STROKE OR TIA - REAL OR IMITATION

Faculty: Frank L. Silver MD, FRCPC Professor of Medicine (Neurology), University of Toronto Medical Director, Toronto West Stroke Network Medical Director, Ontario Telestroke Program Adjunct Scientist, Institute for Clinical Evaluative Sciences Relationships with commercial interests: ► Consulting Fees : Boehringer Ingelheim Canada, National

Coordinator for RESPECT ESUS RCT ► Speakers’ Bureau: Boehringer Ingelheim, Pfizer, Bristol-Myers

Squibb Potential for conflict(s) of interest: ► Boehringer Ingelheim, Pfizer, Bristol-Myers Squibb develop and

benefit from the sale of products that might be discussed in this program.

Mitigating Potential Bias ► All the recommendations involving clinical medicine are based on evidence that is accepted within the profession. ► All scientific research referred to, reported, or used is in the support or

justification of patient care. ► Recommendations conform to the generally accepted standards. ► The presentation will mitigate potential bias by ensuring that data and

recommendations are presented in a fair and balanced way. ► Potential bias will be mitigated by presenting a full range of products that

can be used in this therapeutic area. ► Information of the history, development, funding, and the sponsoring

organizations of the disclosure presented will be discussed.

Making a diagnosis after the symptoms have resolved is difficult

Learning Objectives

1. To discuss neurological and non-neurological conditions that mimic stroke and TIA

2. To discuss the clinical features that differentiate between stroke and these mimics

3. To provide an approach, including relevant investigations, to assist in determining the etiology of an ischemic stroke

Why is stroke important?

• Stroke is common – one of the leading reasons for admission to an adult hospital

• Stroke can be devastating – the leading cause of adult disability and a huge cost to society

• Stroke is treatable – revascularization with thrombolytics and mechanical thrombectomy

• Stroke is preventable – more than half of all stroke could be prevented by applying what we already know

Acute strokes can be very bad!

is a clinical syndrome characterized

by the sudden onset of a focal neurological deficit presumed to be

on a vascular basis

The Definition of Stroke

TIA vs. Ischemic Stroke ?

CT Scan 4 hours MR Scan 4 hours (DWI)

61 year old man with a history of sudden right face and arm weakness and speech difficulties lasting 20 minutes

a clinical syndrome characterized by the sudden onset of a focal neurological symptoms that resolves within 24 hours

AND there is no evidence of infarction on brain imaging

Definition of TIA (revised recently)

Making the Right Diagnosis The Four Questions

• Is it a stroke?

• Where is the lesion? – What is the vascular supply ?

• What is the lesion? – Hemorrhage vs Infarct/Ischemia

• What is the etiology?

Stroke Mimics • Any focal lesion

– tumour, abscess – demyelination

• Seizures (post-ictal Todd’s)

• Old strokes

• Hysterical conversion

• Migraine

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338 / 1532 (22%) of the patients had mimics

Nadarajan V, et al. Pract Neurol 2014;14:23–31

Frequency and Type of Stroke / TIA Mimics

Top Ten Mimics Migraine Syncope

BPPV Seizures

Functional / Anxiety TGA

Bell’s Palsy Peripheral Nerve Disease

Postural Hypotension Tumour

Factors to consider • The presence of vascular risk factors / age of patient

• Focal vs non-focal symptoms

• Positive vs. negative symptoms

• Type of symptoms – motor, speech, visual vs. sensory

• Duration of symptoms

• Accompanying symptoms – Pain – headache, neck pain, chest pain – Cardiac symptoms – palpitations, SOB, – Seizure – Post-ictal confusion, incontinence, tongue biting – Ear – hearing loss, tinnitus

Stroke / TIA • Presence of vascular risk factors

• Onset is sudden, maximal at onset without progression

• Focal negative symptoms – motor weakness, speech (dysarthria and/or aphasia), visual (field loss, diplopia)

• Not isolated – vertigo / diplopia / sensory loss / memory

• Duration – at least 10 minutes (not 10 seconds)

• One or two episodes – worry; many episodes usually benign

• Associated symptoms – headache, pulsatile tinnitus, palpitations

Migraine

• Common

• Family history

• Onset usually at early age, however, late-onset acephalgic migraine is common

• Aura - evolving positive focal symptoms – usually visual, progressing over minutes, can progress stepwise from visual, to sensory, to speech

• Duration – typically 10 – 30 minutes

Seizure

• brief, lasting 1 - 2 minutes, recurrences stereotyped

• often focal onset – with progression over seconds (Jacksonian March)

• post-ictal confusion / drowsiness +/- Todd’s paralysis

• tongue biting, incontinence

• ask about hallucinations of taste, smell, déjà vu

• imaging shows a focal lesion

• EEG may be helpful

TIA Migraine aura Focal Seizures Predisposition • CAD, PVD

• Atherosclerotic risk factors

• Migraines • Brain lesion

Cardiovascular manifestations

• Frequent • Absent • Absent

Neurological manifestations

• Negative (deficit) • Positive • Visual > sensory

>speech • Headaches

• Positive

Symptom onset • Sudden • >10 minutes with progression

• ≤ 2 minutes with progression

Duration • 5-10 minutes (or more)

• 20 minutes • ≤ 5 minutes

Sylvain Lanthier

Syncope / Pre-syncope

• cardiac history – angina / prior MI, palpitations

• often volume depleted or on new medication

• often a prodrome – nausea, NFW, pallor, sweating, vision blurred / diminishing

• often postural or when standing

• lightheaded, not vertigo

• no focal neurological signs

• no post-ictal confusion

• rarely incontinence

Conversion • history of previous functional illness

• secondary gain

• symptoms / signs do not make sense physiologically – do not follow myotomes, dermatomes – absence of abnormal reflexes – inconsistent – e.g. can weight bear / but cannot lift

against gravity

• symptoms fluctuate and improve with encouragement – BEWARE of myasthenia gravis

• normal imaging

Peripheral vestibulopathy

• true vertigo, often positional

• no other focal neurological symptoms – no diplopia, dysarthria, dysphagia, focal weakness /

sensory loss, – no ataxia (except when severely vertiginous)

• tinnitus, hearing loss

• often recurrent over time

you must examine the patient’s gait

How often is acute dizziness related to an acute TIA / stroke?

