If a patient has had a stroke how can we assess/quantify the impairment caused by the stroke?
NIH Stroke Scale (NIHSS)
- 11 sections/items
- Max score = 42
Interpretation:
- 0 = no stroke symptoms
- 1-4 = minor stroke
- 5-15 = moderate stroke
- 16-20 = moderate to severe stroke
- 21-42 = severe stroke
Note: Alteplase thrombolysis is for pts with NIHSS > 5 and < 25 (but final decision is clinical)
What are the 11 categories tested in a NIH Stroke Scale?
- Level of conciousness
- LOC a) responsivess
- LOC b) questions (own age + month)
- LOC c) commands (open + close eyes)
- Horizontal eye movement
- Visual field test
- Facial paresis
- Motor function of arms:
- a) R-arm
- b) L-arm
- Motor function of legs:
- a) R-leg
- b) L-leg
- Limb ataxia
- Sensory (pin prick)
- Language (aphasia)
- Speech (dysarthria)
- Extinction and inattention
What is dysarthria?
What is dysphasia?
Dysarthria = disorder of speech i.e. problem with physical articulation and pronounciation of speech
Dysphasia = disorder of language i.e. problem with processing thoughts and idea to spoken word
What is the difference between receptive and expressive aphasia?
- Receptive aphasia = difficulty in comprehension
- Fluent language, normal rhythm + articulation but it is meaningless and they fail to comprehend what they are saying
- Expressive aphasia = difficulty in putting words together to make meaning
- Not fluent, difficulty forming words + scentences, grammatical error and struggle to find the right word BUT understand what is said to them
Note: often there is overlap of the two in cases of aphasia
Which hemisphere of the brain is dominant for speech for right-handed people?
How/is this different for left-handed people?
Right-handed:
- Left hemisphere dominant in 99% of right-handers (remaining 1% are left-handers who were forced to write right-handed)
Left-handed:
- Left hemisphere dominant in ~70%
- Right hemisphere dominant in ~30%
THUS a right sided stroke which causes left-sided muscle weakness + aphasia = rare!! Occurs in only 30% of left-handers and no right handers
What % of patients who suffer a stroke experience dysphasia?
33%
How does dysarthria in the following present typically?
- Pseudobulbar palsy
- Multiple sclerosis
- Parkinson’s disease
- Pseudobulbar palsy = Slurred speech + weak articulation + weak voice
- Multiple sclerosis (MS) causing cerebellar lesions = slurred + staccato speech
- Parkinson’s disease = dysrhythmic, dysphonic and monotonous voice
What form of imaging is the first line choice in a suspected stroke?
CT-head
(although MRI is more sensitive)
- Cheaper
- Faster
- No need for MRI compatible resuscitation equipment
Before an ischaemic stroke patient is given thrombolysis a pre-thrombolysis checklist is gone through - what is featured on this list?
Must answer YES to ALL of the following:
- Symptoms of acute stroke
- Onset in last 4.5 hours
- Measurable deficit on NIHSS
- Absence of haemorrhage on CT scan
Must answer NO to ALL of the following:
- Symptoms / signs of subarachnoid haemorrhage
- Head trauma, brain/ spinal surgery, stroke in last 3 months
- Major surgery or non head trauma in last 2 weeks
- Hx of any intracranial haemorrhage, cerebral aneurysm or AVM (ateriovenous malformation i.e. cerebral fistulas)
- GI, urinary or gynae haemorrhage within last 21 days or evidence of active bleeding
- Known/ confirmed aortic dissection
- Arterial puncture at non compressible site within 7 days
- Recent lumbar puncture in last 10 days
- Currently pregnant
- Systolic BP >185 and/or diastolic > 110 mmHg
- Known or strongly suspected bacterial endocarditis
- Platelet count 1.4 on warfarin
- Heparin or newer oral anticoagulant within last 48 hours or INR >1.4 on warfarin
What are the two main risks associated with thrombolysis?
- Haemorrhage (6%)
- Angioedema (7%)
What is the ratio of ischaemic to haemorrhagic strokes?
Ischaemic = 85%
Haemorrhagic = 15%
What are the risk factors for stroke?
- Age
- Ethnicity (south east asian, afro-caribbean)
- Men > women (until old age then women > men)
- HTN
- Smoking
- Hyperlipidaemia
- Diabetes mellitus
- Lifestyle:
- Sedentary
- Obesity
- Alcohol
- Illicit drugs e.g. cocaine, amphetamines, IV-associated infective endocarditis
- Hypercoagulable states
- Hx or FHx of stroke
- Atrial fibrillation
What system can be used to classify strokes based on initial symptoms?
Bamford classification
(also called Oxford stroke classification)
What 3 criteria need to be assessed in a stroke patient for the Bamford classification?
- Unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- Homonymous hemianopia
- Higher cognitive dysfunction e.g. dysphasia, visuospatial disorder
According to the Bamford classification system what are the criteria for the following:
- TACS (total anterior circulation infarcts) - 15%
- PACS (partial anterior circulation infarcts) - 25%
- LACS (lacunar infarcts) - 25%
- POCS (posterior circulation infarcts) - 25%
3 criteria to be assesed:
- Unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- Homonymous hemianopia
- Higher cognitive dysfunction e.g. dysphasia, visuospatial disorder
- TACS:
- Involves middle + anterior cerebral arteries
- all 3 of the above criteria
- PACS:
- Smaller arteries of anterior circulation e.g. upper or lower division of MCA
- 2 of the above criteria
- LACS:
- Involves perforating arteries around the internal capsule, thalamus and basal ganglia
- 1 of the following:
- Pure sensory stroke e.g. unilateral face, arm, leg or all
- Pure motor stroke e.g. unilateral weakness of face, arm, leg or all
- Sensori-motor stroke
- Ataxic hemiparesis
- POCS:
- Involves vertebrobasilar arteries
- 1 of the following:
- Cerebellar dysfunction (e.g. ataxia, nystagmus, vertigo)
- Brainstem syndromes (i.e. cranial nerve palsy with contralateral motor/sensory deficit)
- Bilateral motor/sensory deficit
- Loss of consciousness
- Isolated homonymous hemianopia
Symptoms alone often can’t be used to differentiate an ischaemic from a haemorrhagic stroke, but some symptoms are more common in haemorrhagic strokes … name 4
- ↓ level of conciousness
- Headache
- Nausea + vomiting
- Seizures
What medication is given to thrombolyse patients with ischaemic strokes?
Alteplase (0.9 mg/kg)
(tissue plasminogen activator)
What acute medication should be given if a haemorrhagic stroke has been excluded? (not thrombolysis)
300mg aspirin (oral or rectal)
What medications are recommended in the secondary prevention of ischaemic strokes?
Acute:
- Aspirin 300mg
- Alteplase ( < 4.5 hrs)
Secondary prevention:
- Anticoagulation / anti-platelet:
- Clopidogrel = 1st line
- Aspirin + dipyridamole = 2nd line (only if clopidogrel not tolerated or contraindicated)
- Statin
- BP management (see guidelines):
- < 55yrs or T2DM = ACE-inhibitor e.g. ramipril
- > 55 yrs or afro-caribbean + no T2DM = Ca2+ channel blocker e.g. amlodipine
Whilst the FAST screening tool is useful for the general public, the ROSIER score is better for medical professionals - what are the elements of the ROSIER score?
ROSIER score:
Note: exclude hypoglycaemia first, then assess
- Loss of consciousness or syncope = -1
- Seizure activity = -1
- New acute onset of:
- asymmetric facial weakness = +1
- asymmetric arm weakness = +1
- asymmetric leg weakness = +1
- speech disturbance = +1
- visual field defect = +1
Score > 0 = likely stroke
When should anticoagulation for AF which has caused an ischaemic stroke commence?
2- weeks after the stroke (in the absence of haemorrhage)
e.g. warfarin, factor Xa inhibitor (e.g. rivaroxaban / apixaban)
When prescribing GI protection medication i.e. PPIs to go alongside stroke medication, why is Lansoprazole used instead of Omeprazole?
Post acute phase of ischaemic strokes, patient’s are prescribed clopidogrel (1st line anti-platelet)
Clopidogrel interacts with omeprazole but not lansoprazole!!
Omeprazole ↓ action of clopidogrel
If a patient were to have a stroke in the following arteries, what symptoms might they have?
- Anterior cerebral artery
- Middle cerebral artery
- Posterior cerebral artery
- Weber’s syndrome (branches of the posterior cerebral artery that supply the midbrain)
- Anterior inferior cerebellar artery (lateral pontine syndrome)
- Posterior inferior cerebellar artery (lateral medullary syndrome, Wallenberg syndrome)
- Retinal/ophthalmic artery
- Basilar artery
- Lacunar infarct
- ACA:
- Contralateral hemiparesis + sensory loss, lower limb > upper limb
- MCA:
- Contralateral hemiparesis + sensory loss, upper limb > lower limb
- Contralateral homonymous hemianopia
- Dysphasia
- PCA:
- Contralateral homonymous hemianopia
- Muscular sparing
- Visual agnosia (impairment of recognition of visual objects)
- Weber’s syndrome:
- Ipsilateral CN III palsy (eyes abducted and depressed)
- Ipsilateral dilated pupil (parasympathetic fibres travel in CN III)
- Contralateral weakness of upper + lower limb
- Anterior inferior cerebellar artery:
- Same as Wallenberg’s BUT
- Ipsilateral: facial paralysis + deafness
- Posterior inferior cerebellar artery (Wallenberg’s)
- Ipsilateral: facial pain + temp loss
- Contrlateral: limb/torso pain + temp loss
- Ataxia
- Nystagmus
- Retinal / opthalamic:
- Amaurosis fugax (temporary painless visual loss in one or both eyes - “black curtain coming down”)
- Basilar:
- Locked-in syndrome
- Lacunar:
- Isolated hemiparesis, hemisensory loss or hemiparesis + limb ataxia
- Strongly HTN related
- E.g. basal ganglia, thalamus, internal capsule
What conditions are associated with stroke / TIA?
- Diabetes
- Atrial fibrillation
- Asymptomatic carotid stenosis
- Vasculitis
- Infective endocarditis
- Paradoxical embolus (if there is passage between R/L heart chambers e.g. patent ductus arteriosus)
- AV malformation (risk for haemorrhage)
- Brain mets (risk for haemorrhage)
- Aneurysm (risk for haemorrhage)
