Cerebrovascular Disease Flashcards
Define a TIA
A sudden onset focal neurological deficit, resolving in under 24 hours
Modifiable risk factors for a stroke
Diabetes, raised cholesterol, hypertension, smoking, alcohol, obesity, drug abuse, infections
Pathophysiology of an ischaemic stroke
Blood clot stopping blood flow to an area of the brain
Can de due to:
- a thrombus in situ (small vessel disease)
- an embolism from the heart/aortic arch/carotid artery
- vasculitis
- cryptogenic (no cause identified)
Pathophysiology of a haemorrhagic stroke
Bleed in to the brain after rupture of diseased/weakened blood vessels
Primary bleed - usually due to hypertension
Secondary bleed - underlying cause eg. vascular abnormality/tumour/iatrogenic eg. Anticoagulants
Unmodifiable risk factors for stroke
Male, age, family history, previous stroke/TIA
Describe blood supply of the anterior cerebral artery
Supplies the anteromedial cerebrum
Part of the frontal and parietal lobes
Describe blood supply of the middle cerebral artery
Lateral cerebrum
Parts of the frontal, parietal, and temporal lobes
Describe blood supply of the posterior cerebral artery
Supplies the medial and lateral parts of the posterior cerebrum
Supplies the temporal and occipital lobes and the midbrain and thalamus
Which blood vessel is most commonly involved in a stroke?
Middle cerebral artery
Describe a Total Anterior Circulation Stroke (TACS)
Occlusion occurs in the ICA or the proximal MCA
Causes hemiparesis, hemisensory loss, hemianopia, higher cortical dysfunction (eg. Dysphasia, visuospatial disorders)
Usually due to a cardiac emboli
Poor prognosis - 50% mortality
Describe a Partial Anterior Circulation Stroke
Occlusion of MCA, usually due to large vessel disease eg. Carotids/arch of aorta
Causes 2 of hemiparesis/hemisensory loss/hemianopia or higher cortical dysfunction
Describe a Lacunar Stroke
Occlusion of a single perforating artery, due to small vessel disease ie. Atheroma in situ
Gives a pure motor or pure sensory deficit
Describe a Posterior Circulation Stroke
Leads to cranial nerve palsies, motor and sensory loss, cerebellar dysfunction, visual field defects
Can have any cause
Define stroke
A sudden onset focal neurological deficit, lasting over 24 hours
Symptoms of a stroke in the frontal lobe region
Muscle weakness (hemiparesis) Expressive dysphasia (brocas) Personality/behaviour changes
Symptoms of a stroke in parietal lobe
Hemisensory loss (primary sensory cortex) Visuospatial deficit Inferior quadrantanopia (superior optic radiation)
Symptoms of stroke in temporal lobe
Loss of auditory/vestibular function Taste and smell dysfunction Receptive dysphasia (wernickes) Memory loss Superior quadrantanopia (inferior optic radiation)
Symptoms of stroke in occipital lobe
Loss of vision
Symptoms of stroke affecting the cerebellum
Dysdiadokokinesia Ataxia Nystagmus Intention tremor Scanning speech Hypotonia
Stroke differential diagnosis
Hypoglycaemia
Epilepsy
SOL
MS
Investigations of stroke
CT head - to look for bleeding/infarct
Carotid ultrasound/cardiac investigations
Coagulation profile
Management of ischaemic stroke
Thrombolysis - give rTPA, give <3hrs of symptom onset (<4.5hrs if patient <80yrs), only if INR<1.7
Thrombectomy/craniotomy
Carotid endarterectomy (if carotid embolus suspected)
Secondary prevention: Aspirin, risk factor reduction
Management of haemorrhagic stroke
Reverse any anticoagulation
Craniotomy
Secondary prevention: control of BP
Mechanism of action of rTPAs
Give some examples
rTPAs = recombinant Tissue plasminogen activator
Convert plasminogen to plasmin, which acts to cleave fibrin and break down blood clot.
Eg. Alteplase, Reteplase
Give some contraindications for thrombolysis
History of haemorrhagic stroke Active peptic ulcer Recent trauma or surgery CNS neoplasm Uncontrolled hypertension Coagulopathies
