Typical distribution of hypertensive cerebral microbleed: a matched case-control study using primary aldosteronism

The topographical distribution of non-strictly lobar cerebral microbleed (CMB) is considered as a neuroimaging marker of hypertensive arteriopathy, but pathological evidence remains insufficient. This case-control study assessed patients with primary aldosteronism (PA), a leading cause of secondary hypertension, to characterize the CMB distribution features of typical hypertensive arteriopathy. A PA group (n = 11) and an age-matched non-hypertensive control group (n = 22) were classified into subgroups based on the presence of any CMB or no CMB using paramagnetic-sensitive MRI. Patients with any CMB were further divided into strictly lobar CMB and non-strictly lobar CMB, defined as either strictly deep and/or infratentorial (D/I) CMB or "mixed" (i.e., CMB in both lobar and D/I regions). CMB prevalence was higher in the PA group (81.8% vs. 13.6%, p < 0.001), showing non-strictly lobar patterns in all cases. Total CMB count was also higher (median 3 vs. 0; p < 0.001). Adjusted odds ratios for any CMB and non-strictly lobar CMB were 80.24 and 89.89, respectively. These findings suggest that PA-related small vessel injury affects both deep and cortical/leptomeningeal arterioles, demonstrating a strong association between pure hypertensive small vessel disease and non-strictly lobar CMB distribution.