Acute Ischaemic Stroke Flashcards
What are the 5 aspect of acute stroke management to improve outcome?
- Stroke care in specialised units
- Platelet inhibitors within 48hrs
- IV thrombolysis within 4.5 hrs
- Endovascular therapy within 6hrs
- Decompressive craniectomy ASAP within 48hrs
Main goals of acute management of AIS?
- Early recognition & resuscitation
- Early treatment - Thrombolysis or endovascular therapy
- Optimisation - Oxygenation, BP, Temp & glucose
- ICU admission if required
What’s the first line assessment and treatment of AIS?
- ETT & oxygenation
- Haemodynamic optimisation
- Basic monitoring including BMs
- Clinical history
- Physical examination
- Symptomatic treatment (N/V, pain & agitation)
- Assessing contraindications to treatment
- Diagnostics & interventions
Diagnostic tools for rapid recognition of AIS?
- FAST assessment
- ROSIER test
What is ROSIER test?
Recognition of stroke in the emergency room
Neurological assessment tool for AIS?
NIHSS (National institute of health stroke scale)
What are the components of NIHSS?
- GCS
- Cranial nerves assessment
- Higher cortical dysfunction (aphasia, neglect)
- Limb power
- Limb ataxia
- Sensory examination
NIHSS clinical assessment? Demonstrated ?
Watch video
What assessments can be used to localise stroke in the presence of low GCS?
- Pupils
- Brainstem reflexes
- Spontaneous activity
- Response to stimuli
Non-contrast CT brain in diagnosis of AIS?
It can differentiate between ischaemia & haemorrhage
What other diagnostic imaging can be used for diagnosis of AIS?
- CTA
- CT perfusion scan
- MRI
- MRA (Angio)
Sequence of imaging for diagnosis of AIS?
- Non-contrast CT head
- CT angio - Localise vessel
What is the important of multiphase CT angio?
- It can be used to assess collateral supply.
- Patients with collateral supply do better with endovascular therapy than thrombolysis
What are the target times for evaluation of a stroke patient in ED?
- Door to physician <10 mins
- Door to stroke team <15 mins
- Door to CT <25 mins
- Door to CT report <45 mins
- Door to drug <60 mins
- Door to unit admission < 3 hrs
Immediate management of AIS?
- Oxygen PO2 > 10 or Sats > 94%
- BP management
- Blood glucose (4-10)
- Temperature (< 37.5 degrees)
What is the target BP after thrombolysis in AIS?
< 185/110 mmHg for 24 hrs after thrombolysis
> 220/120 mmHg in fit patients and not having thrombolysis
Pharmacological management of HTN is AIS?
- Labetalol
- Urapidil
- Clevedipine
- Nicardipine
First line management for hypotension in AIS?
- IV fluids
- Noradrenaline
- Metataminol
Diagnosis of ischaemic stroke with non-contrast CT heads?
It is usually negative in the acute phase
What are the differential diagnosis of acute ischaemic stroke?
Intracranial haemorrhage
What are the clinical findings favouring ICH?
- Onset during HTN crisis
- Symptom progression within minutes
- Vomiting
- Immediate loss of consciousness
- Acute onset headache
Stroke mimics?
- Hypoglycaemia
- Space occupying lesion
- Seizures ; Todd’s paresis
- Migraine
- Encephalitis & metabolic
- Sepsis
- Drug toxicity
- Functional disorder
Characteristics of microangiopathies or lacunar infarcts?
- Preceding TIA’s (15-20%)
- Insidious on and slow progression
- Lacunar infarcts are small ( symptomatic in cerebral peduncles & brainstem)
- They may present as pure motor, pure sensory, sensory-motor, ataxic hemiparesis or dysarthria-clumsy-hand syndrome
Cardiac conditions predisposing patients to stroke?
- Valvular dysfunction
- AF
- LA or LV thrombus
- Dilated cardiomyopathy
- Recent MI < 4 wks
- LV aneurysm
- Sick sinus syndrome
- Infective myocarditis
- Atrial myxoma
Characteristics of embolic strikes?
- Sudden onset (Maximal effect at onset)
- Onset during activity or I’m awake state
- Recurrent TIA’s
Pathophysiology of large vessel disease ?
- Post-stenosic perfusion deficit
- Artherothrombotic occlusion
- Arterio-arterial embolism
What’s is amaurosis fugax?
