Published online Mar 22, 2016. doi: 10.5498/wjp.v6.i1.177
Peer-review started: July 11, 2015
First decision: October 30, 2015
Revised: November 19, 2015
Accepted: December 29, 2015
Article in press: January 4, 2016
Published online: March 22, 2016
Processing time: 253 Days and 9 Hours
AIM: To identify findings concerning white matter (WM) fibre microstructural alterations in anorexia nervosa (AN).
METHODS: A systematic electronic search was undertaken in several databases up to April 2015. The search strategy aimed to locate all studies published in English or Spanish that included participants with AN and which investigated WM using diffusion tensor imaging (DTI). Trials were assessed for quality assessment according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist and a published quality index guideline.
RESULTS: A total of 6 studies met the inclusion criteria, four of people in the acute state of the illness, one included both recovered and unwell participants, and one included people who had recovered. Participants were female with ages ranging from 14 to 29 years. All studies but one measured a range of psychopathological features. Fractional anisotropy and mean diffusivity were the main DTI correlates reported. Alterations were reported in a range of WM structures of the limbic system, most often of the fornix and cingulum as well as the fronto-occipital fibre tracts, i.e., regions associated with anxiety, body image and cognitive function. Subtle abnormalities also appeared to persist after recovery.
CONCLUSION: This diversity likely reflects the symptom complexity of AN. However, there were few studies, they applied different methodologies, and all were cross-sectional.
Core tip: The present systematic review identifies the latest research on white matter (WM) brain alterations in anorexia nervosa (AN). The WM architecture has been poorly understood due to its structure forming deep parts of the brain. It transmits information between cortical and subcortical structures. New advances in imaging methods with diffusion tensor imaging, allow its characterization and integrity analysis. Alterations in areas of fornix, cingulum, corpus callosum, cerebellum, superior longitudinal fasciculus and thalamus have been found in AN. They could be related to symptoms like anxiety, body image perception, reward processing and cognitive abilities.