Acute Neuro Flashcards
What is the definition of stroke?
a sudden onset focal neurological deficit of presumed vascular origin, lasting for more than 24 hours
- there is a sudden interruption to the blood supply to the brain
- neural tissue is completely dependent on aerobic respiration, so any problem with oxygen supply can quickly lead to irreversible damage
What are the 2 main types of stroke?
haemorrhagic:
caused by vascular rupture that leads to reduction in blood flow
ischaemic:
caused by vascular occlusion / stenosis that stops blood flow
What are the 2 different subtypes of ischaemic stroke?
thrombotic stroke:
* caused by thrombosis from large vessels e.g. carotid
embolic stroke:
* caused by a blood clot / fat / air / clumps of bacteria
* atrial fibrillation is associated with embolus formation in the heart
What are the 2 different subtypes of haemorrhagic stroke?
intracerebral haemorrhage:
* bleeding within the brain tissue
subarachnoid haemorrhage:
* bleeding on the surface of the brain
What are the risk factors for stroke?
general risk factors for CVD:
* hypertension
* diabetes
* obesity
* old age
* hypercholesterolaemia
* smoking
atrial fibrillation is an additional risk factor for cardioembolism
What are the additional risk factors for haemorrhagic stroke?
- old age
- hypertension
- arteriovenous malformation
- anticoagulation therapy
What are the general signs and symptoms of stroke?
- limb weakness / numbness
- facial droop
- dizziness
- loss of coordination / balance
- speech difficulties
- visual changes
THESE ARE ALL ACUTE ONSET
presentation is influenced by which area of the brain is affected
What are the general signs and symptoms of stroke?
- limb weakness / numbness
- facial droop
- dizziness
- loss of coordination / balance
- speech difficulties
- visual changes
THESE ARE ALL ACUTE ONSET
presentation is influenced by which area of the brain is affected
What region is supplied by the anterior cerebral artery (ACA)?
What are the signs of an ACA stroke?
Territory:
* supplies medial / superior frontal lobe
* anterior parietal lobe
Associated signs:
* contralateral hemiparesis (LL > UL)
* behavioural changes
What region is supplied by the middle cerebral artery (MCA)?
What are the associated signs of MCA stroke?
Territory:
* lateral parts of frontal, temporal and parietal lobes
Associated signs:
* contralateral hemiparesis (UL/face > LL)
* contralateral hemisensory loss
* apraxia
* aphasia
* quadrantopias
What is the role of Broca’s area?
What does infarction of this area result in?
- responsible for speech production
- injury results in expressive aphasia
- able to understand speech but not articulate it
remember B for “buccal” - mouth is where speech is produced
What is the role of Wernicke’s area?
What does ischaemia in this region result in?
- responsible for speech comprehension
- injury results in receptive aphasia
- able to produce speech, but it makes no grammatical sense
remember W for “what do you mean?”
What regions are supplied by the posterior cerebral artery (PCA)?
What are the signs of PCA stroke?
Territory:
* occipital lobe
* inferior part of temporal lobe
Associated signs:
* contralateral homonymous hemianopia
* visual agnosia
visual agnosia = difficulty recognising familiar objects / faces
To classify strokes using the Oxford (Bamford) Classification, what must be present in a total anterior circulation stroke?
- 1 - unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- 2 - homonymous hemianopia
- 3 - higher cognitive dysfunction (e.g. dysphasia)
ALL 3 MUST BE PRESENT
TACS involve the middle and anterior cerebral arteries
To classify strokes using the Oxford (Bamford) Classification, what must be present in a partial anterior circulation stroke?
- 1 - unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- 2 - homonymous hemianopia
- 3 - higher cognitive dysfunction
ANY 2 OF THESE MUST BE PRESENT
PACS involve smaller arteries of the anterior circulation
To classify strokes using the Oxford (Bamford) Classification, what must be present in a lacunar stroke??
- pure motor stroke
- sensori-motor stroke
- pure sensory stroke
- ataxic hemiparesis
ONE OF THESE MUST BE PRESENT
involves perforating arteries around the internal capsule, thalamus and basal ganglia
To classify strokes using the Oxford (Bamford) Classification, what must be present in a posterior circulation stroke?
- cerebellar or brainstem syndromes
- loss of consciousness
- isolated homonymous hemianopia
ONE OF THESE MUST BE PRESENT
POCS involves the vertebrobasilar arteries
What features are more prevalent in haemorrhagic stroke?
- decrease in level of consciousness (seen in 50%)
- headache
- N&V
- seizures (in 25%)
but symptoms alone cannot be used to differentiate between haemorrhagic / ischaemic strokes
What cerebellar signs are associated with posterior circulation stroke?
DANISH
- D - dysdiadochokinesia
- A - ataxia (gait & posture)
- N - nystagmus
- I - intention tremor
- S - slurred, staccato speech
- H - hypotonia / heel-shin test
+ decreased consciousness
CEREBELLAR LESIONS GIVE IPSILATERAL SIGNS
What is the first line investigation in suspected stroke?
URGENT non-contrast CT head
performed to rule out haemorrhage
Whilst CT head is being arranged, what can be calculated?
ROSIER score
- a score of 1 or more suggests a stroke is likely
- score of 0 or less does not completely exclude stroke
risk of stroke in the emergency room
What blood tests may be performed in a suspected stroke?
serum glucose:
* hypoglycaemia can mimic stroke
U&Es
* to exclude hyponatraemia
cardiac enzymes:
* e.g. troponin
* to exclude a concomitant myocardial infarction
FBC:
* to check for anaemia or thrombocytopenia
* prior to initiation of thrombolysis / anticoagulants
What other investigations may be performed in suspected stroke?
- ECG
- continue to monitor vital signs for deterioration
