Hippocampal atrophy varies by neuropsychologically defined MCI among men in their 50s

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Gerontology

Background:

• Mild cognitive impairment (MCI) represents a transitional stage between normal aging and dementia.
• Early detection of MCI is crucial for timely intervention and management.
• Neuroanatomical changes, particularly in the hippocampus, are implicated in cognitive decline.

Purpose of the Study:

• To investigate hippocampal volumes and atrophy in middle-aged men.
• To explore neuroanatomical support for various neuropsychological definitions of MCI.
• To assess the utility of hippocampal occupancy (HOC) for early MCI detection.

Main Methods:

• Neuropsychological testing and MRI were performed on 460 men aged 51-60 years.
• MCI was defined using five distinct criteria sets.
• Hippocampal volume and HOC were quantified using FreeSurfer; statistical analyses employed linear mixed models.

Main Results:

• Hippocampal occupancy (HOC) differences were observed between normal cognition and amnestic/non-amnestic MCI groups under specific criteria.
• Standard hippocampal volume differences were only significant between normal and amnestic MCI when using a composite score method.
• HOC demonstrated greater sensitivity in differentiating cognitive states compared to standard volume.

Conclusions:

• Findings support the empirical detection of pre-MCI in younger cohorts.
• The convergence of neuropsychological and neuroanatomical data, especially HOC, aids in the early identification of MCI.
• HOC shows promise as a valuable biomarker for identifying MCI based on specific neuropsychological criteria.