Diurnal Variation of Brain Activity in the Human Suprachiasmatic Nucleus.

The suprachiasmatic nucleus (SCN) is the central clock for circadian rhythms. Animal studies have revealed daily rhythms in the neuronal activity in the SCN. However, the circadian activity of the human SCN has remained elusive. In this study, to reveal the diurnal variation of the SCN activity in humans, we localized the SCN by employing an areal boundary mapping technique to resting-state functional images and investigated the SCN activity using perfusion imaging. In the first experiment (n = 27, including both sexes), we scanned each participant four times a day, every 6 h. Higher activity was observed at noon, while lower activity was recorded in the early morning. In the second experiment (n = 20, including both sexes), the SCN activity was measured every 30 min for 6 h from midnight to dawn. The results showed that the SCN activity gradually decreased and was not associated with the electroencephalography. Furthermore, the SCN activity was compatible with the rodent SCN activity after switching off the lights. These results suggest that the diurnal variation of the human SCN follows the zeitgeber cycles of nocturnal and diurnal mammals and is modulated by physical lights rather than the local time.

Functional connectivity in autism spectrum disorder evaluated using rs-fMRI and DKI.

We evaluated functional connectivity (FC) in patients with adult autism spectrum disorder (ASD) using resting-state functional MRI (rs-fMRI) and diffusion kurtosis imaging (DKI). We acquired rs-fMRI data from 33 individuals with ASD and 33 healthy controls (HC) and DKI data from 18 individuals with ASD and 17 HC. ASD showed attenuated FC between the right frontal pole (FP) and the bilateral temporal fusiform cortex (TFusC) and enhanced FC between the right thalamus and the bilateral inferior division of lateral occipital cortex, and between the cerebellar vermis and the right occipital fusiform gyrus (OFusG) and the right lingual gyrus, compared with HC. ASD demonstrated increased axial kurtosis (AK) and mean kurtosis (MK) in white matter (WM) tracts, including the right anterior corona radiata (ACR), forceps minor (FM), and right superior longitudinal fasciculus (SLF). In ASD, there was also a significant negative correlation between MK and FC between the cerebellar vermis and the right OFusG in the corpus callosum, FM, right SLF and right ACR. Increased DKI metrics might represent neuroinflammation, increased complexity, or disrupted WM tissue integrity that alters long-distance connectivity. Nonetheless, protective or compensating adaptations of inflammation might lead to more abundant glial cells and cytokine activation effectively alleviating the degeneration of neurons, resulting in increased complexity. FC abnormality in ASD observed in rs-fMRI may be attributed to microstructural alterations of the commissural and long-range association tracts in WM as indicated by DKI.

Music Intervention Reduces Persistent Fibromyalgia Pain and Alters Functional Connectivity Between the Insula and Default Mode Network.

OBJECTIVE: The aims of the present study were to examine the effects of short-term music interventions among patients with fibromyalgia (FM) and to clarify the alterations in functional connectivity and persistent pain. DESIGN: Pilot study. SETTING: All participants were evaluated at Juntendo University from November 2017 to January 2019. SUBJECTS: We enrolled female patients who had been clinically diagnosed with FM (N = 23). METHODS: All participants listened to Mozart's Duo for Violin and Viola No. 1, K. 423, in a quiet room for 17 minutes. We compared the degree of pain using resting-state functional magnetic resonance imaging and the numeric rating scale before and after listening to music. RESULTS: Pain scores were significantly reduced after listening to music. Further, we observed there was a significant difference in connectivity between the right insular cortex (IC) and posterior cingulate cortex (PCC)/precuneus (PCu) before and after listening to music. We also found that the difference between the right IC-PCu connectivity and the difference in pain scores were significantly correlated. CONCLUSIONS: We found that a short period of music intervention reduced chronic pain and altered functional IC-default mode network connectivity. Furthermore, music potentially normalized the neural network via IC-default mode network connectivity, yielding temporary pain relief in patients with FM. Further longitudinal studies with larger sample sizes are required to confirm these results.

Difficulty differentiating a case of posterior cortical atrophy from a psychogenic disturbance of vision.

