Example Case

Transient Ischemic Attacks Transient Ischemic Attacks

Rodney W. Smith, MDRodney W. Smith, MD

Clinical Assistant ProfessorClinical Assistant ProfessorDepartment of Emergency MedicineDepartment of Emergency Medicine

University of MichiganUniversity of MichiganAnn Arbor, MIAnn Arbor, MI

Rodney Smith, MD

Example CaseExample Case

• A 55 year old male presents to the emergency department with acute onset of– Left arm weakness: Unable to lift left

arm off of lap– Symptoms improved on the way to the

hospital

Rodney Smith, MD


• PMHx: Hypertension– Takes enalapril

• ROS:– No headache– No other neurologic symptoms

• Social Hx:– Smokes 1 ppd

Rodney Smith, MD


• Physical Exam– Overweight, in NAD– 160/90, 80, 14, 37.5C– Right carotid bruit– Heart with regular rate and rhythm; No

murmur

Rodney Smith, MD


• Neuro exam– Oriented to person, place, and time– Fluent speech– CN II-XII intact– Motor 4/5 strength in left upper extremity– Sensory subjective decrease in pinprick in left

upper extremity compared to the right– DTR +2 except at left biceps +3– Gait steady– Cerebellar intact finger to finger and finger to nose– No extensor plantar response.

Rodney Smith, MD

Summary

• Importance of distinguishing TIA from other causes of transient “spells”

• Essential elements include a careful history, physical exam, and CT scan

• ED treatment and disposition are directed toward prevention of subsequent stroke

• Incidence of early stroke after TIA justifies hospital admission for further evaluation

Rodney Smith, MD

Risk Factors/EpidemiologyRisk Factors/Epidemiology

• 300,000 TIAs per year in US• 5-year stroke risk after TIA 29%

– 43.5% in 2 years with >70% carotid stenosis treated medically

• Many stroke patients have had TIA– 25% - 50% in large artery atherothrombotic

strokes– 11% - 30% in cardioembolic strokes– 11% to 14% in lacunar strokes

Rodney Smith, MD

Risk Factors/EpidemiologyRisk Factors/Epidemiology• Risk factors are the same as stroke

– Increasing age– Sex– Family history / Race– Prior stroke / TIA– Hypertension– Diabetes– Heart disease– Carotid artery / Peripheral artery disease– Obesity– High cholesterol– Physical inactivity

Rodney Smith, MD

ED PresentationED Presentation

• What is a TIA?– Acute loss of focal cerebral function– Symptoms last less than 24 hours– Due to inadequate blood supply

• Thrombosis• Embolism

Rodney Smith, MD


• Acute loss of focal cerebral function– Motor symptoms

• Weakness or clumsiness on one side• Difficulty swallowing

– Speech disturbances• Understanding or expressing spoken

language• Reading or writing• Slurred speech• Calculations

Rodney Smith, MD


• Acute loss of focal cerebral function– Sensory symptoms

• Altered feeling on one side• Loss of vision on one side• Loss of vision in left or right visual field• Bilateral blindness• Double vision• Vertigo

Rodney Smith, MD


• Non-focal Symptoms (Not TIA)– Generalized weakness or numbness– Faintness or syncope– Incontinence – Isolated symptoms (symptoms occurring

alone)• Vertigo or loss of balance• Slurred speech or difficulty swallowing• Double vision

Rodney Smith, MD


• Non-focal Symptoms (Not TIA)– Confusion

• Disorientation• Impaired attention/concentration• Diminution of all mental activity• Distinguish from

– Isolated language or visual-spatial perception problems (may be TIA)

– Isolated memory problems (transient global amnesia)

Rodney Smith, MD

TIA Symptoms RelatedTIA Symptoms Relatedto Cerebral Circulationto Cerebral Circulation

