Stroke Flashcards
Name three examinations you would do on first presentation of stroke
GCS
A to E
NIHSS
NIHSS is used to quantify the severity of stroke, the first response of each category is measured. Give an example of 6 parameters.
Level of Consciousness Blink Eyes and Squeeze Hands Horizontal Ocular Movements Visual Fields Facial Palsy Inattention
What do the NIHSS scores mean?
<4 shows a good prognosis
>26 thrombolysis is CI
What specific things are you looking for on a systems examination
CVS - Sources of Emboli, BP, Arrhythmias, Bruits
Resp - Aspiration Pneumonia, Swallow risk, O2 sats
Abdo - ?Palpable bladder, Liver Cirrhosis, Pregnancy
Cranial Nerves
Outline a peripheral nerve exam
Inspection Tone Power (Out of 5) Reflex Sensation Coordination
How is Power of limbs rated out of 5
1 - Trace of Contraction 2 - Movement if no gravity 3 - Active against gravity 4 - Active against gravity and resistance 5 - Normal
Describe the non imaging investigations for Stroke
- Urine Dip
- Blood Glucose
- Bloods (looking for damage from long lie, or underlying cause)
- ECG
Describe the imaging for Stroke
If suspecting - Non Contrast Head CT in one hour (eg if GCS<13, known bleeding tendency, severe headache)
If going for thrombectomy - CT Angio indicated
How can Stroke Mimics be classified?
1 - Readily identifiable on imaging (eg MS, Subdural Haematomas)
2 - Syndromically distinguishable on clinical grounds after medical assessment
3 - Exclusion requires specialist stroke assessment (eg focal seizures, migraine with aura)
Name five Stroke Mimics
Transient Global Amnesia Migraine with Aura Functional Syndrome Hypoglycaemia Amyloid Spell
What is Transient Global Amnesia?
During the episode, patient is unable to make new memories but old memories are retained
Can last up to 10 hours
Can be triggered (e.g sudden immersion in hot/cold, pain)
What is Migraine with Aura?
- Typically positive symptoms
- Headache may be absent or minimal
- Can have cortical spreading depression (wave of depolarisation causing spreading of aura)
What is an Amyloid Spell?
Presents similarly to Migraine with Aura but lasts less than 10 minutes
MRI shows cerebral amyloid angiopathy
What is Functional Syndrome?
Presence of genuine neurological signs that cannot be attributed to an underlying cause
How can a Stroke Mimic be differentiated from a Stroke?
Onset
Stereotyping (same vessel is unlikely to be repeatedly occluded)
ROSIER score
What is an exception to using stereotyping to differentiate?
Capsular Warning Syndrome in Lacunar Arteries
Intermittent Hypoperfusion over minutes to hours
ROSIER score is important tool to recognise stroke. What are the parameters?
LOC Seizure Face/Arm/Leg Weakness Speech Disturbance Visual Symptoms
What do ROSIER scores mean?
From -2 to +5
> 0 means that stroke is likely
What are Stroke Chameleons
The opposite of mimics
Strokes that look like other conditions
Name five Stroke Chameleons
Venous Infarcts Small Cortical Strokes Limb Shaking TIA Occipital Strokes Intracranial Stenosis
How do Venous Infarcts present?
Gradual Onset
Seizure Activity
Treated with Heparin
How does Intracranial Stenosis Present?
Atherosclerosis in a vessel where each time there is hypoperfusion, patient gets symptoms
Leads to stereotyping
Confirmed with CT Angio
How do Small Cortical Strokes present?
Peripheral Nerve Lesions/Palsies
How do Occipital Strokes present?
Predominantly confused
Visual Field Defects
Vestibular Dysfunction
How can Cerebral Ischaemia transform into Cerebral Infarction?
1) Tissue Hypoperfusion
2) Na+K+ reversal
3) Cytotoxic Oedema
4) BBB break down (allowing RBCs and Macromolecules in)
Describe the four stages of infarct
Hyperacute - first 6h
Acute - up to 7d
Subacute - up to 4m
Chronic - after 4m
Causes of Ischaemic Stroke can be classified using the TOAST tool. What are the 5 types?
