The vascular system and stroke - Stroke Flashcards
What is the definition of stroke (Warlow et al,1996)
Stroke is a clinical syndrome characterised by rapidly developing clinical symptoms/or signs of focal neurological deficit lasting more than 24 hours and thought to be of vascular origin
What are the presenting problems of stroke?
- Unilateral weakness - sudden, progress rapidly and follows a hemipelgic pattern
- Speech distrubance - dysphasia and dysarthia
- Visual deficit
- Visuo-spatial dysfunction
- Ataxia
- Headache
- Seizure
- Coma
List some non-modfiable risk factors of stroke
- Age
- Gender (male > demale except of extreme age)
- Race (Afro-caribbean > asian > european)
- Previous vascular event
- Stroke
- Vasculitis e.g., GCA
- DVT
List some modifiable risk factors of stroke
- Cigarette smoking
- High blood pressure
- High cholesterol
- Excessive alcohol intake
- Heart disease - atrial fibrillation
- Diabetes mellitus
- Infective endocarditis
- Oestrogen-containing drug (contraceptive pill)
What drugs are you most intrested in when it comes to the DH of a patient with a suspected stoke?
- Anticoagulants (more at risk of bleeding)
- Antiplatelets
- Anti-epileptics
- Insulin and other diabetic medications
Describe the examinations involved and findings to look out for when diagnosing a stroke in a patient
General - HR, BP, O2 saturations, temperature, blood glucose, conscious level, facial symmetry
Skin - Xanthelasma, rash, pressure injury
Eyes - Arcus seniles, diabetic retinopathy, hypertensive retinopathy, rentinal emboli
Cardiovascular - heart rhythm, BP, carotid bruits (narrowing of carotid artery’s can cause bruits increasing likelihood of strokes), jugular venous pulse
Respiration - aspiration pneumonia, pulmonary oedema/infection, oxygen saturation
Abdominal - palpable bladder (some with stroke get into urinary retention)
Cranial nerves - neck stiffness, visual fields, nerve palsy
Speech - check comprehension to identify receptive dysphagia
PNS
Motor system - muscle bulk, abnormal posture and movements, tone, strength, including pronator drift, co-ordination, tendon and plantar reflexes
Sensory system - touch sensation, cortical sensory function: sensory inattention or neglect, joint position sense
Gait if possible - ataxic, non-weight bearing, hemiparetic gait pattern
Name the two pathological classifications of stroke and state the percentage of stroke that is due to each
Ischaemic (cerebral infarction) - 85%
Haemorrhagic (primary intracerebal haemorrhage) - 15%^
a) Small vessel disease is an aetiology of stroke. What is small vessel disease?
b) Name 3 conditions that it is secondary to
c) What would you see on a CT scan?
a) Occlusion of small perforating arteries
b) Secondary to hypertension/diabetes/diabetes mellitus
c) Small infarcts in sub cortical white matter/ basal ganglion/thalamus/internal capsule. This is known as “lacunes” or “lacunar infarcts
a) Describe the role of the CHA₂DS₂-VASc score
b) Name the components of the CHA₂DS₂-VASc score including what each component scores
a) Calculates stroke risk for patients with atrial fibrillation
b)
What is the most appropriate scoring scale to aid in triage in the emergency department when suspecting a stroke?
ROSIER - Designed for recognising stroke in the acute setting of the emergency department
Describe the role of the NIH Stroke Scale/Score (NIHSS)
It is a clinical assessment that is used to evaluate and document stroke severity.
What are the two most common primary causes of haemorrhage stroke?
Amyloid angiopathy (deposit of amyloid protein in the blood vessels of the brain reduces the elasticity of the artery and makes it more prone to cracking and leaking)
Hypertension (if you have hypertension for long periods of time, the arteries lose their elasticity and become more rigid and prone to cracking and leaking which make cause cerebral haemorrhage in the brain)
Explain 3 secondary causes of haemorrhage strokes
Arteriovenous malformation (AVM) - this is where you have a direct connection between an artery and vein without a capillary bed, which puts the venous and arterial system at high pressure. Veins are not designed to withstand the pressure, so they are prone to leaking and cracking
Aneurysms - aneurysms are weakness in blood vessels which cause them to expand and sometimes they can burst and cause a haemorrhage
Coagulopathy - most commonly due to anticoagulants e.g., Warafin, heparin, rivaroxaban (DOAC). Can also be due to liver problems and sepsis
What is the name of the clinical classification used for ischaemic (infarct) strokes?