Symptom Anterior Either PosteriorDysphasiaUnilateral weakness UsuallyUnilateral sensory disturbance UsuallyDysarthria Plus otherHomonymous hemianopiaUnsteadiness/ataxia Plus otherDysphagia Plus otherDiplopia Plus otherVertigo Plus otherBilateral simultaneous visual lossBilateral simultaneous weaknessBilateral simultaneous sensory disturbanceCrossed sensory/motor loss

Circulation Involved

Rodney Smith, MD


• Acute loss of focal cerebral function– Abrupt onset – Symptoms occur in all affected areas

at the same time– Symptoms resolve gradually– Symptoms are “negative”

Rodney Smith, MD


• Symptoms last less than 24 hours– Most last less than one hour– Less than 10 percent > 6 hours– Amaurosis fugax up to five minutes

Rodney Smith, MD

ED PresentationED PresentationDifferential DiagnosisDifferential Diagnosis

• Migraine with aura– Positive symptoms– Spread over minutes– Visual disturbances– Somatosensory or motor disturbance– Headache within 1 hour

Rodney Smith, MD


• Aura without Headache– 98% Visual symptoms– 30% with other symptoms

• 26% sensory• 16% aphasia• 6% dysarthria• 10% weakness

– Mean age 48.7 (vs. 62.1)– Fewer cardiovascular risk factors

Rodney Smith, MD


Duration of symptoms

0%

20%

40%

60%

80%

15 15 to 60 > 60

Time in minutes

Time to maximum symptoms

0%

10%

20%

30%

40%

50%

< 1 1 to 5 6 to 30 >30

Time in minutes

Rodney Smith, MD


• Partial (focal) seizure– Positive sensory or motor symptoms– Spread quickly (60 seconds)– Negative symptoms afterward (Todd’s

paresis)– Multiple attacks

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• Transient global amnesia– Sudden disorder of memory– Antegrade and often retrograde– Recurrence 3% per year– Etiology unclear

• Migraine• Epilepsy (7% within 1 year)• Unknown

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• Transient global amnesia– No difference in vascular risk factors

compared with general population– Fewer risk factors when compared

with TIA patients– Prognosis significantly better than TIA

Rodney Smith, MD


• Structural intracranial lesion– Tumor

• Partial seizures• Vascular steal• Hemorrhage• Vessel compression by tumor

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• Intracranial hemorrhage– ICH rare to confuse with TIA– Subdural hematoma

• Headache • Fluctuation of symptoms• Mental status changes

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• Multiple sclerosis– Usually subacute but can be acute

• Optic neuritis• Limb ataxia

– Age and risk factors– Signs more pronounced than

symptoms

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• Labyrinthine disorders– Central vs. Peripheral vertigo– Ménière's disease– Benign positional vertigo– Acute vestibular neuronitis

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• Metabolic– Hypoglycemia– Hyponatremia– Hypercalcemia

• Peripheral nerve lesions– Entrapments– Painful quality

Rodney Smith, MD


O xfordshire C om m unity S troke Pro ject

52 (10%) M igra ine 33 (6%) V ertigo

48 (9%) S yncope 29 (6%) E pi lepsy

46 (9%) Poss . T IA 17 (3%) T G A

45 (9%) F unny turn 47 (9%) O ther

317 O thers 195 (38%) w ith T IA

512 Pa tients re fe rredfor suspec ted T IA

Rodney Smith, MD



• Patient evaluation by senior neurologists with interest in stroke

• Agreement on 48 of 56 patients (85.7%)– 36 with TIA– 12 Not TIA– 8 of 56 disagreement

• 4 of these, both listed firm diagnosis

Rodney Smith, MD

ED Diagnosis and EvaluationED Diagnosis and Evaluation

• History– Characteristics of the attack– Associated symptoms– Risk factors

• Vascular Disease• Cardiac Disease• Hematologic Disorders• Smoking

– Prior TIA

Rodney Smith, MD


• Physical Examination– Neurologic Exam– Carotid Bruits– Cardiac Exam– Peripheral Pulses

