Structural and resting-state connection abnormalities of habenula in obsessive-compulsive disorder.

BACKGROUND: Previous studies have suggested that the habenula (Hb) may be involved in the mechanism of obsessive-compulsive disorder (OCD). However, the specific role of Hb in OCD remains unclear. This study aimed to explore the structural and functional abnormalities of Hb in OCD and their relationship with the clinical symptoms. METHODS: Eighty patients with OCD and 85 healthy controls (HCs) were recruited as the primary dataset. The grey matter volume, resting-state functional connectivity (FC), and effective connectivity (EC) of the Hb were calculated and compared between OCD group and HCs. An independent replication dataset was used to verify the stability and robustness of the results. RESULTS: Patients with OCD exhibited smaller Hb volume and increased FC of right Hb-left hippocampus than HCs. Dynamic causal model revealed an increased EC from left hippocampus to right Hb and a less inhibitory causal influence from the right Hb to left hippocampus in the OCD group compared to HCs. Similar results were found in the replication dataset. CONCLUSIONS: This study suggested that abnormal structure of Hb and hippocampus-Hb connectivity may contribute to the pathological basis of OCD.

Altered functional-structural coupling may predict Parkinson's patient's depression.

We aimed to elucidate the neurobiological basis of depression in Parkinson's disease and identify potential imaging markers for depression in patients with Parkinson's disease. We recruited 43 normal controls (NC), 46 depressed Parkinson's disease patients (DPD) and 56 non-depressed Parkinson's disease (NDPD). All participants underwent routine T2-weighted, T2Flair, and resting-state scans on the same 3.0 T magnetic resonance imaging (MRI) scanner at our hospital. Pre-processing includes calculating surface-based Regional Homogeneity (2DReHo) and cortical thickness. Then we defined the correlation coefficient between 2DReHo and cortical thickness as the functional-structural coupling index. Between-group comparisons were conducted on the Fisher's Z-transformed correlation coefficients. To identify specific regions of decoupling, the 2DReHo for each participant were divided by cortical thickness at each vertex, followed by threshold-free cluster enhancement (TFCE) multiple comparison correction. Binary logistic regression analysis was performed with DPD as the dependent variable, and significantly altered indicators as the independent variables. Receiver operating characteristic curves were constructed to compare the diagnostic performance of individual predictors and combinations using R and MedCalc software. DPD patients exhibited a significantly lower whole-brain functional-structural coupling index than NDPD patients and NC. Abnormal functional-structural coupling was primarily observed in the left inferior parietal lobule and right primary and early visual cortices in DPD patients. Receiver operating characteristic analysis revealed that the combination of cortical functional-structural coupling, surface-based ReHo, and thickness had the best diagnostic performance, achieving a sensitivity of 65% and specificity of 77.7%. This is the first study to explore the relationship between functional and structural changes in DPD patients and evaluate the diagnostic performance of these altered correlations to predict depression in Parkinson's disease patients. We posit that these changes in functional-structural relationships may serve as imaging biomarkers for depression in Parkinson's disease patients, potentially aiding in the classification and diagnosis of Parkinson's disease. Additionally, our findings provide functional and structural imaging evidence for exploring the neurobiological basis of depression in Parkinson's disease.

Alterations in cortical volume and complexity in Parkinson's disease with depression.

AIMS: The aim of this study is to investigate differences in gray matter volume and cortical complexity between Parkinson's disease with depression (PDD) patients and Parkinson's disease without depression (PDND) patients. METHODS: A total of 41 PDND patients, 36 PDD patients, and 38 healthy controls (HC) were recruited and analyzed by Voxel-based morphometry (VBM) and surface-based morphometry (SBM). Differences in gray matter volume and cortical complexity were compared using the one-way analysis of variance (ANOVA) and correlated with the Hamilton Depression Scale-17 (HAMD-17) scores. RESULTS: PDD patients exhibited significant cortical atrophy in various regions, including bilateral medial parietal-occipital-temporal lobes, right dorsolateral temporal lobes, bilateral parahippocampal gyrus, and bilateral hippocampus, compared to HC and PDND groups. A negative correlation between the GMV of left precuneus and HAMD-17 scores in the PDD group tended to be significant (r = -0.318, p = 0.059). Decreased gyrification index was observed in the bilateral insular and dorsolateral temporal cortex. However, there were no significant differences found in fractal dimension and sulcal depth. CONCLUSION: Our research shows extensive cortical structural changes in the insular cortex, parietal-occipital-temporal lobes, and hippocampal regions in PDD. This provides a morphological perspective for understanding the pathophysiological mechanism underlying depression in Parkinson's disease.

