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Background and Purpose: Restless legs syndrome (RLS) is a neurological disorder which is most commonly identified by an urge to move the legs. It often shows alterations in sensory processing which implies the salience network (SN) is experiencing changes. This study investigates the functional connectivity (FC) between the SN and other areas of the brain in RLS patients during the resting state period., Methods: Thirty patients with drug naïve idiopathic RLS and 30 healthy age and gender matched controls were included in this study. Resting state fMRIs were performed in the morning during the asymptomatic period. The SN comparisons were conducted between the two groups., Results: The RLS group showed a reduction in SN FC in the right pyramis, and an increase in SN FC in the bilateral orbitofrontal gyri and right postcentral gyrus., Conclusions: The results of this study give reason to believe that SN FC in RLS patients is altered during asymptomatic periods. This could have an influence on the processing of the saliency of information, particularly sensory information processing and inhibition mechanisms.

Objective: Previous studies have suggested that early-onset RLS (EOR) and late-onset RLS (LOR) might have different etiopathophysiologies. Few previous studies have examined accumulation of cerebrovascular ischemic changes as a potential cause of LOR., Methods: We recruited 39 RLS subjects (LOR: defined as age of RLS onset ≥45, n = 18 and EOR: age of onset <45; n = 21); and 39 healthy control subjects matched on age and sex. Structural magnetic resonance imaging (MRI) of the brain was performed for each subject, and images were graded for severity of periventricular white matter hyperintensities (PVH) and deep white matter hyperintensities (DWMH) independently by trained raters according to standardized methods., Results: Interrater reliabilities were 0.861 (p <0.001) for PVH and 0.900 (p <0.001) for DWMH. LOR subjects had a significantly higher grade of DWMH than the EOR subjects (p = 0.043) and age- and sex-matched controls (p = 0.015). In contrast, there was no difference in DWMH severity rating between the EOR group and the EC group or in PVH severity between the LOR or EOR groups and their age-matched controls., Conclusion: Our findings suggest that the presence and severity of DWMH is associated with LOR, but not with EOR. Further examination of the contribution of cerebrovascular disease to the etiopathogenesis of LOR is warranted., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: The unusual sensations of restless legs syndrome/Willis-Ekbom disease (RLS/WED) are induced by rest or a low arousal state with a circadian variation in the threshold for induction. It has been suggested that the emergence of RLS/WED symptoms relates to abnormal brain functions dealing with internally generated stimuli. The purpose of this study was to investigate the changes in the default mode network (DMN) in RLS/WED subjects., Methods: Sixteen drug-naïve, idiopathic, RLS/WED subjects, and 16 age-matched and gender-matched healthy subjects were scanned in an asymptomatic resting state. A comparison of the DMN was conducted between the two groups. Resting state functional magnetic resonance imaging (MRI), Korean versions of the International RLS scale, and other sleep questionnaires were used., Results: The results showed reductions in the DMN connectivity in the left posterior cingulate cortex, the right orbito-frontal gyrus, the left precuneus, and the right subcallosal gyrus of the RLS/WED subjects. The DMN connectivity was increased in sensory-motor-associated circuits, which included the right superior parietal lobule, the right supplementary motor area, and the left thalamus. In addition, the connectivity between the DMN and thalamus was negatively correlated with that in the orbito-frontal gyrus and the subcallosal gyrus in the subjects., Conclusions: The results showed disturbances of the DMN in RLS/WED subjects that influence the thalamic relay sensory-motor-associated circuit. These findings may underscore the fact that RLS/WED subjects have disturbances in default mode network functions involving internal stimuli in the resting state. This may be related to compensatory changes to maintain resting., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Goal: Micromagnetic stimulation using coils sufficiently small to be implanted has been suggested as a potential method to overcome the limitations of electrical stimulation. We investigated the temperature increases in the brain implanted with planar coils., Methods: We conducted computational simulations on the thermal effects of implantable magnetic stimulation in a brain model using finite-element analysis, by varying geometric parameters of planar spiral coils, and repetitive stimulation pulse patterns., Results: It was revealed that the temperature increase in the brain can be controlled by a careful design of coils to implant. The coil diameter greater than 8 mm was required to induce a temperature rise in the brain of less than 1 °C. If the coil diameter was larger than 10 mm, the subsequent temperature rises in the brain tissue was maintained consistently at about 0.24 °C or lower., Conclusion: Selection of the number of coil turns must rely on tradeoffs between the required current and voltage that the implanted source can generate, as the required voltage increases while the required current decreases with increasing number of coil turns. Additionally, the coil insulation with a thickness of a few micrometers was found to suppress the temperature rise in the brain effectively., Significance: Although these simulations employed only one threshold value of 10 V/m, which is rather on the lower end of stimulation threshold, the simulation results are expected to serve as guidelines for designing planar coils to be implanted in the brain for magnetic stimulation.

