Small vessel disease (SVD) is an umbrella term for pathological changes in small cerebral vessels that contributes to cerebral microbleeds (CMB), white matter lesions, and lacunar infarcts. An overwhelming amount of evidence has identified CMB as an independent risk factor for stroke and dementia. CMB is associated with an almost 4-fold risk of intracerebral hemorrhage (ICH) and a twofold increased risk of ischemic stroke (IS). On gradient-echo T2-weighted magnetic resonance imaging (MRI), CMB is small, round foci with hypointensities.
CMB is also associated with cognitive impairment and stroke. A high prevalence of CMB was previously reported in patients with Streptococcus mutans expressing Cnm. Cnm is a collagen-binding protein that is present in the oral cavity. One hundred eleven patients were identified; 19% with cnm-positive S.mutans and 81% with a positive outcome. Clinical history, including blood pressure and antithrombotic agents, were comparable between the two groups. The CMB were commonly observed in patients having cnm-positive S.mutans.
In conclusion, cnm-positive S.mutans was found to be associated with an increased incidence of CMB. Although large-scale prospective studies should verify the results, a close association between cnm-positive S.mutans and CMB development suggests treatments targeting cnm-positive S.mutans may act as novel therapeutic approaches for dementia and stroke.
Ref: https://www.ahajournals.org/doi/full/10.1161/STROKEAHA.120.029607
