Stroke symposium Flashcards
Incidence of stroke in the UK per year
- Over 100,000 people in the UK have a stroke per year
How many neurons die per min in stroke
- 1.9 million neurons die/min in stroke
General symptoms of a stroke
- Sudden onset of focal neurological or monocular symptoms
- Symptoms and signs should fit within a vascular territory
- Negative symptoms rather than positive symptoms(
- Vascular injury often shows negative symptoms
Classic presentation of an ACA infarct
- Predominantly the contralateral lower limb
Classic presentation of left MCA infarct
- Dysphasia, right sided weakness/numbness
Classic presentation of right MCA infarct
- Neglect, left sided weakness/numbness
Classic presentation of brainstem infarct
- May involve diplopia, visual field defect, facial weakness, facial weakness, contralateral limb weakness/numbness, incoordination
Differential diagnosis of bell’s palsy and facial weakness caused by a stroke
- Upper motor neurons, such as a stroke, cause contralateral face weakness sparing the forehead due to the bilateral innervation of the occipitofrontalis muscle
- While lower motor neuron lesions, such as a facial nerve injury causing bell’s palsy, typically cause weakness involving the whole ipsilateral face
Two types of strokes
Ischemic - Either thrombotic or embolic
Haemorrhagic - often due to a rise in blood pressure. Eg from an aneurysm , arterio-venous dysplasia.
First test when a stroke is suspected
- CT scan
What are watershed cerebral infarctions
- Also known as border zone infarcts, occur at the border between cerebral vascular territories where the tissue is furthest from arterial supply and thus most vulnerable to reductions in perfusion
What type of infarct may not always show up immediately on a CT scan
- Ischaemic
How might a haemorrhagic infarct show on a CT scan
- Hypertension bleed
Normal physiological blood flow to the brain
- 50 ml/100g/min
Blood flow level at which electrical function stops
<20ml/100g/min
- Neurones still alive
- Potentially salvageable
- Reversible ischaemia limited time
Blood flow level at which neuronal death begins to occur
<10ml/100g/min
- Neuronal death within mins - irreversible ischaemia - cerebral infarction
What is the efficacy of thrombolysis for stroke treatment dependent on
- Time
- Due to neuronal damage over time
- Length of clot
What is the NIHSS
- NIH stroke scale for quantifying the severity of a stroke