Stroke Mimics

Paul Guyler

Consultant Stroke Physician at Southend University Hospital

Clinical Lead for Acute Stroke – Essex Cardiac and Stroke Network

Aims • Why worry?

• Stroke Recognition Tools

• History, Examination and imaging

• Defining an approach to acute neurological symptoms

• FAST +ve Mimics

• FAST –ve Strokes

• FAST –ve Mimics

• Non-acute stroke presentations

Distinguishing stroke from mimics

Diagnostic inaccuracy approx 25%

Similar error rate for trained paramedics, A+E and GPs1

Risk of patient being inappropriately thrombolysed

Risk of patient not being given correct treatment promptly2

1Azzimondi et al Stroke 1997

2 Harbison et al Stroke 2003

Pathway activation by A+E

Age 8%

>3hrs 4%

No Time Line 10%

Non Stroke 23%

ICH/SAH 15%

Too severe 4%

Too Mild/TIA 15%

TPA 17%

Other Exclusion 4%

101 cases assessed in A+E, Leeds General Infirmary 1/7/2007-31/10/2008

Causes of Stroke Mimics (n=109)

Condition % <6hrs >6hrs

Seizure 21.1 29.0 10.6

Sepsis 12.8 9.7 17.0

Toxic/metabolic 11.0 9.7 12.8

SOL 9.2 4.8 14.9

Syncope 9.2 14.5 2.1

Delirium 6.4 4.8 8.5

Vestibular 6.4 4.8 8.5

Mononeuropathy 5.5 6.5 4.3

Functional 5.5 6.5 4.3

Dementia 3.7 3.2 4.3

Migraine 2.8 3.2 4.3

Hand et al Stroke 2006

Causes of Stroke Mimics (n=109)

Condition % <6hrs >6hrs

Seizure 21.1 29.0 10.6

Sepsis 12.8 9.7 17.0

Toxic/metabolic 11.0 9.7 12.8

SOL 9.2 4.8 14.9

Syncope 9.2 14.5 2.1

Delirium 6.4 4.8 8.5

Vestibular 6.4 4.8 8.5

Mononeuropathy 5.5 6.5 4.3

Functional 5.5 6.5 4.3

Dementia 3.7 3.2 4.3

Migraine 2.8 3.2 4.3

Used widely by paramedics

Public educational campaigns

Any 1 of 3 symptoms

Rapid. Quick screening tool

Sensitivity/Specificity 80%

Positive predictive value 90%

Rosier scale

Used in Emergency room

7 point scoring system

Higher sensitivity 93%

Specificity= 83%

Positive predictive value 90%

Nor et al , Lancet Neurol 2005

Tools make things easier but not infallible.

Prospective testing ……..

False + False -ve Functional Mild CVAs (LACS)

Hemiplegic/complex migraine POCS

Tools make things easier but not

infallible. FAST +

ve

FAST -

ve

The classic mimic

FALSE

POSITIVES

FAST –ve strokes

FALSE

NEGATIVES

Strokes Non-strokes

Logistic regression model for predicting diagnosis of

brain attack

OR 95%CI

Known cognitive impairment 0.33 0.14-0.76 Exact onset determined 2.59 (1.30-5.15) Definite focal symptoms 7.21 (2.48-20.93) Abnormal vascular findings 2.54 (1.28-5.07) NIHSS 1-4 1.92 (0.70-5.23) 5-10 3.14 (1.03-9.65) >10 7.23 (2.18-24.05) Signs localise to either left or right 2.03 (0.92-4.46) OCSP classification possible 5.09 (2.42-10.70)

Hyperacute radiology for stroke mimic Non contrast CT widely available

Limited role, often normal

Early infarct signs confirm clinical suspicion of stroke

Rarely non stroke neurological mimics seen e.g. SOL

Rarely clarifies clinical picture, if diagnostic confusion

from outset (advanced imaging more useful)

Approach to acute neurological

symptoms FAST +

ve

FAST -

ve

The classic stroke

The classic mimic

FAST –ve strokes

Mimics of

FAST -ve strokes

Strokes Non-strokes

61 M

Approach to acute neurological

symptoms FAST +

ve

FAST -

ve

The classic stroke

The classic mimic

FAST –ve strokes

Mimics of

FAST -ve strokes

Strokes Non-strokes

FAST +ve mimics

• Hypoglycemia

• Migraine with/without aura / Hemiplegic Migraine

• Post-ictal paralysis

• Brain Tumours

• Intracerebral haemorrhage

• Subarachnoid hemorrhage

• Subdural haemorrhage

• Cervical spondylotic myelopathy

• Venous infarction

• Hypertensive encephalopathy

• Functional hemiparesis

• Others!

Hypoglycemia

(Fast +ve mimic)

• Adrenergic symptoms/signs can be absent

• Neuroglycopenia

– Hemiplegia

– Quadreplegic

– brainstem signs

• Signs usually reverse after glucose

• Could lead to permanent neurological sequelae

Ravid JM: Transient insulin hypoglycemic hemiplegias. Am J Med Sci 1928;175:756-759

ROSIER SCALE

Migraine with/without aura

• 2.0-2.5 increase in stroke risk

• Strokes can mimic migraine!

