Investigations for Stroke and TIA What, When and Where (…and Who and Why) K. Butcher, MD, PhD, FRCP(C) University of Alberta WMC Health Sciences Centre

Disclosures Speaker’s Honoraria Novo Nordisk Boeringher Ingelheim Sanofi-Aventis Servier Roche Consultant Novo Nordisk Grant-in-Aid Salary Award Grant-in-Aid Salary Award Grant-in-Aid Salary Award

Learning Objectives The requirement for urgent brain imaging in patients with new onset focal neurological deficits. The tempo of brain imaging required in patients with suspected TIA versus stroke, and the relationship to treatment decisions. The available options for brain as well as intracranial and extracranial vascular imaging. Participants will also appreciate the advantages and disadvantages of each imaging modality. Appropriateness and timing of various cardiac investigations, including ECG, Holter monitoring and echocardiography. Appropriate blood work to be performed in stroke and TIA patients.

Outline 1.Acute investigations Imaging Laboratory/other 2.Secondary prevention investigations Tempo of investigations in Stroke and TIA

Case 58 year old male with a history of hypertension and smoking complains of headache to his office co-workers. One minute later, he develops left sided facial droop and falls to his left. EMS is called and he is brought to your ED. BP is 190/100, HR is 90 BPM and he is in NSR. Investigation of choice?

Acute CT Scan

Acute Stroke Treatment: The Need for Speed Pre-tPA Post-tPA

Time is Brain The ATLANTIS, ECASS, AND NINDS rt-PA Study group, 2002 Adjusted odds ratio of stroke recovery Stroke onset to treatment time [min] N = hours NNT=14

ECASS III Results

Who Needs Imaging? Patients with Focal CNS Symptoms and Signs

Acute Stroke History Primary goal: Stroke or not stroke? Focal neurological deficits –Weakness –Speech problems –Visual symptoms –Headache –Vertigo/Dizziness– never stroke in isolation –Sensory changes

Imaging Triage: Physical Exam The NIH Stroke Scale: RAPID and directed examination

Planning the Tempo of Investigations Establish true time of onset Cardiovascular risk factors: –Previous stroke, ischemic heart disease –Hypertension –Atrial fibrillation –Diabetes –Smoker CV medications Younger patients: –Mimics: Migraine, epilepsy –Specific mechanism (esp. younger patients): dissection

Putting Symptoms into Context Left sided numbness for 1 hour a. 23 year old female with history of migraine b. 52 year old male with history of STEMI 6 weeks ago

IMAGING TEMPO: SUMMARY FIXED/PERSISTENT CNS DEFICITS IMAGE IMMEDIATELY TRANSIENT CNS DEFICITS IMAGE WITHIN 24 H

Investigation and Treatment Strategies

Alberta Provincial Stroke Strategy: Telstroke Alberta Wetaskiwin

Expediting Diagnosis: Tele-Radiology

Future Directions: Portable CT

42 year old F, 2.5 hours of non-fluent dysphasia and Right U/E weakness CT: Early Infarct Sign

24 hour Follow-up Scan (post r-tPA)

Alberta Stroke Program Early CT Score (ASPECTS)

CT: Early Infarct Sign

Hypo-attenuation: Acute Infarction

Extensive Hypo-attenuation and Sulcal Effacement

24 hour Follow-up Scan (post r-tPA)

Isolated Sulcal Effacement/Swelling

24 hour Follow-up Scan (post r-tPA)

Initial Investiagions: ABC’s Airway and Breathing: Oxygen Saturation Keep Sp0 2 >92%

Initial Investigations: ABC’s Circulation: 12 lead ECG, cardiac and NIBP monitor if available

Frequency of Hypertension in Acute Stroke Adapted from Leonardi-Bee et al, Stroke: 33, 1315, 2002 Hypertensive

Laboratory Investigations Glucose (critical…why?) CBC (Platelets >100 for tPA) INR, PTT (INR < 1.7 for tPA) Lytes, Cr, BUN In thrombolysis, the utility of waiting for these labs must be weighed against the time is brain concept

Imaging Blood Vessels

Hyperdense MCA Sign

Hyperdense Dot Sign

ADVANCED IMAGING

CT Angiography

DWI CT T2 Diffusion-Weighted Imaging: DWI

DWI Evolution: Natural History 24 hours 4 hours

Time course of DWI Evolution -11 min +11 min3 hours24 hours Hjort et al, Ann. Neurol, 2005

Value of DWI in Ischemic Stroke

What is the Ischemic Penumbra?

Penumbral Imaging: MRI No Reperfusion Reperfusion

Imaging the Penumbra: CT Perfusion Non-contrast CT Blood Flow CT Angiogram

Investigations for Secondary Prevention

TIA Investigation: Is there a rush? Gladstone D et al. CMAJ Mar 30;170(7):

TIA Risk Stratification: ABCD 2 Score A: age > 60 years – 1 point B: BP (systolic>140mmHg, diastolic>90 mmHg). Either 1 point. (max 1 point) C: clinical – unilateral weakness =2, speech only = 1 D: Duration, >60 minutes =2, =1, <10 =0 D2: Diabetes=1 Rothwell PM, Lancet 2005; 366:29-36, Johnston, SC, Lancet 2007;369:

ABCD 2 score: Front-loaded Risks Score 2-day risk 7day risk 90 day risk High risk % 11.7% 17.8% Moderate risk % 5.9% 9.8% Low risk % 1.2% 3.1%

What do they Need?

1. Brain Imaging: CT or MRI Even brief symptoms cause areas of permanent injury ~50% of all TIA’s are associated with permanent damage, particularly if symptoms last > 1 hour Kidwell C et al. Stroke 1999; 6:

A. Doppler/Duplex Ultrasound Indications? –Symptoms of anterior circulation ischemia Utility? Tempo? 2. Carotid Imaging

B. Cerebral Angiography Utility? Indications? Risks? Digital Subtraction (Conventional Catheter) Angiography

C. CT Angiography Intracranial CT Angiogram Extracranial CT Angiogram

D. MR Angiography Extracranial Intracranial

recent stroke, left hemisphere Indications for Carotid Endarterctomy? Why does CEA prevent stroke?

NNT=6 NNT=9 NNT=3 Carotid Endarterectomy Timing

3. Cardiac Investigations Who needs an Echo? What kind do they need?

Echocardiography Options Transthoracic Echocardiogram Transesophageal Echocardiogram

Echocardiography Summary TEE Young patients without stroke risk factors (a small minority) TTE Patients with cardiac disease or other reasons for investigating ventricular function

Higher Yield Cardiac Investigation? Holter Monitor % of Patients with Paroxysmal Atrial Fibrillation (this changes management!) Number of Infarcts

Secondary Prevention Blood Work Fasting Glucose—Management? Fasting lipids—LDL target? Homocysteine? Tests of Hypercoagulability? –Reserve for younger patients or those with a history of recurrent thrombosis –Anticardiolipin and Lupus Anticoagulant are the higher yield investigations

Summary Diagnosis: –rapid, accurate diagnosis essential ‘Time is Brain’ –History and Physical: identify focal neurological deficits Acute Treatment: –Consider thrombolysis –TIA is also a medical emergency and needs to be investigated urgently