Metabolic change in the right dorsolateral prefrontal cortex and its correlation with symptom severity in patients with generalized anxiety disorder: Proton magnetic resonance spectroscopy at 3 Tesla

Grey matter structural alterations in anxiety disorders: a voxel-based meta-analysis

Anxiety disorders (ADs) are a group of prevalent and destructive mental illnesses, but the current understanding of their underlying neuropathology is still unclear. Employing voxel-based morphometry (VBM), previous studies have demonstrated several common brain regions showing grey matter volume (GMV) abnormalities. However, contradictory results have been reported among these studies. Considering that different subtypes of ADs exhibit common core symptoms despite different diagnostic criteria, and previous meta-analyses have found common core GMV-altered brain regions in ADs, the present research aimed to combine the results of individual studies to identify common GMV abnormalities in ADs. Therefore, we first performed a systematic search in PubMed, Embase, and Web of Science on studies investigating GMV differences between patients with ADs and healthy controls (HCs). Then, the anisotropic effect-size signed differential mapping (AES-SDM) was applied in this meta-analysis. A total of 24 studies (including 25 data sets) were included in the current study, and 906 patients with ADs and 1003 HCs were included. Compared with the HCs, the patients with ADs showed increased GMV in the left superior parietal gyrus, right angular gyrus, left precentral gyrus, and right lingual gyrus, and decreased GMV in the bilateral insula, bilateral thalamus, left caudate, and right putamen. In conclusion, the current study has identified some abnormal GMV brain regions that are related to the pathological mechanisms of anxiety disorders. These findings could contribute to a better understanding of the underlying neuropathology of ADs.

tDCS over the left prefrontal Cortex improves mental flexibility and inhibition in geriatric inpatients with symptoms of depression or anxiety: A pilot randomized controlled trial

BACKGROUND

Patients with depression and/or anxiety are commonly seen in inpatient geriatric settings. Both disorders are associated with an increased risk of cognitive impairments, notably in executive functioning. Transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation, involves the administration of a low-dose electrical current to induce neuromodulation, which ultimately may act on downstream cognitive processing.

OBJECTIVE

The purpose of this study was to determine the effects of tDCS on executive functioning in geriatric inpatients with symptoms of depression and/or anxiety.

DESIGN

Pilot Randomized Controlled Trial.

SETTING

Specialized geriatric wards in a tertiary rehabilitation hospital.

METHODS

Thirty older-aged adults were recruited, of which twenty completed ten-to-fifteen sessions of 1.5 mA anodal or sham tDCS over the left dorsolateral prefrontal cortex. Cognitive assessments were administered at baseline and following the tDCS protocol; analyses examined the effects of tDCS on cognitive performance between groups (anodal or sham tDCS).

RESULTS

tDCS was found to increase inhibitory processing and cognitive flexibility in the anodal tDCS group, with significant changes on the Stroop test and Trail Making Test-Part B. No significant changes were observed on measures of attention or working memory.

DISCUSSION

These results provide preliminary evidence that tDCS-induced neuromodulation may selectively improve cognitive processing in older adults with symptoms of depression and/or anxiety.

CLINICAL TRIALS REGISTRATION

www.clinicaltrials.gov, NCT04558177.

Exploring neurometabolic alterations in bipolar disorder with suicidal ideation based on proton magnetic resonance spectroscopy and machine learning technology

Bipolar disorder (BD) is associated with a high risk of suicide. We used proton magnetic resonance spectroscopy (1H-MRS) to detect biochemical metabolite ratios in the bilateral prefrontal white matter (PWM) and hippocampus in 32 BD patients with suicidal ideation (SI) and 18 BD patients without SI, identified potential brain biochemical differences and used abnormal metabolite ratios to predict the severity of suicide risk based on the support vector machine (SVM) algorithm. Furthermore, we analyzed the correlations between biochemical metabolites and clinical variables in BD patients with SI. There were three main findings: (1) the highest classification accuracy of 88% and an area under the curve of 0.9 were achieved in distinguishing BD patients with and without SI, with N-acetyl aspartate (NAA)/creatine (Cr), myo-inositol (mI)/Cr values in the bilateral PWM, NAA/Cr and choline (Cho)/Cr values in the left hippocampus, and Cho/Cr values in the right hippocampus being the features contributing the most; (2) the above seven features could be used to predict Self-rating Idea of Suicide Scale scores (r = 0.4261, p = 0.0302); and (3) the level of neuronal function in the left hippocampus may be related to the duration of illness, the level of membrane phospholipid catabolism in the left hippocampus may be related to the severity of depression, and the level of inositol metabolism in the left PWM may be related to the age of onset in BD patients with SI. Our results showed that the combination of multiple brain biochemical metabolites could better predict the risk and severity of suicide in patients with BD and that there was a significant correlation between biochemical metabolic values and clinical variables in BD patients with SI.

