Stroke Flashcards
What is the difference between stroke and epilepsy in type of symptoms?
- Stroke - negative symptoms
2. Epilepsy - positive symptoms
What is a stroke?
Sudden interruption in the vascular supply of the brain resulting in focal neurological deficits lasting over 24 hours.
What are the causes of an ischaemic stroke?
- Atherothromboembolism from internal carotid
- Cerebral microangiopathy
- Carotid artery dissection (younger)
- Thrombophilia
- Venous sinus thrombosis
What are the three different types of stroke?
- Ischaemic (85%) - block in blood flow
- Intraparenchymal haemorrhagic (15%) - burst small blood vessel, reduction in blood flow
- Venous stroke (1%)
What are the causes of an intraparenchymal haemorrhagic stroke?
- HTN
2. Coagulopathy
What is the difference between intraparenchymal haemorrhagic stroke and a subarachnoid haemorrhage?
- SAH is intracerebral
2. SAH involves berry aneurysm of large vessel, IHS involves a burst small blood vessel
How does a venous stroke present?
- Raised ICP
2. Focal neurology and seizures
Why are the optic tracts less affected in strokes than other cortical functions?
They are in white matter, so only a large stroke would affect them.
What is the underlying pathophysiology of a haemorrhagic stroke?
- Hyaline arteriosclerosis and microaneurysm formation
2. Cerebral amyloid angiopathy of the small leptomeningeal vessels
What are the risk factors for developing a stroke?
HTN (leading cause), age, smoking, alcohol, diabetes, IHD, AF, PVD, COCP, hyperlipidaemia, coagulopathies.
What are the differentials for a stroke?
Head injury, hypoglycaemia, tumour, migraine, encephalopathy, encephalitis, MS, syncope.
What are the signs seen in a stroke from a cerebral infarct?
- Contralateral sensory loss - hemiplegia
- Hemiparesis - initially flaccid
- Pyramidal weakness - upper limb extensor weakness, lower limb flexor weakness
- Spasticity
- Hyperreflexia
- Dysphasia
- Homonymous hemianopia
What are the signs seen in a stroke from a brainstem infarct?
- Varied - including quadriplegia
2. Vision disturbances
What are the signs seen in a stroke from a lacunar infarct?
- Pure motor, ataxic, pure sensory, or mixed sensorimotor hemiparesis
- Dysarthria/clumsy hand
- Cognition/consciousness intact except in thalamic strokes
What are the signs seen in a haemorrhagic stroke?
Meningism, headache, coma within hours.
Why are Broca and Wernicke areas on the left in most peoples brains?
Because most people are left brain dominant
What are the non-dominant Broca and Wernicke areas responsible for?
- Broca - tone of speech
2. Wernicke - understanding non-verbal language
What is the effect of a unilateral temporal lobe infarction on hearing?
- No contralateral deafness as auditory fibres cross over
2. Patients cannot locate where sounds are coming from
What is the criteria for a partial vs a total anterior stroke?
All 3 = total, any 2 = partial:
- Unilateral weakness (+/- sensory deficit)
- Homonymous hemianopia
- Dysphasia
What is this a presentation of?
Contralateral hemiparesis and sensory loss - LEGS.
Anterior cerebral artery stroke
What is this a presentation of?
Contralateral hemiparesis and sensory loss - ARMS.
Contralateral homonymous hemianopia
Aphasia
Middle cerebral artery stroke
What is this a presentation of?
Contralateral homonymous hemianopia and macular sparing. Visual agnosia and cerebellar signs.
Posterior cerebral artery stroke
What is this a presentation of?
Ipsilateral CN III palsy
Contralateral weakness of upper and lower limb.
Weber’s stroke (branches of PCA that supply the midbrain)
What is this a presentation of?
Ipsilateral facial pain and temperature loss
Contralateral limb pain and temperature loss
Lateral medullary syndrome
Posterior inferior cerebellar artery stroke
