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

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Transient Ischemic Attacks Rodney W. Smith,
MDClinical Assistant ProfessorDepartment of
Emergency MedicineUniversity of MichiganAnn
Arbor, MI
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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

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Example Case

• PMHx Hypertension
• Takes enalapril
• ROS
• No headache
• No other neurologic symptoms
• Social Hx
• Smokes 1 ppd

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Example Case

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

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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.

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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

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Risk Factors/Epidemiology

• 300,000 TIAs per year in US
• 5-year stroke risk after TIA 29
• 43.5 in 2 years with gt70 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

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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

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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

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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

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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

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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

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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)

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TIA Symptoms Relatedto Cerebral Circulation
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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

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ED Presentation

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

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ED PresentationDifferential Diagnosis

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

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ED PresentationDifferential 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

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ED PresentationDifferential Diagnosis
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ED PresentationDifferential Diagnosis

• Partial (focal) seizure
• Positive sensory or motor symptoms
• Spread quickly (60 seconds)
• Negative symptoms afterward (Todds paresis)
• Multiple attacks

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ED PresentationDifferential 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

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ED PresentationDifferential 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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ED PresentationDifferential Diagnosis

• Structural intracranial lesion
• Tumor
• Partial seizures
• Vascular steal
• Hemorrhage
• Vessel compression by tumor

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ED PresentationDifferential Diagnosis

• Intracranial hemorrhage
• ICH rare to confuse with TIA
• Subdural hematoma
• Headache
• Fluctuation of symptoms
• Mental status changes

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ED PresentationDifferential Diagnosis

• 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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ED PresentationDifferential Diagnosis

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

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ED PresentationDifferential Diagnosis

• Metabolic
• Hypoglycemia
• Hyponatremia
• Hypercalcemia
• Peripheral nerve lesions
• Entrapments
• Painful quality

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ED PresentationDifferential Diagnosis
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ED PresentationDifferential 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

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ED Diagnosis and Evaluation

• History
• Characteristics of the attack
• Associated symptoms
• Risk factors
• Vascular Disease
• Cardiac Disease
• Hematologic Disorders
• Smoking
• Prior TIA

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ED Diagnosis and Evaluation

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

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ED Diagnosis and Evaluation

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

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ED Diagnosis and Evaluation

• Symptom vs. Disease
• Significant carotid artery stenosis
• Cardiac embolism
• Admission vs. Discharge
• Traditional approach
• Trend toward outpatient evaluation

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ED Diagnosis and Evaluation

• Stroke Rate After TIA
• Percent (95 CI)

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ED Diagnosis and Evaluation

• Stroke Rate After TIA
• Johnston, et al. JAMA 2842901, 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

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Management

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

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ManagementED Disposition

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

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ManagementED Disposition

• Admission
• Clear indication for anticoagulation
• Severe deficit
• Crescendo symptoms
• Other indication for admission
• Admission or observation unit evaluation
• All others

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ManagementDiagnosis of Carotid Stenosis
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ManagementDiagnosis of Carotid Stenosis

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

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ManagementDiagnosis 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

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ManagementDiagnosis 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

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ManagementCardiogenic 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

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ManagementCardiogenic 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

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ManagementEchocardiogram

• Yield lt 3 in undifferentiated patients
• Higher with risk factors
• TEE preferred
• Specific treatment of many abnormalities unknown

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ManagementEchocardiogram

• Indications
• Age lt 50
• Multiple TIAs in more than one arterial
  distribution
• Clinical, ECG, or CXR evidence suggests cardiac
  embolization

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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
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ManagementAntiplatelet 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.

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Management

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

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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

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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

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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

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Expected Outcome

• 70 stenosis or greater
• Best medical therapy vs. CEA

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Expected Outcome

• 50 - 69 stenosis
• Best medical therapy vs. CEA

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Expected Outcome TIA 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
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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

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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

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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