Near-infrared spectroscopy and plasma homovanillic acid levels in bipolar disorder: a case report

Impaired brain activity in patients with persistent atrial fibrillation assessed by near-infrared spectroscopy and its changes after catheter ablation

Although the prevalence of cognitive impairment and depression is higher in patients with atrial fibrillation (AF) than in the general population, the mechanism has not been fully examined and impact of catheter ablation (CA) of AF also remains unclear. Recently, the development of near-infrared spectroscopy (NIRS) has enabled noninvasive measurements of regional cerebral blood volume and brain activity, in terms of cerebral oxyhemoglobin in the cerebral cortex. We assessed brain activities by NIRS, depressive symptoms by the Center for Epidemiologic Studies Depression Scale (CES-D) and cognitive function by Mini-Mental State Examination (MMSE). We then compared the results between AF patients (paroxysmal AF n = 18 and persistent AF n = 14) and control subjects (n = 29). Next, we also followed up persistent AF patients who kept sinus rhythm at 3 months after CA (n = 8) and measured their brain activities using NIRS, CES-D and MMSE after CA to investigate the associations of changes in brain activities with changes in both CES-D and MMSE. Our results showed that (1) frontal and temporal brain activities were lower in patients with persistent AF than both in control subjects and paroxysmal AF patients (P < 0.01), (2) frontal and temporal brain activities were improved in more than half of the persistent AF patients who kept sinus rhythm at 3 months after CA, especially in those who presented impaired brain activity before CA, and (3) improvement of frontal brain activity was associated with improvement of CES-D (R =  − 0.793, P = 0.019), whereas improvement of temporal brain activity was associated with improvement of MMSE (R = 0.749, P = 0.033). NIRS measurement showed reduced frontal and temporal brain activities in the persistent AF patients, CA improved frontal and temporal brain activities in some of these patients, and associated with improvement of depressive state and/or improvement of cognitive function.

Impaired Frontal Brain Activity in Patients With Heart Failure Assessed by Near-Infrared Spectroscopy

Background The prevalence of depression and/or anxiety disorders is reported to be higher in patients with heart failure (HF) than in the general population, and patients with HF also have coexisting cognitive problems. Recently, the development of near-infrared spectroscopy (NIRS) has enabled noninvasive measurements of regional cerebral blood volume and brain activity, in terms of cerebral oxyhemoglobin in the cerebral cortex, with a high time resolution. The aim of the current study was to determine the associations between frontal brain activity and depressive symptoms, anxiety status, and cognitive function in patients with HF. Methods and Results We measured and compared frontal brain activity determined by NIRS during a verbal fluency task in patients with HF (n=35) and control subjects (n=28). The Center for Epidemiologic Studies Depression Scale for assessment of depressive symptoms, State-Trait Anxiety Inventory for assessment of anxiety status, Mini-Mental State Examination for assessment of cognitive function, and NIRS were simultaneously conducted. NIRS showed that frontal brain activity was significantly lower in the HF group than in the control subjects (28.5 versus 88.0 mM·mm; P<0.001). Next, we examined the associations between frontal brain activity and the findings of Center for Epidemiologic Studies Depression Scale, State-Trait Anxiety Inventory, Mini-Mental State Examination, and verbal fluency task. There were significant correlations between frontal brain activity and State-Trait Anxiety Inventory (R=-0.228, P=0.046), Mini-Mental State Examination (R=0.414, P=0.017), and verbal fluency task (R=0.338, P=0.007), but not with Center for Epidemiologic Studies Depression Scale (R=-0.160, P=0.233). Conclusions Frontal brain activity assessed by NIRS is reduced and is associated with high anxiety status and low cognitive function in patients with HF.

Frontal activity measured by near-infrared spectroscopy in patients taking different atypical antipsychotic drugs: A cross-sectional study

Using near-infrared spectroscopy, we examined changes in the concentration of oxygenated hemoglobin ([oxy-Hb]) in the frontal lobe during a verbal fluency task in 20 patients with schizophrenia (10 patients each receiving olanzapine [OLZ] and risperidone [RIS]) and 10 healthy controls. We found that [oxy-Hb] levels in the prefrontal region were higher in the patients receiving OLZ than in those receiving RIS. These results suggest that antipsychotic drugs have different effects on cerebral hemodynamic patterns, which may reflect frontal lobe function. Further studies with a larger sample size are needed to verify our preliminary findings.

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

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.