Evidence of diffuse damage in frontal and occipital cortex in the brain of patients with post-traumatic stress disorder

Persistence of post-traumatic stress disorder in Chinese Shidu parents is associated with combined gray and white matter abnormalities

Post-traumatic stress disorder (PTSD) is one of the most common mental health disorders among Shidu parents. Identification of gray and white matter differences between persistence of PTSD (P-PTSD) and remission of PTSD (R-PTSD) is crucial to determine their prognosis. A total of 37 Shidu parents with PTSD were followed for five years. Surface-based morphometry and diffusion tensor imaging were carried out to analyze the differences in gray and white matter between P-PTSD and R-PTSD. Finally, 30 patients with PTSD were enrolled, including 12 with P-PTSD and 18 with R-PTSD. Compared with patients with R-PTSD, patients with P-PTSD exhibited lower fractional anisotropy (FA) in Cluster 1 (including body of the corpus callosum, superior longitudinal fasciculus, corticospinal tract) and Cluster 2 (including inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, splenium of the corpus callosum) in the left cerebral hemisphere and higher cortical thickness in the right lateral occipital cortex (LOC). In patients with P-PTSD, FA values of Cluster 2 were negatively correlated with cortical thickness of the right LOC. These results suggest that among Shidu parents, differences were observed in gray and white matter between P-PTSD and R-PTSD. Moreover, some certain gray and white matter abnormalities were often present simultaneously in P-PTSD.

Gray matter differences in adults and children with posttraumatic stress disorder: A systematic review and meta-analysis of 113 studies and 11 meta-analyses

BACKGROUND

In this systematic review and meta-analysis, we aimed to provide a comprehensive overview of gray matter alterations of adult- and underage patients with posttraumatic stress disorder (PTSD) in comparison to healthy trauma-exposed (TC) and non-exposed (HC) individuals.

METHODS

We subdivided our groups into patients with PTSD after trauma exposure in adulthood (aa) or childhood (ac) as well as children with PTSD (cc). We identified 113 studies, including 6.800 participants in our review, which we divided into studies focusing on whole-brain and region-of-interest (ROI) analysis. We performed a coordinate-based meta-analysis on 14 studies in the group of aa-PTSD.

RESULTS

We and found lower gray matter volume in patients with PTSD (aa) in the medial frontal gyrus (PTSD<HC/TC) and Culmen/posterior cingulate cortex (PTSD<TC). Results from ROI-based studies mainly show alterations for patients with PTSD in the prefrontal cortex, hippocampus, anterior cingulate cortex, insula, corpus callosum, and amygdala.

LIMITATIONS

Due to a limited number of studies reporting whole-brain results, the meta-analyses could only be performed in one subgroup and within this subgroup for a limited number of studies.

CONCLUSIONS

Our results are in line with psychobiological models of PTSD that associate the identified regions with brain circuits involved in context processing, threat detection and emotion regulation.

Dynamic changes in brain structure in patients with post-traumatic stress disorder after motor vehicle accident: A voxel-based morphometry-based follow-up study

Objectives

To investigate the dynamic changes of emotional and memory-related brain regions in post-traumatic stress disorder (PTSD) patients and trauma-exposed subjects, who experienced motor vehicle accident (MVA).

Materials and methods

Functional Magnetic Resonance imaging (fMRI) and general data were collected from trauma victims who had experienced MVA within 2 days, and their social support and coping style were evaluated. The PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (PCL-5) is used for screening and diagnosis. Subsequently, 17 PTSD patients and 23 car accident trauma-exposed individuals completed a second fMRI scan at 2 months. Data were analyzed by using voxel-based morphometry (VBM) to examine the volume changes of relevant brain regions. Correlation analysis was used to assess the correlation between the regions of interest (ROIs) and the total scores on the clinical scales. Subsequently, the relationship between the total PCL-5 scores and the individual dimensions of the Simplified Coping Style Questionnaire (SCSQ) and the Social Support Rate Scale (SSRS) was studied.

Results

In comparison with the control group, the results showed a reduction in right SFG volume in the PTSD group at 2 months. Similarly, a comparison within the PTSD group revealed a reduction in the left STG volume at 2 months. Compared with the control group, PTSD patients showed a more negative coping style and worse performance in objective and subjective support. In addition, the total PCL-5 scores were negatively associated with positive coping, objective support, and subjective support.