Measurement of Post-Treatment Changes in Brain Metabolites in Patients with Generalized Anxiety Disorder using Magnetic Resonance Spectroscopy

BACKGROUND

From previous studies, we know the correlations of some brain metabolites with a generalized anxiety disorder (GAD) and its symptoms. The response of GAD patients to various treatments is not the same and finding the best treatment option for each patient takes a long period of time.

OBJECTIVE

In this study, we try to examine if there is any relationship between a special treatment option and GAD patients' response and brain metabolite correlation with anxiety level change.

MATERIAL AND METHODS

This study is a clinical trial type of studies. We have used proton MRS (1H-MRS) with field strength of 3 Tesla to assess whether a different treatment option makes different responses based on metabolite changes. We chose 16 patients based on Hamilton's anxiety rate and a psychiatrist diagnosis. Patients were divided into two groups randomly. Each group took different treatments. Before treatment started, patients underwent MRS imaging and 8 weeks after treatment as well. Our study lacked a control group, and the results were analyzed by comparing the measured values of metabolites and clinical scores before and after treatment.

RESULTS

The NAA and Cho concentration increased after treatments and Cr concentration remained constant in both groups. Both groups showed improvements in their symptoms of anxiety and also in their clinical score rates. Sertraline group showed a more increase in NAA concentration than CBT and also a more decrease in HAMA and HAMD-17 scores.

CONCLUSION

A simultaneously increase in NAA and Cho in both groups and a decrease in clinical anxiety levels demonstrate that NAA and Cho concentration are associated negatively with anxiety levels. In addition, both CBT and sertraline are effective in the improvement of anxiety symptoms.

Neurometabolic alterations in bipolar disorder with anxiety symptoms: A proton magnetic resonance spectroscopy study of the prefrontal whiter matter

To identify the pathophysiological mechanism of bipolar disorder (BD) patients with anxiety symptoms, we analyzed the differences of brain biochemical metabolism in BD patients with and without anxiety symptoms. We collected 39 BD patients who had been untreated with drugs in one month and were divided into the anxiety symptoms group (20 cases) and non-anxiety symptoms group (19 cases) according to whether they had anxiety symptoms. We used proton magnetic resonance spectroscopy (¹H-MRS) to detect the biochemical metabolite ratios of the prefrontal whiter matter (PWM) in all patients. The right PWM mI/Cr ratios in BD patients with anxiety symptoms were higher than those in BD patients without anxiety symptoms and the Cho/Cr ratios in the left PWM were negatively correlated with age and age of onset in BD patients with anxiety symptoms. These findings indicated that BD patients with anxiety symptoms have increased levels of inositol metabolism in the right PWM. Furthermore, the level of membrane phospholipid catabolism in the left PWM of BD patients with anxiety symptoms decreased with increasing age and onset age. Our results provide some references for the pathophysiological mechanism in BD patients with anxiety symptoms.

tDCS-Augmented in vivo exposure therapy for specific fears: A randomized clinical trial

Exposure therapy is highly effective for anxiety-related disorders, but there is a need for enhancement. Recent trials of adjunctive neuromodulation have shown promise, warranting evaluation of transcranial direct current stimulation (tDCS) as an augmentation. In a double-blind, placebo-controlled trial, contamination- and animal-phobic participants (N = 49) were randomized to active tDCS (1.7 mA, 20 min; n = 27), or sham tDCS (1.7 mA, 30 s; n = 22), followed by 30 min of in-vivo exposure. Active tDCS targeted excitation of the left mPFC and inhibition of the right dlPFC; polarity was counterbalanced for controls. We predicted tDCS would result in accelerated and better maintained gains, contingent on the subsequent in-session response, and baseline negative prognostic indicators. Consistent with predictions, tDCS promoted engagement and reductions in threat appraisals during exposure, and greater reductions in distress and threat appraisals through 1-month, although effects did not uniformly generalize. tDCS was most beneficial given high phobic severity, anxiety sensitivity, and a suboptimal early response. tDCS may promote engagement and response among individuals who are resistant or refractory to standard treatment. tDCS should be applied to more severe anxiety-related disorders, with parameters yoked to individual differences to improve outcomes in exposure-based interventions.

