Cnm-positive Streptococcus mutans and diffusion-weighted imaging hyperintensities in acute intracerebral hemorrhage.

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 (odds ratio, 2.38; 95% confidence interval, 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.