Stroke Flashcards
meningeal signs: rapid onset of headache with nuchal rigidity, headache and photophobia
subarachnoid haemorrhage or meningitis
initial evaluation
primary survey
identify risk factors for stroke, including presence of carotid bruits
determine time of onset and last known normal
investigations
serum glucose, vitals
ECG
FBC, INR, APTT, UECs, trops
?urine drug screen and BAL
lab studies should not delay imaging for patients with acute stroke
imaging
Non-contrast head CT to rule out haemorrhage before administering thrombolytic therapy
diffusion-weighted MRI
or CTA
if imaging is negative but suspicion for sub arachnoid haemorrhage remains high
Lumbar puncture - CSF may show xanthochromia
the presence of bilirubin in the CSF secondary to the breakdown of RBCs resulting in yellow discolouration
may be falsely negative in the first 12 hours of symptoms onset as xanthochromia is a late sign
findings of ischaemic stroke on non contrast CT
hyperdense MCA sign (suggesting presence of a thrombus)
effaceemnt of sulci
loss of cortico-medulllary differentiation
oedema
findings on CT for intracranial haemorrhage
hyperdense lesion within cerebral parenchyma
findings on non contrast head CT for subarachnoid haemorrhage
extensive area of hyperdense signals around the circle of willis
treatment options for ishcaemic stroke
- tPA (tissue plasminogen activator) if within 4.5 hours on onset of symptoms
- endovascular thrombectomy within 6 hours
- aspirin within 48 hours
tissue plasminogen activator
a serine protease found on endothelial cells of blood vessels
catalyses the conversion of plasminogen to plasmin, which is the main enzyme responsible for clot breakdown
recombinant tissue plasminogen activators (eg. alteplase, reteplase, tenecteplase) are used as thrombolytics in patients with acute coronary syndrome, pulmonary embolism, or ischaemic stroke
intravenous thrombolysis process
IV alteplase
if within 4.5 hours of onset of symptoms and as soon as possible
lower BP to below 185/110
endovascular thrombectomy
when the stroke is due to the occlusion of a large vessel
within 6 hours of symptom onset
what kinds of patients usually get endovascular thrombectomy
eligible patients are usually a subset of those for whom alteplase is indicated, and they can have both surgery and alteplase
endovascular thrombectomy may also be appropriate for those for whom alteplase is contraindicated (eg. patients taking anticoagulants) or those presenting too late for alteplase (between 4.5 hours and 6 hours)
endovascular thrombectomy may also be used for some patients who present up to 24 hours if there is occluded large vessel and salvageable brain tissue
general measures in acute ischemic stroke
assess swallow ability before giving oral drugs, if the patient has difficulty swallowing then make them nil by mouth and refer to speech pathology
avoid blood pressure lowering drugs except for patients with malignant hypertension or to lower blood pressure for alteplase
give supplimental oxygen if hypoxic
VTE prophylaxis
treatment for intracerebral haemorrhage
reversal of coagulopathy eg. cease anticoagulant
urgently lower BP to reduce hematoma expansion to <140
surgical intervention to evacuate the hematoma may be considered
symptoms of subarachnoid haemorrhage
75% present with acute severe headache, the rest present with LOC
mortality is high
many patients die before reaching the hospital
sentinel bleed
minor subarachnoid bleed occurring before the main rupture
sudden headache several weeks before the acute event
treatment of subarachnoid haemorrhage
patients are managed with a neurosurgeon
most subarachnoid haemorrhages are due to ruptured intracranial aneurysm
inconclusive non contrast CT with thunderclap headache
lumber puncture for sub arachnoid haemorrhage
if a non contrast CT shows no haemorrhage
ischaemic stroke
is the patient elligible for tPA
is it <4.5 hours from symptom onset -> IV tPA
then consider antiplatelet therapy and supportive management
and initiate secondary prevention
if non contrast CT shows haemorrhage
intracranial haemorrhage
neurovascular imaging: CTA, carotid duplex sonography
consider neurosurgery
treat hypertension
stop anticoagulation
supportive management
MCA stroke
contralateral weakness and sensory loss more marked in upper limbs and lower half of face than lower limbs
gaze deviated toward the side of infarction (ipsilateral)
aphasia if in dominant hemisphere
contralateral homonymous hemianopia without macular sparing
hemineglect if in nondominat hemisphere
broca aphasia
language comprehension intact
non-fluent, grammatically incorrect speech
supplied by superior division of the MCA
wernicke aphasia
affected patients speak fluently but produce nonsensical phrases
supplied by inferior division of the MCA
damage to optic radiations in MCA stroke
contralateral homonymous hemianopia without macular sparing
(or contralateral superior or inferior quatrantanopsia)
Anterior cerebral artery stroke
