2- Stroke: Summary (1) Flashcards
1
Q
define stroke
A
Stroke
“a neurological deficit attributed to an acute focal injury of the central nervous system (CNS) by a vascular cause, including cerebral infarction, intracerebral hemorrage (ICH), and subarachnoid hemorrhage (SAH)”
2
Q
physiology of stroke
A
- stroke symptoms are caused by hypoperfusion in the endothelial lumen
- this reduces oxygen and glucose which in turn reduces ATP synthesis in neurovascular unit
- this leads to impairment of energy dependent cell processes → causes action potential arrest
- this reduces neuronal transmission
3
Q
TIA
A
“a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction.”
- symptoms usually resolve <24hr
4
Q
types of stroke
A
- Ischaemic (85%)
- thromboembolic
- Haemorrhagic (10%)
- Intracerebral
- Subarachnoid
- Other (5%)
- Dissection
- Venous sinus thrombosis
- Hypoxic brain injury
5
Q
causes of stroke in the young…
A
- Vasculitis
- Thrombophilia
- Subarachnoid haemorrhage
- Venous sinus thrombosis
- Carotid artery dissection e.g. via near strangling or fibromuscular dysplasia
6
Q
causes of stroke in the old…
A
- Thrombosis in situ
- Athero-thromboembolism e.g. from carotid arteries
- Cardiac emboli (e.g. atrial fibrillation, infective endocarditis or MI)
- CNS bleed associated with hypertension, head injury, aneurysm rupture)
- Sudden blood pressure drop by more than 40 mmHg
- Vasculitis e.g. giant cell arteritis
- Venous sinus thrombosis
7
Q
key causes o
A
8
Q
RF for stroke
A
- HTN
- smoking
- DM
- heart disease
- valvular
- ischaemic
- atrial fib
- peripheral arterial disease
- Post-TIA (high risk pf early stroke)
- carotid artery occlusion
- polycythemia vera
- COCP
- hyperlipidaemia
- excess alcohol
- clotting disorders
9
Q
RF for stroke
A
- HTN
- smoking
- DM
- heart disease
- valvular
- ischaemic
- atrial fib
- peripheral arterial disease
- Post-TIA (high risk pf early stroke)
- carotid artery occlusion
- polycythemia vera
- COCP
- hyperlipidaemia
- excess alcohol
- clotting disorders
10
Q
stroke presentation
A
will be dependent on which cerebral artery is affected → ref to Bamford/oxford classification
general signs and symptoms:
- Sudden numbness or weakness in the face, arm, or leg, especially on one side of the body.
- Sudden confusion, trouble speaking, or difficulty understanding speech.
- Sudden trouble seeing in one or both eyes.
- Sudden trouble walking, dizziness, loss of balance, or lack of coordination
11
Q
DD for stroke
A
- Always exclude hypoglycaemia as a cause of sudden-onset neurological symptoms.[6]
- TIA in the first 24 hours of the stroke.
- Brain tumour.
- Subdural haematoma.
- Todd’s palsy.
- Consider acute poisoning if the patient is comatose.
12
Q
investigations for stroke
A
-
Bedside
- BP
- ECG
- BMs
-
Blood tests
- FBC
- test for sickle cell
- thrombophilia screen
- ESR- giant cell arteritis
- syphillis
- blood culture (endocarditis)
-
Brain imaging
- non-enhanced CT scan
- CT contrast angiography
-
Further investigations
- carotid duplex US
- Echocardiogram
- CXR
- 24hr tape
13
Q
brain imaging for strpke
A
Brain imaging with non-enhanced CT should be undertaken immediately if the patient:
- Has indications for thrombolysis or early anticoagulant treatment.
- Is currently taking anticoagulant treatment.
- Has a known bleeding tendency.
- Has a depressed level of consciousness (Glasgow Coma Score below 13).
- Has unexplained progressive or fluctuating symptoms.
- Has papilloedema, neck stiffness or fever.
- Has severe headache at onset of stroke symptoms.
14
Q
when should imaging with CT contrast angiography be performed
A
if thrombectomy might be indicated.[
15
Q
when should imaging occur
A
s soon as possible and within 24 hours of symptom onset in everyone with suspected acute stroke without indications for immediate brain imaging.
