Background: Strains of Streptococcus mutans expressing the cell surface collagen-binding protein, Cnm, encoded by cnm (cnm-positive S. mutans), are associated with hypertensive intracerebral hemorrhage (ICH) and the occurrence of cerebral microbleeds (CMBs). Small diffusion-weighted imaging (DWI) hyperintensities in patients with acute ICH are also associated with CMBs. However, the association between cnm-positive S. mutans and DWI hyperintensities is unclear. Hence, this study aimed to investigate the association between cnm-positive S. mutans and DWI hyperintensities in patients with acute ICH.
Methods: Patients with acute ICH were prospectively registered at three hospitals. Dental plaque specimens were collected within 4 days after admission, and cnm-positive S. mutans was detected using the polymerase chain reaction. Magnetic resonance imaging at 14 ± 5 days after admission was used to evaluate DWI hyperintensities and CMBs.
Results: A total of 197 patients were enrolled in this study. cnm-positive S. mutans was detected in 30 patients (15.2%), and DWI hyperintensities were observed in 56 patients (28.4%). Patients with cnm-positive S. mutans had a higher frequency of DWI hyperintensities (50.0% vs 24.6%; p = 0.008) and a higher number of CMBs (5.5 vs 1.5; p < 0.001) than those without cnm-positive S. mutans. Multivariable logistic analysis revealed that the presence of cnm-positive S. mutans was independently associated with DWI hyperintensities (OR 2.38; 95% CI 1.01-5.61; p = 0.047) after adjusting for several confounding factors.
Conclusion: This study found an association between the presence of cnm-positive S. mutans and DWI hyperintensities in patients with acute ICH.
Keywords: cerebral microbleeds; cnm-positive Streptococcus mutans; diffusion-weighted imaging; intracerebral hemorrhage.
© 2021 European Academy of Neurology.