Internal carotid artery stenosis.
Characteristic of large artery infarcts or embolism or thrombosis?
- Atherogenic risk factors
- Frequent TIA’s (amaurosis fagux) in the same arterial territory
- Onset during sleep or activity
- Gradual progression mins to hours
- Gradual onset due to thrombus accumulation or low BP
Characteristics of basilar artery stroke?
- 1% of all strokes
- Results in thalamic or brainstem infarcts
- Sudden & severe neurological impairments
Characteristics of proximal occlusion of basilar artery?
- Quadriparesis
- Preserved consciousness
Characteristics of distal occlusion of the basilar artery?
- Visual deficit
- Oculomotor deficit
- Behaviour disturbances
- Hallucinations
- Sudden death
- Low GCS
Management of acute basilar occlusion??
Amenable to immediate neurosurgical intervention - Endovascular procedure
Pathophysiology of acute vessel occlusion? 3 main mechanisms
- Systemic embolism
- Large artery thrombosis
- Large artery embolism
Characteristics of MCA infarcts?
- Contralateral motor weakness
- Contralateral sensory deficit
- Face & arm more than legs
- Aphasia - Broca, wernicke or global
- Apraxia
- Dysarthria
- Ipsilateral eye deviation
- Homonymous visual defect
- Neglect
Characteristics of ACA infarcts?
- Contralateral hemiparesis - Lower limbs
- Contralateral sensory deficit - Lower limbs
- Urinary incontinence
- Apraxia
- Anosmia
- B/L; Apathy, motor inertia & muteness
Components of the posterior cerebral circulation?
- Vertebral
- Basilar
- Posterior cerebral artery
Characteristics of posterior cerebral circulation infarcts?
- Ipsilateral cranial nerve palsy + Contralateral motor /sensory deficit
- Bilateral motor & sensory deficit
- Disorder of conjugate eye movement - Vertical (midbrain) & horizontal (pons)
- Cerebellar dysfunction without ipsilateral long tract deficit
- Altered consciousness
- Dysarthrophonia / Dysphagia
- Horner syndrome
- Contralateral homonymous hemianopsia
- Bilateral lesions: Cortical blindness (Anton’s syndrome)
- Behavioral disturbances
Risk factors for cervical dissection?
- Trauma
- Previous infection
- Connective tissue disease
What are the signs and symptoms of ICA dissection?
- Focal neurology
- Unilateral headache
- Neck pain
- Pulsatile tinnitus
- Ipsilateral Horner’s syndrome
Image modality with the highest sensitivity and specificity for detecting Ischemic stroke?
MRI
Components on the Alberta Stroke Program Early CT score (ASPECT)?
Caudate
Putamen
Internal capsule
Insular cortex
M1: anterior MCA cortex
M2: MCA cortex lateral to insular ribbon
M3: Posterior MCA cortex
M4: Anterior MCA territory immediately superior to M1
M5: Lateral MCA territory immediately superior to M2
M6: Posterior MCA territory immediately superior to M3
Significance of the ASPECT score?
- Any score < 7 has the poorest prognosis at 3 months
- Increased risk of thrombolysis related ICH
What are the tests in stroke patient management ?
- Electrolytes
- Glucose
- FBC
- Urea & Creatinine
- CK, CKMB, Trop I
- Transaminases
- Coagulation / Protein C, S & AT III
- ESR
- Cholesterol & Triglycerides
Decision making in management of stroke?
Reperfusion options in AIS?
- Intravenous thrombolysis
- Intra-arterial thrombolysis
- Mechanical clot removal
- Angioplasty/Stenting
Reasons why reperfusion therapy might be necessary even after 5-10 mins of supposed cessation of blood flow?
- Good collateral supplies
- Only for a limited time
What is Penumbra?
This is an area of ischaemic territory which can be saved.
What is the infarct core?
This is an ischaemic area with none or little collateral supply - Irreversible damage
Thrombolysis
Recommendation - rt-PA use within 4.5 hrs after exclusion of a haemorrhage stroke on imaging
Considerations prior to thrombolysis ?
