Clinically overt and silent cerebral embolism in the course of infective endocarditis

The data on cerebral embolism prevalence in the course of infective endocarditis (IE) are most probably underestimated. Part of the cerebral embolism episodes are clinically silent. The objective of this study was to assess the prevalence of clinically silent cerebral embolism in the course of IE and to correlate hematological, inflammatory, and echocardiography parameters with the presence of clinically overt or silent cerebral embolisms. For this purpose, we examined 65 patients with IE by blood test, cultures, echocardiography, and MRI/CT imaging. Clinically overt cerebral embolism was found in 13 patients; 52 patients had no clinically overt cerebral embolism. MRI/CT examinations revealed that among patients with no clinically overt cerebral embolism, 24 had clinically silent cerebral embolism. Thus, 37 patients in all were diagnosed with a cerebral embolism episode (overt + clinically silent). Clinically silent cerebral embolism was diagnosed in 36.9% of all patients, being as high as 64.8% of cerebral embolism cases. Silent or overt embolism development did not depend on the localization of the inflammatory process in either native or artificial valves. The type of cerebral embolism was not found to be influenced by leukocytosis, platelet count, ESR, or hsCRP levels. Neither was the type of embolism found to be influenced by the etiologic factor. Nine patients died. In three patients, the cause of death was hemorrhage from a cerebral apoplectic focus. These results suggest that clinically silent central nervous system embolism is a common complication of infective endocarditis and each patient should undergo a neuroimaging examination.