Proton Magnetic Resonance Spectroscopy to Detect Correlations between Clinical Symptoms and Brain Metabolite Levels in Patients with Tension-type Headache

Background:

Proton magnetic resonance spectroscopy (¹HMRS) is a noninvasive method to quantify pain. A ¹HMRS spectrum is a group of peaks at different radiofrequencies, showing proton nuclei in various chemical environments. These MR spectra provide information about metabolite concentrations, and make MRS a useful procedure to monitor metabolic fluctuations due to disease, and to track the efficacy of treatment.

Objective:

This study aims to identify correlations between clinical symptoms in patients with tension-type headache (TTH) and concentrations of brain metabolites.

Material and Methods:

In this observational study, twenty-four patients (4 men and 20 women) with chronic TTH were included. To evaluate their clinical symptoms, the number of trigger points, headache frequency and headache intensity were recorded. The levels of anxiety and depression were recorded with the Beck Anxiety Inventory (BAI) and Beck Depression Inventory II (BDI- II). Concentrations of brain metabolites were determined in the anterior cingulate cortex, thalamus and primary somatosensory cortex of left hemisphere with ¹HMRS.

Results:

There was a negative correlation between trigger point count and choline/creatine (Cho/Cr) ratio in the primary somatosensory cortex [r= −0.509, n= 24, p= 0.01]. There were no correlations between other clinical symptoms of TTH and concentrations of brain metabolites.

Conclusion:

Patients with more trigger points had a lower Cho/Cr ratio, which may indicate alterations in brain metabolic activity.

Differential Experiences of Mental Health among Trans/Gender Diverse Adults in Michigan

Transgender and gender diverse individuals experience high rates of health disparities, as compared with their cisgender (non-transgender) counterparts. One area in which these disparities is most grave is that of mental health, with some studies indicating transgender and gender diverse individuals as having a 40% rate of lifetime suicide attempts and similarly high rates of depression, anxiety, and suicidal ideation. These rates vary further within this population, with differential rates seen across sociodemographic factors, including race/ethnicity, gender, sexual orientation, disability status, education level, and income. This study explores mental health experiences across different social identities, using data from the 2018 Michigan Trans Health Survey (N = 659), a community-based participatory action research project collected in Michigan, United States, analyzed using chi-square tests of independence and logistic regressions. Findings indicate incredibly high rates of mental health concerns; 72.2% had been diagnosed with depression in their lifetime and 73.0% had been diagnosed with anxiety in their lifetime. In the past year, 49.9% had had non-suicidal self-injury (NSSI) thoughts, 45.4% had suicidal thoughts, 26.3% engaged in NSSI, and 7.7% had attempted suicide. Bivariate regressions showed some nuanced experiences of rates of mental health diagnoses and experiences, such as greater odds of experiencing all mental health disparities among those with disabilities, and differential odds across gender in regard to ever having a depression diagnosis, non-suicidal self-injury thoughts and engaging in non-suicidal self-injury behavior. This indicates a need for social workers, counselors, therapists, and other human services professionals to act more intentionally and with an intersectional lens when it comes to exploring the mental health of transgender and gender diverse persons.

Development of the short version of the spielberger state-trait anxiety inventory

The Spielberger State-Trait Anxiety Inventory (STAI) has been widely used to measure the state and trait components of anxiety. We sought to develop a short, yet reliable and valid form of these scales for use in circumstances where the full-form is not feasible. We abbreviated the scales using item response theory analyses to retain the items that could discriminate the best among participants. One sample (N = 922) completed the state scale, a second sample (N = 2227) completed the trait scale, while a third sample (N = 250) completed the short forms. Our participants completed the Hungarian version of STAI alongside other measures to observe external validity. We calculated cut-off scores for the state (>9.5,) and trait (>13.5) scales. A total of 19.5% and 20.1% of the respondents reached the cut-off scores. The five-item short forms of STAI had sound psychometric properties that are comparable to those obtained on the full-form. The external validity of the scales is also demonstrated. We report detailed descriptive statistics that could be used in further studies as standards. The short scales are reliable measures that could be used in clinical screening and behavioural research; especially where practical considerations preclude the use of a longer questionnaire.

Systematic review and meta-analyses of neural structural and functional differences in generalized anxiety disorder and healthy controls using magnetic resonance imaging

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PFC-amygdala FC is altered in GAD, indicating top-down processing deficits.

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GAD had reduced activity for emotion regulation and working memory in the culmen.

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Salience, default, and central executive nodes have altered structure and function.

