Table 2.

Criteria for Embolic Stroke of Undetermined Source.

1. Stroke that is not lacunar:

Lacunar is defined as a subcortical (this includes pons and midbrain) infarct in the distribution of the small, penetrating cerebral arteries whose largest dimension is ≤1.5 cm on CT, ≤2.0 cm on MRI diffusion images, or ≤1.5 cm on MRI T2-weighted images

The following are not considered lacunes: multiple simultaneous small deep infarcts, lateral medullary infarcts, and cerebellar infarcts

Patients with a clinical lacunar stroke syndrome and no infarct on imaging are excluded

2. Stroke that is not due to large-artery atherosclerosis:

Absence of extracranial or intracranial atherosclerosis causing ≥50% luminal stenosis of the artery supplying the area of ischemia

Patients must undergo vascular imaging of the extracranial and intracranial vessels using either catheter angiography, CT angiogram, MR angiogram, or ultrasound, as considered appropriate by the treating physician and local principal investigator

3. Stroke that is not due to a major-risk cardioembolic source*:

Atrial fibrillation

Intracardiac thrombus

Mechanical prosthetic heart valve

Atrial myxoma or other cardiac tumor

Mitral stenosis

Myocardial infarction within prior 4 weeks

Left ventricular ejection fraction <30%

Valvular vegetations

Infective endocarditis

4. Stroke that is not due to another specific cause:

Arteritis

Dissection

Migraine

Vasospasm

Drug abuse

Hypercoagulability

^*Patent foramen ovale is not exclusionary, whether repaired or not