Cortical gyrification pattern of depression in Parkinson's disease: a neuroimaging marker for disease severity?

Background: Although the study of the neuroanatomical correlates of depression in Parkinson's Disease (PD) is gaining increasing interest, up to now the cortical gyrification pattern of PD-related depression has not been reported. This study was conducted to investigate the local gyrification index (LGI) in PD patients with depression, and its associations with the severity of depression. Methods: LGI values, as measured using FreeSurfer software, were compared between 59 depressed PD (dPD), 27 non-depressed PD (ndPD) patients and 43 healthy controls. The values were also compared between ndPD and mild-depressed PD (mi-dPD), moderate-depressed PD (mo-dPD) and severe-depressed PD (se-dPD) patients as sub-group analyses. Furthermore, we evaluated the correlation between LGI values and depressive symptom scores within dPD group. Results: Compared to ndPD, the dPD patients exhibited decreased LGI in the left parietal, the right superior-frontal, posterior cingulate and paracentral regions, and the LGI values within these areas negatively correlated with the severity of depression. Specially, reduced gyrification was observed in mo-dPD and involving a larger region in se-dPD, but not in mi-dPD group. Conclusion: The present study demonstrated that cortical gyrification is decreased within specific brain regions among PD patients with versus without depression, and those changes were associated with the severity of depression. Our findings suggested that cortical gyrification might be a potential neuroimaging marker for the severity of depression in patients with PD.

Distinct changes in global brain synchronization in different motor subtypes of Parkinson's disease.

This study investigated alterations in degree centrality (DC) in different motor subtypes of Parkinson's disease (PD) and analyzed its clinical significance during disease occurrence. A total of 146 subjects were recruited in the study, including 90 patients with PD [51 and 39 with tremor dominant (TD) and akinetic-rigid dominant (ARD) disease, respectively] and 56 healthy controls (HCs). The resting-state functional magnetic resonance imaging data of all the subjects were obtained by 3.0 T magnetic resonance scans. The DC values, an indicator of whole brain synchronization, were calculated and compared among the TD, ARD, and HC groups. Disparities in DC values among the three groups were evaluated by analysis of variance and post hoc two-sample t-tests. Correlation between brain regions with DC differences and clinical variables were performed using partial correlation analysis after controlling for age, gender, and disease duration. Compared to the HCs, both TD and ARD groups demonstrated increased DC values bilaterally in the cerebellum; DC values were decreased in the left putamen and paracentral lobule in the TD group and in the left anterior cingulate gyrus and right supplementary motor area in the ARD group. Compared to the ARD group, the TD group showed decreased DC values in bilateral cerebellar hemispheres and increased DC values in the left anterior cingulate gyrus and right supplementary motor area. The DC of the whole brain showed inconsistencies and shared neural bases among patients with the two subtypes of PD. The differences between brain regions with abnormal DC values may be closely related to different clinical presentations of the two motor subtypes. Our findings provide new insights into the clinical heterogeneity of PD with respect to different motor subtypes.

Surface-Based Functional Alterations in Early-Onset and Late-Onset Parkinson's Disease: A Multi-Modal MRI Study.

This study used a surface-based method to investigate brain functional alteration patterns in early-onset Parkinson's disease (EOPD) and late-onset Parkinson's disease (LOPD) to provide more reliable imaging indicators for the assessment of the two subtypes. A total of 58 patients with Parkinson's disease were divided into two groups according to age at onset: EOPD (≤50 years; 16 males and 15 females) and LOPD (>50 years; 17 males and 10 females) groups. Two control groups were recruited from the community: young adults (YC; ≤50 years; 8 males and 19 females) and older adults (OC; >50 years; 12 males and 10 females). No significant differences were observed between the EOPD and YC groups or the LOPD and OC groups in terms of age, sex, education, and MMSE scores (p > 0.05). No statistically significant differences were observed between the EOPD and LOPD groups in terms of education, H-Y scale, UPDRS score, or HAMD score (p > 0.05). Data preprocessing and surface-based regional homogeneity (2D-ReHo) calculations were subsequently performed using the MATLAB-based DPABIsurf software. The EOPD group showed decreased 2D-ReHo values in the left premotor area and right dorsal stream visual cortex, along with increased 2D-ReHo values in the left dorsolateral prefrontal cortex. In patients with LOPD, 2D-ReHo values were decreased in bilateral somatosensory and motor areas and the right paracentral lobular and mid-cingulate. The imaging characterization of surface-based regional changes may serve useful as monitoring indicators and will help to better understand the mechanisms underlying divergent clinical presentations.

