Hiroaki Kumano

Mindfulness-based stress reduction and cancer: a meta-analysis

Objective: This meta‐analysis was conducted to investigate the effects of mindfulness‐based stress reduction (MBSR) on the mental and physical health status of various cancer patients.

Effects of value and reward magnitude on feedback negativity and P300.

Feedback negativity is a negative component of the event-related brain potential observed 250–300 ms after feedback stimuli. The present study investigated the effects of value (correct or incorrect) and reward magnitude (no, small or large) on feedback negativity and P300. Feedback negativity was larger after incorrect feedback than after correct feedback, irrespective of reward magnitude. In contrast, P300 amplitude increased with reward magnitude, irrespective of value. The amplitude of feedback negativity was correlated with a trait score of negative affect and not positive affect, whereas P300 amplitude was correlated with positive affect and not negative affect. These results suggest that value and reward magnitude are processed separately in the brain.

Cerebral glucose metabolism associated with a fear network in panic disorder

The present study was performed to assess cerebral glucose metabolism in patients with panic disorder using positron emission tomography. 18F-fluorodeoxyglucose positron emission tomography with voxel-based analysis was used to compare regional brain glucose utilization in 12 nonmedicated panic disorder patients, without their experiencing panic attacks during positron emission tomography acquisition, with that in 22 healthy controls. Panic disorder patients showed appreciably high state anxiety before scanning, and exhibited significantly higher levels of glucose uptake in the bilateral amygdala, hippocampus, and thalamus, and in the midbrain, caudal pons, medulla, and cerebellum than controls. These results provided the first functional neuroimaging support in human patients for the neuroanatomical hypothesis of panic disorder focusing on the amygdala-based fear network.

DECREASE IN SERUM CORTISOL DURING YOGA EXERCISE IS CORRELATED WITH ALPHA WAVE ACTIVATION

We examined changes in brain waves and blood levels of serum Cortisol during yoga exercise in 7 yoga instructors and found that alpha waves increased and serum Cortisol decreased. These two measures were negatively correlated (r = -.83). Comparison with a control group of nonpractitioners is desirable.

Clinical and psychological aspects of restless legs syndrome in uremic patients on hemodialysis

BACKGROUND The pathogenesis of restless legs syndrome (RLS) is still unclear. The purpose of this study is to determine relationships of the presence of RLS in uremic patients regularly undergoing hemodialysis (HD) with demographic, clinical, and psychological factors. METHODS In 490 uremic patients on HD therapy in Japan, RLS was diagnosed based on diagnostic criteria established by the International Restless Legs Syndrome Study Group. Data were compared between patients with and without RLS. RESULTS There were univariately significant (P < 0.05) differences in serum phosphorus levels, anxiety levels determined using the Hospital Anxiety and Depression Scale, and degrees of emotion-oriented and avoidance-oriented coping determined using the Coping Inventory for Stressful Situations. In multivariate analyses, low hemoglobin levels, high serum phosphorus levels, high anxiety levels, and a great degree of emotion-oriented coping were independently related to the presence of RLS in uremic patients on HD therapy, with statistical significance (P < 0.05). CONCLUSION Hyperphosphatemia, anxiety, and a great degree of emotion-oriented coping with stress were independently related to the presence of RLS in uremic patients on HD therapy. The pathogenesis of RLS seems to involve more than one mechanism, which leads to restless legs as the final common pathway. These findings may provide new clues to the pathogenesis of RLS.

Error-related negativity reflects detection of negative reward prediction error.

Error-related negativity (ERN) is a negative deflection in the event-related potential elicited in error trials. To examine the function of ERN, we performed an experiment in which two within-participants factors were manipulated: outcome uncertainty and content of feedback. The ERN was largest when participants expected correct feedback but received error feedback. There were significant positive correlations between the ERN amplitude and the rate of response switching in the subsequent trial, and between the ERN amplitude and the trait version score on negative affect scale. These results suggest that ERN reflects detection of a negative reward prediction error and promotes subsequent response switching, and that individuals with high negative affect are hypersensitive to a negative reward prediction error.