Bamford (Oxford) classification
Name the four different classifications of the Bamford (Oxford) classification
Total anterior circulation syndrome (TACS)
Partial anterior circulation syndrome (PACS)
Lacunar syndrome (LACS)
Posterior circulation stroke (POCS)
a) What are the signs of a total anterior circulation syndrome (TACS)
b) What is the most common cause?
a) All of the following:
- Contralateral motor or sensory loss
- High cortical dysfunction (dysphagia, neglect, aphasia etc)
- Contralateral homonymous hemianopia
b) Middle cerebral artery occlusion (embolism from heart or major vessels)
a) What are the signs of a partial anterior circulation syndrome (PACS)
b) What is the most common cause?
a) 2 of the following:
- Contralateral motor or sensory loss
- High cortical dysfunction (dysphagia, neglect, aphasia etc)
- Contralateral homonymous hemianopia
OR high cortical function only
b) Occlusion of a branch of the middle cerebral artery or anterior cerebral artery (embolism from heart of major vessels)
a) What are the signs of a lacunar syndrome (LACS)
b) What is the most common cause?
a) Contralateral pure motor or sensory loss only
- No cortical/higher cerebral dysfunction or hemianopia
b) Thrombotic occlusion of small perforating arteries (Thrombosis in situ)
a) What are the signs of a posterior circulation stroke (POCS)
b) What is the most common cause?
a) - Isolated/cortical hemianopia
- Nystagmus
- Vertigo
- Diplopia (double vision)
- Dysarthria & dysphagia
- Hemiparesis
- Hemisensory loss
- Brain stem signs/cranial nerve syndrome
- Respiratory failure
- Coma and death
- Cerebellar (locked in) syndrome
b) Occlusion in vertebral basilar or posterior cerebral artery territory (Cardiac embolism or thrombosis in situ)
Wallenberg syndrome, also known as lateral medullary syndrome due to its location, is a type of POCS that presents with a constellation of features. Name 6 features of this.
DANVAH
-Dysphagia & dysarthria
- Ataxia (ipsilateral)
- Nystagmus (ipsilateral)
- Vertigo
- Anaesthesia (ipsilateral facial numbness and contralateral pain loss on the body)
- Horner’s syndrome (Ipsilateral)
+ Diplopia
a) What artery is occluded in Wallenberg’s syndrome?
b) Where is the lesion/infarct in Wallenberg’s syndrome found in the brain?
a) Occlusion of the posterior inferior cerebellar artery
b) Lateral medulla
Which stroke system affects the brain stem?
Weber’s syndrome/medial midbrain syndrome
a) What is the intracerebellar haemorrhage stroke (ICH) score?
b) What are the components of the ICH score?
c) Explain the relationship between the infraentorial origin and mortality
d) What is the relationship between the ICH score and mortality
a) It is the cerebral haemorrhage score for prognosis
b) Glasgow component score (GCS), ICH volume (size of the bleed), Infraentorial origin of ICH, age
c) If the bleed is in the back of the brain the risk is higher (higher mortality) because there is less space there for swelling
d) The higher the ICH score the higher the mortality
Define transient ischaemic attack (TIA)
Neurological signs that are consistent with a stroke that lasts for less than 24 hours
What is the diagnostic investigation for a stroke?