Conclusion

The occurrence of PTSD may be related to reduced volume of the right SFG and left STG, and that patients with PTSD receive less social support and tend to cope in a negative manner in the face of stressful events. These results suggest that within 2 months of the MVA, changes in gray matter volume have occurred in some brain regions of those suffering from PTSD. We believe the results of our study will provide useful insights into the neuropsychological mechanisms underlying PTSD.

Extended functional connectivity of convergent structural alterations among individuals with PTSD: a neuroimaging meta-analysis

Background

Post-traumatic stress disorder (PTSD) is a debilitating disorder defined by the onset of intrusive, avoidant, negative cognitive or affective, and/or hyperarousal symptoms after witnessing or experiencing a traumatic event. Previous voxel-based morphometry studies have provided insight into structural brain alterations associated with PTSD with notable heterogeneity across these studies. Furthermore, how structural alterations may be associated with brain function, as measured by task-free and task-based functional connectivity, remains to be elucidated.

Methods

Using emergent meta-analytic techniques, we sought to first identify a consensus of structural alterations in PTSD using the anatomical likelihood estimation (ALE) approach. Next, we generated functional profiles of identified convergent structural regions utilizing resting-state functional connectivity (rsFC) and meta-analytic co-activation modeling (MACM) methods. Finally, we performed functional decoding to examine mental functions associated with our ALE, rsFC, and MACM brain characterizations.

Results

We observed convergent structural alterations in a single region located in the medial prefrontal cortex. The resultant rsFC and MACM maps identified functional connectivity across a widespread, whole-brain network that included frontoparietal and limbic regions. Functional decoding revealed overlapping associations with attention, memory, and emotion processes.

Conclusions

Consensus-based functional connectivity was observed in regions of the default mode, salience, and central executive networks, which play a role in the tripartite model of psychopathology. Taken together, these findings have important implications for understanding the neurobiological mechanisms associated with PTSD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12993-022-00196-2.

An exploratory study of resting-state functional connectivity of amygdala subregions in posttraumatic stress disorder following trauma in adulthood

We carried out an exploratory study aimed at identifying differences in resting-state functional connectivity for the amygdala and its subregions, right and left basolateral, centromedial and superficial nuclei, in patients with Posttraumatic Stress Disorder (PTSD), relative to controls. The study included 10 participants with PTSD following trauma in adulthood (9 females), and 10 controls (9 females). The results suggest PTSD was associated with a decreased (negative) functional connectivity between the superficial amygdala and posterior brain regions relative to controls. The differences were observed between right superficial amygdala and right fusiform gyrus, and between left superficial amygdala and left lingual and left middle occipital gyri. The results suggest that among PTSD patients, the worse the PTSD symptoms, the lower the connectivity. The results corroborate the fMRI literature that shows PTSD is associated with weaker amygdala functional connectivity with areas of the brain involved in sensory and perceptual processes. The results also suggest that though the patients traumatic experience occured in adulthood, the presence of early traumatic experiences were associated with negative connectivity between the centromedial amygdala and sensory and perceptual regions. We argue that the understanding of the mechanisms of PTSD symptoms, its behaviors and the effects on quality of life of patients may benefit from the investigation of brain function that underpins sensory and perceptual symptoms associated with the disorder.

Evaluation of gray matter reduction in patients with typhoon-related posttraumatic stress disorder using causal network analysis of structural MRI

BACKGROUND

The structural changes recent-onset posttraumatic stress disorder (PTSD) subjects were rarely investigated. This study was to compare temporal and causal relationships of structural changes in recent-onset PTSD with trauma-exposed control (TEC) subjects and non-TEC subjects.

METHODS

T1-weighted magnetic resonance images of 27 PTSD, 33 TEC and 30 age- and sex-matched healthy control (HC) subjects were studied. The causal network of structural covariance was used to evaluate the causal relationships of structural changes in PTSD patients.

