4. Stroke Flashcards
(49 cards)
What are the two main types of stroke?
1) Infarction (~80%)
2) Haemorrhage (~20%)
Outline how stroke symptoms arise.
1) Cerebral hypoperfusion results in a lack of ATP
2) Active membrane transport ceases
3) Action potential threshold is not reached
What are the key features of stroke symptoms?
- evolves suddenly (reflecting AP cessation)
- focal (only neurovascular units in the concerned vascular territory are affected)
- predominantly negative (reflecting loss of function due to AP cessation)
- symptoms fit into vascular territory
Which area of the brain do the anterior cerebral arteries (ACA) supply?
Anteromedial area of the cerebrum
Which area of the brain do the middle cerebral arteries (MCA) supply?
Lateral cerebrum
Which area of the brain do the posterior cerebral arteries (PCA) supply?
Medial and lateral areas of the posterior cerebrum
What is the most commonly used classification for ischaemic strokes?
Bamford stroke classification
Which artery is affected in total anterior circulation stroke (TACS)?
TACS is a large cortical stroke affecting areas of the brain supplied by the anterior circulation.
What are the features of TACS?
All three of the following:
1) unilateral weakness of the face, arm and leg
2) homonymous hemianopia
3) higher cerebral dysfunction (e.g. dysphasia, visuspatial disorder)
Which artery is affected in partial anterior circulation stroke (PACS)?
PACS is a less severe form of TACS, in which only part of the anterior circulation (MCA and ACA) has been compromised.
What are the features of PACS?
Two of the following:
1) unilateral weakness of the face, arm and leg
2) homonymous hemianopia
3) higher cerebral dysfunction* (e.g. dysphasia, visuspatial disorder)
*Higher cerebral dysfunction alone is also classified as PACS.
Which artery is affected in posterior circulation syndrome (POCS)?
POCS involves damage to the area of the brain supplied by the posterior circulation.
What are the features of POCS?
One of the following:
- cranial nerve palsy and a contralateral motor/sensory deficit
- bilateral motor / sensory deficit
- cerebellar dysfunction (e.g. vertigo)
- isolated homonymous hemianopia
Which artery is affected in lacunar strokes (LACS)?
LACS is a subcortical stroke occurring secondary to occlusion of lenticulostriate arteries.
What are the features of LACS?
No loss of higher cerebral functions, plus one of:
- pure sensory stroke
- pure motor stroke
- sensori-motor stroke
- ataxic hemiparesis
What is neurological stereotyping?
The episodic recurrence of neurological disturbance in an identical fashion with complete resolution in between.
When there is evidence of stereotyping, this is suggestive of stroke mimics.
What are the mechanisms that can result in ischaemic strokes?
TOAST criteria:
1) Large artery atherosclerosis (embolus or thrombosis)
2) small vessel occlusion (lacune)
3) cardioembolism
4) stroke of other determined aetiology
5) stroke of undertermined aetiology
What are the divisions of inrtacerebral haemorrhage?
- central / deep
- lobar haemorrhage
How can haemorrhagic vs ischaemic strokes be differentiated?
CT or MRI imaging
What are the complications of stroke?
Premature death - usually related to post stroke complications and not the immediate compromise of brain cells.
Recurrence of stroke due to suboptimal secondary prevention.
Extension of stroke into ischaemic penumbra due to delayed treatment.
Infections due to aspiration (LRTI) or incomplete bladder emptying (UTI).
VTE, constipation and bed sores due to immobility.
Post stroke pain and fatigue.
Muscle spasticity, contractures and secondary epilepsy.
What is included in the stroke bundle?
- admission to stroke unit
- revascularisation therapy
- optimising physiology via surveillance, prevention and early intervention of complications
- nutritional support
- secondary prevention
- rehabilitation and reablement
What are the three broad recovery trajectories following stroke?
Early, high functioning plateau (e.g. TIA, minor stroke) showing excellent functional prognosis.
Early, low functioning plateau (e.g. TACS) with no meaningful improvement in function as time passes, signifying poor functional prognosis.
Delayed, medium functioning plateau (e.g. PACS) in which patients benefit from sustained rehabilitation efforts until a functional plateau is reached.
What are the rules on driving following a stroke?
4-week period of driving restriction applies for standard car licenses.
1-year period of driving restriction applies for HGV licenses.
Residual field dysfunction is subjected to separate requirements before license reinstatement.
Persisting impairments is not an automatic disqualification - referral to Regional Driving Assessment Centres needed.
What is the FAST test?
FAST test can help you recognise the most common signs of a stroke:
- facial weakness
- arm weakness
- speech problems
- time (acute onset)
If a patient is FAST positive, urgent assessment by stroke team required.
