Stroke Flashcards
What is the definition of a stroke?
Is sudden onset of focal or global neurological symptoms caused by ischaemia or haemorrhage and lasts more than 24hrs
What is a TIA?
Transient ischaemic attack
Is if symptoms resolve within 24hrs
What are the main causes of an ischaemic stroke?
Carotid plaque with arteriogenic emboli
Cardiogenic emboli - AF, valve disease and left ventricle thrombosis
Small artery disease
Carotid dissection
What are the risk factors of a stroke?
Previous stroke, age, male and FH
Smoking, Oestrogen pills, obesity, diabetes, alcohol, cocaine, high BP and cholesterol
What is the most important modifiable risk factor?
Hypertension
Esp. lacunar ischaemic strokes and small vessel haemorrhages esp. in brainstem, basal ganglia and subcortical areas
Describe AF and strokes
5 x increased risk of emboli with atrial fibrillation
More severe strokes
Anticoagulants reduce risk of ischaemic stroke
What is the anterior circulation of the brain?
2 x internal carotid arteries - 2 x anterior cerebral arteries and 2 x middle cerebral arteries
What is the posterior circulation of the brain?
2 vertebral arteries - 1 basilar artery
3 pairs of cerebellar arteries
2 posterior cerebellar arteries
Where are Borderzone anastomoses?
Between peripheral branches of anterior, middle and posterior cerebral arteries
Where does the carotid system supply?
Most of hemispheres and cortical deep white matter
Where does vertebro-basilar system supply?
Brainstem, cerebellum and occipital lobes
What are the functions of the frontal lobe?
High level cognitive functions
Memory
Motor control of speech
Motor cortex
Urinary continence
Emotion and personality
What are the functions of the parietal lobe?
Sensory cortex, sensation, awareness of parts of body, spatial orientation and ability to perform learned motor tasks
What are the functions of the temporal lobe?
Primary auditory area, comprehension of speech, visual, auditory and olfactory perception, learning and memory
What does an ACA and MCA more cause?
ACA - more leg than arm weakness
MCA - face and arm more than leg weakness
What is the function of the occipital lobe?
Primary visual cortex, visual perception and involuntary smooth eye movement
What are the clinical presentations of a stroke?
Sudden onset loss of function - motor, sensory, dysphasia, neglect, vision affected and gaze palsy
Ataxia, vertigo, and nystagmus
What classifies strokes?
Oxford Community Stroke Project Classification OCSP
What are the subtypes of strokes?
TACS - total anterior circulation stroke
PACS - partial anterior circulation stroke
LACS - lacunar stroke
POCS - posterior circulation stroke
Describe a total anterior circulation stroke (TACS)
Main artery to one hemisphere
Has 3 symptoms - complete hemiparesis/ numbness, loss of vision on one side and loss of awareness on non-dominant side or dysphasia dominant
Blocked carotid or middle artery
Describe a partial anterior circulation stroke
Branch of main artery
In between TACS and LACS
Has 2/3 of TACS criteria or one higher cortical defect (inattention or dysphasia) or monoparesis
Describe a lacunar stroke
Small perforating artery
Movement and sensation pathways
Weakness and numbness of face, arm and leg
May have dysarthria
Ataxic hemiparesis
No effect on higher function
Describe posterior circulation stroke (POCS)
Any posterior artery
Combination of symptoms - loss of balance, vertigo, double vision, dysarthria and visual loss
Describe a basilar artery occlusion
Ischaemia in pons, predominantly motor signs, bilateral but asymmetrical
Alteration of consciousness common
May present with reduced consciousness
What are some things which can mimic a stroke?
Seizures, syncope, sugar, sepsis, severe migraine, space occupying lesions, vestibular disorders, demyelination and mononeuropathy
What type of symptoms are more present in strokes?
Negative
Loss or reduction in CNS function
Loss of vision, sensation and limb power
Describe a migraine aura
Is due to cortical spreading depression
Classical spreading onset and causes visual disturbances
Can be sensory, motor and speech disturbance too
What is Hoover’s sign?
Test hip extension - weak
Test contralateral hip flexion against resistance - hip extension has become strong
What are the investigations used for a stoke?
Routine blood tests, CT/MRI, ECG and Holter, and carotid doppler US
Some patients may need Echo, cerebral angiogram and hyper-coagulable blood screen
What acute stroke treatment has biggest effect on individual?
Thrombolysis and thrombectomy
Thrombolysis by TPA
What stroke treatment has the biggest effect on most patients?
Stroke unit admission
What is the criteria for TPA use?
Use under 4.5hrs from symptom onset
Disabling neurological deficit
Symptoms more than 60 mins
Consent is obtained
What is the exclusion criteria for IV TPA?
Anything which increases risk of haemorrhage - blood on CT, recent surgery, recent episode of bleeding and coagulation problems
BP more than 185 systolic and 110 diastolic
Glucose more than 2.8 or less than 22mmol/l
What is used for secondary prevention of stroke?
Anti-hypertensives, anti-platelets, lipid lowering agents, warfarin for AF and carotid endarterectomy in ICA stenosis
