Detection of prefrontal lobe blood flow changes in patients with obsessive-compulsive disorder during a verbal fluency task by near-infrared reflectance spectroscopy

The purpose of this work was to use near-infrared reflectance spectroscopy (NIRS) to investigate the spectral characteristics and frontal lobe activation in patients with obsessive-compulsive disorder (OCD) during a verbal fluency task. Thirty-seven patients with OCD, who met the diagnostic criteria of International Classification of Diseases 10 (ICD-10), were recruited. The total score of the Symptom Checklist (SCL-90, grade 1-5) was ≥160 points. The total score of the Yale-Brown Obsessive Compulsive Scale was ≥7 points. The changes in frontal lobe blood flow were measured by NIRS when completing a verbal fluency task. Then, the differences between obsessive-compulsive thoughts and obsessive-compulsive behaviors in OCD, and the concentration variation of oxygenate hemoglobin (Oxy-Hb) and deoxygenate hemoglobin (Deoxy-Hb) were investigated. The difference was significant (P<0.03) between obsessive-compulsive behaviors and obsessive-compulsive thoughts. Obsessive-compulsive behaviors were positively correlated (P<0.01, P<0.05) with depression, anxiety, psychosis and other factors in the SCL-90, and significantly positively correlated (P<0.01, P<0.03) with somatization, hostility and paranoid factor scores in the SCL-90. There was also a trend of partial overlap between the waveform and task period, and the difference was significant (P<0.01) between these. Obsessive-compulsive thoughts were negatively correlated (P<0.05) with channels 9 and 19. The NIRS monitoring spectrum for patients with OCD has certain spectral characteristics of schizophrenia, but there is a repetitive trend between the recovery period and the task period.