Stroke Flashcards
What is a stroke ?
Neurological deficit of sudden onset
Lasting more than 24hrs
Of vascular origin
When does a transient ischaemic attack occur ?
<24hrs
What is the epidemiology of stroke ?
1/4 people worldwide will have a stroke One stroke every 5 mins in the UK 1/8 pateints die within first 30 days 3rd biggest killer in Scotland 50% of survivors ae dependent on others
What is the cause of stroke ?
Blockage with thrombus or clot
Disease of vessel wall
Disturbance of normal properties of blood
Rupture of vessel wall
What % have a ischaemic stroke ?
85-90%
What % have a haemorrhagic stroke ?
10-15%
What is the most important modifiable risk factor ?
Hypertension
What is the risk of smoking ?
2-fold increased risk of ischamic stroke
3-fold increased risk for sub-arachnoid haemorrhage
What are the risk factors for stroke ?
Hypertension Current smoker Waist to hip ratio Diet Diabetes Alcohol Stress/depression Cardiac causes Bleeding disorders Family history Ratio of ApoB to ApoA Oral contraceptive with high oestrogen
What is the pathophysiology of haemorrhage ?
Hypertension Amyloid Excess alcohol Hypocholesterolaemia Haemorrhagic transformation
What is the pathophysiology of iscahemic stroke ?
Ischaemia results from failure of cerebral blood flow to a part of the brain
Ischamia can be transient- TIA
Ischamia results in varying degrees of hypoxia and hypoglycaemia
What is anoxia ?
No oxygen
What can anoxia lead to ?
Results in infarction- leads to necrosis - completed stroke
What is the timing for stroke symptoms ?
Come on quickly
What are the symptoms of stroke ?
Motor (clumsy or weak limb) Sensory (loss of feeling) Speech- Dysphagia/ dysarthria Neglect/ visuospatial problems Vision- loss in one eye or hemianopia Gaze palsy Ataxia/ vertigo/ Incoordination/ nystagmus
What do most symptoms present with ?
Loss of function
What are the symptoms of arterial cerebral artery occlusion ?
Paralysis of contralateral foot and leg
Sensory loss over contralateral toes, foot and leg
Impairement of gait and stance
What are the symptoms of middle cerebral artery occlusion ?
Contralateral paralysis of face arm and leg
Contralateral sensory impairement
Contralateral homonymous hemianopia
Gaze paralysis to opposite side
Aphasia if stroke on the dominant side
Unilateral neglect for half of external space if non-dominant stoke
What are the symptoms of lacunar stroke ?
Pure motor stroke
Pure sesnory stroke
Dysarthria- clumsy hand syndrome
Ataxic hemiparesis
What are posterior circulation symptoms ?
Brain stem/ cerebellum/ thalamus/ parts of occipital and temporal lobes are involves
Coma, drop attacks, vertigo, nausea, vomiting, cranial nerve paralysis, ataxia
Hemiparesis, hemisensory loss
Crossed sensori-motor deficits
Visual fields deficits
What are the stroke subtypes ?
TACS- total anterior circulation stroke
PACS- partial anterior circulation stroke
LACS- lacunar stroke
POCS- posterior circulation stroke
What are the associated diseases of stroke ?
Previous TIA or stroke BP poorly controlled Angina MI Peripheral vascular disease Aortic aneurysm Carotid bruits Renovascular disease Cocaine/ alcohol abuse
What is the aim of treatment for stroke ?
Protect the damaged brain before ischaemia becomes cell death
Get rid of clot
Prevent the clot happening in the first place
What are the acute therapies for stroke ?
Restore blood supply Prevent extension of ischaemic damage Protect vulnerable brain tissue Avoid reperfusion injury Be non-toxic
What is the main treatment for stroke ?
Thrombolysis
What agent is used in thrombolysis ?
Altepase
What are other treatment of stroke ?
Antiplatelets
Statins
BP management
Anticoagulation- apixaban, rivaroxaban
What are the investigations for stroke ?
CT scan: - First choice - Advanced imaging will help if avaible - CT scan hair lines MRI: - Safety issues with MRI - Fast-field cycling MRI- low magnetic field CT angiogram
