1(E) - Cerebrovascular Accident Flashcards
Define stroke
Interruption in vascular supply to the brain
What are the two main types of stroke
Ischaemic
Haemorrhagic
What is ischaemic stroke
Occlusion of blood vessel
What % of strokes are ischaemia
85%
What are two types of ischaemic stroke
- Thrombotic
- Embolic
What is a thrombus
Narrowing of vessel due to atherosclerosis
What is an embolic stroke
Blood Clot, Air , Fat or bacteria that travel and occlude an artery
What is haemorrhage stroke
Rupture blood-vessel causing reduction in blood flow
What % of strokes are haemorrhage
15%
What are the two types of haemorrhagic stroke
- Intracerebral (10%)
- SAH (5%)
What is the new definition of TIA
- transient episode neurological dysfunction caused by ischaemia to cerebral cortex, spinal cord or retina
What was the old definition of TIA
- Transient neurological dysfunction lasting less than 24-hours
What is difference between TIA and Ischaemic Stroke
TIA = ischaemia Stroke = infarction
What are modifiable risk-factors for TIA
- Smoke
- Obesity
- Alcohol
- High-Lipids
- CVD
- DM
- COCP
- HRT
- HTN
What are 5 non-modifiable risk factors for TIA
- Male
- Over 65-years
- African American
- FH
- migraine with aura
What is amaurosis fugax
Occlusion retinal or ophthalmic artery
If an individual had a TIA in past 7-days, how quickly should they be referred to specialist
24 hours
If an individual had a TIA more than one week ago, how soon should they be seen by a stroke specialist
7 days
What is given to manage TIA in short-term
Aspirin (300mg)
What imaging is ordered same-day in TIA and why
MRI
What is given as secondary prevention in TIA
Clopidogrel
What imaging do all patients with TIA received
Carotid Artery US
If carotid stenosis is present, what imaging is used
CTA
What are indications for carotid endarterectomy
More than 70%
Symptomatic and 50-99% Occluded
What are individuals with TIA at highest risk of and when is this most common
Ischaemic stroke - more common in first few days following TIA
What scoring system was used to predict individuals with TIA risk of developing ischaemic stroke
ABCD2
What is an ischaemic stroke
Occlusion cerebral blood vessel causing tissue infarction
Wha % of strokes are ischaemic
85
What is the main cause of ischaemic strokes
Thrombus
What are other causes for ischaemic stroke
Embolus
Global cerebral hypo perfusion
Hyper coagulable state
What causes thrombotic stroke
Atherosclerosis of cerebral blood vessels
Where are thromboses most likely to form
Branching-points
Which artery to embolic strokes most commonly affected
MCA
What causes embolic strokes
Clots from atrium
What causes a paradoxical embolus
Patent foramen ovale - enables thrombus from DVT to pass to cause stroke
What causes global cerebral hypo perfusion
- Bilateral carotid artery stenosis
- Global hypoperfusion
What other causes of stroke
- Polycythaemia
- Thrombophilia
- COCP
- HRT
- Sickle Cell
- Vasculitis
- Arterial Dissection
What are 3 risk factors for embolic ischaemic stroke
AF
Endocarditis
Patent FO
What are modifiable risk factors for ischaemic thrombotic stroke
Cardiovascular RF: Smoking, HTN, Alcohol. DM, PVD, CAD,. COCP
What are non modifiable risk factors for thrombotic ischaemic stroke
Male
Age
FH
How does occlusion ACA present clinically
Hemiplegia (usually) of the leg and hemiparesis (weakness) of the arm
How will MCA occlusion present