RESULTS

Volumes of bilateral hippocampal and left lingual gyrus were significantly smaller in PTSD patients and TEC subjects than HC subjects. As symptom scores increase, reduction in gray matter volume began in the hippocampus and progressed to the frontal lobe, then to the temporal and occipital cortices (p < 0.05, false discovery rate corrected). The hippocampus might be the primary hub of the directional network and demonstrated positive causal effects on the frontal, temporal and occipital regions (p < 0.05, false discovery rate corrected). The frontal regions, which were identified to be transitional points, projected causal effects to the occipital lobe and temporal regions and received causal effects from the hippocampus (p < 0.05, false discovery rate corrected).

CONCLUSIONS

The results offer evidence of localized abnormalities in the bilateral hippocampus and remote abnormalities in multiple temporal and frontal regions in typhoon-exposed PTSD patients.

Structural brain correlates in major depression, anxiety disorders and post-traumatic stress disorder: A voxel-based morphometry meta-analysis

The high comorbidity of Major Depressive Disorder (MDD), Anxiety Disorders (ANX), and Posttraumatic Stress Disorder (PTSD) has hindered the study of their structural neural correlates. The authors analyzed specific and common grey matter volume (GMV) characteristics by comparing them with healthy controls (HC). The meta-analysis of voxel-based morphometry (VBM) studies showed unique GMV diminutions for each disorder (p < 0.05, corrected) and less robust smaller GMV across diagnostics (p < 0.01, uncorrected). Pairwise comparison between the disorders showed GMV differences in MDD versus ANX and in ANX versus PTSD. These results endorse the hypothesis that unique clinical features characterizing MDD, ANX, and PTSD are also reflected by disorder specific GMV correlates.

The Role of the Thalamus in Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) has a high lifetime prevalence and is one of the more serious challenges in mental health care. Fear-conditioned learning involving the amygdala has been thought to be one of the main causative factors; however, recent studies have reported abnormalities in the thalamus of PTSD patients, which may explain the mechanism of interventions such as eye movement desensitization and reprocessing (EMDR). Therefore, I conducted a miniature literature review on the potential contribution of the thalamus to the pathogenesis of PTSD and the validation of therapeutic approaches. As a result, we noticed the importance of the retinotectal pathway (superior colliculus−pulvinar−amygdala connection) and discussed therapeutic indicators.

Common and distinct patterns of gray matter alterations in borderline personality disorder and posttraumatic stress disorder: A dual meta-analysis

BACKGROUND

Borderline personality disorder (BPD) and posttraumatic stress disorder (PTSD) are severe psychiatric disorders and often co-occur, either of the two will seriously threaten to public health. However, we lack ample evidences to understand the potential pathophysiologic mechanisms of gray matter (GM) alterations in the two disorders.

METHODS

We performed a meta-analysis in both BPD (15 datasets including 442 BPD subjects versus 441 healthy controls) and PTSD (11 datasets including 214 PTSD subjects versus 258 healthy controls) applying anisotropic effect-size-based algorithms (AES-SDM) method.

RESULTS

Conjunction analysis found relative GM volume reductions in both disorders in the orbitofrontal gyrus and anterior cingulate cortex, contrarily, differences were predominantly observed that GM volume increased in the posterior cingulate gyrus and precuneus in BPD subjects, and GM volume decreased in the amygdala-hippocampal fear circuit, fusiform gyrus in PTSD subjects.

CONCLUSIONS

Group comparisons and conjunction analyses in BPD and PTSD identified same regions of GM volume reductions in the orbitofrontal gyrus and anterior cingulate cortex, which may provide clues for the neurobiological mechanisms and clinical diagnosis underpinning two disorders.

Reduced gray matter volume in the left prefrontal, occipital, and temporal regions as predictors for posttraumatic stress disorder: a voxel-based morphometric study

The concept of acute stress disorder (ASD) was introduced as a diagnostic entity to improve the identification of traumatized people who are likely to develop posttraumatic stress disorder (PTSD). Neuroanatomical models suggest that changes in the prefrontal cortex, amygdala, and hippocampus play a role in the development of PTSD. Using voxel-based morphometry, this study aimed to investigate the predictive power of gray matter volume (GMV) alterations for developing PTSD. The GMVs of ASD patients (n = 21) were compared to those of PTSD patients (n = 17) and healthy controls (n = 18) in whole-brain and region-of-interest analyses. The GMV alterations seen in ASD patients shortly after the traumatic event (T1) were also correlated with PTSD symptom severity and symptom clusters 4 weeks later (T2). Compared with healthy controls, the ASD patients had significantly reduced GMV in the left visual cortex shortly after the traumatic event (T1) and in the left occipital and prefrontal regions 4 weeks later (T2); no significant differences in GMV were seen between the ASD and PTSD patients. Furthermore, a significant negative association was found between the GMV reduction in the left lateral temporal regions seen after the traumatic event (T1) and PTSD hyperarousal symptoms 4 weeks later (T2). Neither amygdala nor hippocampus alterations were predictive for the development of PTSD. These data suggest that gray matter deficiencies in the left hemispheric occipital and temporal regions in ASD patients may predict a liability for developing PTSD.

