Evaluation of Patients with Transient Ischemic Attack Rodney Smith, MD Clinical Assistant Professor Department of Emergency Medicine University of Michigan Ann Arbor, MI

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Evaluation of Patients with Transient Ischemic
AttackRodney Smith, MD Clinical Assistant
ProfessorDepartment of Emergency
MedicineUniversity of MichiganAnn Arbor, MI
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Introduction

• 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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Introduction

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

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Introduction

• 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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Introduction

• 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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Objectives

• 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?

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Transient 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

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Transient 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

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Transient 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

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Transient 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

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Transient 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

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Transient 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

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Transient Ischemic Attack

• 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
• Gradual resolution

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Differential Diagnosis

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

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Differential 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

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Differential 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

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Differential Diagnosis

• Aura without Headache
• 98 Visual symptoms
• 30 with other symptoms
• 26 sensory
• 16 aphasia
• 6 dysarthria
• 10 weakness

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Differential Diagnosis

• Aura without HA
• Onset of symptoms in minutes
• Over 50 with onset over gt 5 min.

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Differential Diagnosis

• Aura without HA
• Duration of symptoms in minutes
• 20 with slight headache
• 20 with prior headaches without aura

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Differential Diagnosis

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

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Differential 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

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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

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Differential Diagnosis

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

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Differential Diagnosis

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

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Differential 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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Differential Diagnosis

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

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Differential Diagnosis

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

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Likelihood of TIA
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Likelihood 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?

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Likelihood of TIA

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

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Likelihood 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

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Likelihood of TIA

• TIA yes or no
• kappa 0.65
• TIA circulation involved
• kappa 0.31

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Emergency Department Evaluation

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

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Emergency Department Evaluation

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

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Emergency Department Evaluation

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

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Decision 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 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

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Likelihood of Early Stroke

• Stroke rate after TIA
• Annual rate during 5-year follow-up
• 6.7 Oxfordshire
• 6.6 Rochester, MN

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Likelihood of Early Stroke

• Stroke Rate After TIA
• Percent (95 CI)

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Carotid Endarterectomy and Stroke

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

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Carotid Endarterectomy and Stroke

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

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Diagnosis of Carotid Stenosis
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Diagnosis of Carotid Stenosis

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

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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

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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

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Cardiogenic 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

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Cardiogenic 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

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Echocardiogram

• Yield lt 3 in undifferentiated patients
• Higher with risk factors
• Indications
• Age lt 50
• Multiple TIAs in more than one arterial
  distribution
• Clinical, ECG, or CXR evidence suggests cardiac
  embolization

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TIA Evaluation

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

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TIA Evaluation

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

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Antiplatelet Therapy

• Aspirin
• Not dose dependent
• Ticlopidine
• Clopidogrel
• Aspirin plus Dipyridamole

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Risk Factor Modulation

• Obesity
• Smoking
• Hypertension
• Cholesterol
• Excessive alcohol
• 1 to 2 glasses of wine per day may be protective