Altered network of limbic system in multiple system atrophy with mild cognitive impairment (P8-11.008)

Abstract

<h3>Objective:</h3> The purpose of this study is to investigate the structural network of limbic system in Multiple system atrophy with mild cognitive impairment (MCI). <h3>Background:</h3> Cognitive impairment (CI) is considered as a non-supporting feature of multiple system atrophy (MSA). However, CI has been frequently observed in MSA. Despite changing concept of CI in MSA, exact characteristics and pathophysiology are still uncertain. We would investigate structural and functional change in limbic system in MSA with CI. <h3>Design/Methods:</h3> 15 MSA patients with normal cognition and 11 MSA patients with MCI were enrolled in this study. All participants underwent brain MRI with 3D T1 imaging and Seoul Neuropsychological Screening Battery which is widely used neuropsychological test in Korea. Volumetric analysis of the limbic structures was carried out using the FreeSurfer program. We applied Graph Theory program (BRAPH; http://braph.org) to calculate network measures such as characteristic path length, global efficiency, local efficiency, mean clustering coefficient, and small-worldness index to determine the limbic covariance network. <h3>Results:</h3> In neuropsychological test, MCI patients showed decreased memory and executive function, however attention, visuospatial and language function was relatively preserved. In volumetric analysis, there was significant decreased volume of nucleus accumbens in MSA with MCI than MSA with normal cognition (0.026±0.005 vs 0.021±0.00, p=0.03). Among network measures for covariance network, the small-worldness index in the MSA with MCI was lower than that in the MSA with normal cognition (0.973 vs. 0.849, <i>p</i>=0.008). <h3>Conclusions:</h3> This study is the first report to investigate the limbic system in MSA with CI. We found that volumetric difference and the altered functional network connectivity of the limbic system in MSA with MCI compared to MSA with normal cognition. Our findings suggest that structural and functional changes in subcortical limbic structure may be associated with CI in MSA. <b>Disclosure:</b> The institution of Dr. Park has received research support from Korean ministry of SMEs and Startups. Prof. Cha has nothing to disclose. Dr. Seo has nothing to disclose.