QOL-08. Leisure-based cognitive reserve and neural resilience after brain tumor surgery

Abstract BACKGROUND Cognitive reserve (CR) is recognized as a protective factor against cognitive decline in neurodegenerative diseases. However, its role in modulating cognitive outcomes after brain tumor resection remains unclear. This study investigated the association between CR, particularly derived from leisure activities, and postoperative cognitive function, in the context of white matter network disruption. METHODS We retrospectively analyzed 40 patients in the chronic phase following resection of brain tumors: CNS WHO grade 1 (n = 4), 2 (n = 16), 3 (n = 8), 4 (n = 10), and metastases (n = 2). Cognitive function was assessed using the Mini-Mental State Examination (MMSE) and the Japanese Adult Reading Test (JART) as a proxy for premorbid intelligence. CR was evaluated using a culturally adapted version of the Cognitive Reserve Index (CRI), developed for the Japanese population and comprising education, occupational attainment, and leisure activities. Postoperative 3D T1-weighted MR images were normalized to the MNI152 template. Resection cavities were delineated and overlaid onto normative white matter tracts using the BCB Toolkit® and TRACTOTRON®. Disconnection ratios were calculated for major fiber pathways. RESULTS JART and MMSE scores were moderately correlated (r = 0.43). Among CRI subdomains, only CRI-leisure was significantly associated with both JART (p = 0.034) and MMSE (p < 0.001) scores. Disconnection analysis identified the corpus callosum, anterior commissure, right cingulum, and right superior longitudinal fasciculus (SLF) as frequently affected tracts. Multiple regression analysis revealed that disruptions in the left inferior fronto-occipital fasciculus (IFOF) (p = 0.0127) and right posterior SLF (p = 0.0051) significantly contributed to lower JART scores. CONCLUSIONS CR derived from leisure activities may confer resilience against cognitive decline after brain tumor resection. Preservation of the left IFOF and right posterior SLF is essential for cognitive integrity, supporting the integration of lifestyle-based CR into surgical planning and rehabilitation.