The purpose of this study was to demonstrate whether or not restless legs syndrome (RLS) is associated with any morphological change in gray matter. Forty-six RLS subjects and 46 controls were enrolled. We performed voxel-based morphometry analysis and compared the results of the two groups. The RLS subjects showed significant regional decreases of gray matter volume in the left hippocampal gyrus, both parietal lobes, medial frontal areas and cerebellum (uncorrected, P<.001). We found that RLS patients showed structural alteration in the brain and alterations in certain parts of the brain in RLS patients are relevant to RLS., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Patients with schizophrenia often show abnormal social interactions, which may explain their social exclusion behaviors. This study aimed to elucidate patients' brain responses to social rejection in an interactive situation. Fifteen patients with schizophrenia and 16 healthy controls participated in the functional magnetic resonance imaging experiment with the virtual handshake task, in which socially interacting contents such as acceptance and refusal of handshaking were implemented. Responses to the refusal versus acceptance conditions were evaluated and compared between the two groups. Controls revealed higher activity in the refusal condition compared to the acceptance condition in the right superior temporal sulcus, whereas patients showed higher activity in the prefrontal regions, including the frontopolar cortex. In patients, contrast activities of the right superior temporal sulcus were inversely correlated with the severity of schizophrenic symptoms, whereas contrast activities of the left frontopolar cortex were positively correlated with the current anxiety scores. The superior temporal sulcus hypoactivity and frontopolar hyperactivity of patients with schizophrenia in social rejection situations may suggest the presence of mentalizing deficits in negative social situations and inefficient processes of socially aberrant stimuli, respectively. These abnormalities may be one of the neural bases of distorted or paranoid beliefs in schizophrenia.

Aim: Attention deficit has been reported in both schizophrenia patients and patients with major depressive disorder (MDD). The aim of this study was to elucidate the deficits in sustained attention and associated neural network dysfunctions in schizophrenia patients and MDD patients, and to investigate the difference between the two patient groups., Methods: Twelve schizophrenia patients, 12 patients with non-psychotic MDD, and 12 healthy control subjects participated in this study. A sustained attention to response task (SART) was used to measure attention capacity. Cerebral blood flow (CBF) during attention tasks was measured using H(2) (15) O positron emission tomography. Statistical parametric mapping and analysis of covariance were performed to compare the behavioral performance and CBF changes during SART among three groups., Results: Behavioral performances were not significantly different among the three groups except for an increased commission error rate in the schizophrenia group. Regional CBF during SART was significantly reduced in the left inferior frontal gyrus, the left cuneus, and the right superior parietal lobule and increased in the right superior frontal gyrus and the right cuneus in the schizophrenia group compared to the healthy control group. In the MDD group, neither significant regional CBF difference nor behavioral deficit was found compared to the healthy control group., Conclusion: Behavioral performance deficit and perfusion changes in the prefrontal and parietal cortices during SART were observed only in the schizophrenia group. Prefrontal and parietal network dysfunction for sustained attention may be involved in the pathophysiology of schizophrenia., (© 2012 The Authors. Psychiatry and Clinical Neurosciences © 2012 Japanese Society of Psychiatry and Neurology.)

