stroke Flashcards
define stroke
cerebrovascular event caused by abnormal perfusion of cerebral tissue
- Clinical syndrome characterised by sudden onset of developing focal or neuro disturbance that lasts more than 24hr or leads to death
what is an ischaemic stroke?
occlusion of blood vessels –
which type of stroke is most common?
ischaemic - 85%
haemorrhagic - 15%
what is infarction?
- Infarction: tissue death due to ischaemia
what types of haemorrhagic strokes are there?
- Intracerebral haemorrhage or subarachnoid haemorrhage
what is the pathophysiology causing an ischaemic stroke?
thrombus formation
emboli
thrombosis
dissection
all resulting in occlusion to cerebral vessels
how can a thrombosis lead to ischaemic stroke?
- Result of thrombus (atheromatous plaque) within vessel, embolus (blood clot) arising from distant site or even dissection
- Thrombosis: blockage of vessel due to atherosclerosis (CVS RF or small vessel disease – vasculitis, sickle cell disease)
how can an emboli lead to a stroke?
- Emboli: propagation of blood clot leading to acute obstruction and ischaemia – AF or carotid artery disease
how can a dissection lead to an ischaemic stroke?
- Dissection: rare cause of cerebral ischaemia from tearing intimal layer of artery leads to intramural haematoma that comprises cerebral blood flow. May be secondary to trauma
what is the most common cause of a haemorrhagic stroke?
hypertension
what are non traumatic causes of a haemorrhagic stroke?
- Other causes of non-traumatic intracerebral haemorrhage include vascular malformations eg AV malformation, AV fistula, brain tumour, vasculitis, bleeding disorder
what RF are there for a stroke?
- Smoking
- DM
- Hypertension
- Hypercholesterolemia
- Obesity ‘
- AF
- Cartodi artery disease
- Thrombophilia disorders eg antiphopspholipid syndrome
- Sickle cell disease
what symptoms are seen in a haemorrhagic stroke?
more likely to have global features such as headache and altered mental status
- Headache
- Altered mental status
- N+V
- Hypertension
- Seizures
- Focal neuro deficits – dependent on location of bleeding
what signs/ symptoms are seen with a anterior ischaemic stroke?
Unilateral weakness/ sensory deficits eg face/ arms/ legs
- Homonymous hemianopia: visual field loss on same side
- Higher cerebral dysfunction: dysphasia, visuospatial dysfunction eg neglect , agnosia
what is agnosia?
Agnosia: rare disorder where a patient can not recognise and identify objects, persons or sounds using one or more senses despite otherwise normally functioning senses
what features are seen within a posterior ischaemic stroke?
Posterior ischaemic stroke: affects balance, vision, cranial nerves
- Dizziness
- Diplopia
- Dysarthria and dysphagia
- Ataxia
- Visual field defects
- Brainstem syndromes
what assessments are required for a suspected stroke?
- FAST test
- Assessed using NIHSS score with urgent cross sectional imaging eg CT head with/without CT head angiography
what NIHSS score is linked to good outcomes?
<4
what NIHSS score is linked to ischaemic stroke?
22-26
what score is linked to haemorrhagic stroke and therefore contra-indicated thrombolysis?
> 26
what is the FAST test?
new facial weakness, new arm weakness and new speech difficulty
what is the acute management of a stroke?
- ABCDE
- NIHSS assessment
- capillary blood glucose measurement ‘
4> imaging - determine ischaemic or haemorrhagic stroke
why would you do a capillary blood glucose?
remove hypoglycaemia/ hyper as differential
similar symptoms
what imaging can be done to differentiate between ischaemic or haemorrhagic?
CT angiogram
MRI FAST - assess if still perfusion and if they can have thrombolysis
what is the window for thrombolysis within an ischaemic stroke?
<4.5hrs
what is thrombolysis?
IV infusion of altepase - clot busting drug
why is thrombolysis contra-indicated within haemorrhagic?
would make them bleed more - stops all clotting
would turn into catastrophic event
if someone missed thrombolysis window, what other options are available?
mechanical thrombectomy
medicinal
what is mechanical thrombectomy?
endovascular removal of clot from large cerebral vessel
when in mechanical thrombectomy indicated?
NIHSS score of >5
presenting <6hrs
if a patient can not have thrombolysis or surgery, what options can they have for an ischaemic stroke?
- aspirin 200mg for 2 weeks and then clopidrogrel for life time (75mg)
- life long anticoags eg apixaban
what is the management for haemorrhagic stroke?
Anticoag reversal discuss with haemtology
Blood pressure Lowering aim for <140 systolic if <6hrs
Referral to neurosurgery eg Burr Holes procedure
what lifelong management is required post stroke?
blood pressure control
blood glucose control
anti-lipid therapy
anticoags
antiplatelets
lifestyle advice
why would anticoags be needed post stroke?
incase a clot cause
common in those with AF
what anti-lipid therpay is needed, when do you start it post stroke?
start statin 48hrs post stroke
what lifestyle management is needed post stroke?
improve diet
more exercise
stop smoking
reduce alcohol
what is the DVLA advice following a stroke?
do not drive initially
if symptoms resolve 1mth post - do not need to inform
inform if haemorrhagic stroke occurred
inform if drive larger than car
what are early complications of a stroke?
