Central nervous system head - part 2 Stroke Flashcards
What are the causes of stroke
A) Infarction 75% - unknown 50% - lacunar 25% - embolic 20% - artherosclerosis 5% B) Hemorrhagic 25% - intracerebral 50% - subarrachnoid 50%
How to rule out stroke mimic from real stroke
Stroke screening tool
ROSIER Tool
Rule Out Stroke In the Emergency Room
Rosier scale to differentiate stroke and "stroke mimics" 1) Has there been loss of consciousness or syncope yes -1 , no 0 2) Has there been seizure activity yes -1, no 0 Is there a new onset (or waking from sleep)? - relate to onset i) Asymmetric facial weakness Y (+1) N (0) ii) Asymmetric arm weakness Y (+1) N (0) iii) Asymmetric leg weakness Y (+1) N (0) iv) Speech disturbance Y (+1) N (0) v) Visual field defect Y (+1) N (0)
Stroke is likely if total score > 0
Scores of < / = 0 have low probability of stroke but not excluded
Most common Stroke mimics
- Seizures 21% - common in elderly with previous stroke
- Sepsis 13%
- Toxic/ metabolics - 11% likehypoglycemia, drugs, hypoxia, hyponatremia
- Space ocupying lesion 9%
- Syncope and presyncope 9%
What are other stroke mimics
- migraine
- Subdural hematoma
- Herpes encephalitis
- Psychogenic
- Aortic disection
What are the feature of Middle cerebral artery syndrome
a) contralateral hemiplegia and hemisensory loss
b) homonymous hemianopia
c) eye deviate to side of the leson
d) face and arm weakness > legs
What are the feature of the Anterior cerebral artery syndrome
a) contralateral leg and foot weakness
b) behavioural disturbnce + confusion
c) abulia
d) grasp reflex
e) urinary incontinence
What are the feature of the posterior cerebral artery syndrome
a) eye - hemianopia or quadrantanopia or cortical blindness
b) Memory loss
c) dyslexia
d) Hemisensory loss
e) ipsilateral 3rd nerve palsy
What are the feature of vertebrobasilar infarction
a) ataxia and dizziness
b) nystagmus, nausea and vomiting
c) variety of cranial palsy eg interneuclear opthalmoplegia
What is a lacunar infarct
- Small infarct in distribution of short penetrating aterioles of - basal ganglia, pons, cerebellum anterior limb of the internal capsule or deep cerebtral white matter
- account for 15% of all cerebral infarct
what is clincal syndrome of Lacunar infarct
- lesion in mid pons - clummsy hand / dysarthria
- lesion pons or internal capsule - Ataxia and leg paresis
- Thalamic - pure sensory - face, arn and leg
- pons / internal capsule - pure motor hemiplegia ( Arm more than legs)
What is theassociated factors, management and prognosis of Lacunar infarct
- associated with poorly controlled hypertension and diabetes
- rarely have prodromal TIA
- good prognosis and management is aimed at controlling BP and normalising sugar
- Partial or complete recovery over 4 to 6 weeks
What are the different type of Stroke Assessment scale
1) Stroke deficit scale - NIH or Canadian neuro scale
2) Mental status screening test - MMSE,
3) Language scales - Boston diagnostic aphasia, ASHA
4) Depression scales - Geriatric depression scale
5) ADL scales - Barthel index, FIM, PGC instrumental activities of daily living
What are the features of Cerebral infarction in CT
- Parenchymal hypodensity
- Loss of grey white differentiation
- effacement of cortical sulci
- local mass effect
- Obscuration of the lentiform nucleus
- Hyperdense middle or other cerebral artery
- 100% specificity, 50% sensitivity for MCA occlusion
What are CT features of poor outcome
- Cortical hypodensity in >1/3 of MCA teritory
- sulcal effacement
- mass effect
- cerebral oedema
Describe your initial resuscitation of a patient who present with a stroke to your ED with regard to airway and breathing
NB hypotension, hypertension, hyperglycemia, fever, hypoxia - are associated with poor outcome
A) Airway - 1) simple measure - positioning/ oral or nasal airways
- prepare to intubate if good outcome likely and simple measures above failing
2) NGT if poor gag reflex
B) Breathing - supplementary oxygen if the O2 sat < 95% ( aim 99 to 100%)
Describe your initial resuscitation of patient with stroke with regadr to circulation
C) Circulation - BP > 180 by 10mmhg - 40% neurological damage and poor outcome in 23%
- hypotension - fluid + pressor - target >100/>70mmhg
- hypertension - not thrombolyse treat if > 220/120mmhg
- hypertension for thrombolysis treat >180/110mmhg
What are your options for management of high BP in stroke patient
1)Labetolol - load 10mg IV
start infusion at 2mg /min - up to 8mg /min
2) alternative Nicardipine 20mg load
3) or nitroprusside infusion
With regard to NINDs trial for stroke thrombolysis - what are the weakness and criticism of this trial
1) Imbalance of stroke severity between the 2 groups
2) Selective enrolment to artificially increase number of patients treated early
3) Success found at 3 months can be due to no control over post thrombolytic therapy
4) No comparison of the medians of the NIH stroke score published
ECASS studies results
ECASS II - No satistical significant difference between tPA and placebo group at 30days and 90 days
- tPA had higher incident of ICH and Cerebral oedema
ECASS III - global outcome score showed benefit tPA over placebo ( a new combined score)
- High incidence of ICH with tPA
- overall mortality no satistically significant
( again criticism of selection bias)
What are the contraindications for Thrombolysis
- timing - unknown or > 4.5hrs
- BP - > 185/110mmhg
- spontaneous rapid improvement of symptoms
- minor or isolated neurological signs
- major neurological deficit
- High risk CT findings
- seizure
- platelet 15s
glucose < 2.7 >22.2mmol/L
Tests required prior to Thrombolysis
- Head CT
- FBC
- U&E, CR
- Clotting
- Glucose
- ECG
- CXR
What is tPA administration requirement
- must comence within 3 hrs of onset
- dose 0.9mg/kg ( max 90mg) - 10% bolus, 90% over 60min
- no anticoagulation or antiplatelet agents for 24 hrs
What are the aftercare for thrombolysis patient
- Require specialised stroke beds or HDU for increase care required
- BP monitor and control
- Every 15min 1st 2 hrs
- every 30 min next 6hrs
- every hour for next 16hrs