Social support modulates the association between PTSD diagnosis and medial frontal volume in Chinese adults who lost their only child

Losing an only child is a devastating life event that a parent can experience and may lead to post-traumatic stress disorder (PTSD). Social support could buffer against the negative influence of this trauma, but the neural mechanism underlying this alleviation effect remains poorly understood. In this study, voxel-based morphometry was conducted on brain MRI of 220 Han Chinese adults who had lost their only child. We performed multiple regression analysis to investigate the associations between social support scores – along with PTSD diagnosis, age, sex, body mass index (BMI) – and brain grey matter (GM) volumes in these bereaved parents. For all trauma-exposed adults, social support-by-diagnosis interaction was significantly associated with medial prefrontal volume (multiple comparisons corrected P ˂ 0.05), where positive correlation was found in adults with PTSD but not in those without PTSD. Besides, PTSD diagnosis was associated with decreased GM volume in medial and middle frontal gyri (P ˂ 0.001, uncorrected); older age was associated with widespread GM volume deficits; male sex was associated with lower GM volume in rolandic operculum, insular, postcentral gyrus (corrected P ˂ 0.05), and lower GM in thalamus but greater GM in parahippocampus (P ˂ 0.001, uncorrected); higher BMI was associated with GM deficits in occipital gyrus (corrected P ˂ 0.05) and precuneus (P ˂ 0.001, uncorrected). In conclusions, social support modulates the association between PTSD diagnosis and medial frontal volume, which may play an important role in the emotional disturbance in PTSD development in adults who lost their only child.

Shared gray matter reductions across alcohol use disorder and posttraumatic stress disorder in the anterior cingulate cortex: A dual meta-analysis

The considerable comorbidity of posttraumatic stress disorder (PTSD) and alcohol use disorders (AUD) poses a greater public health burden than either condition alone. Although there is a substantial body of evidence linking the direct neurotoxic effect of heavy drinking to gray matter (GM) deficits, as well as a growing body of literature supporting a strong association between PTSD and GM alterations, there is scant research interrogating the direct interaction of the two disorders. In order to generate data-driven, specific hypotheses regarding the overlapping neural substrates of PTSD and AUD, we conducted a meta-analysis of GM volumes in each disorder relative to healthy control subjects. We found shared GM deficits in the anterior cingulate cortex (ACC) across both disorders relative to healthy control participants. These findings suggest that reduced volumes of the ACC across PTSD and AUD may have implications for the development, expression, or treatment of symptoms linked to these frequently co-existing disorders. Recommendations are made for future work aimed at delineating the specific and shared effects of traumatic stress and alcoholism on neural integrity.

Brain atrophy in the visual cortex and thalamus induced by severe stress in animal model

Psychological stress induces many diseases including post-traumatic stress disorder (PTSD); however, the causal relationship between stress and brain atrophy has not been clarified. Applying single-prolonged stress (SPS) to explore the global effect of severe stress, we performed brain magnetic resonance imaging (MRI) acquisition and Voxel-based morphometry (VBM). Significant atrophy was detected in the bilateral thalamus and right visual cortex. Fluorescent immunohistochemistry for Iba-1 as the marker of activated microglia indicates regional microglial activation as stress-reaction in these atrophic areas. These data certify the impact of severe psychological stress on the atrophy of the visual cortex and the thalamus. Unexpectedly, these results are similar to chronic neuropathic pain rather than PTSD clinical research. We believe that some sensitisation mechanism from severe stress-induced atrophy in the visual cortex and thalamus, and the functional defect of the visual system may be a potential therapeutic target for stress-related diseases.

