Table 4.
DWI studies with LLD, HC, and additional comparison groups.
| References |
N (LLD/HC/MCI/ LLD+aMCI) |
Study type | Depression status | Analysis method | Frontal-executive findings |
Corticolimbic findings |
Other findings |
|---|---|---|---|---|---|---|---|
| Li et al. (2014) | 84 (20/33/18/13) |
Cross-sectional | Current | ROI (FA, MD, AD, RD) CCG1, CGH2, CC3, fornix, UNC4 |
Corrected p <0.05 LLD vs. HC Higher MD, AD, RD in fornix higher AD in CC3 LLD+aMCI vs. HC Higher MD, AD and RD in fornix |
LLD vs. HC higher MD, AD, RD in CGH2, higher AD in UNC4 tracts aMCI vs. HC higher MD, RD in CGH2 LLD+aMCI vs. HC higher MD, AD, RD in CGH2 |
|
| Tract-specific voxelwise in the five ROIs |
LLD vs. HC Higher FA in CC tracts Higher MD in fornix tracts LLD vs. aMCI Higher MD in CC3 tracts LLD vs. LLD+aMCI Lower FA in CC3 tracts aMCI vs. HC Lower FA, higher MD in fornix tracts LLD+aMCI vs. HC Lower FA, higher MD in fornix tracts LLD+aMCI vs. aMCI Lower FA, higher MD in CC3 tracts Higher MD in fornix tracts |
LLD vs. HC Lower FA in UNC4 tracts Increased MD CGH2 LLD vs. aMCI Lower MD in CGH and UNC4 LLD vs. LLD+aMCI Higher MD in UNC, CCG1 aMCI vs. HC Lower FA in UNC4 Lower FA, higher MD in CGH2 LLD+aMCI vs. HC Lower FA, higher MD in UNC4 Higher MD CGH2 LLD vs. aMCI Lower MD in CGH and UNC LLD vs. LLD+aMCI Higher MD in UNC4, and CCG1 LLD+aMCI vs. aMCI Lower FA in UNC tracts LLD+aMCI vs. all other Lower FA in bilat-CGH2 |
|||||
| Mai et al. (2017) | 69 (24/30/-/15a) |
Cross-sectional | Current | Network analysis probabilistic tractography (AAL atlas regions) |
LLD+MD vs. LLD Decreased connections nodes: Frontal (R-IFG-operc5, R-L-IFG- triang6, L-inf-ORB7, R-mid-TPO8), subcortical (R-L-Put9, R-L-Thal10), and temporal (L-MTG11) |
LLD+MD vs. LLD Decreased connections nodes: paralimbic (R-med-SFG12, R-sup.med-ORB13, R-ACC14, L-MCC15, R-Pcun16), subcortical (R-L-Hippo17) |
LLD vs. HC Stronger local connection, lower circuitry density LLD vs. LLD+MD Stronger local connection LLD and LLD+MD vs. HC Weaker rich-club connection LLD vs. LLD+MD Stronger local connection LLD+MD vs. LLD and HC Weaker connective strength, lower shortest path length, global efficiency, fault tolerant efficiency |
| Bai et al. (2012) | 103 (35/30/38/-) |
Cross-sectional | Remitted | Graph theory |
LLD and aMCI vs. HC Lower nodal efficiency in frontal and parietal cortices |
LLD hub region Left Pcun16 LLD vs. aMCI Higher nodal efficiency in PCC18 |
LLD vs. HC Lower circuitry strength global efficiency, higher absolute path length LLD vs. aMCI: no difference |
a
memory deficit LLD (LLD+MD).
1
Cingulum-cingulate gyrus tract (CCG);
2
Cingulum-hippocampus tract (CGH);
3
corpus callosum (CC);
4
uncinate fasciculus (UNC);
5
opercular part of the inferior frontal gyrus (IFG-operc);
6
triangle part of the inferior frontal gyrus (IFG- triang);
7
orbital part of the inferior frontal gyrus (inf-ORB);
8
temporal pole of middle temporal gyrus (mid-TPO);
9
putamen (Put);
10
thalamus (Thal);
11
middle temporal gyrus (MTG);
12
medial part of the superior frontal (med-SFG);
13
medial orbital part of the superior frontal gyrus (med-sup-ORB);
14
anterior cingulate cortex (ACC);
15
middle cingulate cortex (MCC);
16
precuneus (Pcun);
17
hippocampus (Hippo);
18
posterior cingulate cortex (PCC).