Table 1 A summary of AD studies that have measured grey matter diffusion changes
Study | Familial or sporadic | n | Methods | Main findings |
|---|---|---|---|---|
Kantarci et al. 2005 [17] | Sporadic | 21 MCI, 54 NC | Hippocampi manually segmented. Volume and MD measured. 36 month clinical follow-up | Hippocampal MD better than hippocampal volume for predicting conversion from MCI to AD over the 36 month follow-up |
Muller et al. 2005 [18] | Sporadic | 18 MCI, 18 NC | Hippocampi manually segmented. Volume, MD + FA measured | Increased MD in hippocampus is strongest independent predictor of episodic memory decline, and is more sensitive than volume loss |
Fellgiebel et al. 2006 [31] | Sporadic | 18 MCI | Hippocampi manually segmented. Volume and MD measured. 18 month clinical follow-up with convertors and non-convertors compared | Increased left hippocampal MD at baseline in convertors compared with non-convertors |
Rose et al. 2008 [33] | Sporadic | 13 AD, 13 NC | Voxelwise GM MD analysis | Elevated MD in hippocampus, amygdala, and medial temporal, parietal, and frontal GM in AD. Largest number of abnormal voxels in PCC |
Scola et al. 2010 [34] | Sporadic | 21 AD, 21 MCI, 20 NC | Whole brain GM + WM MD; followed by ROI analysis. 2 year clinical follow-up with MCI convertors and non-convertors compared | Trend seen over normal/MCI/AD for GM + WM MD. Volume alone could not predict convertors, but diffusivity could |
Kantarci et al. 2010 [35] | Sporadic | 30 AD, 30 DLB, 60 NC | ROI analysis using FLAIR diffusion imaging, measuring MD (plus volumes) in GM | Compared to DLB, AD has elevated MD in hippocampi, parahippocampal gyri, amygdala, temporoparietal association cortices, PCC + precuneus. Measuring MD increases ability to identify AD |
Douaud et al. 2013 [32] | Sporadic | 35 MCI | Voxelwise GM MD measured, with convertors and non-convertors compared (36 month follow-up) | Elevated left hippocampal and amygdala MD in convertors. Left hippocampal MD was the best predictor of conversion |
Jacobs et al. 2013 [36] | Sporadic | 20 MCI, 20 NC | Whole-brain CTh, MD analysis on GM. ROI analysis then applied | MCI showed increased MD in precuneus, PCC, supramarginal + frontal cortices; largest effect in the PCC |
Fortea et al. 2010 [39] | Familial | 6 PMC, 5 SMC, 18 NC | ROI analysis of cortical and subcortical GM MD (plus CTh and subcortical volumes) | Reduced MD (plus CTh) in precuneus, PCC + parietotempral association cortices in PMCs Widespread elevated MD in SMCs |
Ryan et al. 2013 [38] | Familial | 10 PMC, 10 SMC, 20 NC | ROI MD and FA (GM and WM) + GM volumes | In PMC, reduced MD in right hippocampus (without atrophy) + cingulum, with increased FA in thalamus and caudate. In SMCs MD rises |