Stroke Mimics

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Stroke Mimics

• Dr Val Jones
• Consultant Stroke Physician
• Epsom St Helier NHS Trust

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Outline

• Importance difficulty of TIA diagnosis
• Diagnosing TIAs
• Frequency and diagnosis commonest TIA mimics
• Stroke mimics

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Diagnosis of TIA

• Often difficult
• Based on description
• Risk factor of stroke IHD
• MRI may be helpful
• Definition
• clinical syndrome characterised by sudden onset
  focal neurological disturbance lasting lt24 hours
  and which is thought to be due to vascular cause
  (low blood flow, arterial thrombosis, embolism)
  or associated diseases of the arteries, heart or
  blood

Hankey and Warlow. Transient Ischaemic attacks of
the Brain and Eye, 1994
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TIA-an opportunity to prevent stroke
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Importance of TIAs

• Risk of stroke in first week after TIA is 10
• 30 in highest risk group
• Half of events occur in first 48-72hrs
• Now a method of risk stratifying TIAs ABCD2 score

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ABCD2 (Rothwell et al) Age
gt60yrs 0 points
?
60yrs 1 point BP at presentation SBPlt140
DBPlt90 0 points SBPgt140 or DBP?90
1 point Clinical features
Unilateral weakness 2 points Speech
disturbance 1 point Sensory
loss/other symptom0pt Duration of symptoms
? 60 minutes 2 points
10-59 mins 1 point lt 10
mins 0 points Diabetes
absent0 points
present1 point
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High Risk if score 4 or recurrent episode in
same week
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(No Transcript)
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• 80 risk reduction of stroke at 90 days from
  10.3 to 2.1.

80 risk reduction of stroke at 90 days from
5.96 predicted to 1.24
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How good are we at diagnosing TIA?
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Accuracy of Diagnosis

• Final diagnosis in OCSP
• TIA 209 (38)
• Other diagnoses 303 (62)
• Migraine 52
• Syncope 48
• Possible TIA 46
• Funny Turn 45
• Isolated vertigo 33
• Epilepsy 29
• Transient Global Amnesia 17

Dennis MS et al, Stroke 1989
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• Hypoglycaemia
• Hyperventilation
• Demyelination,
• Entrapment neuropathy
• Structural brain lesion
• Intracerebral haemorrhage

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How do we recognise TIA?
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Clinical Diagnosis of TIA

• Time course of Symptoms
• Abrupt onset
• Maximal at onset
• Average 15 minutes
• Nature of Symptoms
• Focal deficit
• Quality of Symptoms
• Negative

Sandercock PAG, Quarterly Journal Of Medicine,
1991
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MRI with DWI in TIA

• Recommended in NICE guidelines
• Positive in up to 50 patients
• More likely to be positive if unilateral
  weakness, longer duration, higher ABCD2 score or
  AF
• More likely to have early stroke with ve DWI
• If positive independent risk factor for early
  stroke risk
• Calvet et al Stroke 2009

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82 year old man with transient dysphasia and
incoordination R hand
Normal CT
Abnormal DWI image
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• 
  
• Unilateral weakness
  50
• Unilateral sensory symptoms 35
• Slurred speech
  23
• Transient monocular blindness 18
• Difficulty speaking
  18
• Unsteadiness
  12
• Vertigo
  5
• Homonymous hemianopia 5
• Double vision
  5
• Bilateral limb weakness
  4
• Difficulty swallowing
  1
• Crossed motor sensory signs 1
• (OCSP data, Dennis,1988)

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Common TIA mimics

• Migraine
• Epilepsy
• Blackouts/syncope
• Transient Global Amnesia
• Metabolic Causes
• Tumour
• Psychogenic

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Migraine

• Commonest mimic
• Many forms
• 3 main types recognised as stroke mimic
• Migraine with aura
• Aura without headache
• Hemiplegic migraine

