Transient Ischemic Attack (TIA)

Basics

Description

  • A transient episode of neurologic dysfunction due to focal brain, retinal, or spinal cord ischemia without acute infarction
  • Major predictor of stroke: 7.5–17.4% of patients with transient ischemic attack (TIA) experience a stroke within 3 months (1). 15% of patients with stroke report recent TIA.
  • Synonym(s): ministroke

Epidemiology

Prevalence

  • Prevalence of TIA in general population: ~2%
  • Predominant age: Risk increases >60 years of age; highest in 7th and 8th decades of life
  • Predominant sex: male > female
  • Predominant race/ethnicity: African Americans > Hispanics > Caucasians

Etiology and Pathophysiology

Temporary reduction/cessation of cerebral blood flow adversely affecting neuronal function

  • Carotid/vertebral atherosclerotic disease (artery-to-artery thromboembolism, low-flow ischemia)
  • Lacunar infarcts: small, deep vessel disease associated with hypertension (HTN) and diabetes
  • Embolism secondary to the following:
    • Valvular (mitral valve) pathology
    • Mural hypokinesias/akinesias with thrombosis (acute anterior MI/congestive cardiomyopathies)
    • Cardiac arrhythmia (atrial fibrillation accounts for 5–20% incidence)
  • Hypercoagulable states (antiphospholipid antibodies, increased estrogen [e.g., oral contraceptives], pregnancy and parturition)
  • Arteritis (vasculitis)
  • Sympathomimetic drugs (e.g., cocaine)
  • Other causes: spontaneous and posttraumatic (e.g., chiropractic manipulation) arterial dissection
  • Fibromuscular dysplasia

Genetics
Inheritance is polygenic, with tendency to clustering of risk factors within families.

Risk Factors

  • Older age (i.e., >60 years old)
  • HTN, cardiac diseases (atrial fibrillation, MI, valvular disease)
  • Atherosclerotic disease (carotid/vertebral stenosis)
  • Obesity, diabetes, hyperlipidemia
  • Cigarette smoking
  • Thrombophilias

General Prevention

  • Lifestyle changes
  • Control of medical risk factors: diabetes, HTN, hyperlipidemia
  • Anticoagulation when high risk of cardioembolism (e.g., atrial fibrillation, mechanical valves)
  • Improved blood pressure (BP) control has been very useful, with antiplatelet therapy being key for preventing recurrence if previous TIA (2)
ALERT
  • 1.5–3.5% risk of stroke in first 48 hours after TIA
  • Up to 40% of patients with stroke have history of TIA

Geriatric Considerations

  • Older patients have a higher mortality rate—highest in 7th and 8th decades.
  • Atrial fibrillation is a frequent cause among the elderly.

Pediatric Considerations

  • Congenital heart disease is a common cause among pediatric patients.
  • Genetic: Marfan syndrome, moyamoya, or sickle cell disease

Pregnancy Considerations

  • Preeclampsia, eclampsia, and HELLP syndrome
  • Thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome
  • Postpartum angiopathy
  • Cerebral venous thrombosis
  • Hypercoagulable states related to pregnancy

Commonly Associated Conditions

  • Atrial fibrillation, uncontrolled HTN
  • Carotid stenosis
  • Some disease processes mimic TIA presentation (seizures, migraines, metabolic disturbances, syncope, multiple sclerosis); difference: gradual onset with nonspecific symptoms (headache, memory loss) versus acute onset with specific neurologic deficits (TIA)

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