Objective

To compare structure, functional connectivity (FC) and task-based neural differences in subjects with generalized anxiety disorder (GAD) compared to healthy controls (HC).

Methods

The Embase, Ovid Medline, PsycINFO, Scopus, and Web of Science databases were searched from inception until March 12, 2018. Two reviewers independently screened titles, abstracts, and full-text articles. Data were extracted from records directly contrasting GAD and HC that included structure (connectivity and local indices such as volume, etc.), FC, or task-based magnetic resonance imaging data. Meta-analyses were conducted, as applicable, using AES-SDM software.

Results

The literature search produced 4,645 total records, of which 85 met the inclusion criteria for the systematic review. Records included structural (n = 35), FC (n = 33), and task-based (n = 42) findings. Meta-analyses were conducted on voxel-based morphometry and task-based results.

Discussion

The systematic review confirms and extends findings from previous reviews. Although few whole-brain resting state studies were conducted, key nodes of resting state networks have altered physiology: the hippocampus (default network), ACC and amygdala (salience network), have reduced volume, and the dlPFC (central executive network) and ACC have reduced FC with the amygdala in GAD. Nodes in the sensorimotor network are also altered with greater pre- and postcentral volume, reduced supplementary motor area volume, and reduced FC in anterior and increased FC in posterior cerebellum.

Conclusions

Despite limitations due to sample size, the meta-analyses highly agree with the systematic review and provide evidence of widely distributed neural differences in subjects with GAD, compared to HC. Further research optimized for meta-analyses would greatly improve large-scale comparisons.

Associations of neurofunctional, morphometric and metabolic abnormalities with clinical symptom severity and recognition deficit in obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) causes neural dysfunction associated with cognitive deficit and emotional dysregulation. This study assessed the associations of the neurofunctional changes, gray matter (GM) and white matter (WM) volume alterations in conjunction with in vivo metabolic changes on the working memory tasks in patients with OCD.

METHODS

Eighteen patients with OCD and 18 healthy controls matched for age, sex, and educational levels underwent high-resolution T1-weighted magnetic resonance imaging (MRI), event-related functional MRI (fMRI), and proton magnetic resonance spectroscopy (¹H-MRS) at 3T.

RESULTS

In fMRI, patients with OCD showed lower activities in the cerebellum, inferior temporal gyrus, orbitofrontal gyrus, dorsolateral prefrontal cortex and calcarine gyrus compared to the controls. In VBM, the patients showed significantly reduced GM volumes, especially in the cerebellum, hippocampus, and superior temporal gyrus, together with significantly reduced WM volumes in the retrolenticular part of the internal capsule, dorsolateral prefrontal cortex (DLPFC) and orbitofrontal gyrus. In ¹H-MRS, the ratios of N-acetylaspartate/creatine and choline/creatine were significantly lower in the DLPFC of the patients than in the controls, whereas the ratio of β∙γ-glutamine-glutamate/creatine was significantly higher in the patients than in the controls.

LIMITATIONS

This study examined small numbers of subjects in each one of the groups.

CONCLUSIONS

The findings will be helpful to aid us in understanding of neurocognitive impairment in OCD, and thus, enhancing the diagnostic accuracy for OCD by additional information on the associated brain functional deficit, cerebral volume change and metabolic abnormality.

Biological markers of generalized anxiety disorder

Generalized anxiety disorder (GAD) is a prevalent and highly disabling mental health condition; however, there is still much to learn with regard to pertinent biomarkers, as well as diagnosis, made more difficult by the marked and common overlap of GAD with affective and anxiety disorders. Recently, intensive research efforts have focused on GAD, applying neuroimaging, genetic, and blood-based approaches toward discovery of pathogenetic and treatment-related biomarkers. In this paper, we review the large amount of available data, and we focus in particular on evidence from neuroimaging, genetic, and neurochemical measurements in GAD in order to better understand potential biomarkers involved in its etiology and treatment. Overall, the majority of these studies have produced results that are solitary findings, sometimes inconsistent and not clearly replicable. For these reasons, they have not yet been translated into clinical practice. Therefore, further research efforts are needed to distinguish GAD from other mental disorders and to provide new biological insights into its pathogenesis and treatment.