Population based study in Nueces County, Texas (2011–2012) of patients presenting to an emergency department with acute dizziness

1,273 patients age ≥45 followed median 347 days

• Stroke was diagnosed in 25 (2.2%) of the patients.

• Of the remaining 1,245 non-stroke dizzy patients - 15 (1.2%) had a stroke in follow-up Note: Dizziness was defined as a presenting symptom of “dizziness,” “vertigo,” or “imbalance.”

Kerber KA et al. Ann Neurol 2014 75:899-907.

Transient Global Amnesia

• sudden loss of recent and ongoing memory

• patients still know who they are and recognise their family / friends

• lasts hours

• no other neurologic deficits

• associated with migraine

✓ ✘

Metabolic / Toxic Disorders

• Hypoglycemia – focal findings can be present – corrects with glucose but may take time

• Acute metabolic / infectious disturbance with focal findings related to a past stroke

• Hyperglycemia

• Hypocalcemia

• Hyponatremia

• Hepatic encephalopathy

• Ethanol and other psychotropic drugs

Just to confuse us, these are really on the basis of cerebral ischemia / infartion • Capsular Warning Syndrome

• Limb-shaking TIAs

• Penduncular Hallucinations

• Brain stem posturing / involuntary movement

• Anton’s Syndrome – cortical blindness

• Hemiballismus – infarct of the subthalamic nucleus

The Value of Imaging

• Brain Imaging (CT / MR) – evidence of old infarcts / hemorrhages – evidence of acute infarction / hemorrhage

• Vascular Imaging (CTA, MRA, DSA, Duplex doppler) – significant arterial stenosis / occlusion of a relevant artery – other vascular lesions – AVMs, aneurysms, SVT

• Perfusion imaging (CTP, MRP) – perfusion abnormality

Left MCA Stroke: Frontal Lesions

Diffusion Weighted MRI - cardioembolic

CT Head: September 21, 2016 12:56 hours

CTA September 21, 2016 12:56 hours

RAPID CTP September 21, 2016 12:56 hours

Risk of Early Recurrent Stroke Increased Risk for Early Stroke:

motor weakness

speech disturbance

symptoms > 10 minutes

diabetes

age > 60

90 day risk of stroke following a TIA is ~ 10%

half occur with in the first 48 hours

ABCD2 • A – age 60 years or older (1 point)

• B – blood pressure elevation on first assessment after TIA (1 point; systolic ≥140 mm Hg or diastolic

• C – clinical features of TIA (unilateral weakness, 2 points; or speech impairment without weakness, 1 point);

• D – duration of TIA (≥60 minutes, 2 points; or 10–59 minutes, 1 point)

• D – diabetes (1 point)

In 4799 patients 2-day risk of stroke was: » 1·0% with a score of zero to three (low risk) » 4·1% with four or five (moderate risk) » 8·1% with six or seven (high risk)

Johston, Rothwell, et al. Lancet 2007; 369:283-92

Small infarct

Diffusion Weighted MR

Coutts SB, Simon JE, Eliasziw M, et al Ann Neurol 2005;57:848–854

MR Findings

30-day Risk of Stroke

Overall

No DWI Lesion

DWI Lesion & Vessel Occlusion

11.7%

4.4

32.6

Dai Q. et al Neurol 2015;84:1426-1432

ABCD3-I Score!

Risk of Recurrent Stroke at One Year

TIAregistry. org Project • TIA / Minor Stroke with 7 days • seen in rapid TIA clinic

One Year Risk • Stroke, MI, Vascular Death 6.2% • Stroke 5.1% (3.7% at 90 days)

Risk of Recurrent Stroke at One Year

Ontario Stroke Registry • ED patients with TIA / Minor Stroke • 2008/9 and 2010/11

Kapral MK et al Neurology 2016;86:1-8.

Making the Right Diagnosis The Four Questions

• Is it a stroke?

• Where is the lesion? – What is the vascular supply ?

• What is the lesion? – Hemorrhage vs Infarct/Ischemia

• What is the etiology?

Ischemic Stroke: Mechanisms

BLOOD VESSELS

BLOOD

HEART

Investigations • Image the brain

– to determine the location, size and pattern of the infarct(s)

• Image the arteries – to look for an embolic source – to explain a hemodynamic mechanism

» look for proximal occlusion/ stenosis » assess the collateral circulation

• If suspected – assess cerebral perfusion or CVR

• Look for a cardiac source – echo, Holter, cardiac MR

• Look for a prothrombotic state

Ischemic Stroke by Etiology

Adapted from the Stroke Databank Lancet Neurol 2014; 13: 429-38

ESUS

Lancet Neurol 2014; 13: 429-38

Ischemic Stroke by Etiology

20%

25%

30%

20%

5% LAACardioemLacunarUnknownOther

Adapted from the Stroke Databank

Anticoagulant Rx

Casaubon et al. Int J Stroke. 2015 Aug;10(6):924-40.

http://www.strokebestpractices.ca