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• EKG

• CBC, Coags, and Chemistries

• Chest Xray

• Head CT without contrast

• Expedite if early presentation

Rodney Smith, MD


• Symptom vs. Disease– Significant carotid artery stenosis– Cardiac embolism

• Admission vs. Discharge– Traditional approach– Trend toward outpatient evaluation

Rodney Smith, MD

ED Diagnosis and EvaluationED Diagnosis and EvaluationED Diagnosis and EvaluationED Diagnosis and Evaluation

• Stroke Rate After TIA– Percent (95% CI)

Oxfordshire Rochester

1 month 4.4 (1.5 - 7.3) 8 (4.2 - 11.8)

6 months 8.8 (4.7 - 12.9) 10 (6.7 - 14.3)

12 months 11.6 (6.9 - 16.3) 13 (8.1 - 17.9)

5 years 29.3 (21.3 - 37.3) 29 (22.0 - 36.0)

Rodney Smith, MD


• Stroke Rate After TIA• Johnston, et al. JAMA 284:2901,

2000.

– Follow-up of 1707 ED patients diagnosed with TIA

– Stroke rate at 90 days was 10.5%– Half of these occurred in the first 48

hours after ED presentation

Rodney Smith, MD

ManagementManagement

• Goal: Prevention of Stroke• Expedited Evaluation

– Carotid Artery Disease– Cardioembolism– Inpatient vs. Observation Unit vs. Outpatient

• Antiplatelet Therapy• Risk Factor Modulation

Rodney Smith, MD

ManagementManagementED DispositionED DispositionManagementManagement

ED DispositionED Disposition

• Discharge– Further testing will not change

treatment– Prior workup– Not a candidate for CEA or

anticoagulation

Rodney Smith, MD

ManagementManagementED DispositionED DispositionManagementManagement

ED DispositionED Disposition

• Admission– Clear indication for anticoagulation– Severe deficit– Crescendo symptoms– Other indication for admission

• Admission or observation unit evaluation – All others

Rodney Smith, MD

ManagementManagementDiagnosis of Carotid StenosisDiagnosis of Carotid Stenosis

Carotid bruit related to stenosis

0%

10%

20%

30%

40%

Normal 1 - 24 25 - 49 50 - 74 75 - 99 Occluded

Percent stenosis of symptomatic ICA

Pe

rce

nt

of

pa

tie

nts

No Bruit Bruit

Rodney Smith, MD


• Carotid Duplex Ultrasound– Sensitivity of 94 - 100% for > 50% stenosis– May overdiagnose occlusion– Non-invasive

Rodney Smith, MD


• Magnetic Resonance Angiography– Similar sensitivity to carotid

ultrasound– Overestimates degree of stenosis– Gives information about

vertebrobasilar system– Accuracy of 62% in detecting

intracranial pathology– Cost and claustrophobia

Rodney Smith, MD


• Cerebral Angiography– Gold standard for diagnosis– Invasive, with risk of stroke of up to 1%– For patients with positive ultrasound– For patients with occlusion on ultrasound– First test if intracranial pathology

suspected

Rodney Smith, MD

ManagementManagementCardiogenic EmbolismCardiogenic Embolism

• Major risk factors: Anticoagulation Indicated

– Atrial fibrillation– Mitral stenosis– Prosthetic cardiac valve– Recent MI– Thrombus in LV or LA appendage– Atrial myxoma– Infective endocarditis (No anticoagulation)– Dilated cardiomyopathy

Rodney Smith, MD

ManagementManagementCardiogenic EmbolismCardiogenic Embolism

• Minor risk factors: Best treatment unclear

– Mitral valve prolapse– Mitral annular calcification– Patent foramen ovale– Atrial septal aneurysm– Calcific aortic stenosis– LV regional wall motion abnormality– Aortic arch atheromatous plaques– Spontaneous echocardiographic contrast

