Stroke Flashcards
What are the different mechanisms of stroke?
- Ischaemic - due to occlusion of blood vessels, 85% - thrombosis, emboli or dissection
- Haemorrhagic - from bleeding inside or around brain tissue, 15%, ICH or SAH
What are the RFs of stroke?
- HTN
- Smoking
- DM
- Hypercholesterolaemia
- Obesity
- Afib
- Carotid artery disease
- Age
- Thrombophilic disorders eg. antiphospholipid syndrome
- Sickle cell
Draw the circle of Willis
Find answers in anki flashcards
What is the blood supply of the brain divided into?
Ant circulation - blood vessels arising from the carotid arteries
Post circ - blood vessels arising from the vertebrobasilar arteries
What are the 3 main cerebral arteries?
- Ant cerebral artery
- Middle cerebral artery
- Post cerebral arter
What does the ant cerebral artery supply?
Midline structures of the front 2/3 of the brain
Part of the ant circ.
What does the middle cerebral artery supply?
Lateral structures of frontal, temporal and parietal lobes inc internal and basal ganglia, occipital pole
Part of the ant circ.
What does the post cerebral artery supply?
Occipital lobe and inf temporal lobe and thalamus.
Part of the post circ.
What is the Bamford/Oxford classification of stroke?
TACS - total ant circ stroke, ACA or MCA
PACS - partial ant circ stroke, ACA or MCA
LACS - lacunar stroke, deep perforating arteries
POCS - post circ stroke, vertebrobasilar arteries
What are the features of an ant cerebral artery stroke?
- Contralateral weakness and sensory problems in the lower limb - lower limb more medial in cortex
- Urinary incontinence if para central lobules affeccted
- Split brain/alien hand syndrome if corpus callosum affected
- Frontal lobe features eg. personality change, apraxia
What are the features of a proximal middle cerebral artery stroke?
- Contralat sensory problems in face and arm, upper body more lateral on cortex
- Contralat hemiparesis - int capsule affected
- Contralat hemianopia w/o macular sparing
- Aphasia if L sided occlusion
- Contralat hemispatiel neglect if R sided lesion
What are the features of a sup distal MCA stroke?
- Broca’s aphasia = expressive aphasia
- Contralat weakness to face and arm
What are the features of a inf distal MCA stroke?
- Contralat sensory probs in face and arm
- Wenicke’s aphasia = fluent aphasia
- Quandrantopia or homonomous hemianopia w/o macular sparing
What are the features of a PCA occlusion?
- Contralateral homonomous hemianopia w macular sparing (MCA = back up blood supply to macula)
- Contralat sensory probs due to damage to thalamus
What are the criteria of a TACS?
- Contralat hemiplegia or hemiparesis
- Contralat homonymous hemianopia
- Higher cerebral dysfunc eg. aphasia and neglect
What are the criteria of PACS?
Two of the TACS criteria or higher cerebral dysfunc alone
What are the criteria of LACS?
- Pure motor or pure sensory or sensorimotor signs
- Affects lenticulostriate arteries which supply int capsule and basal ganglia
- Face, arm and leg affected equally because of damage to int capsule not homonculus
What are the criteria of POCS?
One of:
- Cerebellar dysfunc
- Conjugate eye movement disorder
- Bilat motor/sensory deficit
- Ipsilateral CN palsy w contralat motor/sensory deficit
- Cortical blindness
What are the ix into suspected stroke?
- CT head immediately, MRI better but slow so not suitable in emergencies, sensitive for haemorrhage but in ischaemic imaging often normal after a few hours
- Obs, BM, ECG
- Bloods - FBC, U+E, LFT, ESR, coag, lipids, HbA1c
- Echo, carotid dopplers
What is the management of haemorrhagic stroke?
- Small bleed = no requirement for neurosurgical intervention
- Decompressive hemicraniectomy if pt meets criteria
What is the management of ischaemic stroke?
