Application Of FMRI In The Study Of Abnormality Of Brain Function And Structure In Senile Depression Patients

ObjectiveBy using resting-state fMRI,we observe the diffrences in characteristics of brain structure and changes in some metabolites of brain tissue between senile depression and healthy controls.And then we explore the clinical application value to early diagnosis of senile depression.Methods1.15 in our hospital from November 2015 to April 2016(diagnosed according to the clinical diagnostic criteria of ICD related depression,with a first major depressive episode,ranging in age from 50 to 65,with HAMD scores greater than 24)and 14 healthy controls were recruited in study.And at the same time,we recorded their gender,age,educational background and other general data.2.Observe the characteristics of brain structure between the first-episode group and healthy controls by using fMRI.Firstly,the brain structure image of the object was standardized in accordance with the requirements,so that it was in the same standard three-dimensional space,the coordinates were consistent;the image was segmented and processed,and the t test of two samples was carried out based on voxel based mor:phological analysis(VBM).The test level was uncorrected<0.01,the threshold range was 200 voxels,and the changes of gray matter and white matter density were compared between the two groups.3.Scan every object by fMRI,and the software automatically completed the measurement of metabolize content from brain tissue including NAA,Cho,Glx and Cr,giving the ratio of all metabolite using Cr as a reference,such as NAA/Cr,Cho/Cr and ml/Cr.Results1.There was no statistically significant differences between the senile depression group and the healthy group in sex,age,educational background and so on.2.Compared with the healthy group,the density of gray matter of bilateral superior frontal gyrus,bilateral medial frontal gyrus,bilateral middle frontal gyrus,the left hippocampus,cuneus,left precuneus,right parietal lobe and right precuneus regional with depression was decreased,while the density of gray matter of left posterior lobe and cingulate in the left superior temporal gyrus was increased.Besides,the white matter density in the left superior temporal gyrus was decreased,and the white matter density in the right cingulate gyrus was increased.The result indicates that senile depression is associated with the frontal subcortical circuit abnormalities.3.As for the metabolites in bilateral frontal areas,direct comparison showed that the relative peak areas of Cho and mI in the depression group were larger,and Cho/Cr and ml/Cr were bigger than the healthy group,while the relative peak area and NAA or NAA/Cr were smaller.The data above indicates that the metabolic disorder of brain tissue may be responsible for the symptoms of senile depression.ConclusionFMRI,known as a kind of non-invasive examination,is feasible to discover abnormalities of the frontal subcortical circuit and some metabolites of brain tissue,which may provide an early diagnosis reference for senile depression.