Strokes Flashcards
Define a stroke
- Stroke is any sudden onset in neurological deficit
- Can be Ischaemic or Haemorrhagic (Intracerebral + subarachnoid hemorrhage)
- Lack of blood supply leads to irreversible cell death
What’s the difference between a TIA and stroke?
A stroke is is focal neurological deficit lasting 24+ hrs with infarction
What are 2 types of stroke?
Haemorrhagic and ischaemia
Describe an ischaemic stroke
- Arterial embolism occludes a vessel resulting in infarction
- Sites such as carotids, vertebral or basilar arteries
- 80-90% of strokes
Describe a haemorrhagic stroke
- Rupture of blood vessel, leads to infarction
- May also caused raised ICP
- 10-20% of strokes
Describe the pathophysiology of an ischaemic stroke
- Caused by occlusion of blood vessels by a clot
- Infarcted area dies causing permanent deficit, penumbra surrounding may regain function with recovery
What are causes of ischaemic stroke?
Anything that increases the risk of an embolus forming
- Atherothromboembolism - e.g. from carotid artery
- Cardioembolsim - AF, post MI, valve disease, IE
- Hyperviscosity syndrome - e.g. Waldenstrom’s macroglobulinemia, polycythaemia vera
- Hypoperfusion - systemic blood loss
- Vasculitis
- Fat emboli - long bone fracture
- Venous sinus thrombosis - infection, injury, pregnancy, inflammatory conditions (very rare only 1%)
Risk factors for strokes?
Increasing age >65*
Hypertension*
Smoking*
Male
Diabetes
Recent/past TIA
Black, Asian
What are investigations for stroke?
- Immediate CT scan -
Distinguish ischaemic from haemorrhagic, shows site of infarct, may be negative in
first few hours - Diffusion-weighted MRI -
More sensitive, for confirmed diagnosis - Blood tests -
Glucose (rule out hypoglycaemia), FBC (polycythaemia), ESR (vasculitis), U&Es,
cholesterol, INR (if on warfarin) - ECG -
In AF or MI
What are the 4 types of stroke in Bamford stroke classification?
- Total anterior circulation stroke (TACS)
- Partial anterior circulation stroke (PACS)
- Lacunar syndrome (LACS)
- Posterior circulation syndrome (POCS)
What is the criteria needed for total anterior circulation stroke (TACS)?
3 of the following:
- Unilateral weakness (and/or sensory deficit of the face, arm and leg
- Homonymous hemianopia
- Higher cerebral dysfunction (dysphasia, visuospatial disorder)
What is the criteria for partial anterior circulation stroke (PACS)?
2 of the following
- Unilateral weakness (and/or sensory deficit) of the face, arm and leg
- Homonymous hemianopia
- Higher cerebral dysfunction (dysphasia, visuospatial disorder)
What is the criteria of lacunar syndrome (LACS)?
1 of the following
- Pure sensory stroke
- Pure motor stroke
- Sensori-motor stroke
- Ataxic hemiparesis
What is the criteria for posterior circulation syndrome (POCS)
1 of the following:
- Cranial nerve palsy and a contralateral motor/sensory deficit
- Bilateral motor/sensory deficit
- Conjugate eye movement disorder (eg. gaze palsy)
- Cerebellar dysfunction (eg. ataxia, nystagmus, vertigo)
- Isolated homonymous hemianopia or cortical blindness
What does clinical presentation of a stroke depend on?
Size and location of the infarct
