Mapping the Progressive Degeneration of the Olfactory Cortex from Normal Cognition to Alzheimer's Disease

Motivation: Olfactory dysfunction is an early indicator of Alzheimer's disease (AD), with olfactory cortical changes as potential progression biomarkers. Goal(s): To map olfactory cortex degeneration patterns across normal cognition (NC), mild cognitive impairment (MCI), and AD. Approach: Using structural MRI, resting-state fMRI, and olfactory-task fMRI to assess olfactory regions in 105 participants, alongside olfactory and cognitive assessments. Results: Findings suggested a progression from unilateral degeneration in dominant olfactory cortex (NC-MCI) to widespread bilateral impairment (MCI-AD). Impact: These findings advance our understanding of hemispheric vulnerability in early neurodegeneration, offering potential insights for therapeutic intervention before widespread impairment occurs. The identified progression pattern may contribute to developing more sensitive early detection strategies in AD.