Imaging and Genetic Approaches to Inform Biomarkers for Anxiety Disorders, Obsessive-Compulsive Disorders, and PSTD

Anxiety disorders are the most common mental health problem in the world and also claim the highest health care cost among various neuropsychiatric disorders. Anxiety disorders have a chronic and recurrent course and cause significantly negative impacts on patients' social, personal, and occupational functioning as well as quality of life. Despite their high prevalence rates, anxiety disorders have often been under-diagnosed or misdiagnosed, and consequently under-treated. Even with the correct diagnosis, anxiety disorders are known to be difficult to treat successfully. In order to implement better strategies in diagnosis, prognosis, treatment decision, and early prevention for anxiety disorders, tremendous efforts have been put into studies using genetic and neuroimaging techniques to advance our understandings of the underlying biological mechanisms. In addition to anxiety disorders including panic disorder, generalised anxiety disorder (GAD), specific phobias, social anxiety disorders (SAD), due to overlapping symptom dimensions, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD) (which were removed from the anxiety disorder category in DSM-5 to become separate categories) are also included for review of relevant genetic and neuroimaging findings. Although the number of genetic or neuroimaging studies focusing on anxiety disorders is relatively small compare to other psychiatric disorders such as psychotic disorders or mood disorders, various structural abnormalities in the grey or white matter, functional alterations of activity during resting-state or task conditions, molecular changes of neurotransmitter receptors or transporters, and genetic associations have all been reported. With continuing effort, further genetic and neuroimaging research may potentially lead to clinically useful biomarkers for the prevention, diagnosis, and management of these disorders.

Metabolic alterations in generalised anxiety disorder: a review of proton magnetic resonance spectroscopic studies

Generalised anxiety disorder (GAD) is a common psychiatric illness characterised by selective morpho-functional brain alterations. The breath of neuroimaging studies investigating the neural basis of GAD is extensive; however, its pathophysiology is still largely unknown. Specifically for proton Magnetic Resonance Spectroscopy (¹H MRS) investigations, which have the aim of identifying differences in metabolite levels between conditions in key brain areas, often showed contrasting results. Indeed, there are selected ¹H MRS studies reporting deficits of key metabolites in GAD patients; however, collectively the literature remains mixed with respect to consistency of major findings. In this review, we evaluate published ¹H MRS studies on GAD with the final aim of providing a comprehensive overview of the extent of neurometabolic dysfunctions associated with GAD. Interestingly, the majority of the studies reviewed showed altered metabolite levels in the dorsolateral prefrontal cortex and hippocampus suggesting regional specificity. These results also provide evidence of the utility of ¹H MRS not only for elucidating the pathophysiology of neuropsychiatric diseases, but also for the identification of more beneficial and targeted pharmacological interventions. Additionally, future studies are warranted to overcome methodological differences observed across the studies.

Risk Factors and Clinical Manifestations of Juxtacortical Small Lesions: A Neuroimaging Study

Background and objective

White matter hyperintensities can be easily identified by brain imaging. Juxtacortical small lesion (JCSL) is a special type of white matter lesion, defined as no greater than 5 mm in diameter and adjacent to the cerebral cortex in location. We notice lately that JCSLs alone may be associated to various neurological symptoms. Here, we design the present study to determine the risk factors for JCSLs and their clinical manifestations in patients in our neurology clinic.

Methods

206 participants suffered from neurological disorders and completed magnetic resonance imaging (MRI) examinations were divided into two groups: patients with JCSLs and patients without lesions on MRI. Meanwhile, 129 age- and sex-matched healthy volunteers were also recruited. Laboratory examinations and the phenotypes and distributions of the symptoms of the three groups were compared.

Results

The serum levels of apoB and homocysteine (HCY) were independently related to the appearance of JCSLs and HCY level was also associated with the number of JCSLs. Patients with JCSLs might present with headache, insomnia, and/or anxiety/depression, which were related with the anatomical locations of the lesions.

Conclusion

These data suggest that JCSLs are symptomatic and might in result fromarteriole atherosclerosis, which should raise our attention.

Functional and morphological alterations associated with working memory dysfunction in patients with generalized anxiety disorder