Neural functional network of early Parkinson's disease based on independent component analysis.

This work explored neural network changes in early Parkinson's disease: Resting-state functional magnetic resonance imaging was used to investigate functional alterations in different stages of Parkinson's disease (PD). Ninety-five PD patients (50 early/mild and 45 early/moderate) and 37 healthy controls (HCs) were included. Independent component analysis revealed significant differences in intra-network connectivity, specifically in the default mode network (DMN) and right frontoparietal network (RFPN), in both PD groups compared to HCs. Inter-network connectivity analysis showed reduced connectivity between the executive control network (ECN) and DMN, as well as ECN-left frontoparietal network (LFPN), in early/mild PD. Early/moderate PD exhibited decreased connectivity in ECN-LFPN, ECN-RFPN, ECN-DMN, and DMN-auditory network, along with increased connectivity in LFPN-cerebellar network. Correlations were found between ECN-DMN and ECN-LFPN connections with UPDRS-III scores in early/mild PD. These findings suggest that PD progression involves dysfunction in multiple intra- and inter-networks, particularly implicating the ECN, and a wider range of abnormal functional networks may mark the progression of the disease.

Neural substrates for dissociation of cognition inhibition in autogenous- and reactive-type obsessive-compulsive disorder.

BACKGROUND: The taxonomy of autogenous- and reactive-type obsessive-compulsive disorder (OCD) (AO vs. RO) is one of the most valid subtyping approaches to the heterogeneity of OCD. The present study aimed to seek evidence of neural substrates supporting the dissociation of cognition inhibition in AO and RO which was revealed by our previous behavioral and electrophysiological work. METHODS: A total of 165 patients with OCD (86 AO versus 79 RO), and 79 healthy controls (HC) underwent resting-state functional magnetic resonance imaging scans. Within-network connectivity, node strength, and edge-wise functional connectivity (FC) in cognition and response inhibition networks were calculated. Results from 3 cognition and 2 response inhibition network atlases were compared to confirm the robustness of the findings. RESULTS: Both AO and RO showed lower within-network connectivity in response inhibition networks, while lower within cognition inhibition network connectivity was only detected in AO. Besides shared weaker node strength in the anterior insula (AI), anterior cingulate cortex (ACC), and supplementary motor area (SMA), AO had a broader range of nodes within cognition inhibition networks exhibiting weaker strength, including nodes in right inferior frontal gyrus (IFG), left parietal and occipital regions. Decreased FC of left AI-CC, left IFG-ACC, and frontal-parietal regions in cognition inhibition networks were found in AO. CONCLUSIONS: Findings indicate that unlike deficits in connectivity within response inhibition networks which may reflect a common pathology in AO and RO, deficits in connectivity within cognition inhibition networks were more pronounced in AO. These findings strengthen our insight into the heterogeneity in OCD.

Altered intrinsic functional network connectivity is associated with impulsivity and emotion dysregulation in drug-naïve young patients with borderline personality disorder.