Differentiating posterior cortical atrophy (PCA) from other diseases can be difficult and time-consuming, and there is a particularly high possibility of misdiagnosis when psychiatrists diagnose complaints related to visual perception. Here, a case of PCA involving prominent visual perceptual disorders is reported; PCA was difficult to distinguish from psychogenic disturbance of vision in this case. For a year, a 59-year-old woman had had visual perceptual disorders, including a distorted view and prosopagnosia. She underwent examinations at multiple clinical departments at several medical institutions before receiving a definitive diagnosis of PCA. This PCA diagnosis was based on clinical symptoms, including Gerstmann syndrome, Bálint's syndrome, and transcortical sensory aphasia, and hypoperfusion in the occipital lobe observed on single-photon emission computed tomography. This case was initially misdiagnosed as a psychogenic disease partly because characteristic clinical manifestations of PCA include visual agnosia with a disjunctive component. This patient displayed a disordered perception of stationary objects but an intact perception of moving objects. For example, she had to grope her way through a room at home, but she could visit a familiar hair salon on foot without hindrance. Behaviours like claiming to be blind while inexplicably moving without colliding with surrounding objects may lead to the misdiagnosis of PCA as a psychogenic or dissociative disorder involving histrionic or neurologically irrational symptoms with an expectation of sympathy or personal gain. It is critical to make every effort to exclude organic diseases, even in cases provisionally diagnosed as psychogenic disease. Despite its low prevalence, PCA should be considered a syndrome caused by Alzheimer's disease, dementia with Lewy bodies, or other dementias.

Functional Connectivity of the Caudate in Schizophrenia Evaluated with Simultaneous Resting-State Functional MRI and Electroencephalography Recordings.

BACKGROUND: Aberrant functional connectivity (FC) is increasingly implicated in the clinical phenomenology of schizophrenia. This study focused on the FC of the cortico-striatal network, which is thought to be disrupted in schizophrenia and to contribute to its clinical manifestations. METHODS: We used simultaneous resting-state functional magnetic resonance imaging (rsfMRI) and electroencephalography (EEG) recordings to investigate FC in patients with schizophrenia. The study included 20 patients with schizophrenia and 20 healthy controls (HCs). Simultaneously recorded rsfMRI and EEG data were collected with an MR-compatible amplifier, and rsfMRI data were analyzed with the CONN toolbox to calculate FC. The study focused on the caudate, which was defined as the seed. We also performed between-group comparisons of standardized low-resolution electromagnetic tomography intracortical lagged coherence for each EEG frequency band. RESULTS: Compared to HCs, patients with schizophrenia showed enhanced FC between the caudate nucleus and the posterior cingulate cortex, temporal, and occipital regions on rsfMRI. It is thus possible that HCs have negative FC between these regions, whereas patients with schizophrenia have non-negative FC. The EEG results showed no significant differences in oscillations or in FC between the groups in any frequency band in any region. CONCLUSIONS: Increased FC in the caudate may represent aberrant between-network FC resulting from the disruption of segregation between networks.

White matter alterations in adult with autism spectrum disorder evaluated using diffusion kurtosis imaging.

PURPOSE: Autism spectrum disorder (ASD) is related to impairment in various white matter (WM) pathways. Utility of the recently developed two-compartment model of diffusion kurtosis imaging (DKI) to analyse axial diffusivity of WM is restricted by several limitations. The present study aims to validate the utility of model-free DKI in the evaluation of WM alterations in ASD and analyse the potential relationship between DKI-evident WM alterations and personality scales. METHODS: Overall, 15 participants with ASD and 15 neurotypical (NT) controls were scanned on a 3 T magnetic resonance (MR) scanner, and scores for autism quotient (AQ), systemising quotient (SQ) and empathising quotient (EQ) were obtained for both groups. Multishell diffusion-weighted MR data were acquired using two b-values (1000 and 2000 s/mm2). Differences in mean kurtosis (MK), radial kurtosis (RK) and axial kurtosis (AK) between the groups were evaluated using tract-based spatial statistics (TBSS). Finally, the relationships between the kurtosis indices and personality quotients were examined. RESULTS: The ASD group demonstrated significantly lower AK in the body and splenium of corpus callosum than the NT group; however, no other significant differences were identified. Negative correlations were found between AK and AQ or SQ, predominantly in WM areas related to social-emotional processing such as uncinate fasciculus, inferior fronto-occipital fasciculus, and inferior and superior longitudinal fasciculi. CONCLUSIONS: Model-free DKI and its indices may represent a novel, objective method for detecting the disease severity and WM alterations in patients with ASD.

The parietal opercular auditory-sensorimotor network in musicians: A resting-state fMRI study.

