Brain infarction in young adults: etiology and imaging findings.

The causes of stroke in young adults differ substantially from those in older adults. In many instances, the diagnosis can be made by taking a clinical history and performing laboratory studies (e.g., in patients who have multiple thromboses associated with anti-phospholipid antibodies). In other circumstances, clues to the diagnosis can be found on routine CT and MR studies. However, in many circumstances, imaging tailored to a specific diagnosis is important (e.g., MR imaging of the neck in patients with suspected arterial dissection). In yet other cases, additional studies (e.g., echocardiography in suspected cardiogenic embolism) are important to establish the cause.