- Alteplase: w/i 4.5 hours sx onset, NIH score >26, no thrombolysis contraindications - need to exclude ICH
- Mechanical thrombectomy - w/i 6 hours of sx onset
- Need to go to hyper acute stroke unit to be monitored
- Together called stroke revascularisation therapy
What is ongoing management of a pt who has had a stroke?
- BP control
- BM control
- Weight loss and smoking cessation
- Statin started 48hrs after stroke - total cholesterol <4, LDL cholesterol <2, 80mg atorvastatin
- 2 weeks 300mg aspirin and then 75mg clopidogrel daily for ever
- Carotid doppler to assess - may need carotid endarterectomy, urgently if >50% stenosis, 70% if asymptomatic?
or 75% stenosis = stent? - Swallow and nutrition assessment
- Rehab at local stroke unit or palliative care
What are the early complications of stroke?
- Haemorrhagic transformation of ischaemic stroke
- Cerebral oedema
- Seizures
- Infection
- Cardiac arrhythmias
- Venous thromboembolism
- Death
What are the late complications of stroke?
- Mobility and sensory issues
- Bladder and bowel dysfunction
- Pain
- Fatigue
- Cognitive and visual problems
- Emotional and psychological issues
- Probs w swallowing = probs w hydration and nutrition
How do you differentiate strokes from the stroke mimics?
- Can differentiate on CT - SOL, MS, subdural haematoma
- Can differentiate w clinical dx - BPPV, vestibular neuronitis, transient global amnesia
- Subtle differences that need additional ix and specialist assessment - complicated migraine w aura, focal seizures, FND
- Apparent neurological deficit
- BEHIND
- Encephalopathy
What makes up the stroke service?
- Acute stroke unit
- TIA and outpt clinics
- Stroke rehab services
- Early supported discharge schemes
What are some different stroke assessment tools?
- NIHSS - assesses stroke severity, estimating prognosis, recovery and suitablity for diff therapies
- ASPECTS - CT scan score for MCA stroke
- OCSP - POCS, TACS etc
- Modified Rankin scale - assess baseline, evaluate outcomes and treatment impact
- Rosier scale - stroke vs stroke mimics
- CHADVASC in AF
- Barthel - funcitonal capacity
What does BEHIND stand for?
Differentials for stroke mimics:
Brain - mass, haemorrhage, contusion
Epilepsy
Hyponatraemia, Hypoglycaemia
Intoxication and infection
Neuro - migraine, MS
Dissection, disc prolapse
How do you assess the prognosis of a pt w stroke?
- 20-30% of pt die w/i. amonth
- 5 year risk of recurrent stroke is 30-40%
- Good factors - absence of coma, early motor recovery, continence
- Poor factors - severe communication defecit, old age, incontinence esp faecal incontinence, no leg movement at 2 weeks, severe upper limb weakness at 4 weeks
What are the criteria for rehab transfer?
- Medically stable
- On <24% O2
- NG feeding w no risk of refeeding syndrome
- Stroke consultant review twice a week
- Not awaiting echo
What is the difference between ischaemia and infarction?
Ischaemia = not enough blood flow = cerebral hypoxia, this can then lead to death of brain tissue which is cerebral infarction
Ischaemia = reversible
Infarction = irreversible
TIA vs stroke
TIA - brief episode of neuro dysfunc due to focal brain ischaemia, sx typically last less than 1 hour, no evidence of infarction
Stroke - neuro dysfunc due to cerebral ischaemia, >24 hours
What are some of the thrombolysis contraindications?
- Haemorrhagic stroke
- ICH/recent head injury - need to exclude haemorrhage before give thrombolysis
- Cerebral malignancy - primary or mets
- Aortic dissection
- Recent surgery
- Ischaemic stroke < 3 months
- On DOAC or high dose LMWH
- Abnormal APTT or INR
- Acute pancreatitis
- Child birth w/i 4 weeks
What imaging is used in suspected stroke?
- Non contrast CT head - effacement, loss of grey/white matter distinction, increased density of blood vessel = signs of early cerebral ischaemia, increased attenuation = ICH
- MRI head - good for looking at acute infarction
- and can try CT angiogram and CT perfusion studies and CT venogram
What in the hx indicates a stroke is more likely to be haemorrhagic than ischaemic?