Frontal and subcortical grey matter reductions in PTSD

Post-traumatic stress disorder (PTSD) is characterised by a range of debilitating psychological, physical and cognitive symptoms. PTSD has been associated with grey matter atrophy in limbic and frontal cortical brain regions. However, previous studies have reported heterogeneous findings, with grey matter changes observed beyond limbic/frontal areas. Seventy-five adults were recruited from the community, 25 diagnosed with PTSD along with 25 healthy and 25 trauma exposed age and gender matched controls. Participants underwent clinical assessment and magnetic resonance imaging. The data-analyses method Voxel Based Morphometry (VBM) was used to estimate cortical grey matter volumes. When compared to both healthy and trauma exposed controls, PTSD subjects demonstrated decreased grey matter volumes within subcortical brain regions-including the hippocampus and amygdala-along with reductions in the anterior cingulate cortex, frontal medial cortex, middle frontal gyrus, superior frontal gyrus, paracingulate gyrus, and precuneus cortex. Significant negative correlations were found between total CAPS lifetime clinical scores/sub-scores and GM volume of both the PTSD and TC groups. GM volumes of the left rACC and right amygdala showed a significant negative correlation within PTSD diagnosed subjects.

A systematic review on comorbid post-traumatic stress disorder in schizophrenia

Post-traumatic stress disorder (PTSD) appears to commonly co-occur with schizophrenia, which is widely considered the most disabling mental illness. Both conditions share neurological risk factors, and present with symptoms that are superficially similar, complicating diagnostic accuracy. The presence of comorbid PTSD is also of concern as additional diagnoses tend to worsen functioning and quality of life. In the current review, EMBASE, Medline, and PsycINFO were searched for articles pertaining to PTSD comorbidity in schizophrenia spectrum disorders. Articles went through two stages of review prior to inclusion - one at the abstract level and another at the full-text level. Thirty-four articles were ultimately included in the present review. Prevalence of PTSD in schizophrenia ranged from 0 to 57%, likely due to study heterogeneity. Findings generally indicated that comorbid PTSD was associated with higher levels of positive symptoms, general psychopathology, and neurocognitive impairment, as well as worse functioning and quality of life. As such, it is important for clinicians to differentiate between psychotic and PTSD symptoms, and to pay attention to the associated features of comorbid PTSD in order to provide the most appropriate intervention. Unfortunately, epidemiological and longitudinal studies in this area are lacking.

Multimodal MRI-Based Classification of Trauma Survivors with and without Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a debilitating psychiatric disorder. It can be difficult to discern the symptoms of PTSD and obtain an accurate diagnosis. Different magnetic resonance imaging (MRI) modalities focus on different aspects, which may provide complementary information for PTSD discrimination. However, none of the published studies assessed the diagnostic potential of multimodal MRI in identifying individuals with and without PTSD. In the current study, we investigated whether the complementary information conveyed by multimodal MRI scans could be combined to improve PTSD classification performance. Structural and resting-state functional MRI (rs-fMRI) scans were conducted on 17 PTSD patients, 20 trauma-exposed controls without PTSD (TEC) and 20 non-traumatized healthy controls (HC). Gray matter volume (GMV), amplitude of low-frequency fluctuations (ALFF), and regional homogeneity were extracted as classification features, and in order to integrate the information of structural and functional MRI data, the extracted features were combined by a multi-kernel combination strategy. Then a support vector machine (SVM) classifier was trained to distinguish the subjects at individual level. The performance of the classifier was evaluated using the leave-one-out cross-validation (LOOCV) method. In the pairwise comparison of PTSD, TEC, and HC groups, classification accuracies obtained by the proposed approach were 2.70, 2.50, and 2.71% higher than the best single feature way, with the accuracies of 89.19, 90.00, and 67.57% for PTSD vs. HC, TEC vs. HC, and PTSD vs. TEC respectively. The proposed approach could improve PTSD identification at individual level. Additionally, it provides preliminary support to develop the multimodal MRI method as a clinical diagnostic aid.

