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