1. Transient Ischemic Attacks Rodney W
Transient Ischemic Attacks Rodney W. Smith, MD Clinical Assistant Professor Department of Emergency Medicine University of Michigan Ann Arbor, MI 54 1 54

2. Example 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

3. Example Case PMHx: Hypertension ROS: Social Hx: Takes enalapril
No headache
No other neurologic symptoms
Social Hx:
Smokes 1 ppd

4. Example Case Physical Exam Overweight, in NAD 160/90, 80, 14, 37.5C
Right carotid bruit
Heart with regular rate and rhythm; No murmur

5. Example Case 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.

6. 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

7. Risk 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

8. Risk 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

9. ED Presentation What is a TIA? Acute loss of focal cerebral function
Symptoms last less than 24 hours
Due to inadequate blood supply
Thrombosis
Embolism

10. ED Presentation 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

11. ED Presentation 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

12. ED Presentation 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

13. ED Presentation 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)

14. TIA Symptoms Related to Cerebral Circulation

15. ED Presentation Acute loss of focal cerebral function Abrupt onset
Symptoms occur in all affected areas at the same time
Symptoms resolve gradually
Symptoms are “negative”

16. ED Presentation Symptoms last less than 24 hours
Most last less than one hour
Less than 10 percent > 6 hours
Amaurosis fugax up to five minutes

17. ED Presentation Differential Diagnosis
Migraine with aura
Positive symptoms
Spread over minutes
Visual disturbances
Somatosensory or motor disturbance
Headache within 1 hour

18. ED Presentation Differential Diagnosis
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

19. ED Presentation Differential Diagnosis

20. ED Presentation Differential Diagnosis
Partial (focal) seizure
Positive sensory or motor symptoms
Spread quickly (60 seconds)
Negative symptoms afterward (Todd’s paresis)
Multiple attacks

21. ED Presentation Differential Diagnosis
Transient global amnesia
Sudden disorder of memory
Antegrade and often retrograde
Recurrence 3% per year
Etiology unclear
Migraine
Epilepsy (7% within 1 year)
Unknown

22. ED Presentation Differential 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

23. ED Presentation Differential Diagnosis
Structural intracranial lesion
Tumor
Partial seizures
Vascular steal
Hemorrhage
Vessel compression by tumor

24. ED Presentation Differential Diagnosis
Intracranial hemorrhage
ICH rare to confuse with TIA
Subdural hematoma
Headache
Fluctuation of symptoms
Mental status changes

25. ED Presentation Differential Diagnosis
Multiple sclerosis
Usually subacute but can be acute
Optic neuritis
Limb ataxia
Age and risk factors
Signs more pronounced than symptoms

26. ED Presentation Differential Diagnosis
Labyrinthine disorders
Central vs. Peripheral vertigo
Ménière's disease
Benign positional vertigo
Acute vestibular neuronitis

27. ED Presentation Differential Diagnosis
Metabolic
Hypoglycemia
Hyponatremia
Hypercalcemia
Peripheral nerve lesions
Entrapments
Painful quality

28. ED Presentation Differential Diagnosis

29. ED Presentation Differential Diagnosis
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

30. ED Diagnosis and Evaluation
History
Characteristics of the attack
Associated symptoms
Risk factors
Vascular Disease
Cardiac Disease
Hematologic Disorders
Smoking
Prior TIA

31. ED Diagnosis and Evaluation
Physical Examination
Neurologic Exam
Carotid Bruits
Cardiac Exam
Peripheral Pulses

32. ED Diagnosis and Evaluation
EKG
CBC, Coags, and Chemistries
Chest Xray
Head CT without contrast
Expedite if early presentation

33. ED Diagnosis and Evaluation
Symptom vs. Disease
Significant carotid artery stenosis
Cardiac embolism
Admission vs. Discharge
Traditional approach
Trend toward outpatient evaluation

34. ED Diagnosis and Evaluation
Stroke Rate After TIA
Percent (95% CI)

35. ED Diagnosis and Evaluation
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

36. Management Goal: Prevention of Stroke Expedited Evaluation
Carotid Artery Disease
Cardioembolism
Inpatient vs. Observation Unit vs. Outpatient
Antiplatelet Therapy
Risk Factor Modulation

37. Management ED Disposition
Discharge
Further testing will not change treatment
Prior workup
Not a candidate for CEA or anticoagulation

38. Management ED Disposition
Admission
Clear indication for anticoagulation
Severe deficit
Crescendo symptoms
Other indication for admission
Admission or observation unit evaluation
All others

39. Management Diagnosis of Carotid Stenosis

40. Management Diagnosis of Carotid Stenosis
Carotid Duplex Ultrasound
Sensitivity of % for > 50% stenosis
May overdiagnose occlusion
Non-invasive

41. Management Diagnosis 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

42. Management Diagnosis 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

43. Management Cardiogenic 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

44. Management Cardiogenic 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

45. Management Echocardiogram
Yield < 3% in undifferentiated patients
Higher with risk factors
TEE preferred
Specific treatment of many abnormalities unknown

46. Management Echocardiogram
Indications
Age < 50
Multiple TIAs in more than one arterial distribution
Clinical, ECG, or CXR evidence suggests cardiac embolization

47. Management TIA 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

48. Management Antiplatelet 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.

49. Management Ticlopidine Small absolute risk reduction compared with ASA
Side effects preclude use in up to 5%
Serious adverse effects
Neurtropenia
Thrombotic thrombocytopenic purpura

50. Management Clopidogrel
Similar to Ticlopidine in reducing composite endpoint
Reduction in risk of stroke alone less than with Ticlopidine
Similar side effect profile to ASA

51. Management 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

52. Management 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

53. Expected Outcome
70% stenosis or greater
Best medical therapy vs. CEA

54. Expected Outcome
% stenosis
Best medical therapy vs. CEA

55. Expected Outcome TIA with Atrial Fibrillation
Rate of stroke
Placebo % per year
Aspirin % per year
Warfarin - 4% per year
Major bleed in 2.8% per year
No increase in ICH occurrence
EAFT Study Group, Lancet, 1993

56. Future 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

57. Outcome 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

58. 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 dispostition are directed toward prevention of subsequent stroke
Incidence of early stroke after TIA justifies hospital admission for further evaluation