16
Q
assessments used after initial stroke presentation
A
NIHHS
17
Q
general management of stroke
A
Maintenance of homeostasis
* Oxygen therapy \<95% * Optimum blood sugar control * blood pressure control
Screening:
* swallow screen prior to any oral food, fluid or medication * malnutrition screen
-
Anti-platelet therapy
- Short term: 300mg Aspirin daily for TIA and ischaemic stroke
- Long term: clopidogrel 75mg daily
-
If ischaemic stroke:
- Alteplase- thrombolytic treatment (if fit in with guideline)
- anticoagulants should not be used untill haemorrhage has be excluded
- Thrombectomy
If haemorrhagic stroke: follow guidelines
- Stops drugs which suppress CNS e.g. sedatives
- Stop anticoagulants
- Contact neurosurgery
General
- do not start new statin treatment immediately
- patient should be encouraged to sit out of bed, stand or walk as their condition permits→ active management programme
- physio/OT/SALT input throughout
18
Q
acute management of ischaemic stroke
A
REPERFUSION
Opening up the blocked vessel in ischaemic stroke to reperfuse the ischaemic brain
-
Thrombolysis = clot busting
- Alteplase
- Thrombectomy = mechanically removed clot
19
Q
thrombolysis MOA
A
20
Q
when is thrombolysis appropriate
A
- Clinical diagnosis of acute ischaemic stroke causing one or more of an NIH score ≥ 4, aphasia, binocular visual field deficit, a swallowing deficit.
- Imaging appearances consistent with ischaemic stroke
- Symptom-onset within 4.5 hours prior to initiation of thrombolysis treatment
- give as early as possible
- The old benefit as much as the young
- No contraindications (think bleeding risk)
- E.g. bleeding tendencies which could make them more likely to haemorrhage
21
Q
why use thrombolysis
A
- Opens up blocked vessels
- Improves independence
22
Q
main complication of thrombolyis
A
haemorrhage
- make sure patient has CT before and after to check
23
Q
thrombectomy
A
- Other way of opening up blood vessels
- Mechanical
*
24
Q
Acute ischaemic stroke- not all about tPA
A
Early secondary prevention works
- Aspirin
- Initiate statin
- Control BP
-
Anticoagulated if in AF
- Timing depends on stroke severity
- DOAC now used 1st line
- No role for antiplatelet
- Carotid surgery
25
acute management of intracerebral haemorrhage
* Reversal of coagulopathy
* BP lowering \<150mmHg if hypertensive
* Surgery only if
* haemorrhage with hydrocephalus
* lobar haemorrhage with GCS between 9 and 12
* cerebellar haemorrhage
**What doesn’t work?**
* Surgery
* Steroids
* Platelets
* VTE prophylaxis with compression stockings or LMWH
* Aspirin!
26
complications after stroke
* Pneumonia
* Sit up
* Safe swallow
* Early identification and treatment
* Seizures
* Pressure sores
* Prevention through positioning/turning/pressure relief
* Dehydration/malnutrition
* IV fluids/NG
* Early dietician involvement
* Constipation
* Hydration
* Laxatives
* Enemas
* Incontinence/ retention
* Depression
* Spasticity
* DVT
27
primary prevention of stroke
* control blood pressure
* minimise cholesterol levels e.g. with statins
* prevent and control diabetes mellitus
* treat atrial fibrillation.
28
stroke secondary prevention toolbox i.e. after first stroke
* Antithrombotic therapy (antiplatelet versus anticoagulation)
* BP control(average BP\<130/80)
* Lipid control (t. chol\<4, LDL chol\<2)
* Glycaemic control (HbA1c \<7)-
* Carotid endarterectomy (symptomatic ICA \>50% lumen reduction NASCET)
* Lifestyle changes (smoking cessation, weight loss, optimisation of sleep, exercise)
* Other interventions
29
key causes of stroke which can be treated with secondary prevention
* Atrial fibrillation
* Metabolic syndrome
* obesity
* HTN
* insulin resistance
* dyslipidaemia
* Carotid disease
30
atrial fibrillation
* commonest cause of stroke
* causes severe stroke due to larger size of clots from heart
* with increasing age comes increased risk of AF
* identification
* ECG and 24hr tape
31
management of AF and stroke
* risk of stroke assessed with CHA2DS2VASc
* anticoagulation → DOACs
* edoxaban
* HASBLED assess bleeding risk
* left atrial appendage closure alternative to anticoagulation
32
management of temporal arteritis to prevent stroke
steroid therapy ideally before vascular complication
33
managing/ preventing metabolic syndrome
* BP control(average BP\<130/80)
* Lipid control (t. chol\<4, LDL chol\<2)
* Glycaemic control (HbA1c \<7)
* Lifestyle changes (smoking/recreational drug use cessation, weight loss, optimisation of sleep, exercise, alcohol reduction or cessation)
* Others (eg stop OCP/HRT)
34
carotid disease and stroke
¡Disease progression§Laminar flow§Endothelial injury and repair§¡Stroke mechanisms – the unstable plaque and “symptomatic carotid disease”¡¡Intervention
35
carotid disease management
Best medical therapy
1.Smoking cessation
2.Aggressive BP control
3.Dual antiplatelet therapy
4.High dose statin therapy
5.Maintenance of good glycaemic control in diabetics
Carotid endarterectomy (CEA)
* NASCET threshold 50% lumen reduction
* Suitability for surgery and the assessment of benefit vs risk
* Timing of surgery
Carotid artery stenting (CAS) vs. CEA