Current Status of Transcranial Direct Current Stimulation in Posttraumatic Stress and Other Anxiety Disorders

Several empirically supported treatments have been identified for post-traumatic stress disorder (PTSD), yet a sizable number of patients are either unable to tolerate these approaches or remain symptomatic following treatment. Transcranial direct current stimulation (tDCS) is a well-tolerated method of modulating neuronal excitability that may hold promise as a novel intervention in PTSD and related disorders. The current review summarizes literature on the disrupted neural circuitry in PTSD and discusses the rationale for the commonly targeted prefrontal cortex (PFC) as it relates to PTSD. We then review the few prior (case) studies that have evaluated tDCS in patients with PTSD (1 study) and other anxiety disorders (4 studies). There was considerable variability in both the methods/justification for selecting the targeted brain region(s) and the tDCS montage used, which obscured any clear trends in the data. Finally, we describe the rationale for our ongoing study that specifically targets the lateral temporal cortex as a method of treating the symptoms of hyperarousal and re-experiencing in PTSD. Overall, it is clear that additional work is needed to establish dosing (e.g., intensity and duration of sessions, number of sessions) and optimal treatment targets as well as to identify synergistic effects with existing treatments.

Breakdown of Inter-Hemispheric Connectivity Is Associated with Posttraumatic Symptomatology and Memory Impairment

Altered brain anatomy in specific gray-matter regions has been shown in patients with posttraumatic stress disorder (PTSD). Recently, white-matter tracts have become a focus of research in PTSD. The corpus callosum (CC) is the principal white-matter fiber bundle, crucial in relaying sensory, motor and cognitive information between hemispheres. Alterations in CC fibers have been reported in PTSD and might be assumed to underlie substantial behavioral and cognitive sequelae; however most diffusion tensor imaging (DTI) studies in adult-onset PTSD failed to address the clinical correlates between imaging and PTSD symptoms severity, behavioral manifestation and cognitive functions. In the current study we examined (a) to what extent microstructural integrity of the CC is associated with memory performance and (b) whether imaging and cognitive parameters are associated with PTSD symptom severity. DTI data were obtained and fractional anisotropy (FA) values were computed for 16 patients and 14 controls. PTSD symptom severity was assessed by employing the clinician administered PTSD scale (CAPS) and memory was tested using a task probing item and associative memory for words and pictures. Significant correlations were found between PTSD symptoms severity, memory accuracy and reaction-time to CC FA values in the PTSD group. This study demonstrates meaningful clinical and cognitive correlates of microstructural connectivity. These results have implications for diagnostic tools and future studies aimed at identifying individuals at risk for PTSD.

Oxytocin affects spontaneous neural oscillations in trauma-exposed war veterans

Exposure to combat-related trauma often leads to lifetime functional impairments. Previous research demonstrated the effects of oxytocin (OT) administration on brain regions implicated in post-traumatic stress disorder (PTSD); yet OT’s effects on brain patterns in trauma-exposed veterans have not been studied. In the current study the effects of OT on spontaneous brain oscillatory activity were measured in 43 veterans using magnetoencephalography (MEG): 28 veterans who were exposed to a combat-related trauma and 15 trauma-unexposed controls. Participants participated in two experimental sessions and were administered OT or placebo (PBO) in a double-blind, placebo-control, within-subject design. Following OT/PBO administration, participants underwent a whole-head MEG scan. Plasma and salivary OT levels were assessed each session. Spontaneous brain activity measured during a 2-min resting period was subjected to source-localization analysis. Trauma-exposed veterans showed higher resting-state alpha (8–13 Hz) activity compared to controls in the left dorsolateral prefrontal cortex (dlPFC), specifically in the superior frontal gyrus (SFG) and the middle frontal gyrus (MFG), indicating decreased neural activity in these regions. The higher alpha activity was “normalized” following OT administration and under OT, group differences were no longer found. Increased resting-state alpha was associated with lower baseline plasma OT, reduced salivary OT reactivity, and more re-experiencing symptoms. These findings demonstrate effects of OT on resting-state brain functioning in prefrontal regions subserving working memory and cognitive control, which are disrupted in PTSD. Results raise the possibility that OT, traditionally studied in social contexts, may also enhance performance in cognitive tasks associated with working memory and cognitive control following trauma exposure.

