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.

Evaluation of Brain Activity Using Near-infrared Spectroscopy in Inflammatory Bowel Disease Patients.

Depression is implicated as a risk factor for the recurrence of inflammatory bowel disease (IBD). Near-infrared spectroscopy (NIRS) and brain-derived neurotrophic factor (BDNF) are useful tools for evaluation of brain activity and a depressive state, respectively. The aim of this study was to clarify the association between brain activity or depressive symptoms and IBD using NIRS and BDNF. This study included 36 ulcerative colitis (UC) patients, 32 Crohn's disease (CD) patients, and 17 healthy controls (HC). Center for Epidemiologic Studies Depression Scale (CES-D) scores were determined, NIRS was performed, and serum BDNF levels were measured in all subjects. NIRS showed that the mean oxygenated hemoglobin concentration was significantly lower in the frontal lobe in the UC group than in the HC group (HC 167 ± 106 vs. UC 83.1 ± 85.3, p < 0.05). No significant difference was seen between the HC and CD groups. There were also no significant differences in CED-D scores and BDNF levels among the groups. Changes in the NIRS values of the UC group may indicate decreased brain activity and a fundamental difference between UC and CD, which are often lumped together as two types of IBD.

Reduced brain activity in female patients with non-alcoholic fatty liver disease as measured by near-infrared spectroscopy.

Patients with non-alcoholic fatty liver disease (NAFLD) have impaired health-related quality of life including physical and mental state. Near-infrared spectroscopy (NIRS) is a useful tool for evaluation of brain activity and depressive state. This study aimed to determine the brain activity of female NAFLD patients using NIRS. Cerebral oxygenated hemoglobin (oxy-Hb) concentration during a verbal fluency task (VFT) was measured using NIRS in 24 female NAFLD patients and 15 female healthy controls. The Center for Epidemiologic Studies Depression Scale (CES-D) questionnaire was administered to both groups before NIRS. There was no significant difference in CES-D score between groups. However, the oxy-Hb concentration and number of words during the VFT were less in NAFLD compared to healthy controls. The mean value of oxy-Hb concentration during 0-60 s VFT in the frontal lobe was also smaller in NAFLD patients compared to healthy controls (0.082 ± 0.126 vs. 0.183 ± 0.145, P < 0.001). Cerebral oxygen concentration is poorly reactive in response to VFT in female NAFLD patients. This may indicate an association between decreased brain activity and NAFLD regardless of depression.

Dynamic changes in near-infrared spectroscopy (NIRS) findings in first-episode schizophrenia: a case report.

The clinical course of schizophrenia is characterized by recurrence and chronicity and has a large burden on society.　Nevertheless, diagnosis of schizophrenia is based only on distinctive symptoms and the disease course.　Near-infrared spectroscopy (NIRS) is a useful method for measuring changes in the hemoglobin concentration in the cortical surface area and reflects brain function.　We measured NIRS four times during the clinical course in a patient with first-episode schizophrenia.A 17-year-old woman admitted to our hospital because of hallucinations, delusions and appetite loss. After treatment with low-dose antipsychotics, NIRS findings showed a prompt increase in the cerebral blood volume in the frontal region.　On the basis of the clinical course of this patient, we introduce a new point of view, namely, that NIRS findings may be useful as a state marker that indicates the severity of schizophrenia in some cases.

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.

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

Misdiagnosis of bipolar disorder is a serious, but not unusual problem for patients. Nevertheless, there are few biomarkers for distinguishing unipolar and bipolar disorder. Near-infrared spectroscopy (NIRS) is a noninvasive and useful method for the measurement of hemoglobin concentration changes in the cortical surface area, which enables the assessment of brain function. We measured NIRS and plasma monoamine metabolite levels in a patient with bipolar disorder. A 22-year-old man was admitted due to major depression. At admission, NIRS findings showed oxygenated hemoglobin reincrease in the posttask period, which is characteristic of schizophrenia. After treatment with paroxetine, he became manic with psychotic symptoms. His plasma level of homovanillic acid just before the manic switch was ten times higher than that just after paroxetine initiation. Treatment with lithium and antipsychotics was successful, and plasma homovanillic acid decreased after treatment. In this case, the NIRS findings may predict a possible risk of a manic switch, which is likely induced by paroxetine. NIRS may be able to help distinguish unipolar and bipolar disorder in clinical settings.

A study of the method of the video image presentation for the manipulation of forceps.

Recently, surgical operations have sometimes been tried under laparoscopic video images using teleoperation robots or forceps manipulators. Therefore, in this paper, forceps manipulation efficiencies were evaluated when images for manipulation had some transmission delay (Experiment 1), and when the convergence point of the stereoscopic video cameras was either fixed and variable (Experiment 2). The operators' tasks in these experiments were sewing tasks which simulated telesurgery under 3-dimensional scenography. As a result of experiment 1, the operation at a 200+/-100 ms delay was kept at almost the same accuracy as that without delay. As a result of experiment 2, work accuracy was improved by using the zooming lens function; however the working time became longer. These results seemed to show the relation of a trade-off between working time and working accuracy.