Background Generalized anxiety disorder (GAD) has been related to functional brain activities and structural brain abnormalities. Purpose To investigate the neural mechanism on working memory dysfunction in patients with GAD in terms of the combined functional and morphological brain abnormalities. Material and Methods Patients with GAD and healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted (T1W) magnetic resonance imaging (MRI) and functional MRI (fMRI). In this study, fMRI and voxel-based morphometry (VBM) were used for assessing the differential brain activation patterns, as well as for comparing the morphological alterations between the two groups. Results In response to the neutral distractors, the patients showed significantly lower activities in the regions of the fusiform gyrus (FuG), superior parietal gyrus (SPG), precuneus (PCu), superior occipital gyrus (SOG), lingual gyrus (LiG), cuneus (Cun), calcarine cortex (CaC), parahippocampal gyrus (PHG) and cerebellar cortex (Cb) compared to the controls. In response to the anxiety-inducing distractors, the patients showed significantly higher activity in the hippocampus and lower activities in the regions of the dorsolateral prefrontal cortex (DLPFC), FuG, SPG, PCu, SOG, and Cb. Also, the patients showed a significant reduction of the white matter volumes in the DLPFC, anterior limb of the internal capsule (ALIC) and midbrain. Conclusion This study provides the first evidence for the association between the morphometric alterations and functional deficit in the working memory processing with the neutral and anxiety-inducing distractors in GAD patients. These findings would be helpful to understand the neural mechanisms on working memory impairment in connection with GAD symptoms.

Abnormalities in gray and white matter volumes associated with explicit memory dysfunction in patients with generalized anxiety disorder

Background The neuroanatomical abnormalities associated with behavioral dysfunction on explicit memory in patients generalized anxiety disorder (GAD) have not yet been clearly identified. Purpose To investigate the regional gray matter (GM) and white matter (WM) volume alterations over the whole brain in patients with GAD, as well as the correlation between the brain structural abnormality and explicit memory dysfunction. Material and Methods Twenty patients with GAD and 20 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted magnetic resonance imaging (MRI). The participants performed the explicit memory tasks with the neutral and anxiety-inducing words. Results Patients with GAD showed significantly reduced GM volumes in the midbrain (MB), thalamus, hippocampus (Hip), insula, and superior temporal gyrus (STG); and reduced WM volumes in the MB, anterior limb of the internal capsule (ALIC), dorsolateral prefrontal cortex (DLPFC), and precentral gyrus (PrG). It is important to note that the GM volume of the Hip and the WM volume of the DLPFC were positively correlated with the recognition accuracy (%) in the explicit memory tasks with neutral and anxiety-inducing words, respectively. On the other hand, the WM volume of the PrG was negatively correlated with the reaction time in the same memory tasks. Conclusion This study demonstrated the regional volume changes on whole-brain GM and WM and the correlation between the brain structural alteration and explicit memory dysfunction in GAD patients. These findings would be helpful to understand the association between the brain structure abnormality and the functional deficit in the explicit memory in GAD.

Spontaneous alterations of regional brain activity in patients with adult generalized anxiety disorder

OBJECTIVE

We aimed to examine how spontaneous brain activity might be related to the pathophysiology of generalized anxiety disorder (GAD).

PATIENTS AND METHODS

Using resting-state functional MRI, we examined spontaneous regional brain activity in 31 GAD patients (mean age, 36.87±9.16 years) and 36 healthy control participants (mean age, 39.53±8.83 years) matched for age, education, and sex from December 2014 to October 2015. We performed a two-sample t-test on the voxel-based analysis of the regional homogeneity (ReHo) maps. We used Pearson correlation analysis to compare scores from the Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale, State-Trait Anxiety Scale-Trait Scale, and mean ReHo values.

RESULTS

We found abnormal spontaneous activity in multiple regions of brain in GAD patients, especially in the sensorimotor cortex and emotional regions. GAD patients showed decreased ReHo values in the right orbital middle frontal gyrus, left anterior cingulate cortex, right middle frontal gyrus, and bilateral supplementary motor areas, with increased ReHo values in the left middle temporal gyrus, left superior temporal gyrus, and right superior occipital gyrus. The ReHo value of the left middle temporal gyrus correlated positively with the Hamilton Anxiety Rating Scale scores.

CONCLUSION

These results suggest that altered local synchronization of spontaneous brain activity may be related to the pathophysiology of GAD.

Aberrant Functional Connectivity between the Amygdala and the Temporal Pole in Drug-Free Generalized Anxiety Disorder

The amygdala and the dorsolateral prefrontal cortex (DLPFC) play important roles in “emotion dysregulation,” which has a profound impact on etiologic research of generalized anxiety disorder (GAD). The present study analyzed both eyes-open and eyes-closed resting state functional MRI (rs-fMRI) of 43 subjects (21 GAD patients with medicine free and 22 matched healthy controls). The amygdala and the DLPFC were defined as regions of interest (ROI) to analyze functional connectivity (FC) in GAD patients compared with healthy controls. The main findings revealed GAD patients had increased FC between the amygdala and the temporal pole compared to healthy controls, which was found in both eyes-open and eyes-closed rs-fMRI. And altered FC between the ROIs and brain regions that mainly belonged to the default mode network (DMN) were found. These findings suggest that the abnormal FC between the amygdala and the temporal pole may contribute to the pathophysiology of GAD, and provide insights into the current understanding of the emotion dysregulation of anxiety disorders.

