Disrupted White Matter Networks from Subjective Memory Impairment to Amnestic Mild Cognitive Impairment

Area of Science:

• Neuroimaging
• Network Neuroscience
• Neurology

Background:

• Subjective memory impairment (SMI) is a preclinical stage preceding amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD).
• Understanding white matter (WM) network integrity in SMI is crucial for early diagnosis.

Purpose of the Study:

• To investigate white matter (WM) network disruptions in patients with subjective memory impairment (SMI).
• To compare WM network characteristics in SMI patients with those in normal controls (NC) and amnestic mild cognitive impairment (aMCI) patients.

Main Methods:

• Diffusion-tensor magnetic resonance imaging (dMRI) was employed to acquire WM data.
• Graph theory analysis was used to construct and analyze WM networks.
• WM networks were compared across three groups: NC, SMI, and aMCI.

Main Results:

• SMI patients exhibited significantly decreased global and local efficiency and increased shortest path length compared to NC.
• SMI patients showed reduced nodal efficiency in frontal, parietal, limbic, and caudate nucleus regions, mirroring patterns seen in aMCI patients.
• These findings indicate widespread WM network alterations in SMI.

Conclusions:

• Subjective memory impairment (SMI) patients demonstrate white matter (WM) network disruptions comparable to those in amnestic mild cognitive impairment (aMCI) patients.
• Detecting these WM network disruptions can facilitate the early identification of SMI.
• This research highlights the potential of neuroimaging for detecting early-stage cognitive decline.