Decreased Cortical Thickness and Local Gyrification in Individuals with Subjective Cognitive Impairment
HyunChul Youn 1, Myungwon Choi 2, Suji Lee 3, Daegyeom Kim 2, Sangil Suh 4, Cheol E. Han 2, Hyun-Ghang Jeong 5, 6*
1Department of Psychiatry, Soonchunhyang University Bucheon Hospital, Bucheon, 2Department of Electronics and Information Engineering, Korea University, Sejong, 3Department of Biomedical Sciences, Korea University Graduate School, Seoul, 4Department of Radiology, Korea University Guro Hospital, Seoul, 5Department of Psychiatry, Korea University Guro Hospital, Korea University College of Medicine, Seoul, 6Korea University Research Institute of Mental Health, Seoul, Korea
Received: August 19, 2020; Revised: October 19, 2020; Accepted: October 26, 2020; Published online: October 26, 2020.
© The Korean College of Neuropsychopharmacology. All rights reserved.

Objective: Subjective cognitive impairment (SCI) is associated with future cognitive decline. This study aimed to compare cortical thickness and local gyrification index (LGI) between individuals with SCI and normal control (NC) subjects.
Methods: Forty-seven participants (27 SCI and 20 NC) were recruited. All participants underwent brain magnetic resonance imaging scanning and were clinically assessed using the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) battery of tests. We compared cortical thickness and LGI between the two groups and analyzed correlations between cortical thickness/LGI and scores on CERAD protocol subtests in the SCI group for region of interests with significant between-group differences.
Results: Cortical thickness reduction in the left entorhinal, superior temporal, insular, rostral middle frontal, precentral, superior frontal, and supramarginal regions, and right supramarginal, precentral, insular, postcentral, and posterior cingulate regions was observed in the SCI compared to the NC group. Cortical thickness in these regions correlated with scores of constructional praxis, word list memory, word list recall, constructional recall, trail making test A, and verbal fluency under the CERAD protocol. Significantly decreased gyrification was observed in the left lingual gyrus of the SCI group. In addition, gyrification of this region was positively associated with scores of constructional praxis.
Conclusions: Our results may provide an additional reference to the notion that SCI may be associated with future cognitive impairment. This study may help clinicians to assess individuals with SCI who may progress to mild cognitive impairment and Alzheimer’s dementia.
Keywords: Alzheimer disease, subjective cognitive impairment, mild cognitive impairment, cortical thickness, local gyrification index, lingual gyrus