Evaluation of Patients with Evaluation of Patients with Transient Ischemic AttackTransient Ischemic Attack

Rodney Smith, MDRodney 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

IntroductionIntroduction

• 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

IntroductionIntroduction

• PMHx: Hypertension• Takes enalapril

• ROS:• No headache• No other neurologic symptoms

• Social Hx:• Smokes 1 ppd

Rodney Smith, MD

IntroductionIntroduction

• 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

IntroductionIntroduction

• 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

ObjectivesObjectives

• What is a transient ischemic attack (TIA)?

• What is the differential diagnosis of patients with possible TIA?

• What is the ED approach to TIA?• What is the treatment and

disposition of patients with TIA?

Rodney Smith, MD

Transient Ischemic AttackTransient Ischemic Attack

• 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

Transient Ischemic AttackTransient Ischemic Attack

• 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

Transient Ischemic AttackTransient Ischemic Attack

• 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

Transient Ischemic AttackTransient Ischemic Attack

• Non-focal Symptoms• Generalized weakness or numbness• Faintness or syncope• Incontinence • Isolated symptoms

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

Rodney Smith, MD

Transient Ischemic AttackTransient Ischemic Attack

• Non-focal Symptoms• Confusion

• disorientation• impaired attention/concentration• diminution of all mental activity• distinguish from isolated language,

memory, or visual-spatial perception problems

Rodney Smith, MD

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

Transient Ischemic AttackTransient Ischemic Attack

• 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

Transient Ischemic AttackTransient Ischemic Attack

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

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Differential DiagnosisDifferential Diagnosis

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

Rodney Smith, MD

Differential DiagnosisDifferential Diagnosis

• Aura without Headache• Gradual onset with spread over

minutes OR• Positive visual symptoms• Headache totally absent or mild• No prior symptoms of classic migraine

Rodney Smith, MD

Differential DiagnosisDifferential Diagnosis

• Aura without Headache• 50 patients with case control TIA

patients• 10 year follow-up• Mean age 48.7 (vs. 62.1)• 60% male (vs. 68%)• Fewer cardiovascular risk factors

Rodney Smith, MD

Differential DiagnosisDifferential Diagnosis

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

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

Rodney Smith, MD

Differential DiagnosisDifferential Diagnosis

0%

5%10%

15%20%

25%

30%35%

40%45%

50%

< 1 1 to 5 6 to 30 >30

• Aura without HA• Onset of

symptoms in minutes

• Over 50% with onset over > 5 min.

Rodney Smith, MD

Differential DiagnosisDifferential Diagnosis

• Aura without HA• Duration of

symptoms in minutes

• 20% with slight headache

• 20% with prior headaches without aura 0%

10%

20%

30%

40%

50%

60%

70%

80%

15 15 to 60 > 60

Rodney Smith, MD

Differential Diagnosis Differential Diagnosis

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

paresis)• Multiple attacks

Rodney Smith, MD

Differential DiagnosisDifferential Diagnosis

• Transient global amnesia• Sudden disorder of memory

(confusion)• Antegrade and often retrograde• Recurrence 3% per year• Etiology unclear

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

Rodney Smith, MD

Differential DiagnosisDifferential Diagnosis

• 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

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Differential DiagnosisDifferential Diagnosis

• Structural intracranial lesion• Tumor

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

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Differential DiagnosisDifferential Diagnosis

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

• Headache • Fluctuation of symptoms• Mental status changes

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Differential DiagnosisDifferential Diagnosis

• Multiple sclerosis• Usually subacute but can be acute

• optic neuritis• limb ataxia

• Age and risk factors• Signs more pronounced than

symptoms

Rodney Smith, MD

Differential DiagnosisDifferential Diagnosis

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

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Differential DiagnosisDifferential Diagnosis

• Metabolic• Hypoglycemia• Hyponatremia• Hypercalcemia

• Peripheral nerve lesions• Entrapments• Painful quality

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Likelihood of TIALikelihood of TIAO 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

Likelihood of TIALikelihood of TIALikelihood of TIALikelihood of TIA

• Diagnosis of TIA• Kraaijeveld, et al. 1984• 56 patients evaluated by 2 of 8 “senior

neurologists”• Decide if TIA (yes or no)• If yes, territory involved (carotid,

vertebro-basilar, either, both)• Is conclusion firm or doubtful?

