Stroke Flashcards
Which acute neurological conditions can result in collapse? (7)
Stroke/TIA* Epilepsy* Guillain-Barré Syndrome Hydrocephalus Cord compression Radiculopathy/spondylopathy GCS
A 70-year-old right-handed man is discovered by a family member to have difficulty speaking and comprehending spoken language, and an inability to raise his right arm. On examination, power is 2/5 in his right arm, 4/5 in his right leg and 5/5 in his left arm and leg. A CT head scan is performed and an ischaemic stroke is diagnosed.
What type of stroke is it?
Left total anterior circulation stroke Right anterior cerebral artery stroke Left middle cerebral artery stroke Right middle cerebral artery stroke Left brainstem stroke
MCA
Mrs Smith, an 85-year-old woman, is brought to A & E by her husband. When she woke up this morning her husband noticed that Mrs Smith’s smile looked strange and that she was unable to move her right arm. She seemed fine last
night going to bed after watching the news as normal. On examination she had right sided hemiparesis and a positive Babinski sign. A CT-head done at the A & E excluded a haemorrhage. What is the next most appropriate step in her
management?
Carotid doppler 300mg aspirin, orally 75 mg clopidogrel, orally ECG IV alteplase
Aspirin 300 mg orally
Difference between stroke and TIA?
Stroke: A sudden onset focal neurological deficit of
presumed vascular origin lasting more than 24 hours.
Transient Ischaemic Attack (TIA): Same thing but
symptoms resolve in < 24 hours.
How common is stroke?
Third leading cause of death in the UK
Three pathological mechanisms of ischaemic stroke
Thrombosis
Emboli
Hypotension
What does brain ischaemia due to atherosclerosis affecting mainly smaller cerebral vessels result in?
Lacunar infarcts
What three mechanisms can lead to stroke from thrombosis?
Atherosclerosis
And prothrombotic states:
Dehydration
Thrombophilia
What four mechanisms can lead to ischaemic stroke from emboli?
from intimal flap of carotid dissection
atheromatous plaques in the carotid arteries
from the heart (e.g. atrial fibrillation)
Rarely they can arise fomr venous circulation and pass through a right-left heart defect (VSD)
Which larger cerebral artery is commonly affected by thrombosis?
Middle cerebral artery
What is a watershed stroke
Defined as abrain ischemiathat is localized to the vulnerable border zones between the tissues supplied by theanterior,posteriorandmiddlecerebral arteries
Pathologies that can lead to intracerebral haemorrhage: (7, 4 common 3 less common)
Hypertension, Charcot-Bouchard microaneurysm rupture, amyloid angiopathy, arteriovenous malformation. Less commonly: trauma, tumours, vasculitis
What scoring system is used to assess the risk of stroke in patients with AF
CHADSVASC
What scoring system is used to assess the risk of bleeding from anti-coagulation
HAS-BLED
Stroke/TIA risk factors (6)
Hypertension Diabetes Obesity Old age Hypercholesterolaemia Smoking
Stroke presentation: (5)
SUDDEN onset Weakness/numbness in the face, arm or leg Change in vision Dizziness, loss of coordination/balance Problems with speech
Pointers to ischaemic stroke (4)
carotid bruit, AF, past TIA, IHD
Pointers to haemorrhagic stroke (2)
meningism, severe headache
Which artery supplies the medial aspect of the frontal and parietal lobes
ACA
What part of the brain does the ACA supply
The medial aspect of the frontal and parietal lobes
Which artery supplies the lateral surface of the hemispheres
MCA
Which artery supplies subcortical structures
MCA
What does the MCA supply
The lateral surface of the frontal and parietal lobe, the superior-lateral part of the temporal lobe and also subcortical structures
Which artery does the ACA arise from
Terminal branch of the internal carotid artery
Which artery does the MCA arise from
Branch of the internal carotid artery
Which artery does the PCA arise from
Basilar artery
What does the PCA supply
The occipital lobe and the inferomedial part of the temporal lobe.
What artery supplies the occipital lobe
PCA
What are the distinguishing features of an anterior cerebral artery stroke (2)
Contralateral hemiparesis affecting the lower limb more than the upper limb
Behavioural changes
What are the distinguishing features of a middle cerebral artery stroke (5)
Contralateral hemiparesis affecting the upper limb/face more than the lower limb Contralateral hemisensory loss Apraxia Aphasia Quadrantopias
Which cerebral artery stroke causes apraxia and why
MCA. Apraxia is a disorder of skilled movement. If you think about it it makes sense to have this in lesions where the parietal lobe is affected, bc the parietal lobe is involved in bringing together and combining information needed to perform skillfull actions.
