Reduced frontal activation during verbal fluency task in chronic hepatitis C patients with interferon-based therapy as measured by near-infrared spectroscopy

Abstract

Aim: Psychiatric side-effects are the main reason for discontinuation of interferon (IFN)-based therapy. Recent developments in near-infrared spectroscopy (NIRS) have enabled non-invasive clarification of brain functions in psychiatric disorders. We prospectively evaluated brain activation in 20 chronic hepatitis C patients with or without IFN-based therapy by using NIRS during a verbal fluency task (VFT). Methods: The relative concentrations of oxygenated hemoglobin were measured while patients completed a questionnaire survey at the start of treatment and at 4 and 12 weeks during treatment, using NIRS. Results: The VFT performance did not change among the two groups. Patients with IFN-based therapy showed significantly lower activation during VFT in frontal channels at 12 weeks than those at the start of treatment and control (P < 0.05). Their Center for Epidemiologic Studies Depression Scale scores were significantly higher at 12 weeks than those at the start of treatment, although major depressive symptoms were not found (8.3 ± 7.9 vs. 13.2 ± 6.0, P < 0.001). Conclusion: The decrease in oxygenated hemoglobin concentrations of the frontal lobe detected using NIRS in this study reflects hypofunction of the frontal lobe. This functional decline that was caused by IFN-based therapy may be associated with the prodromal phase of depression.