Lithium-associated anterior cingulate neurometabolic profile in euthymic Bipolar I disorder: A 1H-MRS study.

OBJECTIVE: In the treatment of Bipolar disorder (BD), achieving euthymia is highly complex and usually requires a combination of mood stabilizers. The mechanism of action in stabilizing mood has not been fully elucidated, but alterations in N-Acetylaspartate (NAA), Myo-Inositol (mI) and Choline (Cho) have been implicated. Proton magnetic resonance spectroscopy (1H-MRS) is the gold standard technique for measuring brain NAA, Cho and mI in vivo. The objective of this study was to investigate the association of lithium use in BD type I and brain levels of NAA, mI and Cho in the (anterior cingulate cortex) ACC. METHODS: 129 BD type I subjects and 79 healthy controls (HC) were submitted to a 3-Tesla brain magnetic resonance imaging scan (1H-MRS) using a PRESS ACC single voxel (8cm3) sequence. RESULTS: BD patients exhibited higher NAA and Cho levels compared to HC. Lithium prescription was associated with lower mI (combination + monotherapy) and higher NAA levels (monotherapy). CONCLUSION: The results observed add to the knowledge about the mechanisms of action of mood stabilizers on brain metabolites during euthymia. Additionally, the observed decrease in mI levels associated with lithium monotherapy is an in vivo finding that supports the inositol-depletion hypothesis of lithium pharmacodynamics.

Neurochemical differences between bipolar disorder type I and II in superior temporal cortices: A proton magnetic resonance spectroscopy study.

BACKGROUND: Despite the diagnostic challenges in categorizing bipolar disorder subtypes, bipolar I and II disorders (BD-I and BD-II respectively) are valid indices for researchers. Subtle neurobiological differences may underlie clinical differences between mood disorder subtypes. The aims of this study were to investigate neurochemical differences between bipolar disorder subtypes. METHODS: Euthymic BD-II patients (n = 21) are compared with BD-I (n = 28) and healthy comparison subjects (HCs, n = 30). Magnetic Resonance Imaging (MRI) and proton spectroscopy (1H MRS) were performed on a 3T Siemens Tim Trio system. MRS voxels were located in the left/right superior temporal cortices, and spectra acquired with the single voxel Point REsolved Spectroscopy Sequence (PRESS). The spectroscopic data were analyzed with LCModel (Version 6.3.0) software. RESULTS: There were significant differences between groups in terms of glutamate [F = 6.27, p = 0.003], glutamate + glutamine [F = 6.08, p = 0.004], inositol containing compounds (Ino) (F = 9.25, p < 0.001), NAA [F = 7.63, p = 0.001] and creatine + phosphocreatine [F = 11.06, p < 0.001] in the left hemisphere and Ino [F = 5.65, p = 0.005] in the right hemisphere. Post-hoc comparisons showed that the BD-I disorder group had significantly lower metabolite levels in comparison to the BD-II and the HC groups. LIMITATIONS: This was a cross-sectional study with a small sample size. In addition, patients were on various psychotropic medications, which may have impacted the results. CONCLUSIONS: Neurochemical levels, in the superior temporal cortices, measured with 1H-MRS discriminated between BD-II and BD-I. Although further studies are needed, one may speculate that the superior temporal cortices (particularly left hemispheric) play a critical role, whose pathology may be related to subtyping bipolar disorder.

Cyclothymic temperament and glucose metabolism in the right superior parietal lobule.

Cyclothymic temperament possesses a central dimension that includes rapid fluctuations in mood and emotional instability, and it is regarded as a prodromal state of bipolar disorder. The aim of the present study is to explore the neural correlates of cyclothymic temperament. We used the data of 55 healthy participants in our previous study and analyzed the association between cyclothymic temperament scores rated by the Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Autoquestionnaire (TEMPS-A) and the uptake of [18F]-FDG measured by positron emission tomography (PET). A whole brain analysis revealed a cluster of [18F]-FDG uptake significantly and positively associated with cyclothymic temperament scores, located in the right superior parietal lobule (SPL). Even after adjustment for relevant factors, there remained a significant cluster of [18F]-FDG uptake with cyclothymic temperament scores in the right SPL. In ROI analyses, there were similar significant peaks in the right SPL in association with cyclothymic temperament scores. These findings suggest that the right superior parietal lobule may be one of the neural correlates of cyclothymic temperament.

Morphology according to cranial computed tomography of first-episode cycloid psychosis and its long-term-course: differences compared to schizophrenia.

Cranial computed tomography (CCT) findings for 37 patients with cycloid psychosis and 19 patients with DSM-III-R schizophrenia were compared with findings for age- and sex-matched controls. Schizophrenic patients showed enlarged ventricles compared both to controls and to patients suffering from cycloid psychosis. In patients with cycloid psychosis, neither at the first episode nor after many years (mean 16.6 years) of disease were significant differences found compared to control subjects. Over the course of the illness, patients with cycloid psychosis showed ventricular enlargement which was correlated with age but not with the duration of illness. The morphological differences provide further evidence for the proposed nosological distinction between cycloid psychosis and schizophrenia.