Amygdala signal abnormality and cognitive impairment in drug-naïve schizophrenia

Abstract

Background: Recently studies had showed that the amygdala may take part in the cognitive impairment in schizophrenia (SC). However, the mechanism is still unclear, so we explored the relationship between the amygdala resting state magnetic resonance imaging (rsMRI) signal and cognitive function, to provide a reference for the follow-up study.

Methods: We collected 59 drug-naïve SCs and 46 healthy controls (HCs) from the Third People's Hospital of Foshan. The rsMRI technique and automatic segmentation tool were used to extract the volume and functional indicators of the SC's amygdala. The Positive and Negative Syndrome Scale (PANSS) was used to assess the severity of the disease, and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess cognitive function. Pearson correlation analysis was used to compare the relationship between the structural and functional indicators of the amygdala and PANSS and RBANS.

Results: (1) There was no significant difference between SC and HC in age, gender and years of education. Compared with HC, the PANSS score of SC increased and the RBANS score decreased significantly. Meanwhile, the left amygdala volume decreased (t=-3.675, p < 0.001), and the Fractional amplitude of low-frequency fluctuations (FALFF) values of bilateral amygdala increased (t_L=3.916, p < 0.001; t_R=3.131, p = 0.002). (2) The volumes of the left amygdala were negatively correlated with the PANSS score (r_L=-0.243, p = 0.039). While the FALFF values of the bilateral amygdala were positively correlated with the PANSS score (r_L=0.257, p = 0.026; r_R=0.259, p = 0.026). Bilateral amygdala volumes and FALFF values were positively correlated (r_L=0.445, p < 0.001; r_R=0.326, p = 0.006) and negatively correlated with RBANS score (r_L=-0.284, p = 0.014; r_R=-0.272, p = 0.020), respectively.

Conclusion: The abnormal volume and function of the amygdala play important roles in the disease process of SC, and are closely related to cognitive impairment.

Keywords: Amygdala; Cognition; MRI; PANSS; RBANS; Schizophrenia.