Changes in regional homogeneity of parieto-temporal regions in panic disorder patients who achieved remission with antidepressant treatment

Enhanced interhemispheric resting-state functional connectivity of the visual network is an early treatment response of paroxetine in patients with panic disorder

This study aimed to detect alterations in interhemispheric interactions in patients with panic disorder (PD), determine whether such alterations could serve as biomarkers for the diagnosis and prediction of therapeutic outcomes, and map dynamic changes in interhemispheric interactions in patients with PD after treatment. Fifty-four patients with PD and 54 healthy controls (HCs) were enrolled in this study. All participants underwent clinical assessment and a resting-state functional magnetic resonance imaging scan at (i) baseline and (ii) after paroxetine treatment for 4 weeks. A voxel-mirrored homotopic connectivity (VMHC) indicator, support vector machine (SVM), and support vector regression (SVR) were used in this study. Patients with PD showed reduced VMHC in the fusiform, middle temporal/occipital, and postcentral/precentral gyri, relative to those of HCs. After treatment, the patients exhibited enhanced VMHC in the lingual gyrus, relative to the baseline data. The VMHC of the fusiform and postcentral/precentral gyri contributed most to the classification (accuracy = 87.04%). The predicted changes were accessed from the SVR using the aberrant VMHC as features. Positive correlations (p < 0.001) were indicated between the actual and predicted changes in the severity of anxiety. These findings suggest that impaired interhemispheric coordination in the cognitive-sensory network characterized PD and that VMHC can serve as biomarkers and predictors of the efficiency of PD treatment. Enhanced VMHC in the lingual gyrus of patients with PD after treatment implied that pharmacotherapy recruited the visual network in the early stages.

Breaking the Fear Barrier: Aberrant Activity of Fear Networks as a Prognostic Biomarker in Patients with Panic Disorder Normalized by Pharmacotherapy

Panic disorder (PD) is a prevalent type of anxiety disorder. Previous studies have reported abnormal brain activity in the fear network of patients with PD. Nonetheless, it remains uncertain whether pharmacotherapy can effectively normalize these abnormalities. This longitudinal resting-state functional magnetic resonance imaging study aimed to investigate the spontaneous neural activity in patients with PD and its changes after pharmacotherapy, with a focus on determining whether it could predict treatment response. The study included 54 drug-naive patients with PD and 54 healthy controls (HCs). Spontaneous neural activity was measured using regional homogeneity (ReHo). Additionally, support vector regression (SVR) was employed to predict treatment response from ReHo. At baseline, PD patients had aberrant ReHo in the fear network compared to HCs. After 4 weeks of paroxetine treatment (20 mg/day), a significant increase in ReHo was observed in the left fusiform gyrus, which had shown reduced ReHo before treatment. The SVR analysis showed significantly positive correlations (p < 0.0001) between the predicted and actual reduction rates of the severity of anxiety and depressive symptoms. Here, we show patients with PD had abnormal spontaneous neural activities in the fear networks. Furthermore, these abnormal spontaneous neural activities can be partially normalized by pharmacotherapy and serve as candidate predictors of treatment response. Gaining insight into the trajectories of brain activity normalization following treatment holds the potential to provide vital insights for managing PD.

Can the aberrant occipital-cerebellum network be a predictor of treatment in panic disorder?

BACKGROUND

This study aimed to detect altered brain activation pattern of patients with panic disorder (PD) and its changes after treatment. The possibilities of diagnosis and prediction of treatment response based on the aberrant brain activity were tested.

METHODS

Fifty-four PD patients and 54 healthy controls (HCs) were recruited. Clinical assessment and resting-state functional magnetic resonance imaging scans were conducted. Then, patients received a 4-week paroxetine treatment and underwent a second clinical assessment and scan. The fractional amplitude of low-frequency fluctuations (fALFF) was measured. Support vector machine (SVM) and support vector regression (SVR) analyses were conducted.