BACKGROUND: Despite impulse control and emotion regulation being altered in borderline personality disorder (BPD), the specific mechanism of these clinical features remains unclear. This study investigated the functional connectivity (FC) abnormalities within- and between- default mode network (DMN), salience network (SN), and central executive network (CEN) in BPD, and examined the association between aberrant FC and clinical features. We aimed to explore whether the abnormal large-scale networks underlie the pathophysiology of impulsivity and emotion dysregulation in BPD. METHODS: Forty-one young, drug-naïve patients with BPD (24.98 ± 3.12 years, 20 males) and 42 healthy controls (HCs; 24.74 ± 1.29 years, 17 males) were included in resting-state functional magnetic resonance imaging analyses. Independent component analysis was performed to extract subnetworks of the DMN, CEN, and SN. Additionally, partial correlation was performed to explore the association between brain imaging variables and clinical features in BPD. RESULTS: Compared with HCs, BPD showed significant decreased intra-network FC of right medial prefrontal cortex in the anterior DMN and of right angular gyrus in the right CEN. Intra-network FC of right angular gyrus in the anterior DMN was significantly negatively correlated with attention impulsivity in BPD. The patients also showed decreased inter-network FC between the posterior DMN and left CEN, which was significantly negatively correlated with emotion dysregulation. CONCLUSION: These findings suggest that impaired intra-network FC may underlie the neurophysiological mechanism of impulsivity, and abnormal inter-network FC may elucidate the neurophysiological mechanism of emotion dysregulation in BPD.

Disrupted functional connectivity of the cerebellum with default mode and frontoparietal networks in young adults with major depressive disorder.

Cerebellar dysconnectivity has repeatedly been documented in major depressive disorder (MDD). The cerebellum is composed of multiple functionally distinct subunits, and whether those subunits show similar or distinct dysconnectivity patterns with the cerebrum in MDD, is still unclear and needs to be further clarified. In this study, 91 MDD patients (23 male and 68 female) and 59 demographically matched healthy controls (22 male and 37 female) were enrolled to explore the cerebellar-cerebral dysconnectivity pattern in MDD by using the cutting-edge cerebellar partition atlas. Results showed that MDD patients exhibit decreased cerebellar connectivity with cerebral regions of default mode (DMN), frontoparietal networks (FPN), and visual areas. The dysconnectivity pattern was statistically similar across cerebellar subunits, with no significant diagnosis-by-subunit interactions. Correlation analyzes showed that cerebellar-dorsal lateral prefrontal cortex (DLPFC) connectivity is significantly correlated with anhedonia in MDD patients. Such dysconnectivity pattern was not affected by sex, which, however, should be further replicated in larger samples. These findings suggest a generalized disrupted cerebellar-cerebral connectivity pattern in MDD across all cerebellar subunits, which partially accounts for depressive symptoms in MDD, thus highlighting the pivotal role of the disrupted connectivity of cerebellum with DMN and FPN in the neuropathology of depression.

Abnormal intra- and inter-network functional connectivity of brain networks in early-onset Parkinson's disease and late-onset Parkinson's disease.

Objective: The purpose of this study is to look into the altered functional connectivity of brain networks in Early-Onset Parkinson's Disease (EOPD) and Late-Onset Parkinson's Disease (LOPD), as well as their relationship to clinical symptoms. Methods: A total of 50 patients with Parkinson' disease (28 EOPD and 22 LOPD) and 49 healthy controls (25 Young Controls and 24 Old Controls) were admitted to our study. Employing independent component analysis, we constructed the brain networks of EOPD and Young Controls, LOPD and Old Controls, respectively, and obtained the functional connectivity alterations in brain networks. Results: Cerebellar network (CN), Sensorimotor Network (SMN), Executive Control Network (ECN), and Default Mode Network (DMN) were selected as networks of interest. Compared with their corresponding health controls, EOPD showed increased functional connectivity within the SMN and ECN and no abnormalities of inter-network functional connectivity were found, LOPD demonstrated increased functional connectivity within the ECN while decreased functional connectivity within the CN. Furthermore, in LOPD, functional connectivity between the SMN and DMN was increased. The functional connectivity of the post-central gyrus within the SMN in EOPD was inversely correlated with the Unified Parkinson's Disease Rating Scale Part III scores. Age, age of onset, and MMSE scores are significantly different between EOPD and LOPD (p < 0.05). Conclusion: There is abnormal functional connectivity of networks in EOPD and LOPD, which could be the manifestation of the associated pathological damage or compensation.

Right amygdala-right precuneus connectivity is associated with childhood trauma in major depression patients and healthy controls.

