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

Incidence
200,000 to 500,000 new TIA cases reported each year. Nearly 800,000 patients experience stroke per year in the United States, of which nearly 700,000 are acute ischemic stroke (1).

Prevalence

• 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)
• Atherosclerotic disease (carotid/vertebral stenosis)
• Diabetes
• Hyperlipidemia
• Obesity
• 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)
• Improved blood pressure control has been very useful, with antiplatelet therapy being key for preventing recurrence if previous TIA (2)

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
• 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) vs acute onset with specific neurologic deficits (TIA)