- Hemiparesis of face (forehead sparing) and arm
- Contralateral homonymous hemianopia
- Expressive and receptive aphasia (Brocca’s and Wernicke’s)
- If non-dominant = semi-spatial neglect
Where does the ophthalmic artery originate
Internal carotid artery
What causes amaurosis fugax
Clot in opthalmic which passes to occlude central retinal artery
If a patient with a stroke has hemianopia, what vessels must be affected
PCA or MCA
How do PCA strokes present
Homonymous hemianopia with macula sparing. May not present acutely but can present to opticians with history bumping into things
Why does MCA cause homonymous hemianopia
Due to ischaemia Meyer’s loop and Baum’s loop
Where is broccas areas
Pars opercularis, Pars triangularis
Where is Wernicke’s area
Superior temporal gyrus
What do the vertebrobasilar arteries supply
Occipital Lobe
Cerebellum
Brain Stem
What is weber syndrome also known as
Medial Midbrain Syndrome
What causes weber syndrome
Occlusion branches PCA than innervate midbrain
How does weber syndrome present clinically
- Ipsilateral CN3 palsy = Lateral Gaze Palsy
- Contralateral hemiparesis
What causes marie-fox syndrome
Occlusion anterior-inferior cerebellar artery (AICA)
What is Marie-fox syndrome also known as
Lateral pontine syndrome
What causes Marie-Fox Syndrome
- Ipsilateral: Gait ataxia, Weakness, Vertigo, Facial Paralysis, Hearing Loss, Horner’s Syndrome
- Contralateral: loss pain, temperature. And weakness
What is Wallenberg syndrome also known as
Lateral Medullary Syndrome
What causes a lateral medullary syndrome
Occlusion PICA
How does Wallenberg syndrome present clinically
Ataxia and Nystagmus
Ipsilateral: facial numbness, dysphagia, Horner
Contralateral: sensory loss in limbs
What causes locked in syndrome
Bilateral basilar artery occlusion
How does locked in syndrome present
- Paralysis all voluntary muscles
- Eye movements and blinking
What classification is used to determine presentation strokes
Oxford Stroke Classification
What % of strokes are TACI
15%
What does TACI strokes involve
ICA: ACA and MCA
What is the presentation of TACI
All 3 Of:
Homonymous hemianopia
Hemiparesis face, arm and leg
Higher cortical dysfunction
What % of strokes are PACI
25
What is a PACI
Occlusion of MCA or ACA
Describe clinical presentation of PACI
2 Of:
Homonymous hemianopia
Hemiparesis face, arm and leg
Higher cortical dysfunction
What % of strokes are lacunar infarcts
15
What causes lacunar infarcts
occlusion arteries supplying basal ganglia, thalamus, internal capsule
What is the Oxford stroke criteria for lacunar infarcts
One of:
- Pure Sensory Stroke
- Ataxic hemiparesis
- Unilateral weakness face, arm and leg
What % of strokes are posterior-circulation infarcts
25%
What causes a POCI
Occlusion vertebrobasilcar artery
How does a POCI present clinically
One of:
- Cerebellar/Brain-stem syndrome
- LOC
- Isolated homonymous hemianopia
What is an isolated homonymous hemianopia
No other symptoms
What is Weber Syndrome
Medial Midbrain Syndrome -
Perforators of PCA
What is Marie Foix syndrome
Lateral Pontine Syndrome -
AICA
What is Wallenberg syndrome
Lateral Medullary Syndrome -
PICA
Explain distinguishing between ischaemic and haemorrhagic strokes from clinical presentation
Cannot distinguish solely on clinical presentation, require CT. However, haemorrhagic more often have nausea, vomitting, headaches and seizures.
