Stroke syndromes/mimics Flashcards
What is a stroke mimic?
Term to distinguish pts who present often acutely with stroke-like symptoms but turn out to have an alternative diagnosis
not a disease but a syndrome
What are some common stroke mimics?
Seizures (epilepsy / alcohol withdrawal)
syncope
Infection e.g. Sepsis
Delirium
Psychiatric e.g. functional (conversion) disorder
Primary headaches e.g. migraine
Brain tumour
Metabolic - hypoglycaemia / hyponatraemia
Peripheral vestibular disorder e.g. Labryinthitis
Dementia
transient global amnesia
Drugs / alcohol
Compare the symptoms you would get with STROKE vs STROKE MIMIC - think negative (take away) vs positive (gain) symptoms
POSITIVE = excess of CNS electrical discharge
Visual : flashing lights / objects / shapes
Sensory: paresthesia / pain
Motor: jerking limb movements
e.g. Seizure and migraine = “POSITIVE”
NEGATIVE = loss / reduction of CNS neuron function
Visual and or hearing : loss
Sensory: loss of sensation
Motor: loss of power
e.g. TIA / Stroke = “NEGATIVE” symptoms
How many of all suspected stroke pts actually have a stroke mimic?
20-50%
medical causes rather than functional mimics are more common
What are some clinical characteristics differentiating stroke from stroke mimics?
What are some systemic signs you might find in a pt with a stroke mimic?
Drowsiness, confusion, agitation and fever
What are some common presenting symptoms in stroke mimic?
vertigo and dizziness,
altered level of consciousness,
paraesthesia and numbness,
monoplegia (paralysis limited to a single limb),
speech dysfunction,
limb ataxia,
headache
visual disturbances
What might be in a pt with a stroke mimics PMHx?
seizures, migraine, depression or other psychiatric disorders or dementia
In terms of a pts neurological symptoms what might point to a stroke mimic?
Mimics
- less clearly defined neurological symptoms which do not adhere to well-defined stroke syndromes e.g. can identify a vascular territory that has been affected.
-not sudden / fluctuate
Note:
v hard to distinguish when symptoms are brief and resolve before pt is examined and MRI is normal!
In terms of a pts neurological symptoms what might point to a stroke mimic?
Mimics
- less clearly defined neurological symptoms which do not adhere to well-defined stroke syndromes e.g. can identify a vascular territory that has been affected.
-not sudden / fluctuate
Note:
v hard to distinguish when symptoms are brief and resolve before pt is examined and MRI is normal!
What screening tool is often used in A&E to quickly gage if a stroke or stroke mimics?
Rosier scale
7 points
What is the NIH stroke scale?
Used to assess neurological status after an acute stroke and quantify stoke severity in a consistent way.
- Predicts lesion size / stroke outcome
- Predicts large vessel occlusion
- used in determining suitability for thrombolysis
11 item (42 point scale)
- Conscious level
- Eye movements
- vision
- motor power in limbs / face
- co-ordination
- sensation
-language
- articulation
- Inattention
LOW NIHSS scale could suggest more of a mimic - but not perfect
What physical exam or history findings might suggest stroke or stroke mimic? (studies have shown - will put links on GDOC)
More likely STROKE:
- abnormal eye movements
- diastolic BP >90mmHg
- Hx of angina / AF
- Lateralisation to R or L cerebral hemispheres
- symptoms with EXACT time onset
- Hx of focal deficit
- ability to determine a clinical stroke subclassifcation e.g. TACI
More likely MIMIC
- decreased LOC (level of consciousness)
- cognitive dysfunction
- normal eye movements
- younger
- female
- w/o RF
What is Todd’s Paresis / Paralysis? Why is it relevant when thinking about stroke mimics
Post seizure paralysis (in any seizure; epilepsy / alcohol withdrawal)
- Brief or prolonged
- +/- confusion, sensory loss, visual changes e.g. hemianopia / blindness, or speech e.g. aphasia
- Resolves 20 mins
but remember pts with epilepsy can have strokes
What specific migraine types might be confused with stroke?
Migraine with aura
Hemiplegic migraine
Migraine with unilateral motor weakness (MUMS)
What features in a pt presenting with suspected acute stroke would make you think migraine more likely?
- often “positive” symptoms
- e.g. visual phenomona e.g. visual scotoma
- +/- headache before / after/ during neuro symptoms
- can develop aphasia, visual loss, hemiplegia confusion etc
- gradual onset
- ‘slow march’ of spreading symptoms with migraine + aura
- prolonged symptoms - hemiplegic migraine
How would a pt with hypoglycameia present? How would you distinguish from stroke mimic
Present:
Weakness, syncope, confusion, focal deficit
Distinguish:
- all pts suspected of stroke get BM checked in hospital
- Neurological abnormalities often resolve rapidly post treatment
Beware: can get a false elevation and mask hypoglycaemia in anaemia, hypoxia, high PH
What are some causes that a pt might present with hypoglycaemia?
Insulin overdose
alcohol intoxication
sulfa medication use / overdose
Insulinomas
Addisonian crisis
Systemic infections e.g. sepsis / meningitis / access / encephalopathy can present like an acute stroke.
- What symptoms may suggest a stroke?
- What ‘extra’ symptoms might suggest other cause e.g. sepsis?
- Features like a stroke:
- Sepsis can result in confusion / delirium can be interpreted as dysarthria / aphasia
- weakness - other symptoms to think MIMIC:
- neck stiffness
- fever
-vital sign abnormalities
- agitation / somnolence
What features would help differenciate between true stroke or stroke mimic caused by brain tumour ?
Brain tumour:
- Gradual onset causing progressive deficits over days - months
- can get focal deficit or seizure if mass affects cerebral vasculature
- Imaging: CT/ MRI does not correspond to vascular distribution and surrounding oedema
- v rarely get acute stroke like presentation e.g. when haemorrhage into lesion / obstructive hydrocephalus
How to differentiate between peripheral vertigo and dizziness due to inner ear dysfunction and true stoke ?
Often hard to distinguish between peripheral (inner ear) or central mechanisms (cerebellar or brainstem stroke)
Stoke:
Brainstem signs: dysarthria, diplopia, ataxia, weakness and numbness
cerebellar stroke: isolated vertigo/ unsteadiness
Hx: onset, triggers (head movements) duration of dizziness
Test: HINTS EXAM
Stroke mimics: MS vs Stroke
Present:
Younger pt
PMHx
multiple neurological abnormalities not following a territory
imaging: MRI white matter lesions in CNS
however pts with MS have 28% increased risk of stroke
Stroke mimics: Bell’s Palsy vs acute stroke
Bell’s Palsy
- most common cause of unilateral facial paralysis
- hours to days onset
- younger pts affected
- Increased auditory sensitivity
- increased lacrimation
- rarely sensory change
- affects upper and lower face
- Hard to close eyelids - exposure keratitis as cornea is dry
Stroke
- forehead sparing
Stroke mimics: true stroke vs functional disorder
Functional disorder:
- Look for inconsistencies in Hx / Examination / Investigations
Hx:
- Multiple symptoms (especially pain and fatigue)
- Atypical / fluctuating symptoms
- Other PMHx e.g. IBS, fibromyalgia
- Psychiatric PMHx e.g. depression / anxiety disorders
Examination:
- Hoover manoeuvre
- Drift without pronation
Imaging:
- no structural lesion to explain symptoms