CT head
Describe the investigations that can be undertaken to diagnose a stroke in a patient
Bloods - FBC, U+E, LFTS, bone, clotting, blood sugar, cholesterol +/- ESR, haemophilia screen, vasculitis screen
ECG (look for AF as it a massive risk factor of strokes)
CT head (diagnostic)
CXR (signs of aspiration pneumonia)
+/- perfusion scan (if onset is unknown), MRI
Carotid doppler/CT angiogram
Echocardiography + 24-hour tape +/- prolonged monitoring
Describe the management of a patient who presented early with a TIA (< 1 week ago)
- Immediate aspirin 300mg (or Clopidogrel 300mg loading then 75mg OD)
- Specialist assessment within 24-hour symptom onset
- Secondary prevention as soon as the diagnosis is confirmed e.g., Statin
- Carotid duplex scanning in anterior circulation events - carotid endarterectomy if significant stenosis (> 50%)
Do you see damage on a CT and MRI if a patient has a TIA?
No damage on CT. May be seen on some MRI
a) What is the ABCD2 score?
b) What are the components of it?
c) What are the NICE guidelines about the ABCD2 score?
a) The risk of stroke during the 7 days after a TIA
b) A - Age > 59
B - Blood pressure >/= 140/80
C - Clinical presentation: unilateral weakness, speech disturbance, other
D - Duration
D - Diabetes
c) NICE guidelines say to see everyone within 24 hours of honest no matter the ABCD2 score
List 10 ‘stroke mimics’
- Migraine
- Metastatic cerebral tumours
- Abscess
- Subarachnoid
- Extradural and subdural haematoma
- Encephalitis
- Cerebral vein thrombosis
- Epilepsy and Todd’s palsy
- Multiple sclerosis
- Myasthenia gravis (rare long-term condition that causes muscle weakness)
- Bell’s palsy
- Functional symptoms
- Hypoglycaemia
- Hypothermia
- Sepsis
- Old strokes who are unwell
- Dementia
- Drug toxicity
- Transient global amnesia (an episode of confusion that comes on suddenly in a person who is otherwise alert.)
Describe the differences in clinical features of stroke and stroke mimics
a) What type of stroke is this?
Haemorrhagic stroke - white (hyper-attenuation) on CT is blood
What is the darkness surrounding the hypoattenuation area on this CT scan
Oedema
Describe the 7 R’s of the management of stroke
Recognise - Symptom recognition, call 999
React - Transfer to hospital with Acute Stroke Unit
Respond - Brain imaging and medical assessment
Reveal - Confirm diagnosis, assess for thrombolysis drugs
Rx/Reperfusion - Thrombolysis diagnosis, assess for thrombolysis drugs
Rehabilitation - Stroke team assessment and treatment
Reintegration - Patient support groups, family, community
Name 2 pre-hospital screening test for stroke/TIA
FAST (Facial, Arms, Speech, Time)
MASS
Describe the management of a TIA presenting late (> 1 week ago)
- Specialist assessment ASAP
- MRI imaging (T2) mode of choice to exclude haemorrhage
- Immediate initiation of clopidogrel
- Secondary prevention as soon as the diagnosis is confirmed
a) When should brain imaging in a suspected acute stroke be done?
b) What are the indications for brain imaging?
c) Why is early scanning important?
a) Immediate (next slot or within 1 hour)
b)
- Indications for thrombolysis
- Been taking anticoagulant therapy
- A known bleeding tendency
- A depress level of consciousness (GCS < 13)
- Unexplained progressive or fluctuating symptoms
- Papilledema, neck stiffness or fever
- Severe headache at onset of stroke
c) To rule out haemorrhage or other mimics
Describe the differences seen on a early CT scan of an acute ischaemic stroke vs acute haemorrhage
Early CT scan after an acute ischaemic stroke can be normal or show only subtle changes (darkness for infarct)
Early CT scan after an acute haemorrhage will show changes in almost all changes (white for bleeding)
a) What is thrombolysis?
b) Describe the mechanism of thrombolysis
c) What is the window for thrombolysis
d) What drug is commonly used in thrombolysis of an ischaemic stroke and how is given?
a) Treatment to dissolve clots in blood vessels using synthetic tissue plasminogen activators
b) Enzymically activates plasminogen to give plasmin which digests fibrin & fibrinogen, lysing the clot
c) <4.5 hours
d) Alteplase bolus followed by an infusion
What are the indications for thrombolysis?
- Symptom onset <4.5 hours
- Definite weakness and/or dysphagia regardless of severity
- Age 18+ years
- GCS <8