Distribution of cerebral microbleeds determines their association with impaired kidney function.

BACKGROUND AND PURPOSE: Cerebral microbleeds (CMBs) are associated with various pathologies of the cerebral small vessels according to their distribution (i.e., cerebral amyloid angiopathy or hypertensive angiopathy). We investigated the association between CMB location and kidney function in acute ischemic stroke patients.

METHODS: We enrolled 1669 consecutive patients with acute ischemic stroke who underwent gradient-recalled echo brain magnetic resonance imaging. Kidney function was determined using the estimated glomerular filtration rate (eGFR). CMBs were classified into strictly lobar, strictly nonlobar (i.e., only deep or infratentorial), and a combination of both lobar and nonlobar. Multinomial logistic regression analyses were used to determine the factors associated with the existence of CMBs according to their location.

RESULTS: The patients were aged 66±12 years (mean±standard deviation), and 61.9% (1033/1669) of them were male. CMBs were found in 27.0% (452/1669) of the patients. The stroke subtypes of small-artery occlusion and cardioembolism occurred more frequently in those with strictly nonlobar CMBs (10.8%) and strictly lobar CMBs (48.8%), respectively. The mean eGFR was lower in the strictly nonlobar CMBs group (72±28 mL/min/1.73 m(2)) and the both lobar and nonlobar CMBs group (72±25 mL/min/1.73 m(2)) than in the no-CMBs group (86±29 mL/min/1.73 m(2)). Multivariate multinomial logistic regression revealed that eGFR <60 mL/min/1.73 m(2) was independently related to strictly nonlobar CMBs (odds ratio=2.63, p=0.001).

CONCLUSIONS: Impaired kidney function is associated with strictly nonlobar CMBs. Our findings indicate that the distribution of CMBs should be considered when evaluating their relationships or prognoses.