RESULTS

Lower fALFF values in the right calcarine/lingual gyrus and left lingual gyrus/cerebellum IV/V, whereas higher fALFF values in right cerebellum Crus II were observed in patients related to HCs at baseline. After treatment, patients with PD exhibited significant clinical improvement, and the abnormal lower fALFF values in the right lingual gyrus exhibited a great increase. The abnormal fALFF at pretreatment can distinguish patients from HCs with 80 % accuracy and predict treatment response which was reflected in the significant correlation between the predicted and actual treatment responses.

LIMITATIONS

The impacts of ethnic, cultural, and other regional differences on PD were not considered for it was a single-center study.

CONCLUSIONS

The occipital-cerebellum network played an important role in the pathophysiology of PD and should be a part of the fear network. The abnormal fALFF values in patients with PD at pretreatment could serve as biomarkers of PD and predict the early treatment response of paroxetine.

Alterations in local activity and functional connectivity in patients with postherpetic neuralgia after short-term spinal cord stimulation

Introduction

The efficacy of short-term spinal cord stimulation (stSCS) as a treatment for neuropathic pain in patients with postherpetic neuralgia (PHN) has already been validated. However, the potential alterations in brain functionality that are induced by such treatment have yet to be completely elucidated.

Methods

This study use resting-state functional magnetic resonance imaging (rs-fMRI) to detect the changes in regional homogeneity (ReHo) and degree centrality (DC) related to stimulator-induced pain relief in patients with PHN. A total of 10 patients with PHN underwent an MRI protocol at baseline and after stSCS. Alterations in ReHo and DC were then compared between baseline and after stSCS. We investigated the relationship between clinical parameters and functional changes in the brain.

Results

Clinical parameters on pain, emotion, and sleep quality were correlated with ReHo and DC. ReHo and DC were significantly altered in the middle temporal gyrus, precuneus, superior frontal gyrus, supramarginal gyrus, inferior parietal lobule, rolandic operculum, middle occipital gyrus, superior parietal gyrus, and the precentral gyrus after stSCS. A significant correlation was detected between ReHo changes in the middle occipital gyrus, precuneus, inferior parietal gyrus, and changes in pain, emotion, and sleep quality. A significant negative correlation was detected between DC changes in the middle temporal gyrus, rolandic operculum, supramarginal gyrus, precuneus, inferior parietal gyrus, and changes in pain, emotion, and sleep quality.

Conclusion

This study found that stSCS is able to induce ReHo and DC changes in patients with PHN, thus suggesting that stSCS can change brain function to alleviate pain, sleep, and emotional disorder.

Alterations of regional spontaneous brain activities in anxiety disorders: A meta-analysis

BACKGROUND

Recent resting-state functional magnetic resonance imaging studies have provided strong evidence of abnormal regional spontaneous brain activities among anxiety-disordered patients. However, the evidence has been divergent and inconclusive. Therefore, it is necessary to perform a meta-analysis identifying a common pattern of altered regional spontaneous brain activity for anxiety disorders.

METHOD

Corresponding research of anxiety disorders, namely, whole-brain rs-fMRI studies that measured differences in regional homogeneity, amplitude of low-frequency fluctuations, or fractional amplitude of low-frequency fluctuations, were analyzed in this study. Overall, seven studies with 235 anxiety-disordered patients and 241 healthy controls were ultimately included in the meta-analysis. The meta-analysis was processed by seed-based d mapping.

RESULTS

Compared with healthy controls, patients with anxiety disorders showed significantly decreased regional spontaneous brain activities in the right putamen, the right orbital inferior frontal gyrus, and the right temporal pole. No increases in regional spontaneous brain activities were detected in patients relative to the controls.

LIMITATION

Limited number of available studies, only Asian samples, and insufficient information of sample characteristics.

CONCLUSION

The present study suggests that anxiety disorders are associated with aberrant regional brain activity in areas connected with emotion processing, which extends our understanding of anxiety disorders' pathophysiology.