Large Artery Atherosclerosis Cardioembolic (confirmed by ECG) Small Vessel disease only (eg Lacunar Stroke, <1.5cm) Other Determined Undetermined
The main aim of Non Contrast Head CT is to rule out Haemorrhagic Stroke. What are the early features of ischaemic?
Hypoattenuation
Sulcal Effacement
Loss of great white matter differentiation
What is ASPECT?
10 point CT scan for MCA stroke
Used for revascularisation and patient outcomes
Describe the use of MRI for Ischaemic Strokes
Shows infarct from 2h to 3wks
Very sensitive
Describe the use of Perfusion CT in Ischaemic Strokes
Uses iodinated contrast, and takes repeated images of the same level as contrast flows
How can the perfusion CT scans be used?
A curve of Arterial input and Venous outflow can be plotted
Can overlay maps of cerebral blood flow and cerebral blood volume
Describe the features of the Overlayed CT Perfusion Scans
Infarct Core (Red) - Reduced venous flow, indicating infarction
Ischaemic Penumbra (Green) - Ischaemic region characterised by reduced blood flow but maintained drainage. This is the only region that will benefit from thrombolysis
What is the risk of thrombolysing a large Infarct Core?
Haemorrhagic Transformation
When can you manage Stroke by Thrombolysis with Alteplase?
If <4.5h
Haemorrhagic Stroke Excluded
No Haemorrhagic Risk Factors
Name three absolute contraindications to Thrombolysis
Stroke in the last two weeks
Surgery/Trauma in the last two weeks
Active Internal Bleeding
Name three complications of Thrombolysis
Extracerebral Haemorrhage
Seizure
Evolution causing raised ICP
When should Thrombectomy be carried out?
- Within 6h alongside Thrombolysis is acute ischaemic stroke with occlusion of proximal anterior circulation (confirmed by angiography)
- Within 6-24h if confirmed anterior circulation infarct with potentially salvagable tissue (limited core infarct)
- up to 24h alongside thrombolysis if confirmed occlusion of posterior circulation (with limited core infarct)
What other medication should be started within 24h of an Ischaemic stroke?
300mg Asparin Orally (alongside PPI)
Continued for 2w before switching to Clopidogrel
How is Central Venous Thrombosis managed?
Full dose Heparin and then Warfarin
Name two other managements which might need to be considered in Ischaemic Stroke
Decompressive Hemicraniotomy (for Malignant MCA)
End Arterectomy (if >50% atherosclerotic occlusion)
CHADS-VASc and HAS BLED are two scores used to determine the need for anticoagulation in AF. Describe CHADS-VASc
CHF HTN Age (>75 - 2p) Diabetes Stroke (2p) Vascular disease Age (60-74) Sex Category (Female)
CHADS-VASc and HAS BLED are two scores used to determine the need for anticoagulation in AF. Describe HAS BLED
HTN Abnormal Liver/Renal Stroke Bleeding Predisposition Labile INR Elderly (>65) Drugs/Alcohol
What is a Watershed Stroke?
Infarcts occurring during systemic hypotension at the boundaries of vascular supply (affecting those furthest from it)
Can be Cortical (between ACA/MCA/PCA territories) or Deep (between ACA/MCA/PCA and perforating Lenticulostriate)
Define TIA
Transient Neurological Dysfunction characterised by focal neurological dysfunction without evidence of acute infarct
USed to be time based (<24h) but is now tissue based
How is TIA managed?
300mg Asparin STAT and refer to TIA clinic
What happens at a TIA clinic?
ECG BP Bloods Smoking Cessation and Lifestyle advice DVLA information (can't drive for a month)
May require MRI or Carotid Doppler
What is ABCD2?
Risk of stroke after TIA
Age>60 BP>140/90 Clinical features (Speech - 1, Unilat weakness - 2) Duration (<60 - 1, >60 -2) Diabetes
Haemorrhagic Strokes account for 15% of strokes. What are they?
Bleeding inside and around leading to hypoperfusion
What are some clinical clues that would point towards Haemorrhagic Stroke?
- Possible underlying PMH
- Reduced consciousness at admission
- Hx of headaches
- Seizures
Name two causes of PRIMARY Haemorrhagic Stroke
Hypertension
Cerebral Amyloid Angiopathy
Name five causes of SECONDARY Haemorrhagic Stroke
Haemorrhagic Transformation Tumour Aneruysm/AVM Coagulopathy/Anticoagulation Cocaine/Alcohol
Initially a Haemorrhagic stroke presentation depends on extent and duration. As it continues to expand, what changes occur?
