Hemodynamic responses in prefrontal cortex and personality characteristics in patients with bulimic disorders: a near-infrared spectroscopy study

Purpose: This study sought to identify the prefrontal cortex hemodynamic response that is dependent on cognitive performance in patients with bulimic disorders (BD), and investigate its association with personality characteristics. Methods: Nineteen female patients with BD and 23 healthy women were recruited. Their personality characteristics related to eating disorders were examined using a self-reporting questionnaire, namely the eating disorder inventory-2 (EDI-2). Cerebral blood flow response in the prefrontal cortex during the digit span backward task (DSBT) was measured using near-infrared spectroscopy (NIRS). Change in oxygenated hemoglobin concentration (ΔoxyHb), obtained using NIRS, were used as an index of brain activity. Further, the relationship between prefrontal cortical activity and personality characteristics was investigated in patients with BD. Results: The cognitive performance of patients with BD was significantly lower in the DSBT compared with healthy subjects. There was no difference between the groups in ΔoxyHb during the task. Task scores of patients with BD correlated with asceticism and perfectionism. Moreover, the asceticism score was negatively correlated with ΔoxyHb of the bilateral prefrontal cortex in patients with BD. Conclusion: The results suggest that cognitive performance and brain activity induced during DSBT might be affected by asceticism in BD patients. Level of evidence: III, case-control study.