Disrupted fronto-temporal function in panic disorder: a resting-state connectome study

Recent neuroimaging studies have identified alterations in activity and connectivity among many brain regions as potential biomarkers for panic disorder. However, the functional connectome of panic disorder is not well understood. Therefore, a graph-theoretical approach was applied in this study to construct functional networks of patients and healthy controls in order to discover topological changes in panic disorder. 31 patients and 33 age and sex matched healthy controls underwent resting-state functional magnetic resonance imaging. Brain networks for each participant were structured using nodes from the Anatomical Automatic Labeling template and edges from connectivity matrices. Then, topological organizations of networks were calculated. Network-based statistical analysis was conducted, and global and nodal properties were compared between patients and controls. Unlike controls, patients with panic disorder displayed a small-world network. Patients also revealed decreased nodal efficiency in right superior frontal gyrus (SFG), middle frontal gyrus (MFG), right superior temporal gyrus (STG), and left middle temporal gyrus (MTG). Decreased functional connectivity was found in panic disorder between right MTG and extensive temporal regions. Among these disrupted regions, the decreased nodal efficiency of SFG showed a positive correlation with clinical symptoms while nodal betweenness centrality in angular gyrus showed a negative correlation. Our results indicated decreased function of global and regional information transmission in panic disorder and emphasized the role of temporal regions in its pathology.

Biomarkers in Panic Disorder

Background:

Panic disorder (PD) is a kind of anxiety disorder that impacts the life quality and functional perspectives in patients. However, the pathophysiological study of PD seems still inadequate and many unresolved issues need to be clarified.

Objectives:

In this review article of biomarkers in PD, the investigator will focus on the findings of magnetic resonance imaging (MRI) of the brain in the pathophysiology study. The MRI biomarkers would be divided into several categories, on the basis of structural and functional perspectives.

Methods:

The structural category would include the gray matter and white matter tract studies. The functional category would consist of functional MRI (fMRI), resting-state fMRI (Rs-fMRI), and magnetic resonance spectroscopy (MRS). The PD biomarkers revealed by the above methodologies would be discussed in this article.

Results:

For the gray matter perspectives, the PD patients would have alterations in the volumes of fear network structures, such as the amygdala, parahippocampal gyrus, thalamus, anterior cingulate cortex, insula, and frontal regions. For the white matter tract studies, the PD patients seemed to have alterations in the fasciculus linking the fear network regions, such as the anterior thalamic radiation, uncinate fasciculus, fronto-occipital fasciculus, and superior longitudinal fasciculus. For the fMRI studies in PD, the significant results also focused on the fear network regions, such as the amygdala, hippocampus, thalamus, insula, and frontal regions. For the Rs-fMRI studies, PD patients seemed to have alterations in the regions of the default mode network and fear network model. At last, the MRS results showed alterations in neuron metabolites of the hippocampus, amygdala, occipital cortex, and frontal regions.

Conclusion:

The MRI biomarkers in PD might be compatible with the extended fear network model hypothesis in PD, which included the amygdala, hippocampus, thalamus, insula, frontal regions, and sensory-related cortex.

Frequency-Specific Changes in the Fractional Amplitude of the Low-Frequency Fluctuations in the Default Mode Network in Medication-Free Patients With Bipolar II Depression: A Longitudinal Functional MRI Study

Objective: This study aimed to examine the treatment-related changes of the fractional amplitude of low-frequency fluctuations (fALFF) in the default mode network (DMN) across different bands after the medication-free patients with bipolar II depression received a 16-week treatment of escitalopram and lithium. Methods: A total of 23 medication-free patients with bipolar II depression and 29 healthy controls (HCs) were recruited. We evaluated the fALFF values of slow 4 (0.027-0.073 Hz) band and slow 5 (0.01-0.027 Hz) band of the patients and compared the results with those of the 29 HCs at baseline. After 16-week treatment of escitalopram with lithium, the slow 4 and slow 5 fALFF values of the patients were assessed and compared with the baselines of patients and HCs. The depressive symptoms of bipolar II depression in patients were assessed with a 17-item Hamilton Depression Rating Scale (HDRS) before and after treatment. Results: Treatment-related effects showed increased slow 5 fALFF in cluster D (bilateral medial superior frontal gyrus, bilateral superior frontal gyrus, right middle frontal gyrus, and bilateral anterior cingulate), cluster E (bilateral precuneus/posterior cingulate, left cuneus), and cluster F (left angular, left middle temporal gyrus, left superior temporal gyrus, and left supramarginal gyrus) in comparison with the baseline of the patients. Moreover, a positive association was found between the increase in slow 5 fALFF values (follow-up value minus the baseline values) in cluster D and the decrease in HDRS scores (baseline HDRS scores minus follow-up HDRS scores) at follow-up, and the same association between the increase in slow 5 fALFF values and the decrease in HDRS scores was found in cluster E. Conclusions: The study reveals that the hypoactivity of slow 5 fALFF in the DMN is related to depression symptoms and might be corrected by the administration of escitalopram with lithium, implying that slow 5 fALFF of the DMN plays a key role in bipolar depression.

