0910 - Stroke Flashcards
What is the classical presentation for stroke?
Headache (sometimes)
Acute-onset neurological symptoms depending on what part of brain and how long effect
Altered consciousness
What determines the symptoms/signs of stroke?
Location of occluded vessel
Size of occluded vessel
Duration of occlusion
Potential for collateral blood supply.
What are the five broad causes of arterial occlusion in stroke
Atherosclerosis (intracranial, carotid)
Cardiac thromboemolism
Pro-coagulant state
Arterial injury
Iatrogenic
Why does the penumbra exist? (in both ischaemic and haemorrhagic stroke)
Ischaemic - As distinct to the core infarct, there is a certain degree of collateral blood supply to keep tissue vulnerable but alive for at least some time.
Haemorrhagic - Inflammation from blood, oedema, etc - very irritated tissue as well as loss of blood supply, but amount of irreversible injury is much smaller than the total symptomatic area.
What are the causes of intracranial haemorrhage?
Vascular macropathology (e.g. aneurysm, arteriovenous malformation)
Vascular micropathology (e.g. hyaline arteriosclerosis, amyloid angiopathy)
Impaired coagulation function (e.g. thrombocytopenia, clotting factor deficiency)
Hypertension.
What is a subarachnoid haemorrhage?
Diffuse bleed over pial surface, causing meningeal and cerebral irritation, altered neuronal function, disturbed CSF flow and cerebral ischaemia.
85% due to rupture of intracranial aneurysm.
What is the key question in a stroke history?
How was the onset? Stroke is usually very sudden.
What are the symptoms of amaurosis fugax?
Retinal (ophthalmic) artery occlusion
Transient monocular blindness
13-fold increased risk of full ischaemic stroke (good DDX vs MS optic neuritis?)
What are the symptoms of carotid T occlusion?
Occlusion where carotid joins circle of willis - removes the value of shunting around circle.
Face-arm-leg weakness/numbness on contralateral side
Global aphasia if dominant side affected
Visual sparing (PCA unaffected)
What are the symptoms of middle cerebral artery occlusion?
More common
Face-arm weakness/numbness on contralateral side. Relative sparing of leg and visual pathways.
Global aphasia if dominant hemisphere (frontal and temporal lobes affected).
What are the symptoms of ACA occlusion?
Less common.
Contralateral leg weakness/ numbness. May involve face and arm.
May have incontinence
What are the symptoms of PCA occlusion?
Cortical homonymous hemianopia with macular sparing (macular right at tip of occipital lobe, some collateral)
Memory impairment if significant temporal lobe involvement
Alexia (inability to read) if dominant hemisphere (disruption of tracts between ipsilateral visual cortex and language centre, and contralateral needs corpus callosum - posterior supplied by PCA).
Weber’s syndrome (contralateral hemiplegia) if proximal.
What are the symptoms of basilar artery occlusion?
Loss of consciousness or locked-in syndrome
Gaze abnormalities
Facial anaesthesia
What are the symptoms of PICA occlusion?
Dizziness/Ataxia on ipsilateral side (cerebellar)
Lateral medullary (Wallenberg) Syndrome - altered pain/temp sensation, ipsilateral face, contralateral body, Horner’s syndrome, dysphagia, dizziness and ataxia (vestibular pattern)
What are the symptoms of Weber’s Syndrome
Involvement of cerebellar peduncles with no supratentorial issues. Ipsilateral CNIII palsy with contralateral hemiplegia or hemiparesis.
