ACH - Stroke Flashcards
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