OPIC - Stroke Flashcards
Transient Ischaemic Attacks (TIAs)
Definition
Referral Criteria
Investigations
Management
1.) Definition - focal neurological deficits due to reduced blood supply to the brain, lasting <24 hours
- negative sx which are sudden and maximal at onset
- patients make a complete recovery
2.) Referral Criteria - seen by stroke/TIA specialist
- urgent admission: >1 TIA (‘crescendo TIA’) or suspected cardioembolic source or carotid stenosis
- assessment within 24hrs: TIA in the last 7 days
- assessment within 7 days: TIA been > 7 days
- ABCD2 Score was previously used to risk stratify
3.) Investigations
- MRI-brain w/ diffusion weighted imaging: to detect ischaemic territory or haemorrhage
- carotid USS: if candidate for carotid endarterectomy
- CT-Head: if suspecting haemorrhagic stroke (on anticoagulants or bleeding disorder) or an alternative
4.) Management
- PO aspirin (300mg) OD until diagnosis established (unless contraindicated)
- lifestyle modification, control BP and hyperlipidaemia
- carotid endarterectomy if carotid stenosis
- cannot drive for 1 month (3 months if recurrent)
Types of Strokes
Ischaemic
Haemorrhagic
Others
1.) Ischaemic (85%)
- TOAST classification used for underlying aetiology:
- 1: large artery atherosclerosis (embolus/thrombosis)
- 2: small-vessel occlusion, 3: cardioembolism (AF)
- 4: other aetiology, 5: undetermined aetiology
2.) Haemorrhagic (10%)
- primary: hypertension, cerebral amyloid angiopathy
- hypertensive bleeds tend to be deep so are present in the basal ganglia and cerebellum
- lobar (peripheral) haemorrhages have varied causes e.g. tumour, vascular (cerebral amyloid angiopathy)
- secondary: trauma, anticoagulation-associated
3.) Other (5%)
- dissection: separation of artery walls –> occlusion
- venous sinus thrombosis: vein occlusion causes back pressure and ischaemia due to ↓blood flow
- hypoxic brain injury: e.g post-MI
Stroke
Definition
Risk Factors
Clinical Features/Differentiating Stroke Mimics
Differential Diagnoses/Stroke Mimics
1.) Definition - focal neurological deficit lasting >24hrs or w/ imaging evidence of brain damage
- negative sx which are sudden and maximal at onset
2.) Risk Factors
- ↑age, FH, previous stroke/TIA/heart attack
- women: pregnancy, (pre-)eclampsia, gestational diabetes, OCP, post-menopausal HRT
- HTN, diabetes, hyperlipidaemia, smoking, obesity
- cardiovascular disease (esp AF), sickle cell anaemia
- haemorrhagic: age, HTN, AVM, anti-coagulated
3.) Clinical Features/Differentiating Stroke Mimics
- sx are focal, sudden, and predominantly negative
- sx do not migrate and are not sequential
- sx are not stereotyping (episodic recurrence in an identical fashion with complete resolution in between)
- haemorrhagic strokes more likely to have headaches, N+V, seizures, and decreased levels of consciousness
4.) Differential Diagnoses/Stroke Mimics
- seizures/post-ictal state: especially focal seizures
- migraine w/ aura, especially a hemiplegic migraine
- systemic infection: sepsis, meningitis
- encephalopathy: encephalitis, hyperglycaemia (HHS), hypoglycaemia, hyponatraemia, hepatic
- SOL: intracranial haemorrhages, abscesses, tumours
- transient global amnesia: no focal deficits
Assessment Tools Used in Stroke
FAST
ROSIER Scale
Oxford/Bamford Classification (OCSP)
National Institute of Health Stroke Score (NIHSS)
Modified Rankin Score
Anticoagulation in AF Patients
1.) FAST - PH campaign for quick stroke recognition
- face: ask them to smile, is one side drooping?
- arms: ask them to raise their arms, is one side weak?
- speech: ask them to speak, is their speech slurred?
