HYPERTENSIVE VASCULOPATHY AS THE CAUSE OF CEREBRAL MICROBLEEDS IN PATIENTS WITH COGNITIVE IMPAIRMENT

Abstract

Hypertensive vasculopathy and cerebral amyloid angiopathy are the two main etiologies of cerebral microbleeds (CMBs). Determining the underlying cause will open doors to preventive and curative strategies in the future. Subjects from the multimodal imaging study and clinic cohort with diagnoses of SCI, MCI, AD, VaD were recruited. CMBs were quantified on SWI and GRE images using MARS. Other markers of small vessel disease were assessed using the SVD score evaluation of FLAIR and T2W images. All MRI quantifications were performed by a single neurologist blinded to the clinical and cognitive measures. Cognitive measures included global cognition (Mini Mental State Examination and Montreal Cognitive Assessment), frontal cognition (Frontal Assessment Battery, Color Trails, Digit Span, Category Fluency) non-frontal cognition (Immediate recall, Delayed recall and Block Design), and executive function (Color Trails, Clock Drawing, and CLOX2) were evaluated. For lifestyle and vascular risk factors, particularly, hypertension, the CAIDE score was used. Interactions among variables were determined using linear regression analysis. Trends and significant effects of each of the variables were also analyzed. 322 subjects (69 SCI, 96 MCI, 123 AD, 34 VaD) with a mean age of 68 and mean years of education of 9 years were analyzed. 54 (17%) of the total study population were noted to have cerebral microbleeds. About 192 participants (60%) fell under CAIDE grade 3 (severe risk) of which 80% (p<0.01) were hypertensive and 86% (p<0.01) were hyperlipidemic. No statistical differences were seen between those with CMB and without in terms of hypertension and hyperlipidemia risk (p=0.15, p=0.18) probably due to sample size. Non-frontal cognition worsens as CAIDE score increases (p<0.01) while frontal cognition is affected only in those with higher CAIDE scores (CAIDE 2 vs 3, p=0.03; CAIDE 3 vs 1, p=0.04). Hyperlipidemia is negatively correlated to the presence of lobar (β= - 0.028, p = 0.011) and age to non-lobar lobar (β= - 0.174, p = 0.020) microbleeds in CAIDE group 3. Hypertension has high incidence among those patients with cognitive impairment and CAIDE score 3. The trend is a positive correlation. Longitudinal studies and greater subject population may strengthen this association.