Altered Function of Superior Parietal Lobule Associated with Perceptive Awareness in First-Episode Drug-Naïve Panic Disorders: A Preliminary fMRI Study

BACKGROUND

Biased fear-related perception is one main characteristic in patients with panic disorder (PD) and their prominent cardiovascular symptoms associated with enhanced heartbeat perception.

PATIENTS AND METHODS

We investigated interoceptive perception in 18 first-onset drug-naïve PD patients and 21 age- and gender-matched healthy controls (HC). Moreover, we compared blood oxygen level-dependent (BOLD) responses between the two groups during a heartbeat perception (interoception) task to assess task-evoked activity and its relationship with heartbeat perception scores (HPSs).

RESULTS

We found that patients with PD compared to HCs revealed a trend higher but insignificant HPSs. Higher activity in the bilateral superior parietal lobule (SPL) was observed in PD patients compared to HCs during the perception of both heartbeats and pure tones compared to rest. Furthermore, patients with PD exhibited a significant positive correlation between BOLD activity in the left SPL during heartbeat > resting-state and HPS.

CONCLUSION

Using a sample of first-episode drug-naïve patients, our study reports that patients with PD show altered activation in the bilateral SPL during both interoceptive and exteroceptive perception. The increased activation during interoceptive stimuli might render PD patients more engaged in processing information associated with their internal states.

Psychoradiological Biomarkers for Psychopharmaceutical Effects

The application of personalized medicine to psychiatry is challenging. Psychoradiology could provide biomarkers based on objective tests in support of the diagnostic classifications and treatment planning. We review potential psychoradiological biomarkers for psychopharmaceutical effects. Although none of the biomarkers reviewed are yet of sufficient clinical utility to inform the selection of a specific pharmacologic compound for an individual patient, there is strong consensus that advanced multimodal approaches will contribute to discovery of novel treatment predictors in psychiatric disorders. Progress has been sufficient to warrant enthusiasm, in which application of neuroimaging-based biomarkers would represent a paradigm shift and modernization of psychiatric practice.

The neural markers of MRI to differentiate depression and panic disorder

Depression and panic disorder (PD) share the common pathophysiology from the perspectives of neurotransmitters. The relatively high comorbidity between depression and PD contributes to the substantial obstacles to differentiate from depression and PD, especially for the brain pathophysiology. There are significant differences in the diagnostic criteria between depression and PD. However, the paradox of similar pathophysiology and different diagnostic criteria in these two disorders were still the issues needing to be addressed. Therefore the clarification of potential difference in the field of neuroscience and pathophysiology between depression and PD can help the clinicians and scientists to understand more comprehensively about significant differences between depression and PD. The researchers should be curious about the underlying difference of pathophysiology beneath the significant distinction of clinical symptoms. In this review article, I tried to find some evidences for the differences between depression and PD, especially for neural markers revealed by magnetic resonance imaging (MRI). The distinctions of structural and functional alterations in depression and PD are reviewed. From the structural perspectives, PD seems to have less severe gray matter alterations in frontal and temporal lobes than depression. The study of white matter microintegrity reveals more widespread alterations in fronto-limbic circuit of depression patients than PD patients, such as the uncinate fasciculus and anterior thalamic radiation. PD might have a more restrictive pattern of structural alterations when compared to depression. For the functional perspectives, the core site of depression pathophysiology is the anterior subnetwork of resting-state network, such as anterior cingulate cortex, which is not significantly altered in PD. A possibly emerging pattern of fronto-limbic distinction between depression and PD has been revealed by these explorative reports. The future trend for machine learning and pattern recognition might confirm the differentiation pattern between depression and PD based on the explorative results.