Comorbidity of Irritable Bowel Syndrome, Panic Disorder, and Agoraphobia in a Japanese Representative Sample

OBJECTIVES:Irritable bowel syndrome (IBS) is considered to be a transcultural functional bowel disorder with high comorbidity and psychiatric disorders; but well-designed epidemiologic studies have never been performed in Japan. The purpose of this study was to establish the prevalence of IBS, together with the comorbidity rates of panic disorder (PD) and agoraphobia, employing a large-scale survey based on stratified random sampling.METHOD:A total of 4,000 subjects aged 20–69 years completed a questionnaire and the results were weighted to ensure representativeness of the Japanese general population. The questionnaire covered key symptoms of IBS, PD, and agoraphobia. The prevalence of IBS and its subtypes was calculated by gender. The comorbidity of PD and agoraphobia with IBS was compared with morbidity in non-IBS subjects; and comorbidity in IBS subjects who had consulted medical practitioners regarding their symptoms and in those who had not was also compared.RESULTS:The prevalence of IBS was 6.1% in total. It was significantly higher in females than in males. Diarrhea-predominant IBS was more prevalent in males and constipation-predominant IBS in females. The morbidity rates of PD and agoraphobia were significantly higher in IBS than in non-IBS subjects. Comorbidity did not differ between female and male IBS subjects, while morbidity was significantly higher in female than in male non-IBS subjects; and comorbidity did not differ between consulter and nonconsulter subjects.CONCLUSIONS:The prevalence of IBS and its comorbidity with PD and agoraphobia in Japan were demonstrated to be similar to those reported in Western industrialized countries.

Decreased response inhibition in middle-aged male patients with type 2 diabetes

BackgroundThis study was performed to examine whether patients with type 2 diabetes have cognitive deficits associated with the prefrontal cortex (PFC).MethodsTwenty-seven middle-aged patients with newly diagnosed type 2 diabetes and 27 healthy controls underwent physical measurements and neuropsychological tasks. Response inhibition, reward prediction, and executive function were assessed by the Go/NoGo task, the reversal and extinction tasks, and the Wisconsin Card Sorting Test (WCST). To examine the interactions of being overweight with diabetes on cognitive performance, performance data were analysed by two-way ANCOVA with diabetes and overweight as factors and age as a covariate.ResultsPatients with type 2 diabetes showed significantly decreased response inhibition in the Go/NoGo task (discriminability index: P = 0.001). There was an interaction of being overweight with diabetes on reaction time in the Go trials of the Go/NoGo task (P = 0.009). Being overweight was related to retained responses to the presentiment of reward in the extinction task (P = 0.029). The four groups showed normal cognitive performance in the WCST.ConclusionsOur results showed that middle-aged, newly diagnosed and medication-free patients with type 2 diabetes have a particular neuropsychological deficit in inhibitory control of impulsive response, which is an independent effect of diabetes apart from being overweight.

Whole-body metabolic map with positron emission tomography of a man after running

body tomograph SET2400W (Shimadzu Co, Japan), with an intrinsic spatial resolution of 3·9 mm. The figure shows PET images of the subject lying supine. Correction of tissue attenuation was made after emission acquisition (postinjection transmission) using a needle Ge/Ga source. We found that F-FDG uptake was increased in the soleus and gastrocemius muscles—those most exercised in endurance running. Lesser accumulations of F-FDG in other muscles including those of the thighs were also noted. These images indicate that PET can identify muscles used in physical activity. The amount of radioactivity required for imaging can probably be reduced to less than 40 MBq, corresponding to a whole body radiation dose of around 0·5 mSv, equivalent to half the exposure of an abdominal radiograph. PET mapping of muscle activity may provide useful information for sports and rehabilitation medicine.

Hikikomori, is it a culture-reactive or culture-bound syndrome? Nidotherapy and a clinical vignette from Oman.

Hikikomori, a form of acute social withdrawal, is becoming a silent epidemic in Japan. As it has not been reported from other parts of the world, hikikomori fulfills the criteria for “a culture-bound syndrome.” We report a case from Oman, in the southern part of Arabia, with all the essential features of hikikomori. We speculate that the social environment of Japanese and Omani society could reinforce behavior akin to hikikomori although this condition may also transcend geography and ethnicity.