A ~1H Magnetic Resonance Spectroscopy Imaging Study On Hippocampus In Patients With Depression

ObjectiveTo study the characteristic of in vivoMR spectroscopy(MRS)in right and left hippocampal regions of patients with major depressive disorder(MDD).Subjects and Methods~1H-MRS was first performed on the right and left hippocampal regions in patients with 13 MDD drug naive patients with first episode depression,all participants met with MDD criterion of the Structured Clinical Interview for DSM-Ⅳ,Hamilton Rating Scale for Depression 17-item version≥17,except for life time posttraumatic stress disorder,schizophrenia,major depressive disorder bipolar disorder(mood disorders attributable to corticosteroid therapy were allowed),substance abuse/dependence,illness with significant neurological manifestations(e.g.,closed head injury,seizures,systemic lupus erythematosus),or contraindications to MRI(e.g., claustrophobia,metal implants),~1H-MRS was second performed after all patients have taken fluoxetine for ten weeks,and ~1H-MRS was also performed on the right and left hippocampal regions in 13 controls of similar age,gender,ethnicity,education.For the ~1H-MRS,a 15mm~3 voxel in the left or right temporal lobe including as much hippocampus as possible was graphically prescribed on a coronal image.An effort was made to include only tissue and to avoid tissue-air interfaces.Spectroscopy parameters were TR/TE 1000/144,FOV 24cm×24cm,thickness of slice 5mm,Spectral analysis was performed automatically by the GE Medical Systems software and provided metabolite(NAA,Cho)ratios relative to Cre,and the ratios of NAA/Cr and Cho/Cr were compared between MDD and the controll.ResultsThe NAA/Cr ratio of left hippocampal region in MDD group was significantly lower than that in the control(t=4.017,P=0.002),but the Cho/Cr ratio in left hippocampal region had no difference between the two groups.Furthermore,the ratios of NAA/Cr and Cho/Cr in right hippocampal region had no significant difference between both groups.Fluorine treats ten weeks later,the ratio of NAA/Cr ratio of in left hippocampal region in MDD group has elevated,but still obviously was lower than the normal control group.The patients take fluorine to treat around ten weeks,the ratios of NAA/Cr and Cho/Cr in two-sided hippocampal region have not statistics significance.ConclusionThe pathological abnormality might exist in the left hippocampus in patients with MDD,and the NAA/Cr ratio of the left hippocampus was lower than normall.