Objective: Most patients with schizophrenia suffer from various types of hallucinations, which commonly produce distress, functional disability or behavioral dyscontrol. The neural process of adapting to hallucinations in patients with schizophrenia remains unknown., Methods: Functional magnetic resonance imaging (MRI) responses to an unusual threatening visual stimulus designed to simulate a hallucinatory experience were compared between 16 patients with schizophrenia and 17 healthy controls. Linear and quadratic repetition-variant as well as repetition-invariant responses to the stimulus were compared between the two groups., Results: Repetition-invariant responses were similar between patients with schizophrenia and healthy controls. Patients with schizophrenia exhibited a linear activation pattern in the anterior cingulate, whereas healthy controls exhibited a parabolic activation pattern in the anterior prefrontal cortex, occipito-temporal junction and amygdala., Conclusions: These results provide us with a better understanding of the neural processes involved in gaining insight into unreality. Patients with schizophrenia may use a salience-related region instead of reality monitoring-related regions to react to the unusual stimuli, and this peculiarity of the neural processes may be related to vulnerability to psychosis., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The degree at which individuals maintain behavioral strategies during uncertain conditions varies widely; however, the neural bases of these individual differences remain unclear. This study examines the functional connectivity of the orbitofrontal cortex during a decision-making task using functional magnetic resonance imaging. The strength of the functional connectivity observed between the medial orbitofrontal cortex and the nucleus accumbens was determined to be correlated with the number of persistent responses made during the decision-making task. It is proposed that top-down control of the orbitofrontal cortex over the ventral striatum is a critical component underlying individual differences in decision making during uncertain conditions.

Attributional style means how people typically infer the causes of emotional behaviors. No study has shown neural basis of attributional style in schizophrenia, although it was suggested as a major area of social cognition research of schizophrenia. Fifteen patients with schizophrenia and 16 healthy controls underwent functional magnetic resonance imaging while performing three (happy, angry, and neutral) conditions of attribution task. Each condition included inferring situational causes of an avatar' (virtual character) emotional or neutral behavior. In the between-groups contrast maps of the happy conditions, the patient group compared to the control group showed decreased activations in the inferior frontal (BA 44) and the ventral premotor cortex (BA 6), in which the % signal changes were associated with negative symptoms. In the angry conditions, the patient group compared to the control group exhibited increased activations in the precuneus/posterior cingulate cortex (Pcu/PCC) (BA 7/31), in which the % signal changes were related to positive symptoms. In conclusion, patients with schizophrenia may have functional deficits in mirror neuron system when attributing positive behaviors, which may be related to a lack of inner simulation and empathy and negative symptoms. In contrast, patients may have increased activation in the Pcu/PCC related to self-representations while attributing negative behaviors, which may be related to failures in self- and source-monitoring and positive symptoms.

There is still debate over the neural mechanisms underlying pathogenic and even recovery processes of Wernicke's encephalopathy. Therefore, we attempted to validate the usefulness of resting-state functional connectivity analysis in assessing memory function and its neural correlation with the mammillothalamic tract in patients recovering from Wernicke's encephalopathy. Seven chronic alcoholics recovering from Wernicke's encephalopathy, 14 alcoholic comparisons without Wernicke's encephalopathy, and 14 healthy comparisons underwent functional connectivity MRI scans, as well as verbal and non-verbal memory tests after at least a 1 month abstinence from alcohol. Resting-state functional connectivity strength between the anterior thalamus and the mammillary bodies was investigated by calculating temporal correlations in magnetic resonance signal levels between the two regions during a 5-min passive viewing task. The mean values of the functional connectivity strength between the left anterior thalamus and the ipsilateral mammillary body differed significantly between Wernicke's encephalopathy patients and healthy comparisons (P = 0.014). This connectivity strength in alcoholic comparisons fell between those of the former two groups, with a significant difference from that of healthy comparisons (P = 0.038). In addition, the strength of this left-sided functional connectivity significantly correlated with delayed verbal recall scores (r = 0.771, P = 0.042) and verbal recognition score (r = 0.825, P = 0.022) in patients with Wernicke's encephalopathy. Our findings indicate that memory function in patients recovering from Wernicke's encephalopathy parallels the level of the mammillothalamic functional connectivity; this supports the usefulness of resting-state functional connectivity analysis as a practical alternative to pathological examination of the mammillothalamic tract in living patients with Wernicke's encephalopathy.