- time to call 999 at the first sign of a stroke
2.) ROSIER Scale - distinguish stroke and stroke mimic
- score of 0 or below suggests stroke is unlikely
3.) Oxford/Bamford Classification - used to identify the vascular region based on sx for an ischaemic stroke
4.) National Institute of Health Stroke Score (NIHSS)
- structured neuro exam used to assess stroke severity
- assesses consciousness, CN (visual), motor, sensory, dysphasia, cerebellar, inattention/neglect
- min = 0 (normal), max = 42 (worst ever stroke)
- score <12 = 80% good outcome, >20 = <20%
5.) Modified Rankin Score - disability assessment of the patient 4 weeks before current stroke presentation
- can be used to decide whether it’s worth attempting thrombolysis on a patient
- 0 = normal, 5 = severe disability
6.) Anticoagulation in AF Patients
- CHADS-VASC2: suitability for anticoagulation in AF
- HAS-BLED: risk of bleeding if on anticoagulation
Oxford/Bamford Classification for Strokes
Total Anterior Circulation Stroke (TACS)
Partial Anterior Circulation Stroke (PACS)
Posterior Circulation Stroke (POCS)
Lacunar Stroke (LACS)
1.) TACS - all 3 of:
- motor OR sensory loss of at least 2 areas of FAL
- homonymous hemianopia w/o macular sparing
- higher cerebral dysfunction: dysphasia OR neglect
2.) PACS - any 2 of the 3:
- motor OR sensory loss of at least 2 areas of FAL
- homonymous hemianopia w/o macular sparing
- higher cerebral dysfunction: dysphasia OR neglect
3.) POCS - one of the following:
- CN palsy + contralateral motor OR sensory deficit
- bilateral motor/sensory deficit
- cerebellar stroke: prolonged dizziness and N+V, vertical nystagmus, difficulty standing w/o support
- brainstem syndromes: Wallenberg (PICA infarct, medullary), lateral pontine syndrome
- a conjugate eye movement disorder
- homonymous hemianopia w/ macular sparing
- cortical blindness
4.) LACS - one of the following:
- pure sensory or motor deficit
- sensorimotor deficit
- ataxic hemiparesis
Management of Strokes
General Management of Ischaemic Stroke
Carotid Endarterectomy
General Management of Haemorrhagic Stroke
Decompressive Hemicraniectomy
1.) General Management of Ischaemic Stroke
- thrombolysis with alteplase if < 4.5hrs of onset
- PO/PR aspirin (300mg) after excluding haemorrhagic
- aspirin continued for OD for 2wks then lifelong PO clopidogrel 75mg (OR aspirin 75mg + MR dipyridamole)
- in AF, start anticoagulation after 2 weeks
- lifestyle: smoking cessation, weight loss, control BP and hyperlipidaemia (TC <3.5)
- cannot drive for 1 month (1y for HGV licences)
2.) Carotid Endarterectomy - ischaemic stroke or TIA
- patients with stable neurological symptoms
- carotid stenosis >50%(NASCET) or >70% (ECST)
- referred w/in 1wk, treated w/in 2wks of onset of sx
3.) General Management of Haemorrhagic Stroke
- supportive, most do not qualify for surgery
- control BP: for patients presenting with sysBP >150, must be lowered to <140 for at least 7 days
- stop +/- reverse anticoagulation: vitK+PCC for warfarin, tranexamic acid +PCC for NOACS
4.) Decompressive Hemicraniectomy - haemorrhagic
- in severe MCA infarct showing rapid neurological deterioration to prevent malignant MCA syndrome
- referred w/in 24h, treated w/in 48h of onset of sx
- <60, NIHSS 15+, infarct >50% of MCA (on CT)
- other criteria for surgical intervention: cerebellar haemorrhage >3cm and deteriorating, obstructive hydrocephalus, structural lesion
Thrombolysis
Usage
Indications
Absolute Contraindications
Complications
1.) Usage - breakdown blood clots in ischaemic strokes using IV alteplase (tissue plasminogen activator)
- ↑ fibrin degradation by activating plasminogen
- can also be used in a STEMI or severe VTE
- infusion: over 1hr, 10% stat , 90% infused over 58mins
- dosage is weight dependent so must be weighed
- 30% chance of improvement, 5% chance of bleeding
2.) Indications
- can be given within 4.5hrs of stroke onset (onset of symptoms or when last seen well)
- exclude haemorrhage stroke: normal/ischaemic CT
- >16yrs, NIHSS > 6, mRS 0-2
3.) Absolute Contraindications
- previous ICH, suspect SAH, active bleeding, recent GI bleed, oesophageal varices, bleeding disorders
- seizure (stroke onset), brain tumour, stroke/traumatic brain injury in preceding 3mths, LP in last 7 days
- pregnancy, uncontrolled HTN >200/120, AVM
- recent history of pericarditis, bacterial endocarditis, acute pancreatitis, GI ulcers
4.) Complications
