Cryptogenic Stroke Initiative

In about 1 in 4 Ischemic Strokes, the root cause is still unknown after testing.

That's why it's important to dig deeper for a definitive diagnosis. Collaboration by neurologists, cardiologists, electrophysiologists and other integral team members may reveal the answers needed to provide targeted treatment for preventing recurrent strokes. Our tools are here to help.

doctor in consultation

Healthcare Professional Resources

Tools for Diagnosis and Treatment

Patient Education Resources

Understanding Strokes of Unknown Cause

Partner Activation Toolkit

How to Get Involved (PDF)
Cryptogenic Stroke Collaborative Care Testimonial

Potential Causes

It's important to consider conditions including (but not limited to):

  • Atrial fibrillation (AF or Afib) – an irregular heartbeat that puts the patient at a 5x greater risk for stroke. Afib may be detected by monitoring the heart's rhythm over time.
  • Patent Foramen Ovale (PFO) – a hole between the heart's chambers that usually closes naturally by adulthood.
  • Thrombophilias – blood clotting disorders.
  • Large-artery atherosclerosis – a buildup of fats, cholesterol and other substances in and on artery walls.

Diagnosis and Treatment

With limited guidelines, many professionals diagnose and treat cryptogenic stroke differently. We've developed resources that can help professionals team up to potentially find the causes, so patients can receive the most targeted treatment for preventing recurring strokes.

Stroke Resource Library

Visit the Stroke Resource Library and you'll find stroke prevention, treatment and recovery tools, including handouts, infographics and community education presentations.

Steps to Help Avoid Another Stroke

Clot-related strokes are largely preventable, even if you've already had one. Learn about prevention plans for reducing the risk.


Supports the American Heart Association/American Stroke Association's Cryptogenic Stroke Initiative.