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Migraine with aura

• At least 2 attacks
• Headache with at least 3 of
• Fully reversible focal aura symptom
• Aura develops gradually gt 4 mins
• No aura symptom lastsgt60 mins
• Headache follows aura within 60 minutes
• Other conditions excluded

ICHD-2 criteria
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Aura without headache

• Commoner as older
• Can arise with no previous history of migraine
• No excess risk of stroke

Fisher CM, Stroke, 1986
Dennis and Warlow, J of Neurology, Neurosurgery
and Psychiatry, 1992
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Hemiplegic Migraine

• May be familial
• Typical headache
• Stereotypical events

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• Focal seizures can cause transient neurological
  symptoms
• Symptoms start abruptly
• Symptoms spread over a minute or so- shorter than
  with migraine
• Symptoms are mainly POSITIVE
• jerking
• tingling

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Epilepsy with Todds paresis

• Can occur following partial or generalised
  seizure
• Diagnosis clear with collateral history
• Stereotypical attacks
• Antecedent symptoms
• Difficulty with negative symptoms

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• Mean age 60
• 11/100,000 each year
• Lasts a few hours typically lt 24 hours
• Sudden disorder of memory-inability to form new
  memories
• Mistaken for acute confusional states
• No increased risk of stroke

Sander and Sander, Lancet Neurology, 2005
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• Attacks witnessed by observer
• Acute onset of anterograde amnesia
• No change of consciousness or loss of
  self-awareness
• No recent head trauma or seizures
• Duration of symptoms 1- 24 hours
• No neurological symptoms bar dizziness, vertigo
  or headache

Hodges and Warlow, Journal of Neurology,
Neurosurgery and Psychiatry, 1990
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• Commonly hypo/hyperglycaemia or hyponatraemia
• Hypoglycaemia can cause transient neuro symptoms
  without classical sympathetic response
• Commonly in people on hypoglycaemic agents
• Pre-meals, post-exercise, nocturnal
• Always check BM

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• Structural lesion in 0.5
• Tumours, AVM
• Clinical features
• Focal jerking or shaking
• Pure sensory phenomena
• Loss of consciousness
• Isolated aphasia or speech arrest

UK TIA Study Group, J of Neurologgy, Neurosurgery
and Psychiatry, 1993
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Stroke
Clinical syndrome characterised by rapidly
developing clinical symptoms and/or signs of
focal (or global) loss of cerebral function with
symptoms lasting more than 24 hours or leading to
death, with no apparent cause other than vascular
origin
Hatano, 1976
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Stroke diagnosis

• History
• Sudden onset
• Rapid maximum
• Fits known patterns of disease
• Vascular risk factors
• Careful examination
• Imaging

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Incidence mimics

• Various studies 9-19 inpatients
• Mayo clinic study
• July 2005-March 2006
• 196 patients
• 22 mimics
• Strongest predictor mimic absence localising
  signs, low DBP, Hx stroke/TIA

Bentley, Bobrow et al
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Stroke mimics

• MS
• Tumour
• Functional
• Old stroke with intercurrent illness
• Epilepsy with Todd's paresis
• Encephalitis
• SAH
• Subdural

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Demyelination

• Younger age group
• Multiple episodes in time
• and space
• Diagnostic MRI

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Tumour

• All age groups
• Progressive history
• Possible history of primary
• Primary secondary
• Imaging diagnostic

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Functional

• Younger
• Atypical presentation
• Signs that dont fit
• Hoovers sign
• Other worrying conditions
• Typical gait
• Normal imaging

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Epilepsy with stroke

• Difficult to tease out whether new stroke
  seizure or whether old stroke seizure
• DWI MRI helpful

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65 Year old man with collapse and 2 Seizures. No
previous history of stroke
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Importance of diagnosing stroke mimics

• Access appropriate secondary prevention
• Correct treatment for mimic
• Avoidance of unnecessary drugs

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Summary

• Importance of rapidly diagnosing and treating TIA
• Diagnosis of TIA and stroke mimics