Stroke presentation & investigation Flashcards
(43 cards)
Why is prevention of stroke important to the NHS?
Commonest cause of long term disability in the UK
Patients who’ve had a stroke occupy 20% of NHS beds
Annual cost of over £5 billion treating stroke
What age demographic has the most strokes?
The elderly
Define what a stroke is
Clinical syndrome of sudden onset, causing a neurological deficit (loss of function)
Lasting more than 24 hours or until death
Of Vascular origin
Symptoms of a stroke are defined as being negative symptoms
What does this mean?
Symptoms are more to do with ‘loss of _______’
Symptoms of stroke: Loss of power Loss of speech Loss of sensation Loss of vision Loss of coordination
Describe the clinical signs, on history/examination, that would indicate a stroke
Motor - clumsy/weak
Sensory loss
Speech - Dysarthria/dysphasia
Neglect / visuospatial problems
Vision - loss in one eye or hemianopia
Gaze palsy
Ataxia / vertigo / nystagmus
What is hemianopia?
Blindness over half the field of vision
What is gaze palsy?
Inability to move both eyes in the same direction
What is ataxia?
lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements
What is nystagmus?
Dancing eyes
Rapid fluttery eye movements
What are the 2 types of causes of strokes?
Cerebral infarction
Haemorrhage
What are the 2 artery groups that supply the brain
Vertebral arteries (L & R)
Common carotid arteries (L & R)
What does the common carotid arteries split into?
Internal & external carotid arteries
What is the fate of the vertebral arteries?
Left and right vertebral arteries join together to form the single Basilar artery
What arteries branch off the Basilar artery?
Posterior inferior cerebellar arteries
Superior cerebellar arteries
Posterior cerebral arteries
What arteries make up the circle of willis?
Anterior communicating artery top
Anterior cerebral arteries
Internal carotid arteries/middle cerebral arteries
Posterior communicating arteries
Posterior cerebral arteries bottom
Most cerebral infarctions involve thrombus lodging in what arteries?
Middle cerebral arteries
The brain’s arterial supply can be thought of as an anterior and posterior circulation
What areas of the brain does the carotid system supply?
Anterior
The carotid system (via internal carotid arteries) supplies most of the hemispheres and cortical deep white matter
What areas of the brain does the vertebral artery system supply?
Posterior
Vertebro-basilar system supplies the brainstem, cerebellum and occipital lobes
In the deep white matter of the brain, a small stroke can cause major deficits
Why?
In the deep white matter of the brain or in the pons, neural fibres from different areas of the brain run alongside each other in tight, internal capsules
A small stroke in this area will affect all these fibres thus have affect lots of different areas
What are the causes of a ischaemic stroke (cerebral infarction)?
Large artery atherosclerosis:
- Typically in the carotid
Cardioembolic:
- Atrial fibrillation most common cause of this
Small artery occlusion - Lacunar
Less common:
- Cryptogenic
- Arterial dissection
- Venous sinus thrombosis
What are the causes of a hemorrhagic stroke?
Primary intracerebral haemorrhage:
- Blood vessel bursting within the brain
- Most common (70% HS’s)
Subarachnoid haemorrhage:
- Blood in the space around the brain
Arteriovenous malformation:
- Poorly formed blood vessels that ‘leak’
What does a hemorrhagic stroke look like on a CT?
Darker grey area
Will extend to the peripheries if subarachnoid haemorrhage
What is a lacunar stroke?
Happens when the small arteries to lacunae (gaps in the brain) are blocked
On a CT, it is a hard to see, slightly darker patch
On an MRI, it is a slightly lighter patch
What is a carotid dissection?
When the intimal layer of a carotid artery separates from the media
Blood clot fills in the space
Can be idiopathic or caused by trauma
It is a rarer cause of cerebral infarction strokes (ischaemic stroke)