Rodney Smith, MD

Likelihood of TIALikelihood of TIALikelihood of TIALikelihood of TIA

• Clinical criteria• Time course• Symptoms of carotid TIA• Symptoms of vertebro-basilar TIA• Symptoms of uncertain territory• Symptoms explicitly not TIA

Rodney Smith, MD

Likelihood of TIALikelihood of TIALikelihood of TIALikelihood of TIA

• 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

Likelihood of TIALikelihood of TIALikelihood of TIALikelihood of TIA

• TIA yes or no • kappa = 0.65

• TIA circulation involved• kappa = 0.31

Rodney Smith, MD

Emergency Department Emergency Department EvaluationEvaluation

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

• Vascular Disease• Cardiac Disease• Hematologic Disorders• Smoking

• Prior TIA

Rodney Smith, MD

Emergency Department Emergency Department EvaluationEvaluation

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

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Emergency Department Emergency Department EvaluationEvaluation

• EKG • CBC, Coags, and Chemistries• Chest Xray• Head CT without contrast• Expedite if early presentation

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Decision PointDecision Point

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

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

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Likelihood of Early StrokeLikelihood of Early StrokeLikelihood of Early StrokeLikelihood of Early Stroke

• Prognosis after TIA• Dennis et al. Oxfordshire, UK 1981 - 1986

• Prospective community-based study• Incident TIA• No history of prior stroke

• Whisnant, et al. Rochester, MN 1955 - 1969• Retrospective community-based study• First-ever TIA

Rodney Smith, MD

Likelihood of Early StrokeLikelihood of Early StrokeLikelihood of Early StrokeLikelihood of Early Stroke

• Stroke rate after TIA• Annual rate during 5-year follow-up

• 6.7% Oxfordshire• 6.6% Rochester, MN

Rodney Smith, MD

Likelihood of Early StrokeLikelihood of Early StrokeLikelihood of Early StrokeLikelihood of Early Stroke

• 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

Carotid Endarterectomy and Carotid Endarterectomy and StrokeStroke

• 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

Carotid Endarterectomy and Carotid Endarterectomy and StrokeStroke

• 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

Diagnosis of Carotid StenosisDiagnosis of Carotid 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

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Diagnosis of Carotid StenosisDiagnosis of Carotid Stenosis

• Carotid Duplex Ultrasound• Sensitivity of 94 - 100% for > 50%

stenosis• May overdiagnose occlusion• Non-invasive

Rodney Smith, MD

Diagnosis of Carotid StenosisDiagnosis of Carotid Stenosis

• 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

Diagnosis of Carotid StenosisDiagnosis of Carotid Stenosis

• 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

Cardiogenic EmbolismCardiogenic Embolism

• Major risk factors• Atrial fibrillation• Mitral stenosis• Prosthetic cardiac valve• Recent MI• Thrombus in LV or LA appendage• Atrial myxoma• Infective endocarditis• Dilated cardiomyopathy

Rodney Smith, MD

Cardiogenic EmbolismCardiogenic Embolism

• Minor risk factors• 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

EchocardiogramEchocardiogram

• Yield < 3% in undifferentiated patients• Higher with risk factors• Indications

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

distribution• Clinical, ECG, or CXR evidence suggests

cardiac embolization

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TIA EvaluationTIA EvaluationTIA EvaluationTIA Evaluation

• ED Disposition• Admission

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

Rodney Smith, MD

TIA EvaluationTIA EvaluationTIA EvaluationTIA Evaluation

• ED Disposition• Discharge

• Further testing will not change treatment• Prior workup• Not a candidate for CEA or anticoagulation

Rodney Smith, MD

Antiplatelet TherapyAntiplatelet Therapy

• Aspirin• Not dose dependent

• Ticlopidine• Clopidogrel• Aspirin plus Dipyridamole

Rodney Smith, MD

Risk Factor ModulationRisk Factor Modulation

• Obesity• Smoking• Hypertension• Cholesterol• Excessive alcohol

• 1 to 2 glasses of wine per day may be protective