CVA Flashcards
Stoke & Types
Sudden disruption in blood supply to the brain
* Haemorrhagic (15%)
* Ischaemic (85%)
Risk factors
- Age, race, history of migraines, family history
- HTN, cardiac disease, hypercholesterolemia, TIAs, DM, lifestyle, obesity, contraceptive
Haemorrhagic Stroke
- Occurs due to ruptured blood vessels or blood leakage into tissue
- Most common cause = HTN, usually in a weak area such as an aneurysm, or arteriovenous malformation
- Arteriovenous malformation is a tangle of blood vessels that leads to irregular connections between arteries and veins
Cerebral aneursym
- Weak bulging spot on the wall of an artery due to wear and tear, injury, infection, hereditary causes
Consequences
Intracerebral haemorrhage: when blood leaks into brain tissue and causes sudden increase in pressure = damage, unconciousness, death
Subarachnoid haemorrhage: bleeding between inner and middle layer of tissue, directly resulting from trauma or aneurysm rupture
Bleeding impedes blood flow to other parts of the brain tissue, and irritates/spasms other vasculature
Manifestations & assessment
- SAH: sudden onset headache, N&V, signs of meningitis (neck stiffness, photophobia)
- Decreased LOC and neurological dysfunction
- ICH: similar but less obvious & more based on neurological deficit = dizziness, muscle weakness, fluctuating LOC, difficulty breathing and speaking, also headache, nausea
Treatment
- Control bleeding (e.g. surgical embolisation)
- Lower BP & ICP (mannitol)
- Antiseizure meds
Ischaemic stroke & types
- Most common
- Caused by an obstruction of an artery to the brain tissue
- Thrombotic or embolic
- Often cardiogenic in origin, valvular or mural (usually left side of the heart)
Thrombotic ischaemic stroke
Large vessel thrombosis:most common, occurs in large cranial arteries
Small vessel: deep very small vessels are blocked
For large vessel strokes: motor weakness, slurred speech, facial droop, neglect or weakness are typical predictors
Embolic ischaemic stroke
- Blood clot that forms in one area of the body travels through the bloodstream and lodges in cranial artery
- Fat, air, plaque, fragments of cardiac clots
- Common cause is AF - blood doesnt pump effectively, becoming stagnant and clotting
Transient ischaemic attack (TIA)
- Transient obstruction to blood flow where no significant damage occurs
- Symptoms resolve within 24h
- MRI is essential to differentiate between TIA and stroke
Common symptoms
- Hemiparesis, sensory deficits, vision loss, facial drop, ataxia, vertigo, aphasoa, changes in LOC
Complications
Herniation/coning: brain tissue that gets pushed down or displaced to an area of lower pressure, due to increased cranial pressure
* Hemiplegia, dilated pupil, restlessness
* May require hemi craniotomy to relieve pressure
Cerebral oedema: common for large multilobe strokes, esp in young people who have no atrophy to allow room (ischemia disrupts BBB & ion gated channels and allows fluid to enter tissue)
* Change in LOC (early sign), neurological deficits, pupilliary changes (late sign) and resp changes
Midline shift: shift of the brain past the centre line due to ICP
* associated with failed pupilliary response to light
Dysphagia
Pneumonia: most common resp complication and cause of fever within 48h (from aspiration, ventilation, positioning, low GCS)
Assessments
- Assessment of all major organ systems starting with ABCs (prepare for airway intervention for haem stroke patients)
- Constant vital monitor to identify deterioration esp BP
- Head, neck and cardiac assessment to identify possible causes and symptom explanation
- Neurological examination (motor, sensory, cerebellar, gait, reflexes, language, GCS, cranial nerves)
- CT, MRI, bloods (cardiac markers, toxicology), angiography, coags
Treatment
- Reperfusion is the main immediate goal
- Thrombolytic medication or device to remove clot
- recombinant tissue plasminogen activator (Activated plasminogen to plasmin which breakd down fibrin clots - but increases risk of haemorrhage)