Which cerebral artery stroke causes contralateral hemisensory loss and why
MCA bc somatosensory cortex (parietal lobe) is affected
Which cerebral artery stroke causes aphasia and why
Left MCA as language centres there
What are the 2 types of aphasia and which area is responsible for is which
Broca’s area: responsible for speech production (expressive aphasia)
Wernicke’s area: responsible for language comprehension (receptive aphasia)
Which cerebral artery stroke causes contralateral visual loss and why
With an MCA stroke you might get visual problems manifesting as quadranopias if the optic radiations are affected. (look again at Dan’s CNS lecture for details of visual pathway)
Optic radiation: contain tracts that carry information from lateral geniculate nucleus to the primary visual cortex in 2 loops:
Meyer’s = inferior optic radiation. They pass through the temporal lobe. If cut causes superior quadrantopia. Baum’s = superior optic radiation. They pass through the parietal lobe. If cut causes inferior quadrantopia
What are the distinguishing features of a posterior cerebral artery stroke (2)
Homonymous contralateral hemianopia
Visual agnosia
Why can PCA stroke be macular sparing (2)
macular representation, found at the posterior pole of the occipital lobe, is disproportionately large. Because of the large macular representation, as well as the dual blood supply to the posterior occipital lobe (both PCA and MCA), sparing of the centre of the visual field is commonly found with occipital lobe lesions
What are the 6 signs of cerebellar damage?
Dysdiadochokinesia Ataxia (gait and posture) Nystagmus Intention tremor Slurred, staccato speech Hypotonia/Heel-shin test
A lesion in one cerebellar hemisphere will cause motor deficits on which side of the body and why
Ipsilateral bc pathways from the cerebellum to the lateral motor systems and then to the periphery are“double crossed”
What signifies brainstem stroke damage
↓ consciousness
CN pathology
What is the internal capsule
is the white matter tract where the pyramidal UMN axons from the primary motor cortex travel through before reaching the brain stem.
What can internal capsule lacunar infarcts present with
Pure motor deficit
What can pontine lacunar infarcts present with
Dizziness/vertigo, bilateral affected
What can thalamic lacunar infarcts present with
Affected consciousness
What can basal ganglia lacunar infarcts present with
Dyskinesias
What causes amaurosis fugax
to occlusion of the retinal artery which is a branch of the ophthalmic artery which is a branch of the ICA
Where do lacunar infarcts occur (4)
the deep cerebral white matter of the internal capsule, basal ganglia, thalamus or pons
What defines a total anterior circulation stroke
All 3 of:
Contralateral motor or sensory deficit
Homonymous hemianopia
Higher cortical dysfunction
What defines a partial anterior circulation stroke
2 of:
Contralateral motor or sensory deficit
Homonymous hemianopia
Higher cortical dysfunction
What defines a posterior circulation stroke
Any of:
Isolated homonymous hemianopia
Brainstem signs
Cerebellar ataxia
What defines a lacunar circulation stroke
Any of:
Pure motor deficit
Pure sensory deficit
Sensorimotor deficit
Ix for a suspected stroke (4)
Urgent within 1 hour non-contrast CT head
Bloods
ECG
Vital signs
What bloods do you request in someone with a stroke and why (6)
Serum glucose (exclude hypoglycaemia as a cause for focal neurological signs)
FBC (excludes anaemia or thrombocytopaenia prior to possible initiation of thrombolytics, anticoagulants, antithrombotics)
Electrolytes (to exclude electrolyte disturbance as a cause for focal neurological signs)
Urea and creatinine (to exclude renal failure – renal failure might be a potential contraindication to some interventions)
Partial thromboplastin and prothrombin times (with international normalised ratio)
Cardiac enzymes (stroke may be associated with concomitant MI
Why do we do an ECG in suspected stroke
An ECG should be performed to exclude cardiac arrhythmia or ischaemia, which are relatively common in ischaemic stroke.
When should you delay the administration of rTPA
the presence of hypoglycaemia has been associated with autonomic and neurological symptoms, including stroke mimics and seizures, and hyperglycaemia has been associated with intracerebral bleeding and worse clinical outcomes in patients treated with r-tPA
Why is lowering blood pressure bad in strokes
Lowering BP could reduce cerebral perfusion pressure and promote stroke extension
Mx of stroke (think about time)
< 4.5 hours
↓
IV alteplase
(recombinant tissue plasminogen activator, r-tPA)
Then give aspirin 24 hours later and ONLY after CT head shows lack of haemorrhage (300 mg, oral)
> 4.5 hours
OR thrombolysis is contraindicated*:
↓
Aspirin (300 mg, oral)
Contraindications for thrombolysis (7)
onset of symptoms >4.5 hrs, CT reveals acute trauma or haemorrhage, symptoms suggestive of SAH, high INR, APPT, PT
What is alteplase
recombinant tissue plasminogen activator, r-tPA
What further management is involved in a stroke patient (3)
Swallowing assessment
VTE prophylaxis
GCS monitoring
What is used to identify patients who are eligible and what is the criteria for carotid endarterectomy
Carotid doppler showing stenosis over 70% or
50-69% and symptomatic
Secondary prevention of stroke in AF patients
Warfarin prophylaxis
Secondary prevention of stroke in non-AF patients
Continue aspirin for 2 weeks then switch to lifelong clopidogrel
Mx of haemorrhagic stroke
Neurosurgical evaluation
leading to either:
Surgery
ICU/stroke unit for monitoring and support
Complications of stroke (7)
Aspiration pneumonia Cerebral oedema (↑ ICP) Immobility Depression DVT Seizures Death
Prognosis for strokes
10% mortality in the first month
Up to 50% that survive will be dependent on others
10% recurrence within 1 year
Prognosis for haemorrhagic is WORSE than ischaemic
For patients with TIA, 8% will have a stroke during hospitalization and >10% in the next 3 months
ABCD2 score estimates the risk of stroke after TIA