• Neurological disturbance is almost always

transient.

Differentiating stroke/TIA from migraine

• Focal symptoms precede headache & are usually +ve

• Note headache seen in up to 50% of TIAs; seen at onset, usually ipsilateral & non-severe1

• Usually visual fortification spectra, hemianopia, perioral tingling & tingling in 1 arm, occ. dysphasia

• Often march over ~15 mins.

1. Chaturvedi et al. Transient ischaemic attacks. Blackwell, 2004

Hemiplegic Migraine

(FAST+ve mimic)

• Watch for the typical ‘march’ of symptoms

• Usual duration of neurological symptoms is 30 minutes to up to 2 hours

• Headaches could be ipsilateral or contralateral

• In this familial variety, neurological signs could become permanent – Frank hemiplegias

– ataxia and other cerebellar signs

– coma

Post-ictal paralysis (Fast +ve mimic)

• Lasts under 24 hours; rarely longer

• The residual neurology strongly points to the

origin of the epileptic focus

• In up to 15% of the epileptic attacks

– Mono or hemiplegia

– aphasia

– gaze deviation

– hemianopia

Brain Tumours

(FAST +ve mimic)

Tumours can cause transient neurological symptoms lasting minutes or indeed permanent There are symptoms which are acute by nature eg Dysphasia, diplopia, dysphagia Remember, without a contrast CT scan, metastasis and tumours can appear like infarcts Remember symptoms relating to the tumour oedema can resolve well with steroids (temporarily).

NE CT

CE CT

67 M

NE CT

CE CT

55 F

55 F

CE MRI

NE CT

Intracerebral haemorrhage

• Acute ischaemic

stroke can only be

differentiated from an

acute haemorrhagic

stroke by brain

imaging (CT or MRI)

48 F

Subarachnoid haemorrhage

• Sudden onset 10/10

headache

• Variable neurology

• History crucial

• Positive history even

with negative CT – C/I

for rTPA

• 5% have normal CT

48 F – Acute Headache,disoriented

Subdural haemorrhage (FAST +ve mimic)

SDH’s can present with transient or permanent FAST +ve neurological deficits Up to a third of the chronic subdural haematomas could be a fast +ve mimic

73 YRS

Cervical spondylotic myelopathy

Different mechanisms

Silent/chronic

Acute

Coexist

Case illustration

• Had a fall, weak right

side with N. signs

• CT normal

• Had unexplained

upgoing left plantar

• History explored

• MR C spine

VENOUS INFARCTION

• Think about it!

• On CT be suspicious if see bilateral low

densities or low density in non-arterial

distribution. NB temporal lobe.

• Look for high attenuation thrombus on non

contrast CT scan

• Can confirm with enhanced scan or

preferably CTV

Low density left temporal

lobe; dense transverse

sinus

Post contrast CT showing

normal right and

occluded/thrombosed left

sigmoid and transverse

sinus

Hypertensive encephalopathy

(FAST +ve mimic)

• Neurological deficits

– Hemiplegia

– Bilateral clumsiness

– Drowsiness

– Coma

– Bilateral upgoing plantars

• Usually occurs in longstanding

HT

• Imaging may show

abnormalities which disappear

after treatment

• Cautious BP control –

overzealous treatment or

undertreatment can cause

strokes!

Functional hemiparesis

(Fast +ve mimic)

Common!

Never underestimate the importance of this

Could be an overlay on some pathology

Fool proof imaging +/_ 2nd opinion

Antidepressants are of value whether or not a patient is depressed

Other potential fast +ve mimics

• Multiple sclerosis

• Encephalitis

• Peripheral nerve palsies

• Musculoskeletal injuries

• Intracerebral abcess

• Early Idiopathic Parkinsonism

41 M - Aids

Approach to acute neurological

symptoms FAST +

ve

FAST -

ve

The classic stroke

The classic mimic

FAST –ve strokes

Mimics of

FAST -ve strokes

Strokes Non-strokes

Fast –ve strokes • Cerebellar strokes

• Occipital infarcts

• Non-dominant parietal lesions

• Sensory strokes

• Frontal infarcts causing just leg weakness

Dense basilar artery due

to thrombosis

Approach to acute neurological

symptoms FAST +

ve

FAST -

ve

The classic stroke

The classic mimic

FAST –ve strokes

Mimics of

FAST -ve strokes

Strokes Non-strokes

Mimics for FAST-ve strokes

• Vestibular neuronitis

• Falls (ataxia)

• Transient Global amnesia

Transient global amnesia

• Sudden onset, loss of ‘registration’ of events

during the attack and associated loss of

retrograde memory.

• Repetitive questioning a hallmark

• Patients appear confused but personal identity

and intellect preserved

Non-acute stroke presentations • Stuttering/progressive symptoms

Non-acute stroke presentations

• Patient who has a stroke and refuses or

unable to accept it!

• Wrong diagnosis due to pitfalls in

investigations

SUMMARY

• Try and have a logical approach to acute neurological symptoms

• FAST +ve vs FAST –ve

• Good luck!!