Prevalence of Attributable Etiology and Modifiable Stroke Risk Factors in Patients With Covert Brain Infarctions

Background: Covert brain infarction (CBI) are incidental lesions of presumably vascular etiology, detected on cerebral imaging and without attributable event of an acute ischemic stroke (AIS). Formerly thought to be completely "silent", CBI do have consequences: patients with CBI have a two-fold increased risk of severe stroke in the future, more often covert neurological deficits, and a steeper decline in cognitive function with increased risk of dementia. Important associations of CBI are described with hypertension, carotid stenosis, chronic kidney disease and metabolic syndrome, heart failure, coronary artery disease, hyperhomocysteinemia and obstructive sleep apnea. No trustworthy guidelines exist how to approach a patient with CBI. Aim and hypothesis: The investigators want to provide a reliable estimate on the yield and relevance of a complete stroke workup to identify modifiable vascular risk factors in patients with CBI searching for an easily treatable cause of the event like a carotid stenosis, atrial fibrillation, hypertension or diabetes. The investigators' hypothesis is that a complete workup in patients with CBI has a similar yield of underlying pathological findings as compared to workup recommended for AIS. Design: The SILENT registry is a prospective, interdisciplinary, multimodal observational registry of 230 patients with CBI. Methods: A standardized workup procedures including cerebral MRI, long-term rhythm monitoring (3 x 7 days ECG), echocardiography and noninvasive angiography of the cervical and intracranial arteries will be performed. Statistics: A sample size calculation estimated a sample size of 230 patients. A prespecified analysis protocol will be used. Significance: This study has the potential to extend the work-up of stroke to patients with CBI. Since CBI are up to three times more frequent than manifest ischemic stroke, this would have huge implications for primary stroke prevention.