Medial Temporal Lobe Subfields Correlate with Alzheimer's Cognitive Domains; Insights from High-Resolution T2 MRI of ADNI Database

Background Alzheimer's Disease (AD) causes multi-domain cognitive decline. Brain imaging biomarkers and neuropsychiatric testing detect difficulties, although it is unclear how cognitive processes and medial temporal lobe subregions relate. High-resolution T2 MRIs of AD patients' medial temporal lobes were compared to composite scores for memory, language, executive function, and visuospatial ability. Methods 156 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants provided data. Composite cognitive scores and high-resolution T2 MRI volumetric assessments of medial temporal lobe subregions were obtained. Multiple linear regression was used to account for factors and analyze composite scores and regional volumes. Results In AD patients, left cornu ammonis (CA), subiculum (SUB), perirhinal cortices (BA35), and bilateral parahippocampal cortex (PHC) size positively linked with memory performance. Language was strongly connected with hippocampi and cortical volumes in moderate cognitive impairment, and right entorhinal cortex (ERC) volume in AD patients. The bilateral SUB in normal cognitive function and the right SUB in AD positively linked with executive ability. Cognitively normal people with bilateral SUB had better visual-spatial skills. Conclusion Across AD stages, medial temporal subregions and cognitive composites had unique structure-function patterns, with left hemisphere effects preceding bilateral participation, underlining their combined value for early disease identification and monitoring.