Description

• A transient episode of neurologic dysfunction due to focal brain, retinal, or spinal cord ischemia without acute infarction
• Major predictor of stroke: 15% of patients with stroke report recent TIA.
• Synonym(s): ministroke

Epidemiology

200,000 to 500,000 new TIA cases reported each year

• 83 cases per 100,000 people/year in the United States

• Prevalence of TIA in general population: ~2.0%
• Predominant age: Risk increases >60 years; highest in 7th and 8th decades
• 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
• Small, deep vessel disease associated with hypertension (HTN) and diabetes
  • Lacunar infarcts
• 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
  • Noninfectious necrotizing vasculitis
  • Drugs
  • Irradiation
  • Local trauma
• 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)
• Diabetes
• Hyperlipidemia
• Obesity
• Atherosclerotic disease (carotid/vertebral stenosis)
• Cigarette smoking
• Thrombophilias

General Prevention

• Lifestyle changes: smoking cessation, diet modification, weight loss, regular aerobic exercise, and limited alcohol intake
• Strict control of medical risk factors: diabetes (glycemic control), HTN (thiazide and/or ACE/ARB), hyperlipidemia (statins), anticoagulation when high risk of cardioembolism (e.g., atrial fibrillation, mechanical valves)
• Causation is key to preventing recurrence (1).

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.
• Other causes include the following:
  • Metabolic: homocystinuria, Fabry disease
  • Central nervous system infection
  • Clotting disorders
  • 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
• TIA mimics
  • 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)