BPV-COGMulticenter Retrospective Study of Visit-to-Visit Variability in Blood Pressure as a Predictor of Poor Cognitive Function

This is a retrospective cohort study. We include patients with cerebral small vessel disease, documented on MRI from Jan 2006 to Dec 2010, who have been regularly followed up. We evaluate the patients' cognitive function after written informed consent. We independently review patients' medical record and analyze MRI data. BP variability parameters include standard deviation(SD, primary measuring parameter), coefficient of variation, successive variation, average real variability (ARV), SD independent of mean(SDIM), SV independent of mean(SVIM), and ARV independent of mean (ARVIM). We will adjust following confounding variables: age, sex, level of education, vascular risk factors, mean SBP and DBP, NIHSS score, and white matter lesion burden on T2-weighted MRI.