Working memory dysfunction associated with brain functional deficits and cellular metabolic changes in patients with generalized anxiety disorder

Generalized anxiety disorder (GAD) is associated with brain functional and morphological changes in connected with emotional dysregulation and cognitive deficit. This study dealt with the neural functional deficits and metabolic abnormalities in working memory (WM) task with emotion-inducing distractors in patients with GAD. Fourteen patients with GAD and 14 healthy controls underwent functional magnetic resonance imaging (fMRI) and proton magnetic resonance spectroscopy ((1)H-MRS) at 3T. In response to the emotional distractors in WM tasks, the patients concurrently showed higher activity in the hippocampus and lower activities in the superior occipital gyrus, superior parietal gyrus, dorsolateral prefrontal cortex (DLPFC) and precentral gyrus compared to the controls. MRS revealed significantly lower choline/creatine (Cho/Cr) and choline/N-acetylaspartate (Cho/NAA) ratios in the DLPFC. In particular, the Cho ratios were positively correlated with the brain activities based on blood oxygenation level-dependent signal change in the DLPFC. This study provides the first evidence for the association between the metabolic alterations and functional deficit in WM processing with emotion-inducing distractors in GAD. These findings will be helpful to understand the neural dysfunction in connection with WM impairment in GAD.

The recovery trajectory of adolescent social defeat stress-induced behavioral, (1)H-MRS metabolites and myelin changes in Balb/c mice

Adolescent exposure to social stress precipitates emotion-related disorders and affects the development and function of medial prefrontal cortex (mPFC). However, this adversity-induced behavioral and neurological changes remain not fully explored. Adolescent Balb/c mice were subjected to intermittent social defeat stress during postnatal days 28 to 42. Proton magnetic resonance spectroscopy (¹H-MRS) measurements, behavioral tests and immunohistochemistry were performed one day or 3 weeks after the last stress episode. Defeated mice exhibited hypoactivity and social avoidance with the latter lasting into the early adulthood, while the anxiety level was unchanged. Social defeat experience lead to temporary decreases in the levels of total creatines (Cr + pCr) and Glx (Glu + Gln), but a delayed increase of N- acetylaspartate (NAA) levels. These alternations were accompanied with a persistent reduction of myelin basic protein expression although the number of mature oligodendrocyte did not change. These findings provide evidence that adolescent adverse social experience permanently impairs the emotion-related behavioral performance and induces biochemical and molecular changes in the brain which at least lasts into early adulthood, thus enhancing our understanding of the neurobiology of social defeat stress. Our finding also implicates that NAA signals on MRS may reflect myelin status.

Effects of donepezil on brain morphometric and metabolic changes in patients with Alzheimer's disease: A DARTEL-based VBM and (1)H-MRS

A few studies have performed on the brain morphometric changes over the whole brain structure following donepezil treatment in patients with Alzheimer's disease (AD). We evaluated the gray matter (GM) and white matter (WM) volume alterations and cellular metabolic changes in patients with AD before and after donepezil treatment, and further to reveal the correlations of the scores of various neuropsychological scales with the volumetric and metabolic changes. Twenty-one subjects comprising of 11 patients with AD and 10 age-matched healthy controls participated in this study. All of the patients participated in the follow-up study 24weeks following donepezil treatment. In this study, a combination of voxel-based morphometry (VBM) and proton magnetic resonance spectroscopy ((1)H-MRS) was used to assess the brain morphometric and metabolic alterations in AD. In the GM volumetric analysis, both of the untreated and treated patients with donepezil showed significantly reduced volumes in the hippocampus (Hip), parahippocampal gyrus (PHG), precuneus (PCu) and middle frontal gyrus compared with healthy controls. However, donepezil-treated patients showed significantly increased volumes in the Hip, PCu, fusiform gyrus and caudate nucleus compared to untreated patients. In the WM volumetric analysis, untreated and treated patients showed significant volume reductions in the posterior limb of internal capsule (PLIC), cerebral peduncle of the midbrain and PHG compared to healthy controls. However, there was no significant WM morphological change after donepezil treatment in patients with AD. In MRS study, untreated patients with AD showed decreased N-acetylaspartate/creatine (NAA/Cr) and increased myo-inositol (mI)/Cr compared to healthy controls, while treated patients showed only decreased NAA/Cr in the same comparison. However, the treated patients showed simultaneously increased NAA/Cr and decreased mI/Cr and choline (Cho)/Cr ratios compared to untreated patients. This study shows the regional GM and WM volume changes in combination with metabolic changes following donepezil treatment in AD. These findings would be helpful to aid our understanding of the neuroanatomical mechanisms associated with effects of donepezil on the cognitive function in AD.