Midline Shift
Twisted Ventricle
Intracranial Herniation
Name four predictors of Poor Outcome
> 30ml
Affecting Deep Basilar or Brainstem
GCS<9
80y
Name the 5 Subtypes of Haemorhagic Stroke
Extradural Haemorrhage Subdural Haemorrhage SAH Intraparenchymal Intraventricular Haemorrhage
Describe the aetiology of Extradural Haemorrhage
Separation of the bone from the Periosteal Layer of Dura
90% associated skull fracture
Often bleeding from MMA
How do Extradural Haemorrhages present?
Classic LOC immediately, then lucid interval, then further deterioration as haematoma expands
Associated cranial nerve examinations, headache, nausea and vomiting
How do Extradural Haemorrhages present on CT?
Biconvex bleed limited by suture lines
How are Extradural Haemorrhages managed?
Small - observation and conservative management
Raised ICP - Hypertonic Saline/Mannitol
Surgically manage if GCS<14 or clot>40ml
What is a Subdural Haemorrhage?
Bleeding between arachnoid and pia matter
Sources of blood - torn bridging veins (acceleration, deceleration, senile atrophy, alcoholism, NAI)
Can be Acute, Subacute (3-7d) or Chronic (2-3 weeks)
Can be Simple (no parenchymal injury) or Complicated (Parenchymal Injury - eg Contusion)
How do Subdural Haemorrhages present?
Acute - lucid interval then deterioration
Chronic - progressive anorexia, nausea and vomiting, neurological deficits , headache
Raised fontanelle in infants
How are Subdural Haemorrhages investigated?
Bloods
CT - Convex shape, as it ages intensity decreases
How are Subdural Haemorrhages managed?
Small - observation and conservative management
Raised ICP - Hypertonic Saline/Mannitol
Surgically manage if GCS<14 or clot>40ml
How are SAH imaged?
CT - Hyperdensity around Circle of Willis/ Basal Cisterns
MRI - good for imaging reactive vasospasm
How are Intraparenchymal Bleeds managed?
Stop and Reverse Anticoagulation Maintain Systolic at 90-130 (for CPP) BP Control (Labetolol, Nimodipine)
May require decompressive hemicraniotomy or EVD
What is Cerebral Amyloid Angiopathy?
Pathological deposition of amylid in tunica media/adventitia of vessels
Fibrinoid degredation and microaneurysms
Association with Alzheimers
Scored on imaging using Boston Criteria CT
Name five complications of stroke
Complications of immobility (pressure sores etc) Raised ICP Infection Mood/Cognition Changes Post Stroke Pain
What are the 5 R’s of Stroke Rehabilitation?
Realisation of Potential Reablement (functional independence) Resettlement (safe transfer of care) Role Fulfillment Readjustment
Where do patients go after a Stroke?
Either: Stroke Rehab Unit (medically stable, established NG) OR Early supported Discharge
What is required for Early Supported Discharge?
Can transfer independently or with carer
Suitable home
Willing to participate
Identified goals
When does peak Stroke recovery occur
Between 1-3 months due to Neuroplasticity
Name three good prognostic factors in Stroke
No coma
Continence
Early motor recovery
What is the Amber Care Bundle?
Patient is very unwell and unsuitable for rehab
Advanced Care Planning
Describe the different types of Stroke Prevention
Primordial - Public Health Campaigns
Primary - for at risk (treat high BP etc)
Secondary (reduce disease progression - Asparin in TIA)
Tertiary - reduce disease progression in establushed
What is the target threshold for Cholesterol
Total <4
What things can be discussed with the patient in terms of Secondary prevention
Smoking Cessation
Diet and Exercise
Treating BP/AF
Maintaining BGC
What is the Modified Rankin Score?
Assesses post stroke baseline function
0 - no symptoms
to
6 - dead
What is a Stroke of unknown aetiology known as?
Cryptogenic Stroke
What does the LACS criteria require?
Symptoms in two areas
If in only one area - PACS
How would you investigate intracranial venous thrombosis?
MRI Angiography