The present study investigated the effect of childhood trauma (CT) on amygdala and hippocampus functional connectivity (FC) and the association with clinical presentations of major depressive disorder (MDD). Participants included 73 MDD patients (42 with moderate-to-severe CT and 31 with no or low CT) and 64 healthy controls (HC; 30 with moderate-to-severe CT and 34 with no or low CT). Seed-based whole-brain resting-state FC analyses were performed with seeds located in amygdala and hippocampus. Individuals with moderate-to-severe CT, irrespective of MDD diagnosis, had decreased right amygdala-right precuneus connectivity compared to those with no or low CT. Right amygdala-right precuneus connectivity was significantly correlated with physical and social trait anhedonia in MDD. Mediation effects of this FC on relationship between CT (specifically neglect but not abuse) and trait anhedonia in MDD were significant. MDD patients demonstrated increased right amygdala-left middle frontal gyrus FC, decreased right amygdala-right medial superior frontal gyrus (mSFG) FC and decreased right hippocampus-bilateral mSFG FC relative to HC. Findings highlight the effect of CT on right amygdala-right precuneus FC irrespective of MDD diagnosis. FC of right amygdala-right precuneus may be involved in the mechanism linking CT and depression through its association with trait anhedonia.

Correlates of poor insight: A comparative fMRI and sMRI study in obsessive-compulsive disorder and schizo-obsessive disorder.

BACKGROUND: Despite the several researches on the correlates of insight in psychosis, less is known regarding the specificity of disease diagnosis on the relationship between insight and the correlates. The current study sought to explore the effects of insight and disease diagnosis on those in patients with obsessive-compulsive disorder (OCD) and patients with schizo-obsessive disorder (SOD). METHODS: We evaluated clinical symptoms and neurocognitions among 111 patients (including 41 OCD with good insight, 40 OCD with poor insight, 14 SOD with good insight and 16 SOD with poor insight. Gray matter volume and spontaneous neural activity were also examined by analyzing the voxel-based morphometry and amplitude of low frequency fluctuation (ALFF), respectively. RESULTS: Interactive effects of insight and diagnosis was found on working memory and the gray matter volume in right superior and middle temporal gyrus. Main effect of insight was found on working and visual memory, compulsion and obsession, and ALFF in right middle and superior occipital cortex. Main effect of diagnosis was found on severity of compulsion, relative verbal IQ, executive function, verbal and visual memory, working memory and ALFF in precuneus, medial superior frontal gyrus, anterior cingulate and paracingulate gyri, and inferior parietal, postcentral gyrus, paracentral lobule. CONCLUSIONS: As a common feature in mental disorders, insight has its own special influence on neurocognition and possible structural/functional alterations in brain, and the influence is partly dependent of disease diagnosis.

Resting-state brain network in Parkinson's disease with different degrees of depression.

Objective: The aim of this study is to explore the neural network mechanism of Parkinson's disease (PD) with different degrees of depression using independent component analysis (ICA) of the functional connectivity changes in the forehead, limbic system, and basal ganglia regions. Methods: A total of 106 patients with PD were divided into three groups: PD with moderate-severe depression (PDMSD, n = 42), PD with mild depression (PDMD, n = 29), and PD without depression (PDND, n = 35). Fifty gender- and age-matched healthy subjects were recruited as a control group (HC). Three-dimensional T1-weighted image and resting-state functional magnetic resonance imaging (RS-fMRI) data were collected. Results: Different functional connectivity was observed in the left precentral gyrus, right precuneus, right inferior frontal gyrus, right medial and paracingulate gyrus, left supplementary motor area, right brain insula, and the inferior frontal gyrus of the left orbit among the four groups (ANOVA, P < 0.05, Voxel size > 5). Both PDMD and PDMSD exhibited increased functional connectivity in the superior-posterior default-mode network (spDMN) and left frontoparietal network (LFPN); they also exhibited a decreased functional connectivity in the interior Salience Network (inSN) when compared with the PDND group. The functional connectivity within the inSN network was decreased in the PDMSD group when compared with the PDMD group (Alphasim correction, P < 0.05, voxel size > 5). Conclusion: PD with different degrees of depression has abnormal functional connectivity in multiple networks, which is an important neurobiological basis for the occurrence and development of depression in PD. The degree of decreased functional connectivity in the inSN network is related to the degree of depression in patients with PD-D, which can be an imaging marker for PD to judge the severity of depression.

Associated factors and abnormal dorsal raphe nucleus connectivity patterns of freezing of gait in Parkinson's disease.