- Underlying cause - HTN, aneurysm, vasculitis, cocaine, warfarin, aspirin, tumour
- Reduced level of consciousness at admission
- Hx of headache - transient or thunderclap
- Seizures
- Features of raised ICP
- N+V
What are some features of typical stroke syndrome?
- Sudden onset
- Focal
- Negative sx eg. weakness, visual loss, numbness
- Vascular territory hypoperfusion can explain all sx
- Sx don’t migrate over time
- Episodes don’t stereotype - no identical recurrent episodes, if so unlikely to be stroke
What is the management of ICH?
IX - CT MRI head
- Small bleed = no need for neuro surgical intervention
- Decompressive hemicraniectomy
- Intra ventricular shunting in hydrocephalus
- Control BP <140.80
- Anticonvulsants to prevent seizures
What is capsular warning syndrome?
Recurrent lacunar TIAs affecting the int capsule, associated w high risk of complete stroke
What are the criteria for decompressive hemicraniectomy?
- W/i 48 hours of sx onset
- NIHSS >15 and clinical defecits suggesting infarction in MCA territory
- Decreased level of consciousness
- Signs on CT of infarct w 50%+ of MCA territory
What is the stroke rehab pathaway?
Acute stroke unit - early supported discharge
Acute stroke unit - stroke rehab unit - supported discharge
What is early supported discharge?
40% of stroke pt eligible - hospital level therapy at home. Prevents hospital related complications eg. infection, delirium and DVT. Increased pt satisfaction.
How does stroke rehab work?
- Brain plasticity - neuro recovery at peak from 1-3 months
- Initial phase - reperfusion of hypoxic brain and reduction of brain oedema
- Late phase - brain remodelling
How do you manage impaired swallowing?
- Immediate dietician referral
- Consideration for alt fluids
- SALT assessment
- Consider for NG tube w/i 24 hours - avoid malnutrition
- Gastronomy if unable to tolerate NG tube and not able to swallow adequately at 4 weeks post stroke
What is the management of incontinence?
- Need to treat urine incontinence as increases skin breakdown = pressure ulceration
- Timed toileting
- Review caffeine intake
- Bladder retraining
- Pelvic floor exercises
- Constipating drugs/oral laxatives
- Med review
What is the management of spasticity?
- Simple measures - positioning, passive movement, analgesia inc treating neuropathic pain
- Focal spasticity - IM botulinum injection
- Generalised spasticity - skeletal muscle relaxants eg. baclofen
What is the management of anxiety and depression post stroke?
- Very common
- Increased social interaction
- Increased exercise
- Psychosocial education groups and support groups
What is ischaemic penumbra?
Tissue at risk that hasn’t yet become infarct, is salvageable
What is ASPECTS score?
Used to assess the prognosis of a stroke, mostly for MCA, take 1 point from 10 for every vascular region involved
<7 - worse functional outcome at 3 months and symptomatic haemorrhage
What are the complications of thrombolysis?
Extracerebral haemorrhage - thin pulse, malaena, distended abdo
Intracerebral haemorrhage - neuro decline, new headache, rising BP, N+V
What is ROSIER score?
Recognition of Stroke In Emergency Room:
-1 seizure activity
-1 LOC
+1 asymmetrical face weakness
+1 asymmetrical arm weakness
+1 asymmetrical leg weakness
+1 speech difficulty
+1 visual field defect
Wernicke’s vs Broca’s aphasia
Wernicke’s - fluent aphasia, L sup temporal gyrus affeced
Broca’s - non fluent, L inf frontal gyrus
AICA vs PICA strokes
Ant inf cerebellar - vertigo and vom, ipsilat facial paralysis and deafness
Post inf cerebellar - lat medullary syndrome = nystagmus, ataxia, ipsilat face pain and temp loss, contralateral limb pain and temp loss
What are the ix into a TIA?
Diffusion weighted MRI head
