Quantitative proton magnetic resonance spectroscopy of the bilateral frontal lobes in patients with bipolar disorder

Background. Using P-31 and H-1 magnetic resonance spectroscopy (MRS) we pre viously reported that phosphocreatine was decreased in the left frontal lob e and choline-containing compounds were increased in the basal ganglia in t he depressive state in patients with bipolar disorder. We applied quantitat ive H-1-MRS for further characterization of biochemical alteration in the f rontal lobes of bipolar patients. Methods. Twenty-three bipolar patients and 20 normal controls were examined by H-1-MRS with a 1.5T MR system. All patients were examined in the euthym ic state, and eight patients were also examined in the depressive state. Vo lumes of interest of 2.5 x 2.5 x 2.5 cm were selected in the left and right frontal lobes, Absolute concentrations of N-acetyl-1-aspartate, creatine p lus phospho-creatine, and choline-containing compounds were calculated from each metabolite peak. Results. Creatine concentration in the left frontal lobe in bipolar patient s in the depressive state was significantly lower than that in the euthymic state. Creatine concentration in the right frontal lobe in the male patien ts was significantly higher than that in the female patients and a similar trend was also found in the control subjects. Conclusions. We found a state-dependent change of creatine metabolism in th e left frontal lobe of bipolar patients. The present results are compatible with our previous report of decreased phosphocreatine measured by P-31-MRS in the left frontal lobe in bipolar disorder. We also found an effect of g ender on the creatine concentration. There may be a gender difference in cr eatine transport function into the brain.