BACKGROUND: Freezing of gait (FOG) is a common, disabling symptom of Parkinson's disease (PD), and its exact pathophysiological mechanism is still poorly understood. The control of gait is a complex process that may be influenced by emotions modulated by serotonergic networks. Therefore, this study aimed to determine factors associated with FOG in PD patients and to evaluate the importance of the dorsal raphe nucleus (DRN; central node in the serotoninergic system) in FOG pathophysiology. METHODS: We combined cross-sectional survey data from 453 PD patients. According to the Freezing of Gait Questionnaire (FOGQ), patients were divided into two groups: the "PD with frozen gait (PD-FOG)" and "PD without frozen gait (PD-nFOG)" groups. Demographic characteristics, clinical features, and motor and nonmotor symptoms (NMS) assessments of PD patients were recorded. Univariate statistical analysis was performed between the two groups, and then regression analysis was performed on related factors. We also acquired resting-state functional MRI (rs-fMRI) data from 20 PD-FOG, 21 PD-nFOG, and 22 healthy controls (HCs) who were randomly chosen. We defined seeds in the DRN to evaluate functional connectivity (FC) patterns. RESULTS: The overall frequency of FOG was 11.9% patients in the PD-FOG group were older, had a longer disease duration, had a higher levodopa equivalent daily dose, had more severe motor symptoms and worse quality of life, had a higher proportion of dyskinesia, wearing-off and postural instability/gait difficulty (PIGD) clinical phenotype, and experienced more depression and impaired sleep function than those in the PD-nFOG group. Logistic regression analysis showed that H&Ystage ≥ 3, UPDRS-III scores, PIGD clinical phenotype and excessive daytime sleepiness were associated with FOG. In addition, there was significantly lower FC between the DRN and some cortical structures, including the supplementary motor area (SMA), left superior frontal gyrus (SFG), and left median cingulated cortex (MCC) in PD-FOG patients than HCs and PD-nFOG patients. CONCLUSIONS: These results demonstrate that the severity of PD and PIGD clinical phenotype are associated factors for freezing and that DRN dysfunction may play a key role in PD-related NMS and FOG. An abnormal cortical and brainstem networks may contribute to the mechanisms underlying FOG.

Decreased functional coupling within default mode network in major depressive disorder with childhood trauma.

OBJECTIVE: Childhood trauma (CT) has been supported to be a high-risk factor for major depressive disorder (MDD), but the neural mechanism linking CT and depression remains unclear. The aim of this study is to deepen our understanding of this issue by establishing the neuroimaging correlations between CT and depression. METHODS: A sample of 123 MDD patients (91 with moderate-to-severe CT and 32 with no or low CT) and 79 healthy controls (HC, 33 with moderate-to-severe CT and 46 with no or low CT) participated. All participants completed assessments of depression level, anxiety, recent perceived stress, and resting-state functional MRI scan. RESULTS: Participants with moderate-to-severe CT showed elevated depression level and trait anxiety, and reduced spontaneous neural activity in left inferior temporal gyrus (ITG). Abnormalities of seed-based functional connectivity (FC) of left ITG - bilateral precuneus/posterior cingulate cortex (PCC), left middle temporal gyrus (MTG), left medial orbitofrontal cortex (mOFC), and bilateral medial prefrontal cortex (mPFC)/anterior cingulate cortex (ACC) were observed. CT was associated with decreased FCs in MDD, but with increased FCs in HC. The total altered FCs of left ITG - bilateral precuneus/PCC and left mOFC mediated relationship between CT and depression in MDD, and total altered FCs and trait anxiety have a significant chain mediation effect in the association between CT and depression in HC. CONCLUSION: These findings highlight the changes of default mode network (DMN) functions and trait anxiety as targets of CT. The decreased functional coupling within DMN may be involved in the mechanism of MDD following CT.

Childhood trauma is associated with social anhedonia and brain gray matter volume differences in healthy subjects.