- NIHSSS - Nat. Institute of Health Stroke Scale Score
- Blood pressure
- Premorbid use of anticoag or antiplatelet
- Seizure activity
- History of; Stroke, ICH, tumor & vascular malformation
rt-PA? What type of drug
Alterplase - 90mg over 60 mins with 10mg given as a bolus over 1 min.
Endovascular treatment efficiency?
- ACA - Benefit from endovascular + Thrombolysis
- Proximal middle cerebral or distal ICA (Between 6-24hrs)
Blood pressure targets for thrombolysis ?
- < 185/110 (For thrombolysis)
- < 220/120 (Not for thrombolysis)
Anti-hypertensive agents used ?
- Nicardipine
- Labetalol
- Urapidil
- Clevedipine
Hyperglycaemia
- Related to stroke severity
- Related to large infarct volumes
- Signifies susceptibility to infection
- Associated with increased M&M @ 90days
- Increased risk of ICH following thrombolysis
- Target levels 8-10
Temperature control?
- Independent determinant of outcome
- Occurs in the abscess of infection
- Treat temperatures > 37.5 degrees
Management of high temperatures?
- First-line : Paracetamol
- Metamizole
- Infusion of cold saline at 4 degrees
- Automatic cooling systems
Anti-coagulation in stroke ?
- ## Contraindicated after use of rt-PA
Meaning of rt-PA?
- Recombinant tissue plasminogen activator
- Example - Alteplase, Reteplase & Tenecteplase
Anti-platelet therapy in stroke?
- High-dose aspirin within 48hrs
- Shouldn’t be used within 24 hrs of thrombolysis
Thrombophylaxis post-stroke?
- LMWH
- Delayed until > 24 hrs after thrombolysis
- IVC filter if full VTE is contraindicated
Hemorrhagic transformation of stroke?
- ## Occurs in 5-6% of patients (Thrombolysis & Anti-coagulation induced)
Management of haemorrhagic transformation?
- Stop all anti-coagulation
- FFP, Cryoprecipitate , Recombinant FVII
- Repeat CTH
Normal intracranial pressures?
- < 20mmHg
Transcranial doppler capabilities for detection of pathologies?
- Acute thrombose or stenosis - All vessels
- Assessment of response to thrombolysis
- Prognostication tool - Extent of occlusion
- Assess cerebral vasoreactivity - Diamox Tx
- Detection of micro-embolism
What is the Diamox test?
Used to assess cerebrovascular reactivity. Diamox (Acetazolamide) - Carbonic Anhydrase Inhibitor. It penetrates the BBB and causes vasodilation. The dose of 1000mg iV - Peak CBF is achieved in 10-15 mins. About 30-60% increase in CBF is achieved . An abnormal response will be < 10% increase in CBF
Disadvantages of transcranial doppler?
- User dependent
- Failed if acoustic window is poor
Main complications associated with stroke?
- ICH
- Cerebral oedema
Complications resulting from ICH & cerebral oedema ?
- Reperfusion injury
- Intracranial HTN
Cerebral oedema in stroke?
- Develops in the first 24-48hrs
Intracranial HTN?
- Risk greater in young patients
Reason for compensation of intracranial HTN in elderly?
- Larger ventricles
- Essential atrophy - Subarachnoid space
Cerebellar infarcts?
They will have more effects than supratentorial infarcts of the same size . Posterior fossa allows for minimal compensation
Consequences of cerebellar swelling?
- Brainstem compression
- Impaired CSF circulation
- Hydrocephalus
Steroids and cerebral oedema associated with AIS
No role in its management
Management of intracranial HTN?
See image attached
Side-effect of repeated use of osmotic agents in cerebral oedema ?
- Increase in cerebral oedema
- Herniation due to dehydration
- Electrolyte imbalance
- Raised serum osmolality
- Hypervolaemia & cardiac failure
- Renal dysfunction
Pharmacological management of seizure following AIS?
- Phenytoin
- Levetiracetam
- Lacosamide
- Valproate
Consequences of untreated seizures?
- Secondary brain damage
- Increased metabolic demand
- Worsening of ischaemic oedema
- Worsening of patient outcome
Secondary prevention of ischaemic stroke?
- Aspirin
- Clopidogrel
- Ticagrelor
Advantages of early rehabilitation in stroke patients?
- Prevention of contracture and joint pain
- Decreased risk of decubitus ulcers
- Decreased risk of pneumonia
- Decreased risk of DVT
