Entorhinal Cortex: Antemortem Cortical Thickness and Postmortem Neurofibrillary Tangles and Amyloid Pathology

Area of Science:

• Neuroimaging
• Neuropathology
• Alzheimer's Disease Research

Background:

• The entorhinal cortex is crucial for memory and an early target in Alzheimer's disease (AD).
• Previous research established MRI methods to measure entorhinal cortex thickness.
• The link between in-vivo entorhinal cortex thickness and postmortem AD pathology remained unclear.

Purpose of the Study:

• To investigate the association between antemortem (before death) MRI-derived entorhinal cortex thickness and postmortem (after death) neuropathological measures of AD.
• To determine if entorhinal cortex thinning correlates with neurofibrillary tangles and amyloid-beta plaques.

Main Methods:

• Utilized structural T1-weighted MRI scans from 50 participants in the Rush Memory and Aging Project.
• Employed a validated MR imaging parcellation system (Desikan-Killiany Atlas in FreeSurfer) to define entorhinal cortex thickness.
• Applied linear regression to assess relationships between entorhinal cortex thickness and tangle/amyloid-beta burden in various brain regions.

Main Results:

• A significant inverse relationship was observed between entorhinal cortex thickness and tangles in the entorhinal cortex and medial temporal lobe.
• Entorhinal cortex thickness was also significantly associated with cortical tangles and amyloid-beta.
• No significant association was found between parahippocampal gyrus thickness and entorhinal cortex or medial temporal lobe tangles.

Conclusions:

• In vivo cortical thinning in the entorhinal cortex may serve as a biomarker for postmortem Alzheimer disease pathology.
• This finding supports the use of MRI to detect early AD-related changes in the brain.
• The study highlights the entorhinal cortex's vulnerability in the progression of Alzheimer's disease.