How do you recognise a stroke or TIA?
F - Facial weakness: can the person smile? Has their mouth or eye drooped?
A - Arm weakness: can they raise both arms?
S - Speech problems: can they speak clearly and understand what you say?
T - time: to call 999
How many neurones die in a minute in a acute stroke?
Approximately 2 million die per minute until blood flow is restored.
Why is it best to send patient’s to acute stroke centres?
Hyper-acute stroke centres are organised so that patient’s can be assessed by specialists trained in delivering emergency stroke treatment immediately on arrival.
What is the NIH Stroke Scale (NIHSS)?
- 0 = no stroke
- 1-4 = minor stroke (possible resolving TIA)
- 5-15 = moderate stroke
- 15-20 = moderate/severe stroke
- 21-42 = severe/devastating stroke
When assessing for thrombolysis NIHSS should be >5 and <25 but final decision remains clinical based.
What is dysarthria?
The disorder of speech. Speech is the process of articulation and pronunciation. It involves bulbar muscles and the physical ability to form words.
What is dysphasia?
The disorder of language. Language is the process in which thoughts and ideas become spoken. It involves the selection of words to be spoken (semantics) and the formulation of appropriate sentences or phrases (syntax).
What are the main investigations for stroke?
- Non-contrast CT scan
- MRI is better but causes a delay in treatment for acute stroke
- CT angiography and perfusion can be used in conjunction to confirm diagnosis
What can be seen on a CT scan of a stroke?
- Visualisation of clot (seen immediately)
- Early parenchymal changes (seen within 1 hour of onset of symptoms)
- Hyperdense artery - represents visualisation of the clot within the lumen of the artery (over time clots become even more dense)
- Grey white matter differentiation is lost after stroke
What other investigations need to be done in acute stroke?
- Bloods - FBC, U+Es, LFTs
- Blood glucose
- Coagulation screen
What is the inclusion criteria for thrombolysis?
All 4 must be yes
- Symptoms of acute stroke
- Onset in the last 4.5 hours
- Measurable deficit on NIHSS
- Absence of haemorrhage on CT scan
What is the exclusion criteria for thrombolysis?
Must be NO to all
- Head trauma, brain/spinal surgery, stroke in last 3mths
- Major surgery or non head trauma in last 2 wks
- Hx of ICH, cerebral aneurysm or AVM
- GI, GU or gynae haemorrhage in last 21 days or evidence of active bleeding
- Known aortic dissection
- Arterial puncture at non-compressible site within 7 days
- Recent lumbar puncture in last 10 days
- Currently pregnant
- Systolic BP >185 +/or diastolic >110mmHg
- Known or strongly suspected IE
- Platelet count 1.4 on warfarin
- Heparin or newer oral anticoagulant within last 48hrs or INR >1.4 on warfarin
What are the complications of thrombolysis in acute stroke?
- 6% risk of haemorrhage (2-3% considered major/life threatening)
- 7% risk of angioedema (risk increased by treatment with ACEi)
What medication is used for thrombolysis?
Alteplase (recombinant tissue plasminogen activator) - 0.9mg IV infusion over 1hr
What are the differentials for stroke?
- Seizures (Todd’s paresis)
- Sepsis
- Syncope
- Hypoglycaemia (check BM)
- Subdural
- Brain tumour
- Migraine
- Space occupying lesion
When is thrombectomy offered?
Offer thrombectomy (within 6hrs) to people who were last known to be well between 6-24 hrs previously (including wake-up strokes):
- Who have acute ischaemic stroke and confirmed occlusion of proximal anterior circulation demonstrated by CTA or MRA
AND
- if there is potential to salvage brain tissue, as shown by imaging such as CT perfusion (weighted MRI sequences)
How common are the different types of stroke?
- Ischaemic stroke is the most common at 85%
- Haemorrhagic strokes account for 15% of all strokes (intracerebral is blood enters the brain substance, subarachnoid is when blood enters various spaces surrounding the brain)
What is Virchow’s triad?
- Hypercoagulability
- Stasis
- Endothelial injury
Where would a TACS be?
- Total anterior circulation stroke
- Large cortical stroke ACA or MCA
How would you diagnose a TACS?
All 3 of the following:
- Unilateral weakness (+/or sensory loss) of face, arm + leg
- Homonymous hemianopia
- Higher cerebral dysfunction (dysphasia, visuospatial disorder)
Where would a PACS be?
- Partial anterior circulation stroke
- Cortical stroke MCA/ACA
How would you diagnose a PACS?
2 of the following:
- Unilateral weakness (+/- sensory loss) of face, arm and leg
- Homonymous hemianopia
- Higher cerebral dysfunction (dysphasia, visuospatial disorder)
Where would a POCS be?
- Posterior circulation syndrome
- Posterior circulation - vertebrobasilar arteries
How would you diagnose a POCS?
1 of the following:
- Cerebellar or brainstem syndrome
- Loss of consciousness
- Isolated homonymous hemianopia
Where would a LACS be?
- Lacunar syndrome
- Subcortical stroke due to small vessel disease - internal capsule, thalamus and basal ganglia
