Affiliations: [a] Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China
| [b] Guangdong Engineering Technology Research Center for Translational Medicine of Mental Disorders, Guangzhou, China
| [c] The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
Correspondence:
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Correspondence to: Dr. Hanna Lu, Department of Psychiatry, The Chinese University of Hong Kong, G/F, Multi-Centre, Tai Po Hospital, Hong Kong SAR, China. Tel.: +(852) 2831 4305; Fax: +(852) 2667 5464; E-mail: hannalu@cuhk.edu.hk.
Note: [1] Data used in preparation of this article were obtained from the Open Access Series of Imaging Studies (OASIS) (https://www.oasis-brains.org/) database. The investigators at OASIS contributed to the design and implementation of OASIS and/or provided data but did not participate in analysis or writing of this paper.
Abstract: Background:Cortical complexity plays a central role in the diagnosis and prognosis of age-related diseases. However, little is known about the regional cortical complexity in the context of brain atrophy. Objective:We aimed to systematically examine the age-related changes of the cortical complexity of left dorsolateral prefrontal cortex (DLPFC) and its subregions. Methods:Two hundred and fourteen cognitively normal adults drawn from the Open Access Series of Imaging Studies (OASIS) were divided into four age groups: young, middle-aged, young-old, and old-old. Based on structural magnetic resonance imaging (sMRI) scans, the multiscale measures of cortical complexity included cortical thickness (mm), surface area (mm2), grey matter volume (mm3), density, gyrification index (GI), and fractal dimension (FD). Results:Advancing age was associated with reduced grey matter volume, pial surface area, density, and FD of left DLPFC, but correlated with increased cortical thickness and GI. Volumetric measures, cerebrospinal fluid volume in particular, showed better performance to discriminate young-old adults from old-old adults, while FD was more sensitive than the volumetric measures to discriminate young adults and middle-aged adults. Conclusion:This is the first demonstration that chronological age has a pronounced and differential effect on the cortical complexity of left DLPFC. Our findings suggest that surface-based measures of cortical region, thickness, and gyrification in particular, could be considered as valuable imaging markers for the studies of aging brain and neurodegenerative diseases.
