Stroke Flashcards
Definition of stroke
Persisting neurological complications due to CVS disease
Types of stroke
Haemorrhagic- 20%- caused by structural abnormality, hypertension, amyloid antipathy
Ischaemic- 80%- atheroembilic, small vessel, cardioembolic
Modifiable risk factore
hypertension, smoking, diabetes, heart disease, pvd, the pill, high cholesterol, increased alcohol use carotid bruits, syphilis
signs of stroke
sudden onset of focal neurological signs
3 criteria for stroke
- Unilateral hemiparesis and/or hemisensory loss of the face, arm and leg
- Homonomous hemianopia
- Higher cognitive dysfunction eg dysphasia
Total anterior circulation infarcts (15%)
Involves middle and anterior cerebral arteries
all 3 criteria are present
Partial anterior circulation infarct (25%)
involves small arteries of anterior circulation eg upper or lower division of middle cerebral artery
2 of the criteria are present
Posterior circulation infarcts
Involves vertibobasilar arteries Presents with cerebellar or brainstem syndromes loss of consciousness isolated homonymous hemianopia
Lacunar infarcts (25%)
Involves perforating arteries around the internal capsule, basal ganglia and thalamus
presents with 1 of the following
Unilateral weakness (and or sensory decifit) of face and arm, arm and leg or all three
pure sensory stroke
ataxic hemiparesis
Consciousness intact except thalamic stroke
Anterior cerebral artery
contralateral hemiparesis and sensory loss
lower extremity> upper
Middle cerebral artery
Contralateral hemiparesis and sensory loss, upper extremity> lower
Contralateral homonymous hemianopia
aphasia
Posterior cerebral artery
contralateral homonymous hemianopia with macular sparing
visual agnosia
webers syndrome (branches of the post. cerebral artery that supply the midbrain)
Ipsilateral CN III palsy. contralateral weakness of upper and lower extremity
anterior inferior cerebellar artery (lateral pontine syndrome)
ipsilateral facial weakness and deafness
retinal/ ophthalmic artery
amaurosis fugax
Basilar artery
locked in syndrome
Investigation
Pulse, BP, ECG, BG
Urgent CT/MRI if thrombolysis considered, cerebellar stroke, unusual presentation, high risk of haemorrhage
otherwise- imaging can wait (<24hr)
What imagine method is most sensitive for acute infarct
Diffusion weighted MRI but CT helps rule out primary haemorrhage
Management
Antiplatelet agents- aspirin 300mg
Thrombolysis- as soon as haemorrhage has been included, as long as onset of symptoms was <4.5hr ago
Thrombectomy
Thrombolysis treatment of choice
anteplase
Laterality of stroke
left side- dominant side for most people- spoken lang, reasoning, written lang
Right side- creativity, music, spatial awareness
left sided strokes- tend to have a bigger impact
things that mimic stroke
seizure, sepsis, SOL, pre syncope, acute confusion, vestibular dysfunction, dementia
Rosier score
new onset Asymmetric facial weakness asymmetric arm weakness asymmetric leg weakness speech disturbance visual field defect
TIA
focal neurological symptoms that occur and leave within 24hr
Not benign- many people have evidence of brain damage on MRI
treatment of TIA
aspirin 300mg for 2 weeks then clopidogrel 75mg
ABCD2 score
age >60- 2 pts BP >140/90 1 point Clinical features- unilateral weakness 2pts speech disturbance without weakness 1pt Duration of symptoms >1hr 2pts 10-59mins 1 pt Diabetes 1pt
what does a score of >4 mean
High risk of an early stroke- must be assessed by specialist within 24hr
what does a score of >6 mean
strongly predicts a stroke within 2 days