- Haemorrhagic transformation of ischaemic stroke
- Cerebral oedema
- Seizures
- Infection eg aspiration pneumonia from dysphagia
- Venous thromboembolism
- Death
what are late complications of a stroke?
- Mobility and sensory issues
- Bladder and bowel dysfunction
- Pain
- Fatigue
- Cognitive problems
- Visual problems
- Emotional and psychological issues
- Issues with swallowing, hydration and nutrition
what are toxic/ metabolite stroke mimics differentials?
hypoglycaemia, drug and alcohol consumption
what are neurological differentials of a stroke?
- Neurological: seizure, migraine, Bell’s Palsy
what infection differentials are there of a stroke?
- Infection: meningitis/ encephalitis, systemic infection with decompensation of old stroke
how would differentiate between seizure and stroke?
Seizure: often cause loss of consciousness
- EMG would reveal the surge in electrical activity
how would you differentiate between migraine and stroke?
Migraine: be sitting in dark room and no stimulation would improve symptoms would not in stoke
- Migraine – positive sensation tingly, prickly, seeing spots
- Stroke: absence of sensation feeling numb or weak, having vision loss
how would you differentiate between bell’s palsy and stroke?
Bell’s Palsy: watering from eye on affected side, changes in ability to taste, sound sensitivity and ringing in ear
- Stroke: trouble finding words, eyes gazing in one direction, trouble walking and vision changes
- Bells: can not move eyebrows and lower portion of face but limbs are not affected
how would you differentiate between stroke and meningitis?
Meningitis: systemically unwell – fever, photophobia and neck stiffness
how would you differentiate between stroke and encephalitis?
Encephalitis: altered consciousness, seizures and focal deficits
how would you differentiate between syncope and stroke?
Syncope: transient loss of consciousness with spontaneous and unaided come around and no further issues following
what would indicate psychogenic/ functional/ conversion therapy?
- Excessive hesitation in locomotion
- Increasing swayings in rombergs test
- Uneconomic postures wasting muscle energy
- Small cautions steps like walking on ice
- Sudden buckling of the knees emotional distress
- Seen in young women most frequently
what is rombergs test?
positive test is inability to maintain an erect posture over 60seconds with eyes closed
which patients is venous sinus thrombosis most common in?
often in obese young women in hypercoagable states
- Pregnant or taking OCP
which type of CT should be used to assess query stroke?
non contrast
if it is haemorrhagic - will cause them to bleed out
what does dysdiadochokinesia indicate?
parkinsons - can not do fast repetitive movements
what is the most common cause of haemorrhagic stroke?
hypertension
if a CT comes back unremarkable following query stroke, what would it indicate?
ischaemic stroke- would not see for a couple weeks after
needs altepase
how long does a TIA last?
less than 24hrs
what is a TIA?
transient ischaemic attack - temporary neuro dysfunction
what is a cresendo TIA?
2+ TIAs in a week - higher risk of stroke
what symptoms would indicate a posterior ischaemic stroke?
ataxia and vertigo
what would be seen in total anterior circulation stroke?
3/3
- unilateral weakness
- homonymous hemianopia
- higher cerebral dysfunction
what would be seen on a partial anterior stroke?
2/3
- unilateral weakness - face, arm, leg
- homonymous hemianopia
- higher cerebral dsyfunction
what is seen within a lacunar syndrome?
1/4
- pure sensory stroke
- pure motor stroke
- sensori- motor
- ataxic hemiparesis
what is seen within a posterior circulation?
1/5
- cranial nerve palsy +/- contralateral motor or sensory
- bilateral motor+/- sensory
- conjugate eye movement
- cerebellar dysfunction
- isolated homonymous hemianopia
what
would an anterior cerebral artery stroke present as?
opposite side weakness (hemiparesis)
sensory loss - mainly lower extremities
how would a middle cerebral artery stroke present as?
opposite side weakness
sensory loss - mainly upper extremities
contralateral homonymous hemianopia
how would a posterior cerebral artery stroke appear as?
contralteral homonymous hemianopia with macular sparing
visual agnosia
what is visual agnosia?
inability to recognise and name known objects
where does ‘weber syndrome’ affect within a stroke in the brain?
branches of posterior supplying midbrain
how does a webber - branches of posterior supplying midbrain stroke present?
ipsilater CNIII palsy
contralateral weakness of upper and lower extemity
how does a posterior inferior cerebellar stroke present?
ipsilateral facial pain and temp loss
contralateral limb/ torso pain and temp loss
ataxia, nystagmus
how does an anterior inferior cerebellar stroke present?
ipsilateral facial pain and temp loss
contralateral limb/ torso pain and temp loss
ataxia, nystagmus
ipsilateral facial paralysis and deafness
how does a basilar artery stroke present?
locked in syndrome
what is a lacunar stroke?
small occlusion in a large artery
how does a lacunar stroke present?
isolated hemiparesis
hemisensory loss
linked to HTN