Auditory-sensorimotor coupling is critical for musical performance, during which auditory and somatosensory feedback signals are used to ensure desired outputs. Previous studies reported opercular activation in subjects performing or listening to music. A functional connectivity analysis suggested the parietal operculum (PO) as a connector hub that links auditory, somatosensory, and motor cortical areas. We therefore examined whether this PO network differs between musicians and non-musicians. We analyzed resting-state PO functional connectivity with Heschl's gyrus (HG), the planum temporale (PT), the precentral gyrus (preCG), and the postcentral gyrus (postCG) in 35 musicians and 35 non-musicians. In musicians, the left PO exhibited increased functional connectivity with the ipsilateral HG, PT, preCG, and postCG, whereas the right PO exhibited enhanced functional connectivity with the contralateral HG, preCG, and postCG and the ipsilateral postCG. Direct functional connectivity between an auditory area (the HG or PT) and a sensorimotor area (the preCG or postCG) did not significantly differ between the groups. The PO's functional connectivity with auditory and sensorimotor areas is enhanced in musicians relative to non-musicians. We propose that the PO network facilitates musical performance by mediating multimodal integration for modulating auditory-sensorimotor control.

Simultaneous resting-state functional MRI and electroencephalography recordings of functional connectivity in patients with schizophrenia.

AIM: It remains unclear how functional connectivity (FC) may be related to specific cognitive domains in neuropsychiatric disorders. Here we used simultaneous resting-state functional magnetic resonance imaging (rsfMRI) and electroencephalography (EEG) recording in patients with schizophrenia, to evaluate FC within and outside the default mode network (DMN). METHODS: Our study population included 14 patients with schizophrenia and 15 healthy control participants. From all participants, we acquired rsfMRI data, and simultaneously recorded EEG data using an MR-compatible amplifier. We analyzed the rsfMRI-EEG data, and used the CONN toolbox to calculate the FC between regions of interest. We also performed between-group comparisons of standardized low-resolution electromagnetic tomography-based intracortical lagged coherence for each EEG frequency band. RESULTS: FC within the DMN, as measured by rsfMRI and EEG, did not significantly differ between groups. Analysis of rsfMRI data showed that FC between the right posterior inferior temporal gyrus and medial prefrontal cortex was stronger among patients with schizophrenia compared to control participants. CONCLUSION: Analysis of FC within the DMN using rsfMRI and EEG data revealed no significant differences between patients with schizophrenia and control participants. However, rsfMRI data revealed over-modulated FC between the medial prefrontal cortex and right posterior inferior temporal gyrus in patients with schizophrenia compared to control participants, suggesting that the patients had altered FC, with higher correlations across nodes within and outside of the DMN. Further studies using simultaneous rsfMRI and EEG are required to determine whether altered FC within the DMN is associated with schizophrenia.

Serum prolactin levels and sexual dysfunction in patients with schizophrenia treated with antipsychotics: comparison between aripiprazole and other atypical antipsychotics.

OBJECTIVES: Antipsychotics, even atypical ones, can induce hyperprolactinemia. Aripiprazole (APZ), a dopamine D2 partial agonist, has a unique pharmacological profile and few side effects. We investigated the incidence of hyperprolactinemia in patients with schizophrenia treated with APZ and other antipsychotics. METHODS: Serum prolactin levels were measured by ELISA (enzyme-linked immunosorbent assay). A questionnaire survey was used to evaluate subjective sexual dysfunction. RESULTS: Based on the results of the questionnaire, approximately half (48.1%) of the patients complained of sexual dysfunction. The serum prolactin levels were significantly higher in patients with sexual dysfunction than in those without. In patients treated with antipsychotic monotherapy, the serum prolactin levels were significantly lower in patients treated with APZ than with other antipsychotics. In patients receiving 2 or more antipsychotics, the serum prolactin levels were significantly lower in patients treated with APZ-containing regimens than in patients treated with APZ-free regimens. CONCLUSIONS: Treatment with APZ did not influence the serum prolactin level, and adjunctive treatment with APZ may ameliorate the hyperprolactinemia that occurs during monotherapy with other antipsychotics.

Use of aripiprazole for delirium in the elderly: a short review.

The effects and tolerability of antipsychotics in delirium treatment remain controversial. Compared to other antipsychotics, aripiprazole differs in pharmacological activity because it exerts its effect as a dopamine D2 partial agonist. The guidelines of the American Psychiatric Association rank aripiprazole highly among antipsychotics with regard to safety, and this drug is likely to be useful for delirium treatment. Here, we reviewed the efficacy and safety of aripiprazole for delirium. The results of our literature review on the efficacy and safety of delirium treatments suggest that aripiprazole is an effective treatment option for delirium in the elderly. Aripiprazole is as effective as other antipsychotics in improving delirium symptoms, and it is safer because it is less likely to cause extrapyramidal symptoms, excessive sedation, and weight gain. However, these findings are based on only a few clinical studies of elderly patients with delirium. Therefore, further investigations are necessary.