Stroke Flashcards
Define stroke?
RAPIDLY developing clinical symptoms and/or signs of FOCAL, and at times global, loss of brain function, with symptoms lasting >24 hours or leading to death with no apparent cause other than that of vascular origin
Difference between a TIA and a stroke?
Strictly speaking, a TIA lasts <24 hours; however, for both, the disease process is the same
Anyone with either a TIA/stroke is at high risk of another. The risk decreases as more time passes
Different types of stroke?
- Haemorrhagic
- Infarct
- Subarachnoid haemorrhage
Imaging used for a diagnosis of stroke?
CT scan are often done as an emergency, esp. if the patient may require thrombolysis
The scan is used to differentiate between the 2 types of stroke, e.g:
• A clot (static blood) may be seen as an area/line of white on a CT
MRI scans (diffusion-weighted imaging) can be used if a patient has symptoms but a normal CT scan
Limitations of CT scan with ischaemic strokes?
Infarct may not initially be seen; once haemorrhage is ruled out but stroke symptoms are obvious, thrombolysis can be attempted
How is the decision of whether or not to thrombolyse made?
On balance of the risk (main one being haemorrhage) and benefits; consider:
- Age
- Time since onset
- Previous intracerebral haemorrhage/infarct (increases risk of bleeding due to necrotic tissue)
- Atrophic changes
- Hypertension, diabetes increase risk of haemorrhage
- Potential function that may be regained if thrombolysis works
What is the ONLY proven treatment for acute ischaemic stroke?
IV tPA (tissue plasminogen activator)
Disadvantages of tPA use?
Limited to <4.5 hours from onset of symptoms
Large and proximal clots are less likely to re-canalise
Overall recanalisation rate are only 40-50% (not all patients benefit)
What is endovascular therapy?
Alternative/additional therapy for patients who respond poorly; it is also used in patients who cannot be treated due to a high bleeding risk
Once a patient receives thrombolysis/thrombectomy, what must follow this?
Re-scan to check for haemorrhage due to thrombolysis
Do a swallow assessment to check if the stroke affected this ability (risk of aspiration)
Check nutrition and hydration Follow-up medication and DVT prevention
How is dysphagia managed?
Initial swallow assessment; if this is abnormal, they should be assessed by a speech and language therapist
They may require NG tube placement or a textured diet and thickened fluids, depending on their swallow; refer to a dietician for specialist nutritional assessment, advice and monitoring
Why is DVT prophylaxis required?
Stroke patients are at risk of DVT due to immobility
Measures that can be used for DVT prophylaxis in stroke patients?
Heparin (inc. LMWH) reduced DVT risk but the benefit is outweighed by the bleeding risk
TED stockings have no overall benefit
Intermittent pneumatic compression reduces the risk of DVT
How to screen for malnutrition?
MUST (Malnutrition Universal Screening Tool) is validated for use in stroke patients
Options for nutrition following a stroke?
If swallowing assessment is normal, oral intake is permitted (soft diet and normal fluids for 48 hours and then normal diet)
Texture modified diet (TMD)/thickened fluids (alters the rate at which food enters into the pharynx)
Patient may choose to eat/drink with knowledge of aspiration risk
Patient refuses food/fluid
Oral nutritional support (food first/oral supplements)
Artificial nutritional support
Nil by mouth (last resort and reviewed daily)
Disadvantages of modifying food and fluids?
Reduced palatibility, choice, texture and fatigue
Reduced intakes
Reduced nutritional value
Must be monitored
Secondary prevention of stroke involves?
Medication
Lifestyle changes:
• Smoking cessation
Carotid surgery
Long-term management of stroke patients?
Rehab and recovery
Types of haemorrhagic stroke?
Structural abnormality, e.g: AV malformation
Hypertensive
Amyloid angiopathy
Types of infarct/ischaemic strokes?
Cardioembolic (AKA red thrombus - formation is fibrin dependent
Atheroembolic (AKA white thrombus) - formation is platelet dependent
Small vessel - vessels of the brain narrow and a blockage develops in-situ:
- Arteriosclerosis
- Microatheroma of the ostium
- Embolism (athero and cardioembolism)
- Etc
Other
What should be identified via Ix in a stroke patient?
Presence of an infarct/haemorrhage:
- CT scan
- MRI scan
Aetiology of the stroke, using:
- Carotid scan
- Angiogram
- ECG, 24 hour tape (for AF)
- Echo
- Bubble TCD
- Bubble echo
Risk factors:
- Lipid profile
- BP
- Glucose
- Smoking
Differences in the long-term treatment of different type of ischaemic strokes?
Cardioembolic/AF - ANTI-COAGULATION (either warfarin or newer agents, not aspirin)
Other types - ANTI-PLATELETS (1st line is clopidogrel)
Secondary prevention of ischaemic strokes?
Medications:
- Anti-coagulation (cardioembolic / AF) OR anti-platelets (if not cardioembolic)
- Statins
Lifestyle measures:
- Manage BP
- Smoking cessation
- Diet and lifestyle advice
How to calculate stroke risk in those with AF?
CHA2DS2 VASc score:
- Congestive heart failure/LV dysfunction
- Hypertension
- Age ≥ 75
- Diabetes mellitus
- Stroke/TIA/thromboembolism
- Vascular disease
- Age 65-74
- Sex category, i.e: female
Each scores 1 point but age ≥ 75 and previous stroke/TIA/thromboembolism score 2; maximum score is 9