What causes lacunar strokes
Small vessel disease
What causes small vessel disease
Hyaline arteriosclerosis, which is caused by hypertension
Outside of hospital what screening tool is used to identify stroke
FAST
What is the FAST tool
Face = is it drooped on one side
In hospital, what scoring system is used to identify stroke
ROSIER (Recognition of stroke in emergency room)
What ROSIER score requires assessment by stroke specialist
> 2
What is first-line investigation in suspected stroke cases
CT Head in one hour
If ischaemic stroke, what other imaging should be ordered
CTA
What is gold-standard for ischaemic strokes and why is it not used
MRI - due to time consuming and not safe to put unstable patient in scanner
What is first line for ischaemic strokes
Aspirin (300mg)
What time frame should aspirin (300mg) be given
Within 24h of haemorrhagic stroke exclusion
How long is aspirin continued for
2W
What should be given with aspirin (300mg)
PPI
What is second-line for stroke
Thrombolysis
What are prerequisites for thrombolysis
Within 4.5 hours symptom onset
What are 5 absolute CIs to thrombolysis
- Previous IC haemorrhage
- IC neoplasm
- SAH
- Stroke or TBI in part 3-months
- LP in past 7 days
- GI haemorrhage in past 3W
- Active bleeding
- Pregnancy
- Varices
- Uncontrolled HTN (200/120mmHg)
When may thrombolysis be considered up to 24h afterwards
Posterior circulation stroke and imaging shows salvageable brain-tissue
What is important regarding anti-platelets after thrombolysis
Do not give anti platelets for 24-hours
In addition to thrombolysis, what are individuals offered to manage stroke
Thrombectomy
What are the criteria for thrombectomy
6h stroke
<3 on modified rankin scale
>5 on NIHSS
What time-frame can an individual receive thrombectomy
Up to 6h afterwards
What are other important points concerning management of stroke patients
NBM - until screened by SALT. May require NG tube
Interpneumatic compression stockings for VTE prophylaxis
Explain measures for secondary prevention of stroke
- Anti-HTN (Aim 130/80)
- Statin
- Control Diabetes
- Carotid endartectomy if stenosis
- Lifestyle: diet, exercise, smoking cessation.
What are two neurorehabillitaiton scales used
Rankin
Barthel
What is a respiratory condition that may result from stroke
Aspiration pneumonia
What is greatest risk 1-2d after ischaemic stroke
Haemorrhagic transformation
What can happen after MCA strokes
Malignant MCA Syndrome
Explain malignant MCA syndrome
Neurological deteriorations - due to to cerebral oedema following MCA stroke. Managing in hemicraniectomy
What is intracerebral haemorrhage
Bleeding within brain parenchyma
What is haemorrhagic stroke
Infarction secondary to haemorrhage
What is the most common cause of intracerebral haemorrhage
HTN
If over 60 what is the second-most common cause of intracerebral haemorrhage
Cerebral amyloid antipathy
As a child, what is the most common cause of intracerebral haemorrhage
AV Malformation
Give 3 other causes of intracerebral haemorrhage
- Infection
- Cocaine, amphetamine
- Anticoagulant
- Vasculitis
How does intracerebral haemorrhage present clinically
Symptoms are identical to to ischaemic stroke. Except slowly progressive and worsen over minutes-hours
Explain pathophysiology of HTN cause haemorrhagic stroke
Chronic HTN causes atherosclerosis of lenticulostriae arteries resulting in lipohyalinosis. This causes charcot-bouchard aneurysms to form which then rupture causing haemorrhage
Explain pathophysiology of cerebral amyloid antipathy
Amyloid is deposited in leptomeningeal arteries - causing inflammation, micro aneurysms and haemorrhage
What is first line investigation for haemorrhagic stroke
CT in 1h
How does haemorrhage present on CT
Bright
What is first-line management for all intracranial haemorrhage
Control BP if within 6-hours and Systolic is 150-220. Control with GTN patch and then IB labetaolol
What BP target is aimed for first 7d following haemorrhagic stroke
130-140 systolic BP
If individual on anticoagulation have a haemorrhage what is offered
Reversal
how is warfarin reversed
Prothrombin complex and vitamin-K
what factors does pro-thrombin complex replace
2 ,7, 9 10
how can dabigatran be reversed
Idarucizumab
when are individuals referred to neurosurgery for hemicraniectomy and clot evacuation
brain herniation (cushing's reflex) posterior fossa bleed obstructive hydrocephalus cerebral haemorrhage with neurological deterioration haemorrhage >3cm