List I - Act Core Conditions Flashcards
What is a TIA?
- Temporary inadequacy of the of the circulation in part of the brain that clinically resembles a stroke, except that it is transient and reversible (it must completely return to normal)
- If TIA within last 7 days but completely resolved - 300mg aspirin + PPI and refer urgently for assessment within 24 hrs
- Duration is no more than 24 hours
- Most last <30 mins
How many people have a TIA?
- 50/100,000 in the UK
- More common increasing age
- M>F
- TIA will often preceed a stroke 15%
- Black race higher risk
What are the risk factors for TIA?
- HTN
- Smoking
- DM
- Heart disease - valvular, ischaemic, AF
- Peripheral arterial disease
- Polycythemia vera - increased RBC’s
- Carotid artery occlusion/bruit
- COCP - previous VTE risk, migraine with aura, coagulopathies
- Hyperlipidaemia
- Excess alcohol
- Cocaine / IVDU
What is thrombus?
- Local occlusion
What is embolus?
- Throw off a clot to somewhere else
Where do emboli occur?
- Carotids - bifurcation
- Heart - AF, mural thrombosis
- MI
- Atrial myxoma
- Valve disease
How do TIA’s present?
- Carotid territory - unilateral weakness/sensory symptoms arm, leg, face
- Dysarthria
- Broca’s dysphagia - expressive speech
- Amaurix fugax (fleeting loss of vision) - unilateral retinal ischaemia
- Vertebrobasilar territory
- Homonymous hemianopia
- Bilateral visual impairment (occipital lobe)
- Hemiparesis
- Hemisensory
- Diplopia/vertigo/vomiting/dysarthria/dysphagia/ataxia
What does the left (dominant hemisphere do in most people)?
- Speech - Broca’s
* Language
What does the right (non-dominant hemisphere do)?
- Spatial awareness
- Facial recognition
- Visual imagery
What is the acronym for remembering the cerebellar examination?
- DANISH
- Dysdiadochokinesia
- Ataxia (gait and posture)
- Nystagmus
- Intention tremour
- Slurred, staccato speech
- Hypotonia/heel-shin test
How do you clerk a patient with suspected TIA?
- Nature of event
- Witnessed
- Happened before
- Time from onset is essential to determine eligibility for acute stroke treatments such as tissue plasminogen activator (tPA)
- If time is unclear as what time the person was last known to be unaffected
- If the person awoke with symptoms the time of onset is defined as when the patient was last awake and symptom free
- Recent surgery - heart or carotids
- Prev stroke or CAD - simultaneous cardiac
- HTN
- DM
- Significant illnesses - hypercoagulable state or vasculitis
- Drug abuse - cocaine
How do you assess a patient with suspected TIA?
- A-E assessment
- Vital signs - BP, HR, O2, temperature, RR
- Full neurological - CN, upper and lower peripheral nerves, ataxia
- Cardiovascular - HR, BP in both arms, carotid bruit, peripheral pulses, look for signs of heart failure, arrhythmias (AF), murmurs, valvular heart disease, endocarditis
- FAST test can be used for rapid assessment - Face, Arm, Speech Test
- Fundoscopy to identify intraocular haemorrhage (1/7 present in people with aneurysmal SAH)
- Check blood glucose to rule out hypoglycaemia (<3.3mmol/L)
- ECG to rule out arrhythmias
What blood examination should you do for suspected TIA?
- FBC, ESR, U&E, lipids, glucose, sickle cell, syphillis
What is the secondary care management of TIA?
- Aspirin 300mg with 24hrs and be seen in specialist clinic
- PPI
- > 1/52 ago - see within 7 days in a specialist clinic
- Confirmed TIA - 75mg clopidogrel daily, high dose statin, modify BP
- Usually require further investigations - echo, carotid dopplers (70%) 72 hr ECG
- MRI - pick up an area of ischaemia
- Argument for full cardiac investigations - biggest cause of death after TIA is stroke
What should patients be made aware of after TIA?
- Cannot drive for 1 month following TIA
- Notify DVLA
- Multiple TIA’s over a short period require 3 months free before can resume driving
- Lorry drivers cannot drive for a year
What is the definition of ischaemic stroke?
- Sudden loss of blood circulation to an area of the brain resulting in residual neurological deficit lasting more than 24hrs or leading to death
Where can people most often have a stroke??
- ACA - supplies medial portions of the frontal and parietal lobes, anterior portions of the basal ganglia and anterior internal capsule
- MCA - supplies lateral portions of frontal and parietal lobes, anterior and lateral portions of the temporal lobes. Perforating branches - globus pallidus, putamen and internal capsule. It is the dominant source of vascular supply
- PCA - supplies the cortical branches, posterior and medial temporal lobes and occipital lobes. Also supplies the perforating branches which supply the thalamus and brain stem
Where is stroke most common?
- MCA
What is the pathophysiology of a stroke?
- Ischaemic neuron depolarised as ATP depleted and membrane ion-transport systems fail
- Na+/K+ impaired - intracellular Na+
What is the possible outcome of an ACA stroke?
- Disinhibition
What is the possible outcome of MCA stroke?
- Speech impairment
- Contralateral hemiparesis
- Contralateral homonimous heminopia
What is the possible outcome of PCA stroke?
- Movement problems?
* Locked in?
What is the possible outcome of lacunar stroke?
*
What are the important differentials for stroke?
- ALWAYS exclude hypoglycaemia
- CNS tumour
- Subdural bleed
- Todd’s/Bell’s palsy
- Consider drug overdose