contraletral weakness and sensory loss in the lower limbs more marked than in upper limbs
abulia (disinterest/slowed mental state)
urinary incontinence
dysarthria
transcortical motor aphasia
frontal release signs
limb apraxia
abulia
a milder from of akinetic mutism that is characterised by disinterest and slowed mental state
when asked to perform centrain motor or verbal tasks, patients display a delay in the motor and/or verbal response, or fail to continue the assigned task after intiially complying
usually results from damage to frontal lobe or its connections
posterior cerebral artery stroke
contralateral homonymous hemianopia with macular sparing due to occipital lobe involvement
contralateral sensory loss due to lateral thalamic involvement - light touch, pinprick, and positional sense may be reduced
memory deficits
vertigo, nausea
PCA territory stroke in the dominant hemisphere
(usually left hemisphere)
alexia without agraphia (can’t read)
anomic aphasia (word finding for nouns and verbs)
agnosia: impairment of recognition of sensory stimulus (most commonly visual)
PCA territory stroke in the non dominant hemisphere
usually right hemisphere
prosopagnosia
features of thalamic injury
because the thalamus contains various nuclei with distinct functions, symptoms depend on the exact location of the lesion
decreased arousal
variable sensory loss
aphasia
visual feild losses
apathy, agitation, personality changes
prosopagnosia
inability to recognise familiar faces, but still able to name parts of the face or identify known individuals by clothes or voices
stroke mimics
tumour
subdural hematoma
migraine
hypoglycaemia
postictal paralysis
cerebral abscess
an episode is considered to be a TIA if
symptoms resolve completely in 24 hours and there is no brain infarction
intravenous thrombolysis
intravenous alteplase (recombinant tissue plasminogen factor) is effective when given within 4.5 hours of onset of symptoms of ischaemic stroke
earlier treatment has better outcomes
immediate treatment options for acute ischaemia stroke
Iv thrombolysis (alteplase)
endovascular thrombectomy
antiplatelet therapy
neurosurgery
endovascular thrombectomy
when stroke is due to occlusion of a large vessel, endovascular thrombectomy is highly effective when performed within 6 hours of symptom onset
physical retrieval or apsiration of the occluding thrombus via th femroal artery using a stent retriever and/or aspiration catheter
when is endovascular thrombectomy used
used in some patients in combination with alteplase
when alteplase is contraindicated (eg. the patient is taking an anticoagulant) or when patients present too late for alteplase
who is eligible for endovascular thrombectomy
within 24 hours of symptom onset
has an occluded large vessel and salvageable brain tissue, as detected by CT or MRI perfusion
antiplatelet therapy for acute ischaemic stroke
aspirin has modest benefit when given within 48 hours of acute ischaemic stroke and is routinely used
do not give aspirin util brain imaging has excluded intracranial haemorrhage
if the patient has recieved alteplase, withhold aspirin for 24 hours and do not start unntil follow up imaging has excluded haemorhage
main adverse effects of alteplase
bleeding, including symptomatic intracranial haemorrhage
do not give aspirin until
imaging excludes intracranial haemorhage
neurosurgery for acute ischameic stroke
due to the effects of cerebral oedema, extensive hemispheric infarct s fatal in over 80%
in a few highly selected patients, hemicraniotomy saves lives and reduces disability
dysphagia management during acute ischaemic stroke
assess patient’s aability to swallow before giving oral ddrugs
maintain as nil by mouth and refer to speech pathology
dysphagia often improves rapidly
blood pressure during acute ischaemic stroke
do not lower blood prssure uring first 48 hours of stroke unless the patient has malignant hypertension, hypertensive encephalopathy, or patients neeing bloow pressure lowering to recieve alteplase
oxygen and fever
give oxygen if the patient is hypoxic, lower fever with panadol
hyperglycaemia
hyperglycaemia is associated with a worse outcomes after stroke, so avoid IV fluids contaning glucose
20% of patients with acute stroke have unrecognised diabetes
monitor blood glucose and maintain euglycaemia
mobilisation
early mobilisation, adequate hydration and antiplatelet therapy can help prevent DVT
if a patient is immobilised, give enoxeparin
how to decide whether to give tPa
no evidence of stroke mimic or intracranial haemorrhage
acute symptoms
consult neurology first
unclear symptoms onset >4.5 hours from last known baselines state: MRI findings will determine whether thrombolysis is indicated
absolute contraindications for tPa
recent ischaemic stroke or severe head trauma (<3 months ago)
revent intracranial or intraspinal surgery
history of intracranial heamorrhage
GI malignancy or recent GI bleed
acute haemorrhage
acute bleeding diathesis
severe uncontrolled hypertension >185/110
