P4‐184: Elevated arterial stiffness and deep‐brain white matter hyperintensity in patients with mild cognitive impairment

Brain white matter hyperintensity (WMH) is a measure of white matter damage which may be related to small cerebral vessel disease. Increases in arterial stiffness and carotid artery intima-media thickness (IMT) are the hallmark of arterial aging indicating the presence of subclinical atherosclerosis. The purpose of this study was to assess arterial stiffness, carotid artery IMT and WMH in patients with mild cognitive impairment (MCI). Twenty-eight MCI patients (14 males, age=67±7yrs, clinical dementia rating score=0.5) and 30 age- and education-matched cognitively normal adults (14 males, age=67±7yrs) participated. The carotid arterial (β) stiffness index and the intima-media thickness (IMT) were measured using high resolution 2D Doppler ultrasonography and applanation tonometry in the left and right common carotid arteries (CCA). Peripheral and central pulse-wave-velocity (PWV) were measured between the right common carotid artery and the right radial and left femoral artery, respectively. WMH was assessed in 22 patients with MCI (12 males, age=67±7yrs) and 19 controls (5 males, age=67±7yrs) using MRI Fluid-Attenuated-Inversion-Recovery (FLAIR) images on a 3T Philips Achieva MR system. Periventricular and deep-brain WMH volumes were quantified and differentiated using semi-automatic programs (MRICro and MatLab). MCI patients showed higher β-stiffness index (7.3±1.8 vs. 6.3±1.5, p<0.05) and decreased distensibility (0.31±0.07 vs. 0.37±0.09%mmHg, P = 0.01) in the CCA when compared to the cognitively normal subjects. No significant differences were found in the carotid artery IMT (0.70±0.11 vs. 0.66±0.10cm/s), peripheral (8.3±1.2 vs. 8.3±1.4cm/s) and central PWV (9.7±2.1 vs. 9.9±2.2cm/s) between the groups. Deep-brain WMH volume, normalized to the whole intra-cranium volume, was twice as high in the MCI group relative to the controls (dWMHx, 0.18±0.10 vs. 0.09±0.07%, P<0.01) although global WMH volume did not differ between the two groups. Deep-brain WMH volume was increased in patients with MCI and was associated with increases in carotid arterial stiffness. The relationship between arterial stiffness and deep-brain WMH volume in MCI merits further investigation.