Systematic Reviews
Copyright ©The Author(s) 2016.
World J Psychiatr. Mar 22, 2016; 6(1): 177-186
Published online Mar 22, 2016. doi: 10.5498/wjp.v6.i1.177
Table 1 Baseline characteristics of the included studies (all cross-sectional in design)
Ref.AN subtypeED subtypeStudy purposeMethod DTIAssessment
Kazlouski et al[13]Current AN restricting and purging subtypeAN purging and restricting subtypeTest of the brain WM integrity alteration and its relation to heightened anxiety in ANGE 3 Tesla whole-body MRI scanner, maximum gradient amplitude of 40 Mt/M and maximum slew rate of 150 T/m per second, 8-channel phased-array head coilSCID-CV
EDI-3
TCI
STAI
BDI
Frank et al[49]Current AN restricting and purging subtypeANAnalysis of GM and WM in a sample of adolescents in comparison to adultsSigna 3T Scanner, axial, 3-dimensional, T-1 weighted magnetization-prepared rapid acquisition gradient echoC-DISC
EDI-3
TCI
STAI
CDI
SPSRQ
9 point Likert scale sweetness-pleasantness of 1 molar sucrose
Nagahara et al[7]Current AN, NS subtypeANExploration of WM abnormalities in AN patients compared to HCWhole body 3 Tesla MR system with an eight-channel phased-array head coilSCID-CV
EDI-2
BDI-II
Via et al[53]Current AN restricting subtypeANAssessment of WM microstructure in a clinical sample of AN patientsGE Signa Excite scanner at 1.5 T equipped with an 8-channel phased-array head coilSCID-CV
SCID-I/NP
GHQ-28
EDI-2
HAM-D
HAM-A
Frieling et al[5]Current AN with NS subtype and recovered women from ANAN and recovered women from ANAssessment of the microstructural integrity of WM pathways through DTI in women with AN3 T Siemens-scanner, with a gradient field strength up to 45 MT/mNone
Yau et al[39]Recovered women from restricting type ANRecovered women from restricting type ANExamination of the microstructural alterations of WM integrity in recovered AN women3.0 Tesla Discovery MR750 scanner with an 8-channel phase-array head coilSCID-CV
MINI
TCI
STAI
MPS
Table 2 Characteristics of the participant samples in the reported studies
Ref.AN subtypeTotal sizeSample characteristics
n
Gender
Mean ± SD:
Age/years
BMI
Duration of illness/years
ED group (AN)Recovered ANHealthy group
Kazlouski et al[13]Current AN restricting and purging subtypen = 33n = 16 (10 resAN, 6 purgAN)-n = 17
FemaleFemale
23.9 ± 7 SD25.1 ±4 SD
16.5 ± 1 SD21.5 ±1 SD
7.5 ± 8 SDNA
Frank et al[49]Current AN restricting and purging subtypen = 41n = 19 (17 resAN, 2 purgAN)-n =22
NSFemale
15.4 ± 1.4 SD14.8 ± 1.8 SD
16.2 ± 1.1 SD21.3 ± 1.9 SD
NSNA
Nagahara et al[7]Current AN, NS subtypen = 35n = 17-n = 18
FemaleFemale
23.8 ± 6.68 SD26.2 ± 5.6 SD
13.6 ± 1.3 SD19.9 ± 2.0 SD
4.93 ± 4.9 SDNA
Via et al[53]Current AN restricting subtypen = 38n = 19-n = 19
FemaleFemale
28.37 ± 9.55 SD28.63 ± 8.58 SD
17.03 ± 1.09 SD21.09 ± 1.80 SD
6.52 ± 6.03 SDNA
Frieling et al[5]Current AN with NS subtype and recovered women from ANn = 41n = 12n = 9n = 20
FemaleFemaleFemale
26.8 ± 6.94 SD27.44 ± 5.3 SD24.80 ± 2.6 SD
15.18 ± 1.39 SD19.31 ± 1.39 SD19.60 ± 0.94 SD
NSNSNA
Yau et al[39]Recovered women from restricting type ANn = 22-n = 12n = 10
FemaleFemale
28.7 ± 7.9 SD26.7 ± 5.4 SD
21.2 ± 1.5 SD22.0 ± 1.1. SD
5.6 ± 5.2NA
Table 3 Main diffusion tensor imaging outcomes and author interpretation
Ref.AN subtypeOutcomes: DTI measures and areas in ANAuthor interpretation
Kazlouski et al[13]Current AN restricting and purging subtypeFA: Lower in the bilateral fimbria-fornix, fronto-occipital and cingulum fiber tractsAnxiety is predicted by the fimbria-fornix FA value. Thus, reduced WM integrity could provide a mechanism for heightened anxiety
Frank et al[49]Current AN restricting and purging subtypeFA: Lower in fornix, cingulum and corpus callosum (corona radiata and forceps mayor)Abnormal fornix integrity could lead to altered feedback between limbic and higher-order brain structures. The corpus callosum could be implicated in taste processing
Nagahara et al[7]Current AN, NS subtypeFA: Lower value in the left cerebellumWM abnormalities in the fornix and the cerebellum may be neural substrates of the pathophysiology of AN. The fornix is one of the important components of the Papez circuit, which links the limbic system with other brain structures. The correlation of WM alteration with physical severity, including BMI and duration of illness may indicate that WM alteration is more relevant with regard to physical severity rather than psychological severity
MD: Higher value in the fornix
Via et al[53]Current AN restricting subtypeFA: Lower in the parietal part of the left SLF and the fornix.The left SLF seem relevant to body image distortion as well as other cognitive processes like the called weak central coherence. The fornix is a key structure involved in the regulation of body-energy balance and processing of reward responses
MD: Higher in the SLF and the fornix. They also reported significantly increased MD in the fornix, accompanied by decreased FA and increased RD and AD
Frieling et al[5]Current AN with NS subtype and recovered women from ANFA (AN and recAN): Lower in the posterior thalamic radiation bilaterally (which includes the of optic radiation) and the left mediodorsal thalamusThe posterior thalamic radiation fibres project to areas involved in the processing of the body image, whose alteration could explain the AN body image distortion. The left mediodorsal thalamic nucleus is connected to regions contributing to impairments in cognitive domains, especially set/shifting ability, executive control, habit learning and reward processing
Yau et al[39]Recovered women from restricting type ANFA (recAN): Insignificant alterationLower MD was associated with harm avoidance, suggesting a possible underlying trait associated with AN. Localization of disturbances in frontal-parietal and cingulum WM suggests that these pathways, which are important for cognitive control, may be susceptible to core AN pathology. Malnutrition seems to have potentially lasting effects on WM integrity and degree of recovery
MD: Lower in frontal, parietal and cingulum
Table 4 Quality assessment of the retrieved studies
Ref.Q1Q2Q3Q5Q6Q15Q18Q25
Hypothesis clearly describedMain outcomes clearly described in the introduction or methods sectionParticipants characteristics clearly describedDistributions of confounders in each group of subjects clearly describedMain study findings clearly describedStudy measurement blindAppropriateness of the statistical testsAdjustment for confounding
Kazlouski et al[13]YesYesYesNoYesUUNo
Frank et al[49]YesYesYesPartiallyYesUYesYes
Nagahara et al[7]YesYesYesNoYesUYesNo
Via et al[53]YesYesYesYesYesUYesYes
Frieling et al[5]YesYesYesYesYesUYesYes
Yau et al[39]YesYesYesNoYesUYesNo