Individuals sometimes experience an illusory or hallucinatory perception. This unreal perception is usually resolved after the individual recognizes that the perception was not real. In this study, we investigated the brain mechanisms involved in the process to an illusory or hallucinatory perception through 'obtaining insight into unreality'. We used a novel and intuitive paradigm designed by combining functional magnetic resonance imaging and augmented reality technology to simulate visual illusory stimuli that mimic hallucinations during brain scanning. The results showed various brain activations, predominantly in the amygdala in the early phase, the medial frontal cortex and the occipitotemporal junction in the middle phase, and the thalamus in the late phase, which correlated with a subject's proneness to hallucinating. These activations may correspond to a 'responding stage' for a perception-based immediate emotional reaction, a 'monitoring stage' for integration and recalibration to ascertain that the perception was not real, and a 'resolving stage' for controlling the information and finally settling it, respectively. Our paradigm and findings may be useful in understanding the mechanisms for discriminating and coping with hallucinatory perceptions.

To react appropriately in social relationships, we have a tendency to simulate how others think of us through mental imagery. In particular, simulating other people's facial affective expressions through imagery in social situations enables us to enact vivid affective responses, which may be inducible from other people's affective responses that are predicted as results of our mental imagery of future behaviors. Therefore, this ability is an important cognitive feature of diverse advanced social cognition in humans. We used functional magnetic imaging to examine brain activation during the imagery of emotional facial expressions as compared to neutral facial expressions. Twenty-one right-handed subjects participated in this study. We observed the activation of the amygdala during the imagining of emotional facial affect versus the imagining of neutral facial affects. In addition, we also observed the activation of several areas of the brain, including the dorsolateral prefrontal cortex, ventral premotor cortex, superior temporal sulcus, parahippocampal gyrus, lingual gyrus, and the midbrain. Our results suggest that the areas of the brain known to be involved in the actual perception of affective facial expressions are also implicated in the imagery of affective facial expressions. In particular, given that the processing of information concerning the facial patterning of different emotions and the enactment of behavioral responses, such as autonomic arousal, are central components of the imagery of emotional facial expressions, we postulate the central role of the amygdala in the imagery of emotional facial expressions.

Background: Previous studies on patients diagnosed with social anxiety disorder (SAD) reported changed patterns of the resting-state functional connectivity network (rs-FCN) between the prefrontal cortices and other prefrontal, amygdalar or striatal regions. Using a graph theory approach, this study explored the modularity-based community profile and patterns of inter-/intra-modular communication for the rs-FCN in SAD.Methods: In total, for 28 SAD patients and 27 healthy controls (HC), functional magnetic resonance imaging (fMRI) data were acquired in resting-state and subjected to a graph theory analysis.Results: The within-module degree z-score for a hub region [out of a total of 10 hub regions ranked using the participation coefficient] named left middle temporal gyrus was impaired in SAD compared to HC, proportional to the severity of clinician-scored and patient-reported functional impairment in SAD.Limitations: Most of participants included in this study were undergraduate students in their early-to-mid 20's.Conclusions: This study showed the importance of functional communication from the left middle temporal gyrus with other opercular-insular-subcortical regions for better objective functioning and lesser subjective disability in SAD. [ABSTRACT FROM AUTHOR]