Neurochemical alterations in anterior cingulate cortex in bipolar disorder: a proton magnetic resonance spectroscopy study (1H-MRS)

The aim of this study was to determine neurochemical alterations in bipolar disorder using proton magnetic resonance spectroscopy (1H-MRS).

We investigated a group of 27 patients diagnosed with bipolar disorder (with manic and mixed episodes, depression and after remission of symptoms) and 10 healthy subjects. MR imaging and 1H-MRS were performed on a 1.5 T scanner. Voxels of 8 cm3 were positioned in the anterior cingulate, left frontal lobe and left temporal lobe. Spectral peaks of NAA (N-acetylaspartate), Glx (glutamate/glutamine/GABA complex), Cho (choline), Cr (creatine/phosphocreatine) and mI (myo-inositol) were analyzed and the ratios of these metabolites to creatine (Cr) and non-suppressed water signal were determined.

In the anterior cingulate cortex of patients with bipolar disorder a significantly higher Cho/H2O ratio (p = 0.029) and a trend toward higher Cho/Cr ratio values (p = 0.096) were observed as compared to healthy controls.

The findings of our study prove that neurochemical changes occurring in the anterior cingulate cortex of bipolar patients are related to altered choline levels.