travels (embolises) to the brain
- Main Risk Factors: Atrial Fibrillation, Cardiac Failure, Valvular Disease, Diabetes, Lipids
Types of ishaemic stroke
- Embolic
- Thrombotic
Explain Ischaemic penumbra
Penumbra = shadow (progress to infarct hence, able to be salvageable)
What is a T.I.A?
- Transient ischaemic attack
- Acute loss of focal cerebral function
OR
- Acute monocular visual loss (amaurosis fugax)
- Lasts < 24 hours (but mostly short-lived) (has the exact same pathophysiology of an ischaemic stroke but, thrombus breaks off)
How to recognise stroke?
Explain the ROSIER scale
Recognition of Stroke In the Emergency Room
- In acute stroke rapid intervention is crucial to maximise early treatment benefits
- A validated scoring system to identify patients with acute stroke from the myriad other non-stroke conditions would be helpful
- 1:1 demographic of people WITH and WITHOUT a stroke (50%)
- Higher ROSIER score = higher chance of it being a stroke
Things that look like stroke but are not stroke (non-stroke diagnosis)
- Seizure
- Syncope
- Sepsis
- Migrane (main ones)
- Somatisation
- Orthostatic hypotension
- Labyrinthitis
- Metabolic disorder
- Brain tumour
- Dementia/encephalopathy
- Other
Key questions for stroke to ask
- Acute onset
- Arm weakness
- Leg weakness
- Facial weakness
- Speech disturbance
Key questions that usually rule out stroke
- Dizziness
- Confusion
- Loss on consciousness
- Convulsive fits
Stroke history questions
- Time of onset of symptoms
- Parts of the body affected
- Nature of symptoms (negative or positive)
- Accompanying symptoms
- Previous TIA/stroke
- Past medical history (vascular)
- Family history
- Lifestyle
Have you ever suddenly:
- Lost vision or gone blind in one eye?
- Had double vision for more than a few seconds?
- Had jumbled / slurred speech or difficulty talking?
- Had weakness / loss of feeling in face/arm/leg?
- Had clumsiness of the arm or leg?
- Had unsteadiness walking?
- Had a spinning (dizzy) sensation?
Risk factors for stroke and TIA
- Age
- Family history
- Smoking
- Alcohol
- Recreational drugs
- Hypertension
- Diabetes
- Raised cholesterol
- Ischaemic heart disease
- Peripheral vascular disease
- Atrial fibrillation
How to classify a stroke?
- Anterior (carotid) system
- Posterior (vertebrobasillar system)
Explain Bamford Classification
Explain stroke thrombolysis
- Is a clot buster (tPA) that breaks up the clot = INCREASE blood supply to this area
- Increased outcome and doesn’t reduce outcome
- Doesn’t work for everyone in the same way (the quicker you give the treatment = the better the outcome)
- Odds ratio >1 then means better than NO treatment
Common stroke syndromes
Middle cerebral artery
- Parietal, frontal, superior temporal lobes
- contralateral
- UMN facial weakness
- Hemiplegia (arm > leg)
- Hemianopia
- Aphasia (dominant)
- Visuospatial problems (non- dominant)
- PARTIAL SYNDROMES ARE COMMON
Vertebral & basilar arteries
- Brain stem & cerebellum
- Diplopia, disorders of eye movements
- Nystagmus, vertigo, vomiting
- Dysarthria, dysphagia, bulbar weakness
- Ipsilateral LMN facial weakness
- Respiratory failure, coma
- Contralateral hemiparesis, quadriparesis
What is the Modified Rankin Scale
Modified Rankin Scale
0 No symptoms at all
1 No significant disability despite symptoms; able to carry out all usual duties and activities
2 Slight disability; unable to carry out all previous activities, but able to look after own affairs without assistance
3 Moderate disability; requiring some help, but able to walk without assistance
4 Moderately severe disability; unable to walk without assistance and unable to attend to own bodily needs without assistance
5 Severe disability; bedridden, incontinent and requiring constant nursing care and attention
6 Dead
Alteplase & adminestering
- Also known as:
- r-tPA–Alteplase (generic name)
- Actilyse (brand name)
- No other thrombolytic is licensed for intravenous thrombolysis in acute stroke
- Each box contains 2 bottles
- 1 with the drug in powdered form
- 1 sterile water for injections
- 1 transfer canula to dissolve the drug
- Calculate the dosage from the patient’s weight (estimated)
- 0.9mg/kg up to a maximum of 90mg (100kg)
- Dissolve the powder using the supplied water for injections and transfer canula
- Gives a 1mg/ml solution
- Draw up 10% of the total dose into a 10mL syringe and give as a slow iv push over 1 minute
- Draw up the remaining 90% of the dose into a 50mL syringe and infuse over 1 hour using a syringe driver
- Discard the remaining solution
Limitations of IV rtPA
- Generalizability
- 4% utilization of rtPA
- 25% present within 3 hours: 29% eligible
- Major strokes are difficult
- Baseline NIHSS >10 or dense MCA sign predicted poor clinical outcome
- Large vessel recanalization rate low.
- Increased risk of sICH with larger strokes
What is IV thrombolysis is ineffective?
- Consider intra-arterial therapies
- Intra-arterial clot removal
- Intra-arterial thrombolysis
- Age < 60
- Major stroke with proven proximal Middle Cerebral Artery thrombus on CT Angiography
- No sign of rapid improvement with intravenous thrombolysis
- Rapid transfer to RVI Neurosciences
- Likely to become more common treatment
- REQUEST CT HEAD + CTA in PATIENTS < 60y of AGE with signs of major stroke (TACI)
Endovascular treatment
- Femoral or radial access
- Series of catheters
- Sheath
- Guide Catheter
- Micro catheter
- Wire navigation
Treatment: mechanical embolectomy, merci device
