Changes of gray matter volume and amplitude of low-frequency oscillations in amnestic MCI: An integrative multi-modal
Zhi-Lian Zhao1, Feng-Mei Fan2, Jie Lu1
1Department of Radiology, Xuanwu Hospital of Capital Medical University, Beijing, PR China Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics, Beijing, PR China.
Background:
Numerous studies have reported that the amnestic-type mild cognitive impairment (aMCI) patients have impaired brain structural integrity and functional alterations separately.
Purpose:
To investigate the changes of gray matter and amplitude of low-frequency oscillations in patients with aMCI by combining structural and functional magnetic resonance imaging (fMRI).
Material And Methods:
Thirty-four patients with aMCI and 34 controls were recruited. We adopted optimized voxel-based morphometry to detect regions with gray matter volume (GMV) loss induced by aMCI. Then regional differences in amplitude of slow-4 band (0.027-0.073 Hz) oscillations among these regions between patients and healthy controls were examined. Both slow-4 amplitude of low-frequency fluctuations (ALFF) and slow-4 fractional ALFF (fALFF; the relative amplitude that resides in the low frequencies) were employed.
Results:
Patients with aMCI demonstrated significant GMV loss in the ventral medial prefrontal cortex (vMPFC), posterior cingulate cortex (PCC), bilateral hippocampus, right superior parietal gyrus, left insula and left middle temporal gyrus (P < 0.01). The patients exhibited significant decreases of slow-4 ALFF in the left hippocampus (P = 0.05) and PCC (P = 0.02), while the decreased slow-4 fALFF was detected in PCC (P = 0.01) and increased slow-4 fALFF in vMPFC (P = 0.03). In PCC, aMCI and controls exhibited significant different GMV-fALFF correlation (P < 0.05), with opposite correlation trend.
Conclusion:
The correlates between anatomical deficits and functional alterations in aMCI suggest that anatomical and functional deficits are linked to each other. The differences of GMV-fALFF correlations demonstrated altered anatomical-functional relationship in aMCI.
Insights
This study reveals that amnestic-type mild cognitive impairment (aMCI) patients exhibit both gray matter volume loss and altered brain activity. These structural and functional changes are interconnected, highlighting a disrupted anatomical-functional relationship in aMCI.
Area of Science:
- Neuroimaging
- Cognitive Neuroscience
- Medical Imaging
Background:
- Numerous studies indicate impaired brain structural integrity and functional alterations in amnestic-type mild cognitive impairment (aMCI) patients.
- Previous research has investigated these changes separately.
Purpose of the Study:
- To investigate combined structural and functional magnetic resonance imaging (fMRI) changes in aMCI patients.
- To examine gray matter volume and amplitude of low-frequency oscillations in aMCI.
Main Methods:
- Utilized optimized voxel-based morphometry to detect gray matter volume (GMV) loss in 34 aMCI patients and 34 controls.
- Examined regional differences in slow-4 band amplitude of low-frequency fluctuations (ALFF) and fractional ALFF (fALFF) using fMRI.
- Analyzed correlations between GMV and fALFF in the posterior cingulate cortex (PCC).
Main Results:
- aMCI patients showed significant GMV loss in the ventral medial prefrontal cortex (vMPFC), posterior cingulate cortex (PCC), hippocampus, and other regions.
- Significant decreases in slow-4 ALFF were observed in the left hippocampus and PCC.
- Altered slow-4 fALFF was found in the PCC (decreased) and vMPFC (increased), with significant differences in GMV-fALFF correlation in the PCC.
Conclusions:
- Anatomical deficits and functional alterations are linked in aMCI.
- The study demonstrates an altered anatomical-functional relationship in aMCI patients.
- Combined neuroimaging approaches reveal key insights into aMCI pathophysiology.