- intracranial haemorrhage: patient will deteriorate, must stop and get another CT to exclude
- hypertension: must try and reduce BP
- angioedema: contralateral to ischaemic hemisphere, must treat like anaphylaxis
Thrombectomy
Usage
Proximal Anterior Circulation Occlusion
Proximal Posterior Circulation Occlusion
1.) Usage - surgical removal of blood clots
- use depends on the clot location and stroke onset
- criteria: NIHSS 6+, mRS 0-2
2.) Proximal Anterior Circulation Occlusion - must be confirmed via CT or MR angiography
- can be performed within 6hrs of stroke onset, often also done along with thrombolysis (if <4.5 hrs)
- can be performed between 6 to 24 hrs of stroke onset if potential to salvage brain tissue, as shown by via CT perfusion or diffusion-weighted MRI sequences
3.) Proximal Posterior Circulation Occlusion - basilar or PCA, must be confirmed via CT or MR angiography
- consider within 24hrs of stroke onset if also done alongside thrombolysis (<4.5 hrs)
- must be potential to salvage brain tissue, as shown via CT perfusion or diffusion-weighted MRI sequences
Supportive Management in Strokes
BP Management
Fluid and Glycaemic Control
Feeding Assessment and Management
Barthel Index (BI)
1.) BP Management
- anti-hypertensives should only be used post-ischaemic stroke if there is a hypertensive emergency:
- Hypertensive encephalopathy/nephropathy/HF/MI, aortic dissection, or pre-eclampsia/eclampsia
- BP can also be controlled in malignant hypertension (>185/110) preventing thrombolysis
2.) Fluid and Glycaemic Control
- regular fluid assessment to remain normovolaemic
- avoid hypovolaemia: ↑risk of infarction, infection, deep vein thrombosis, constipation and delirium
- avoid overhydration: can lead to cerebral oedema, cardiac failure and hyponatraemia
- oral hydration preferred, IV if dysphagic
- often NBM due to swallowing risk so need to closely monitor blood sugar levels to remain between 4-11mM
- use of IV insulin and glucose infusions in diabetics
3.) Feeding Assessment and Management
- must assess all patients for safe swallowing function using videofluoroscopy and flexible endoscopic evaluation of swallowing (FEES) prior to any oral intake
- if any concerns, patients should remain NBM whilst waiting for a specialist assessment of swallowing
- may need an NG feeding tube or gastrostomy
4.) Barthel Index (BI) - assesses the functional status of a patient post-stroke, and monitors their improvement with ongoing rehab to regain independence after the event
- describes 10 tasks (ADLs), out of 100, 0 = completely dependent, 100 = completely independent
Investigations in Stroke
Urgent Non-Contrast CT-Head
Other Imaging
Bedside
Bloods
1.) Urgent Non-Contrast CT-Head
- used to exclude ICH: ↑attenuation (glows bright white), becomes hypodense after 10 days so not useful
- CT in an ischaemic stroke can be normal especially if the stroke is very recent (1-2hrs)
- early ischaemia: hyperdense MCA/dot sign, sulcal effacement, loss of grey/white matter different…
- late ischaemia: hypodense area
- ASPECTS is a CT score used for patients with MCA stroke that can predict their outcome
2.) Other Imaging
- CT/MR angiography: confirms the location of the clot, is required before carrying out a thrombectomy
- CT perfusion: assess the potential to salvage brain tissue in thrombectomy if > 6hours of stroke onset
- CT/MR venography: venous stroke or venous sinus thrombosis
3.) Bedside
- 24hr ECG (Holter monitor): arrhythmias
- ECHO: structural heart disease (bubble ECHO in younger patients (<50) looking for PFO)
- carotid USS: in all anterior circulation stroke
- CHADS-VASC2 and HAS-BLED in AF patients
4.) Bloods
- routine: FBC, CRP, U+Es, LFTs,
- risk factors: clotting/INR, HbA1c, lipid profile
- thrombophilia and autoimmune (vasculitis) screening in younger (<55) patients with no obvious cause
- infection screen: hepatitis, HIV, syphilis
Complications of Stroke
1.) Stroke Progression - ischemic stroke can be at risk of progressing to infarction (ischaemic penumbra)
- strokes can also reoccur due to unaddressed aetiological factors
2.) Raised Intracranial Pressure - many causes:
- haematoma expansion, malignant oedema, haemorrhagic transformation, hydrocephalus
3.) Infections
- chest infections: due to aspiration
- UTIs: due to incomplete bladder emptying from either constipation or bed-bound posture
4.) Mood and Cognitive Dysfunction
5.) Spasticity, Contractures, Secondary Epilepsy