The present study tested the effects of childhood trauma (CT) on trait social anhedonia (SA) and on gray matter volume (GMV) and explored the possible relationships among CT, SA and brain GMV. Forty-three healthy individuals with experience of moderate-to-severe CT and sixty-eight individuals with no or low CT participated in the present study. Trait SA was evaluated using the Revised Social Anhedonia Scale. GMV was measured using voxel-based morphometry. Participants with moderate-to-severe CT had elevated trait SA, as well as brain volumetric differences in left inferior parietal lobule (IPL), left precuneus, right insula, left superior temporal gyrus, and left middle occipital gyrus extending into middle temporal gyrus relative to participants with no or low level of CT. CT was also found to be positively correlated with GMV in right dorsolateral prefrontal cortex (DLPFC) and bilateral precuneus. Partial mediation effect of GMV in left IPL and right DLPFC on the relationship between CT and trait SA was significant. These findings suggest that CT may have effects on trait SA and on GMV of widespread brain regions. GMV differences in DLPFC and left IPL may mediate the effect of CT on trait SA, although this needs to be verified by future longitudinal studies.

Abnormalities in the Fractional Amplitude of Low-Frequency Fluctuation and Functional Connectivity in Parkinson's Disease With Excessive Daytime Sleepiness.

Background: Excessive daytime sleepiness (EDS) is one of the most important non-motor symptoms of Parkinson's disease (PD), and its neuropathologic basis is still unclear. Objective: This study investigated the changes of neuronal activity in PD patients with EDS (PD-EDS) in the resting state. Methods: Forty-three PD patients were recruited and divided into the PD-EDS group (n = 21) and PD-NEDS group (PD patients without excessive daytime sleepiness, n = 22) according to the Epworth sleepiness scale (ESS) scores. Patients in both groups received resting-state functional magnetic resonance imaging (rs-fMRI). The differences in fractional amplitude of low-frequency fluctuation (fALFF) between the two groups, correlations between fALFF and ESS, and functional connection (FC) between the brain regions with different fALFF values and the whole brain were analyzed. Results: PD-EDS patients exhibited a decreased fALFF in the Cingulum-Ant-R, but an increased fALFF in the Putamen-R and Thalamus-L when compared with PD-NEDS patients; an increased functional connectivity between these three seed regions with different fALFF values and the right medial frontal gyrus, bilateral superior temporal gyrus, left insular, and right precuneus was observed (p < 0.05), but a deceased functional connectivity between these three seed regions and the right cerebellum anterior lobe/right brainstem, right middle temporal gyrus and inferior temporal gyrus, right hippocampus/parahippocampal gyrus, right medial cingulate gyrus and bilateral middle occipital gyrus was observed (p < 0.05). The value of fALFF was negatively correlated with the ESS score in the Cingulum-Ant-R, but positively correlated with the ESS score in the Putamen-R and Thalamus-L. Conclusions: EDS in PD patients may be associated with changes in brain neuron activity and functional connectivity.

Spontaneous neural activity in the right fusiform gyrus and putamen is associated with consummatory anhedonia in obsessive compulsive disorder.

BACKGROUND: Accumulating evidence indicated that anhedonia as a transdiagnostic construct might be an inherent feature of obsessive-compulsive disorder(OCD). Moreover, our recent study demonstrated that OCD patients exhibited consummatory anhedonia but not anticipatory anhedonia. However, neural mechanisms of consummatory anhedonia in OCD has not been explored. This study aimed to investigate this issue using resting-state functional magnetic resonance imaging (fMRI). METHODS: 44 OCD patients with high consummatory anhedonia(OCD-HCA), 41 OCD patients with low consummatory anhedonia(OCD-LCA) and 47 healthy controls (HC) underwent fMRI scan. Spontaneous neural activity was analyzed and compared among the three groups by adopting the amplitude of low-frequency fluctuation (ALFF). Relationships between the consummatory anhedonia levels and regional ALFFs were examined in OCD patients. RESULTS: Compared with HC, OCD-HCA showed decreased ALFF in the right putamen and right thalamus, and OCD-LCA showed increased ALFF in the right orbitofrontal cortex and decreased ALFF in the right fusiform gyrus, left Precentral/postcentral gyrus. Notably, ALFF values differed between the two patient groups in the right putamen (OCD-HCA < OCD-LCA), and right fusiform gyrus (OCD-HCA > OCD-LCA). Further analysis revealed that the consummatory anhedonia was positively correlated with ALFF values in the right fusiform, and negatively correlated with ALFFs in the right putamen. CONCLUSIONS: Spontaneous neural activity in right fusiform gyrus and right putamen is associated with consummatory anhedonia in OCD. The findings provided first insights into neural mechanism of consummatory anhedonia in OCD and confirmed the importance of exploring the transdiagnostic role of anhedonia.