Transient ischemic attack: Part I. Diagnosis and evaluation

Transient ischemic attack is defined as transient neurologic symptoms without evidence of acute infarction. It is a common and important risk factor for future stroke, but is greatly underreported. Common symptoms are sudden and transient, and include unilateral paresis, speech disturbance, and monocular blindness. Correct and early diagnosis of transient ischemic attack versus mimicking conditions is important because early interventions can significantly reduce risk of future stroke. Nonspecific symptoms and gradual onset are more likely with mimics than with true transient ischemic attacks. Transient ischemic attacks are more likely with sudden onset, focal neurologic deficit, or speech disturbance. Urgent evaluation is necessary in patients with symptoms of transient ischemic attack and includes neuroimaging, cervicocephalic vasculature imaging, cardiac evaluation, blood pressure assessment, and routine laboratory testing. The ABCD(2) (age, blood pressure, clinical presentation, diabetes mellitus, duration of symptoms) score should be determined during the initial evaluation and can help assess the immediate risk of repeat ischemia and stroke. Patients with higher ABCD(2) scores should be treated as inpatients, whereas those with lower scores are at lower risk of future stroke and can be treated as outpatients.