Investigation of bulbus olfactorius and amigdala volume and functional activity with 18-FDG PET / CT in patients with A diagnosis of bipolar disorder

Objective: Bipolar disorder is a psychiatric disorder that is common in the society and causes disability. In neuroimaging studies in bipolar disorder, structural and metabolic differences were observed in various brain regions. In this study, we investigated the bulbus olfactorius and amygdala volume and metabolism with 18 FDG PET / CT in patients with bipolar disorder. Method: Twenty-six patients diagnosed with bipolar disorder according to DSM-5 diagnostic criteria were included in the study. HAM-A and Golombok Rust Inventory of Sexual Satisfaction were applied to the participants. Participants 18 FDG were scanned with PET / CT. Bulbus olfactorius and amygdala glucose metabolisms were compared with z scores. Bulbus olfactorius and amygdala volumes were compared with 18 FDG PET / CT images of 26 patients who were retrospectively scanned and met the exclusion criteria. Results: In our case group with a diagnosis of bipolar disorder, the volume of bulbus olfactorius was statistically significantly decreased (p: 0.001), and bulbus olfactorius metabolism was found to be statistically significantly higher compared to the control group (p: 0.001). Amygdala volume and metabolism were found to be statistically significantly higher in our case group (p: 0.001).There was a correct correlation between amygdala and bulbus olfactorius volumes. There was a positive correlation between right and left amygdala metabolism and right bulbus olfactorius metabolism. Conclusions: This study is the first to our knowledge to examine the bulbus olfactorius volume and metabolism in bipolar disorder. The data of our study showed that the volume and metabolism of the bulbus olfactorius are affected in bipolar disorder. It has also shown that the bulbus olfactorius may be responsible for the etiopathogenesis of bipolar disorder. Further studies are needed in the future to understand this issue better.