Reader response: Prevalence of and risk factors for cerebral microbleeds in a general Japanese elderly community

We thank Yubi et al.¹ for their study, which reports an intriguing result—a significant association between hypertension and lobar cerebral microbleeds (CMBs). Our concern is as follows: hypertensive arteriopathy is generally associated with nonlobar CMBs.^2,3 Systemic hypertension is also thought to have a role in the pathology of mixed (lobar and deep/infratentorial) CMBs.² Furthermore, current knowledge suggests that hypertension concurrently with cerebral amyloid angiopathy (CAA) synergistically contributes to lobar CMB development.⁴ However, it is unclear in this prospective cohort¹ if the significant association of hypertension with lobar microbleeds is in fact with inclusive lobar microbleeds (those with both lobar and nonlobar CMBs) or exclusive lobar microbleeds (only lobar without nonlobar CMBs). If the former, then it is possible that the association is merely a statistical contribution of the deep/infratentorial CMBs included in the group, also taking into consideration the mean older age group and the undiagnosed CAA burden in the aging population. If the latter, it sheds light on an exciting new course for future neuropathologic and topographic studies in patients with CMBs.