Diagnostic Utility of the Corpus Callosum Index in Mild and Moderate Alzheimer’s Disease and Its Relationship with Mini Mental State Examination Subcomponents

Objective: This study evaluated the utility of the corpus callosum index (CCI) as a discriminative biomarker between the mild and moderate stages of Alzheimer’s 
disease (AD).
Materials and Methods: A total of 168 individuals were included, comprising two patient groups diagnosed with mild and moderate AD and a control group. CCI 
values and Mini-Mental State Examination (MMSE) subcomponent scores were compared. Statistical analyses assessed correlations between MMSE subdomains and 
CCI, group differences, optimal cutoff values using receiver operating characteristic (ROC) analysis, and logistic regression models.
Results: Significant differences in CCI values were observed among the groups (p < 0.001). CCI values decreased progressively with increasing dementia severity. A 
positive correlation was identified between CCI and total MMSE score, as well as orientation, attention-calculation, and language subtests. In the univariate logistic 
regression analysis, age, CCI, and education level were significant variables; in the multivariate logistic regression model, both CCI and age remained independent 
predictors of dementia severity (p < 0.001 for both). In the ROC analysis, CCI demonstrated high discriminative power between controls and patients with mild 
dementia (AUC = 0.922) and acceptable discriminative power between mild and moderate dementia (AUC = 0.756).
Conclusion: The findings suggest that CCI may be a useful measure for the early assessment of AD severity. Its high sensitivity in distinguishing controls from patients 
with mild dementia indicates potential clinical utility as an adjunctive assessment tool. However, larger multicenter prospective studies are needed to draw definitive 
conclusions regarding the prognostic value and clinical applicability of CCI.