Fear Network Model in Panic Disorder: The Past and the Future

The core concept for pathophysiology in panic disorder (PD) is the fear network model (FNM). The alterations in FNM might be linked with disturbances in the autonomic nervous system (ANS), which is a common phenomenon in PD. The traditional FNM included the frontal and limbic regions, which were dysregulated in the feedback mechanism for cognitive control of frontal lobe over the primitive response of limbic system. The exaggerated responses of limbic system are also associated with dysregulation in the neurotransmitter system. The neuroimaging studies also corresponded to FNM concept. However, more extended areas of FNM have been discovered in recent imaging studies, such as sensory regions of occipital, parietal cortex and temporal cortex and insula. The insula might integrate the filtered sensory information via thalamus from the visuospatial and other sensory modalities related to occipital, parietal and temporal lobes. In this review article, the traditional and advanced FNM would be discussed. I would also focus on the current evidences of insula, temporal, parietal and occipital lobes in the pathophysiology. In addition, the white matter and functional connectome studies would be reviewed to support the concept of advanced FNM. An emerging dysregulation model of fronto-limbic-insula and temporooccipito-parietal areas might be revealed according to the combined results of recent neuroimaging studies. The future delineation of advanced FNM model can be beneficial from more extensive and advanced studies focusing on the additional sensory regions of occipital, parietal and temporal cortex to confirm the role of advanced FNM in the pathophysiology of PD.

Thalamic shape and volume abnormalities in female patients with panic disorder

The thalamus is believed to play crucial role in processing viscero-sensory information, and regulating the activity of amygdala in patients with panic disorder (PD). Previous functional neuroimaging studies have detected abnormal activation in the thalamus in patients with PD compared with healthy control subjects (HC). Very few studies, however, have investigated for volumetric abnormalities in the thalamus in patients with PD. Furthermore, to the best of our knowledge, no previous study has investigated for shape abnormalities in the thalamus in patients with PD. Twenty-five patients with PD and 25 HC participants (all female) were recruited for the study. A voxel-wise volume comparison analysis and a vertex-wise shape analysis were conducted to evaluate structural abnormalities in the PD patients compared to HC. The patients with PD demonstrated significant gray matter volume reductions in the thalamus bilaterally, relative to the HC. The shape analysis detected significant inward deformation in some thalamic regions in the PD patients, including the anterior nucleus, mediodorsal nucleus, and pulvinar nucleus. PD patients showed shape deformations in key thalamic regions that are believed to play a role in regulating emotional and cognitive functions.

The regional homogeneity of cingulate-precuneus regions: The putative biomarker for depression and anxiety

OBJECTIVES

In addition to clinical interview, the modern putative biomarker to differentiate depression and anxiety would be warranted. The translational medicine characteristics of neuroimaging, such as the regional homogeneity (ReHo), is an option for depression and anxiety. Therefore we designed this study trying to identify the biomarker pattern for depression and anxiety.

METHODS

Resting-state functional magnetic resonance imaging was acquired for 53 patients with first-episode medicine-naïve major depressive disorder (MDD), 53 first-episode medicine-naïve patients with panic disorder (PD) and 54 controls. The calculation of ReHo was performed. The ANOVA repeated measures were applied for the 3 groups to investigate the putative differences between MDD and PD (FDR corrected p < 0.05).

RESULTS

After multiple comparisons, the major findings of ReHo were found in the bilateral anterior cingulate cortex and bilateral precuneus. MDD group had lower ReHo values than PD group in the left anterior cingulate cortex. MDD group had significant alterations of ReHo in the left anterior cingulate cortex and bilateral precuneus when compared to controls. PD group had alterations in the bilateral precuneus when compared to controls.

CONCLUSION

The specific cingulate alterations might be a putative ReHo biomarker to differentiate MDD from PD in cingulate-precuneus background for ReHo alterations.

