Stroke presentation, investigations and therapy Flashcards
Stroke symptoms (11)
Loss of power
Loss of sensation
Loss of speech
Loss of vision
Loss of coordination
Headache
vomiting
neck stiffness
Photophobia - sensitive to bright light
Fit
Incontinence
WHO definition of stroke
a stroke is a neurological deficit (loss of function) that comes on suddenly. It lasts more than 24 hours and is of vascular origin
if symptoms last less than 24 hours what would the diagnosis likely be?
transient ischaemic attack
what things might you find upon taking a neurological history/examination of a patient who has had a stroke? (5) ie signs
Motor (clumsy or weak limb)
Sensory (loss of feeling)
Speech: Dysarthria - unclear /Dysphasia - can’t generate words
Neglect / visuospatial problems
Vision: loss in one eye, or hemianopia - blindness over half the field of vision.
Gaze palsy
Ataxia/ vertigo / incoordination / nystagmus - involuntary eye movement
what is a stroke?
Damage to part of the brain due to blockage of a blood vessel by thrombus or embolus or for about 10% of patients it can be due to haemorrhage from rupture of a blood vessel
Causes of stroke (4)
Blockage of a vessel with thrombus or clot
Disease of vessel wall
Disturbance of normal properties of blood
Rupture of vessel wall
(haemorrhage)
85% infarction
15% haemorrhage
Describe what happens in an ischaemic stroke
clot stops blood supply to an area of the brain
Describe what happens in a haemorrhagic stroke
haemorrhage/blood leaks into brain tissue
what is the most common cause of cardioembolic stroke?
atrial fibrillation
3 main causes of ischaemic stroke
Large artery atherosclerosis
Cardioembolic
Small artery occlusion
what can you tell about a stroke from a patient’s symptoms? (5)
what side of the brain is affected
whether the lesion is in the brainstem (a brainstem stroke)
whether the cortex is involved (a cortical stroke)
or if the lesion is in the deep white matter (a lacunar stroke)
what blood vessel is involved
Modifiable and non-modifiable risk factors for stroke (8)
Modifiable High blood pressure Atrial fibrillation Smoking Diabetes mellitus
Non-modifiable Age Race Family history History of TIA or stroke
What investigations are done to diagnose a stroke? (6)
Blood tests: Full blood count (platelets, red cells), lipids.
ECG
Imaging:-
CT scan
MRI scan
Carotid doppler - image of arteries using ultrasound
Sometimes an echocardiogram can be helpful to look for clots in the heart
why is a CT a good imaging technique to detect stroke
Quick
shows up blood
why is an MRI a good imaging technique to detect stroke or why might CT be preferred?
shows up ischaemic stroke better than CT does
it takes longer though and can be quite claustrophobic
the longer a stroke is left untreated what happens?
the more neurons that are lost and more damage is caused
what thrombolytic treatment is used for
a patient admitted with a stroke within 4.5 hours of definite onset of symptoms?
if suitable then intravenous rt-PA - Tissue plasminogen activator is a protein involved in the breakdown of blood clots
what should not be used to treat patients in the acute phase of stroke?
Streptokinase - thrombolytic agent
what priorities are in place for patients having a stroke? (5)
ambulance priority (blue light) in appropriate cases
rapid triage on arrival at hospital
immediate access to specialist stroke services
rapid brain imaging
rapid specialist assessment
define aphasia
speech impairment
what is NIHSS
NIH Stroke Scale for quantifying stroke severity
What is the middle cerebral artery infarction mortality rate
up to 80%
what should be offered within 48 hour stroke onset to an individual under age of 60 who has suffered from MCA territory ischaemic stroke complicated by massive cerebral oedema?
surgical decrompession by hemicraniectomy
list the treatment options for acute stroke
stroke unit - focus on things like swallowing, positioning etc early therapy
thrombolysis - only if haemorrhagic cause is ruled out
aspirin - prevents platelet aggregation
hemicraniectomy considered
what presents in 50% of stroke patients?
swallow problems
what is a TIA?
Aetiology no different from definite stroke.
A TIA is a “warning stroke” or “mini-stroke“ with stroke-like
symptoms persisting less than 24 hours, that clears without residual disability.
Prompt evaluation is needed
About 1/3 of those who have a TIA will have an acute stroke some time in the future.
express study
Risks & benefits of urgent assessment & treatment of TIA & minor stroke in a TIA clinic
Phase 1: 0-30 months
daily appointment clinic
Rx advice faxed to GP
Phase 2 : 30-60 months
- emergency access clinic
- treatment started in clinic
what is a carotid endarterectomy?
surgical procedure to remove a build-up of fatty deposits (plaque), which cause narrowing of a carotid artery
more general secondary prevention options
Arrange follow up in primary care
review health, social care needs
speak about lifestyle changes ie not drinking or smoking
what types of drugs are used in seocndary prevention (preventing another stroke)
Anti-hypertensive drugs - beta blockers, ACE inhibitors
Anticoagulant drugs - warfarin or heparin
Lipid modification drug treatment - statins
Antiplatelet therapy - aspirin or clopidogrel
Vitamin K link to stroke
Vitamin K is essential for blood clotting. However, when Vitamin K levels are too high, people can form excessive blood clots quickly, which can cause stroke,
How does Atrial Fibrillation cause stroke?
AFib puts patients at an increased risk for stroke because blood may not be properly pumped out of the heart, which may cause it to pool and form a clot. This clot can then travel to the brain and block the flow of blood to part of the brain which can result in a stroke.
Stroke management/therapy
Acute
protect airway - prevent hypoxia / aspiration
Urgent CT/MRI/ECG - esp if considering thrombolysis
Antiplatelet agent - Aspirin if haemorrhagic cause ruled out
Thrombolysis - alteplase - only if haemorrhagic cause ruled out - always do a CT after thrombolysis to check for bleeding
transfer to stroke unit
prevention primary (before any stroke) - control risk factors, lifelong anticoagulation in AF
secondary (preventing repeat) - Lower BP and cholesterol and control other risk factors
antiplatelet agents - aspirin and clopidogrel
anticoacgulate - warfarin 2 weeks later
2 main treatment drugs given for acute stroke
atelplase - thrombolysis
aspirin - if allergic, give another antiplatelet
