Stroke Mimics

Dr Val JonesConsultant Stroke PhysicianEpsom & St Helier NHS Trust

Outline

• Importance & difficulty of TIA diagnosis

• Diagnosing TIAs

• Frequency and diagnosis commonest TIA mimics

• Stroke mimics

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 <24 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

Diagnosis of TIA

TIA-an opportunity to prevent stroke

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

Importance of TIAs

ABCD2 (Rothwell et al)

Age >60yrs = 0 points 60yrs = 1 point

BP at presentation SBP<140 & DBP<90 = 0 points SBP>140 or DBP90 = 1 point

Clinical features Unilateral weakness = 2 pointsSpeech disturbance = 1 point

Sensory loss/other symptom=0pt

Duration of symptoms 60 minutes = 2 points 10-59 mins = 1 point < 10 mins = 0 points

Diabetes absent=0 points present=1 point

ABCD2 Score % risk of stroke at 7 days (95% CI)

<4 0

4 2.2 (0-6.4)

5 16.3 (6.0-26.7)

6-7 35.5 (18.6-52.3)

High Risk if score ≥4 or recurrent episode in same week

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%

How good are we at diagnosing TIA?

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

Accuracy of Diagnosis

Hypoglycaemia Hyperventilation• Demyelination, • Entrapment neuropathy• Structural brain lesion Intracerebral haemorrhage

How do we recognise 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

Clinical Diagnosis of TIA

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

Normal CT Abnormal DWI image

82 year old man with transient dysphasia and incoordination R hand

% 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)

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

Common TIA mimics

Migraine• Commonest mimic• Many forms• 3 main types recognised as stroke

mimic• Migraine with aura• Aura without headache• Hemiplegic migraine

Migraine with aura

1. At least 2 attacks 2. Headache with at least 3 of:

• Fully reversible focal aura symptom• Aura develops gradually > 4 mins• No aura symptom lasts>60 mins• Headache follows aura within 60 minutes

3. Other conditions excluded

ICHD-2 criteria

Commoner as older Can arise with no previous history of

migraine No excess risk of stroke

Fisher CM, Stroke, 1986

Aura without headache

Dennis and Warlow, J of Neurology, Neurosurgery and Psychiatry, 1992

Hemiplegic Migraine

May be familial Typical headache Stereotypical events

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

Can occur following partial or generalised seizure

Diagnosis clear with collateral history Stereotypical attacks Antecedent symptoms Difficulty with negative symptoms

Epilepsy with Todd’s paresis

Mean age 60 11/100,000 each year Lasts a few hours typically < 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

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

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

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

StrokeClinical 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

Stroke diagnosis• History

• Sudden onset• Rapid maximum• Fits known patterns of disease• Vascular risk factors

• Careful examination• Imaging

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

MSTumourFunctionalOld stroke with intercurrent illnessEpilepsy with Todd's paresisEncephalitisSAHSubdural

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

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

Functional• Younger• Atypical presentation• Signs that don’t fit• Hoover’s sign• Other worrying conditions• Typical gait• Normal imaging

Epilepsy with stroke

• Difficult to tease out whether new stroke + seizure or whether old stroke + seizure

• DWI MRI helpful

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

Importance of diagnosing stroke mimics

Access appropriate secondary prevention

Correct treatment for mimic Avoidance of unnecessary drugs

Summary• Importance of rapidly diagnosing and

treating TIA• Diagnosis of TIA and stroke mimics