Rodney Smith, MD

ManagementManagementEchocardiogramEchocardiogram

• Yield < 3% in undifferentiated patients• Higher with risk factors• TEE preferred• Specific treatment of many

abnormalities unknown

Rodney Smith, MD

ManagementManagementEchocardiogramEchocardiogram

• Indications– Age < 50– Multiple TIAs in more than one arterial

distribution– Clinical, ECG, or CXR evidence suggests

cardiac embolization

Rodney Smith, MD

Management Management TIA with Atrial FibrillationTIA with Atrial Fibrillation

• INR 2.5 (Range 2 to 3)• Aspirin if Warfarin contraindicated• Timing of onset of AC not proven in RCT• AC in other causes of cardioembolic

stroke not proven in RCT

EAFT Study Group, Lancet, 1993

Rodney Smith, MD

ManagementManagementAntiplatelet TherapyAntiplatelet Therapy

• Aspirin– Compared with placebo in patients with

minor stroke/TIA• Relative risk of composite endpoint reduced

by 13% to 17%

– Dose of aspirin probably not important– Lower dose gives lower incidence of GI

side effects.

Rodney Smith, MD


• Ticlopidine– Small absolute risk reduction

compared with ASA– Side effects preclude use in up to 5%– Serious adverse effects

• Neurtropenia• Thrombotic thrombocytopenic purpura

Rodney Smith, MD


• Clopidogrel– Similar to Ticlopidine in reducing

composite endpoint– Reduction in risk of stroke alone less

than with Ticlopidine– Similar side effect profile to ASA

Rodney Smith, MD


• Dipyridamole plus ASA– Small absolute risk reduction for

stroke compared with ASA alone– Risk reduction for composite endpoint

due to stroke reduction alone– Safe side effect profile

Rodney Smith, MD


• Discharged patients should receive ASA 50 - 325 mg/day– Based on cost and small absolute benefit of

other agents

• Patients with TIA on ASA should have change in agent– Dipyridamole plus ASA– Clopidogrel– Increase dose of ASA to 1300 mg/day

Rodney Smith, MD

Expected OutcomeExpected Outcome

• 70% stenosis or greater

• Best medical therapy vs. CEA

Medical SurgicalIpsilateral stroke 26.0% 9.0%Major or fatal ipsilateral stroke 13.1% 2.5%Stroke or death 32.3% 15.8%

Rodney Smith, MD

Expected OutcomeExpected Outcome

• 50 - 69% stenosis

• Best medical therapy vs. CEA

Medical SurgicalIpsilateral stroke 22.2% 15.7%Stroke or death 43.3% 33.2%

Rodney Smith, MD

Expected Outcome Expected Outcome TIA with Atrial FibrillationTIA with Atrial Fibrillation

• Rate of stroke– Placebo - 12% per year– Aspirin - 10% per year– Warfarin - 4% per year

• Major bleed in 2.8% per year• No increase in ICH occurrence

EAFT Study Group, Lancet, 1993

Rodney Smith, MD

Future directionsFuture directions

• Treatment of PFO in patients with TIA– ASA; Warfarin; Surgery

• Ongoing trials of Warfarin vs. ASA for secondary stroke prevention

• Ongoing trials of carotid artery angioplasty and stents

Rodney Smith, MD

Outcome of CaseOutcome of Case

• Patient was evaluated in an Observation Center– Carotid ultrasound demonstrated 80% stenosis of R

ICA– Underwent R CEA, without complication– Patient discharged with plan for risk modification

• Diet for weight reduction• Smoking cessation program• Optimized antihypertensive regimen

Rodney Smith, MD

SummarySummary

• Importance of distinguishing TIA from other causes of transient “spells”

• Essential elements include a careful history, physical exam, and CT scan

• ED treatment and dispostition are directed toward prevention of subsequent stroke

• Incidence of early stroke after TIA justifies hospital admission for further evaluation

Example Case

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