Up to know, there is no clear diagnostic and therapeutic pathway for patients with embolic stroke of undetermined source (ESUS). This prospective registry study, which follows up adult ESUS patients for 36 months, is intended to provide important data for the detection of an individual approach in ESUS patients based on a structured diagnostic and therapeutic pathway.

The open-label, academic, prospective, monocentric, observational registry-study (Catch-up-ESUS registry study) started in 01/2018. All ESUS-patients (≥18 years) treated in our hospital are included and will be followed up for three years. Depending on age (< 60 years or ≥ 60 years), the patients are processed according to a standardized treatment algorithm designed interdisciplinary by neurologists and cardiologists. An insertable cardiac monitor (ICM) is implanted in all of them by default. Patients < 60 years without evidence of atrial fibrillation and co-existing PFO are planned for PFO closure within 6 months after stroke.

Inclusion Criteria:

• Embolic stroke of undetermined source or cryptogenic stroke; defined as: non-lacunar brain infarction without proximal arterial stenosis or cardioembolic source or other etiology (e.g. vasculitis, cervical artery dissection)
• ≥18 years
• written consent to participation in the study register by the patient or the legal guardian or authorised representative at the time of inclusion in the study

All patients (≥18 years) treated in our hospital and diagnosed with an ESUS will be collected.

An extension to additional centres is planned in the course of the project, if good feasibility can be demonstrated.