Altered Brain Functional Activity in Infants with Congenital Bilateral Severe Sensorineural Hearing Loss: A Resting-State Functional MRI Study under Sedation

Early hearing deprivation could affect the development of auditory, language, and vision ability. Insufficient or no stimulation of the auditory cortex during the sensitive periods of plasticity could affect the function of hearing, language, and vision development. Twenty-three infants with congenital severe sensorineural hearing loss (CSSHL) and 17 age and sex matched normal hearing subjects were recruited. The amplitude of low frequency fluctuations (ALFF) and regional homogeneity (ReHo) of the auditory, language, and vision related brain areas were compared between deaf infants and normal subjects. Compared with normal hearing subjects, decreased ALFF and ReHo were observed in auditory and language-related cortex. Increased ALFF and ReHo were observed in vision related cortex, which suggest that hearing and language function were impaired and vision function was enhanced due to the loss of hearing. ALFF of left Brodmann area 45 (BA45) was negatively correlated with deaf duration in infants with CSSHL. ALFF of right BA39 was positively correlated with deaf duration in infants with CSSHL. In conclusion, ALFF and ReHo can reflect the abnormal brain function in language, auditory, and visual information processing in infants with CSSHL. This demonstrates that the development of auditory, language, and vision processing function has been affected by congenital severe sensorineural hearing loss before 4 years of age.

The changes in the low-frequency fluctuations of cingulate cortex and postcentral gyrus in the treatment of panic disorder: The MRI study

OBJECTIVES

The default brain activities in the treatment of panic disorder (PD) have not been studied well. Therefore we designed this longitudinal study to survey the accompanying changes in the fractional amplitude of low-frequency fluctuations (fALFF) when panic disorder (PD) patients achieved remission.

METHODS

We enrolled 21 medicine-naive patients who finished a 6-week therapy of antidepressant. The trial antidepressant was escitalopram. The acquisitions of fALFF in the patients and controls were assessed at baseline and the sixth week. The treatment-related effects and group-related differences (baseline versus sixth week) were obtained by the comparisons of the fALFF data of each group.

RESULTS

The treatment-related effects showed increases in the fALFF values of the right middle cingulate cortex (MCC) and left postcentral gyrus (PCG) after remission in PD patients. The improvements in panic severity and antidepressant dose also correlated positively with the increases in the fALFF values of the right middle cingulate cortex. There were still residual group-related differences of fALFF in the occipital lobe and thalamus after remission.

CONCLUSIONS

The results probably revealed the treatment-related effects of fALFF in the MCC-PCG regions and group-related differences of fALFF in the occipito-thalamic regions for the antidepressant treatment and remission in PD.

Biological predictors of pharmacological therapy in anxiety disorders

At least one third of patients with anxiety disorders do not adequately respond to available pharmacological treatment. The reason that some patients with anxiety disorders respond well, but others not, to the same classes of medication is not yet fully understood. It is suggested that several biological factors may influence treatment mechanisms in anxiety and therefore could be identified as possible biomarkers predicting treatment response. In this review, we look at current evidence exploring different types of treatment predictors, including neuroimaging, genetic factors, and blood-related measures, which could open up novel perspectives in clinical management of patients with anxiety disorders.

Regional homogeneity changes in amnestic mild cognitive impairment patients

OBJECTIVE

Regional Homogeneity (ReHo) measures the local coherence of spontaneous brain activity, and it is sensitive to detect aberrant local functional connectivity of brain region. We tried to explore the activity of brain network by ReHo method in amnestic mild cognitive impairment (aMCI) patients and examine the impact of regional brain atrophy on the functional results.

METHODS

Data of both structural magnetic resonance images (MRI) and resting-state functional MRI scans were collected from 36 aMCI patients and 46 age-matched healthy controls.

