CORTICAL THICKNESS ALTERATIONS IN ALZHEIMER'S PROGRESSIVE MEMORY IMPAIRMENT CONTINUUM: A NETWORK PERSPECTIVE

Objective: Alzheimer's Progressive Memory Impairment Continuum (PMIC) is typically the clinical reflection of the neurofibrillary tangle (NFT) spread of Alzheimer's disease (AD), which starts with subtle memory complaints of subjective cognitive impairment (SCI), passes through objectifiable memory problems of the amnestic mild cognitive impairment (aMCI), and finally reaches the dementia stage of multiple cognitive deficits with an amnestic core (ADD). This study evaluated the patterns of cortical thickness changes across the PMIC, using a network perspective to unravel structural and functional disruptions. Material and Methods: The study included 88 participants: 21 with mild ADD, 34 with aMCI, and 33 with SCI. Clinical and neuropsychiatric evaluations were conducted, followed by structural MRI scanning for cortical thickness measurements. Vertex-wise cortical thickness analyses were conducted using ANCOVA. Age, gender, and education were covariates. Result: The results showed significant cortical thinning across the PMIC, with more pronounced reductions in the ADD group. The cortical thinning overlapped with the Default Mode Network (DMN), Ventral Attention Network (VAN), and Frontopari etal Network (FPN). The comparison between the SCI and aMCI groups revealed no significant difference. Conclusion: Cortical thinning was evident across different stages of PMIC, with more extensive thinning in later stages. The observed network-wide pattern of atrophy that AD-like deterioration affects broader neural systems rather than isolated regions. The findings highlight the importance of a networkbased approach to understand AD-related structural changes and the potential for future research to integrate multimodal imaging to explore functional connectivity alongside structural atrophy.