Brain morphological alterations and cellular metabolic changes in patients with generalized anxiety disorder: A combined DARTEL-based VBM and (1)H-MRS study

Generalized anxiety disorder (GAD) is characterized by emotional dysregulation and cognitive deficit in conjunction with brain morphometric and metabolic alterations. This study assessed the combined neural morphological deficits and metabolic abnormality in patients with GAD. Thirteen patients with GAD and 13 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted MRI and proton magnetic resonance spectroscopy ((1)H-MRS) at 3Tesla. In this study, the combination of voxel-based morphometry (VBM) and (1)H-MRS was used to assess the brain morphometric and metabolic alterations in GAD. The patients showed significantly reduced white matter (WM) volumes in the midbrain (MB), precentral gyrus (PrG), dorsolateral prefrontal cortex (DLPFC) and anterior limb of the internal capsule (ALIC) compared to the controls. In MRS study, the choline/creatine (Cho/Cr) and choline/N-acetylaspartate (Cho/NAA) ratios in the DLPFC were significantly lower in the patients. Particularly, the WM volume variation of the DLPFC was positively correlated with both of the Cho/Cr and Cho/NAA ratios in patients with GAD. This study provides an evidence for the association between the morphometric deficit and metabolic changes in GAD. This finding would be helpful to understand the neural dysfunction and pathogenesis in connection with cognitive impairments in GAD.

Explicit verbal memory impairments associated with brain functional deficits and morphological alterations in patients with generalized anxiety disorder

BACKGROUND

Generalized anxiety disorder (GAD) is associated with brain function and morphological alterations. This study investigated explicit verbal memory impairment in patients with GAD in terms of brain functional deficits in combination with morphologic changes.

METHODS

Seventeen patients with GAD and 17 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted MRI and fMR imaging at 3 T during explicit verbal memory tasks with emotionally neutral and anxiety-inducing words.

RESULTS

In response to the neutral words, the patients showed significantly lower activities in the regions of the hippocampus (Hip), middle cingulate gyrus (MCG), putamen (Pu) and head of the caudate nucleus (HCd) compared with healthy controls. In response to the anxiety-inducing words, the patients showed significantly higher activities in the ventrolateral prefrontal cortex and precentral gyrus. However, they showed lower activities in the Hip, MCG, Pu and HCd. In addition, patients with GAD showed a significant reduction in gray matter volumes, especially in the regions of the Hip, midbrain, thalamus, insula and superior temporal gyrus, compared with healthy controls.

LIMITATIONS

This study examined a small sample sizes in each of the groups, and there was no consideration of a medication effect on brain activity and volume changes.

CONCLUSIONS

This study provides evidence for the association between brain functional deficits and morphometric alterations in an explicit verbal memory task for patients with GAD. This finding is helpful for understanding explicit verbal memory impairment in connection with GAD symptoms.

Alterations in white matter volume and its correlation with clinical characteristics in patients with generalized anxiety disorder

INTRODUCTION

Only a few morphological studies have focused on changes in white matter (WM) volume in patients with generalized anxiety disorder (GAD). We evaluated alterations in WM volume and its correlation with symptom severity and duration of illness in adults with GAD.

METHODS

The 44 subjects were comprised of 22 patients with GAD (13 males and nine females) diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and 22 age-matched healthy controls (13 males and nine females). High-resolution magnetic resonance imaging (MRI) data were processed by voxel-based morphometry (VBM) analysis based on diffeomorphic anatomical registration using the exponentiated Lie algebra (DARTEL) algorithm in SPM8.

RESULTS

Patients with GAD showed significantly reduced WM volume, particularly in the dorsolateral prefrontal cortex (DLPFC), anterior limb of the internal capsule (ALIC), and midbrain. In addition, DLPFC volume was negatively correlated with GAD-7 score and illness duration. ALIC volume was negatively correlated with GAD-7 score. Female patients had significantly less orbitofrontal cortex volume compared to that in male patients.

CONCLUSION

The findings demonstrate localized changes in WM volume associated with cognitive and emotional dysfunction in patients with GAD. The finding will be helpful for understanding the neuropathology in patients with GAD.