RESULTS

Compared with the HC subjects, the aMCI patients showed significant decreased ReHo areas in the right inferior parietal lobule (IPL), left posterior cingulate cortex/precuneus (PCC/PCu), left inferior temporal gyrus (ITG), right supramarginal gyrus (SMG), right fusiform gyrus (FG), bilateral lentiform nucleus (LN) and right cerebellum posterior lobe, with the right IPL being the most significant area. In addition, the aMCI group also had some significant increased ReHo areas in the right medial frontal gyrus (MFG), bilateral postcentral gyrus (PoCG), left cuneus and right lingual gyrus (LG), possibly reflective of some underlining compensatory mechanism. Furthermore, in the aMCI patients, we found the ReHo index of the left PCC was positively correlated with the AVLT-Immediate Recall scores, while the ReHo index of the left cuneus was negatively correlated with the MMSE scores. In addition, we found that after regressing out the identified regional brain atrophy, the significant correlations between fitted ReHo index and clinical variables still remained.

CONCLUSIONS

Our study indicated that aMCI patients showed significant abnormal local coherence of biological activity in resting state and ReHo could serve as a sensitive biomarker in functional imaging studies of aMCI.

Differential alterations of resting-state functional connectivity in generalized anxiety disorder and panic disorder

Generalized anxiety disorder (GAD) and panic disorder (PD) are most common anxiety disorders with high lifetime prevalence while the pathophysiology and disease-specific alterations still remain largely unclear. Few studies have taken a whole-brain perspective in the functional connectivity (FC) analysis of these two disorders in resting state. It limits the ability to identify regionally and psychopathologically specific network abnormalities with their subsequent use as diagnostic marker and novel treatment strategy. The whole brain FC using a novel FC metric was compared, that is, scaled correlation, which they demonstrated to be a reliable FC statistics, but have higher statistical power in two-sample t-test of whole brain FC analysis. About 21 GAD and 18 PD patients were compared with 22 matched control subjects during resting-state, respectively. It was found that GAD patients demonstrated increased FC between hippocampus/parahippocampus and fusiform gyrus among the most significantly changed FC, while PD was mainly associated with greater FC between somatosensory cortex and thalamus. Besides such regional specificity, it was observed that psychopathological specificity in that the disrupted FC pattern in PD and GAD correlated with their respective symptom severity. The findings suggested that the increased FC between hippocampus/parahippocampus and fusiform gyrus in GAD were mainly associated with a fear generalization related neural circuit, while the greater FC between somatosensory cortex and thalamus in PD were more likely linked to interoceptive processing. Due to the observed regional and psychopathological specificity, their findings bear important clinical implications for the potential treatment strategy.

Altered intrinsic regional brain spontaneous activity and subjective sleep quality in patients with chronic primary insomnia: a resting-state fMRI study

STUDY OBJECTIVE

To prospectively explore the underlying regional homogeneity (ReHo) brain-activity deficit in patients with chronic primary insomnia (PCPIs) and its relationship with clinical features.

DESIGN

The ReHo method and Statistical Parametric Mapping 8 software were used to evaluate whether resting-state localized brain activity was modulated between PCPIs and good sleepers (GSs), and correlation analysis between altered regional brain areas and clinical features was calculated.

PATIENTS AND PARTICIPANTS

Twenty-four PCPIs (17 females, seven males) and 24 (12 females, 12 males) age-, sex-, and education-matched GSs.

MEASUREMENTS AND RESULTS

PCPIs disturbed subjective sleep quality, split positive mood, and exacerbated negative moods. Compared with GSs, PCPIs showed higher ReHo in left fusiform gyrus, and lower ReHo in bilateral cingulate gyrus and right cerebellum anterior lobe. Compared with female GSs, female PCPIs showed higher ReHo in the left fusiform gyrus and right posterior cingulate, and lower ReHo in the left cerebellum anterior lobe and left superior frontal gyrus. Compared with male GSs, male PCPIs showed higher ReHo in the right temporal lobe and lower ReHo in the bilateral frontal lobe. The fusiform gyrus showed strong positive correlations and the frontal lobe showed negative correlations with the clinical measurements.

CONCLUSION

The ReHo analysis is a useful noninvasive imaging tool for the detection of cerebral changes and the indexing of clinical features. The abnormal spontaneous activity areas provided important information on the neural mechanisms underlying emotion and sleep-quality impairment in PCPIs.