Risperidone Attenuates Modified Stress-Re-stress Paradigm-Induced Mitochondrial Dysfunction and Apoptosis in Rats Exhibiting Post-traumatic Stress Disorder-Like Symptoms

Mitochondria play a significant role in the pathophysiology of post-traumatic stress disorder (PTSD). Risperidone and paroxetine were evaluated for their effect on mitochondrial dysfunction and mitochondria-dependent apoptosis in discrete brain regions in modified stress re-stress (SRS) animal model of PTSD. Male rats were subjected to stress protocol of 2 h restraint and 20 min forced swim followed by halothane anesthesia on day 2 (D-2). Thereafter, rats were exposed to re-stress (forced swim) on D-8 and at 6-day intervals on D-14, D-20, D-26, and D-32. The rats were treated with risperidone (0.01, 0.1, and 1.0 mg/kg p.o.) and paroxetine (10.0 mg/kg p.o.) from D-8 to D-32. Risperidone at median dose and paroxetine ameliorated modified SRS-induced depressive-like symptom (increase in immobility period) in forced swim, anxiety-like behavior (decrease in percentage of open arm entries and time spent) in elevated plus maze and cognitive deficits (loss in spatial recognition memory) in Y-maze tests on D-32. Risperidone, but not paroxetine, attenuated modified SRS-induced decreases in plasma corticosterone levels. Risperidone ameliorated increase in the activity of mitochondrial respiratory complex (I, II, IV, and V), decreases in the levels of mitochondrial membrane potential, cytochrome-C and caspase-9 in the hippocampus, hypothalamus, pre-frontal cortex, and amygdala. However, both drugs attenuated modified SRS-induced increase in the number of apoptotic cells and caspase-3 levels in all the brain regions indicating anti-apoptotic activity of these drugs. Hence, these results suggest that anti-apoptotic activity could be a common mechanism for anti-PTSD-like effect irrespective of the pathways of apoptosis in the modified SRS model.

Altered blood oxygen level-dependent signal variability in chronic post-traumatic stress disorder during symptom provocation

BACKGROUND

Recent research suggests that variability in brain signal provides important information about brain function in health and disease. However, it is unknown whether blood oxygen level-dependent (BOLD) signal variability is altered in post-traumatic stress disorder (PTSD). We aimed to identify the BOLD signal variability changes of PTSD patients during symptom provocation and compare the brain patterns of BOLD signal variability with those of brain activation.

METHODS

Twelve PTSD patients and 14 age-matched controls, who all experienced a mining accident, underwent clinical assessment as well as fMRI scanning while viewing trauma-related and neutral pictures. BOLD signal variability and brain activation were respectively examined with standard deviation (SD) and general linear model analysis, and compared between the PTSD and control groups. Multiple regression analyses were conducted to explore the association between PTSD symptom severity and these two brain measures across all subjects as well as in the PTSD group.

RESULTS

PTSD patients showed increased activation in the middle occipital gyrus compared with controls, and an inverse correlation was found between PTSD symptom severity and brain activation in the hippocampus and anterior cingulate cortex/medial prefrontal cortex. Brain variability analysis revealed increased SD in the insula, anterior cingulate cortex/medial prefrontal cortex, and vermis, and decreased SD in the parahippocapal gyrus, dorsolateral prefrontal cortex, somatosensory cortex, and striatum. Importantly, SD alterations in several regions were found in both traumatic and neutral conditions and were stratified by PTSD symptom severity.

CONCLUSION

BOLD signal variability may be a reliable and sensitive biomarker of PTSD, and combining brain activation and brain variability analysis may provide complementary insight into the neural basis of this disorder.

Altered spontaneous neuronal activity of visual cortex and medial anterior cingulate cortex in treatment-naïve posttraumatic stress disorder

BACKGROUND

Although no more traumatic stimuli exists, a variety of symptoms are persisting in chronic Posttraumatic Stress Disorder (PTSD) patients. It is therefore necessary to explore the spontaneous brain activity of treatment-naïve PTSD patients during resting-state.

METHOD

Seventeen treatment-naïve PTSD patients and twenty traumatized controls were recruited and underwent a resting functional magnetic resonance imaging (Rs-fMRI) scan. The differences of regional brain spontaneous activity between the participants with and without PTSD were measured by Amplitude of Low-frequency fluctuation (ALFF). The relationship between the altered brain measurements and the symptoms of PTSD were analyzed.

RESULT

Compared to traumatized controls, the PTSD group showed significantly altered ALFF in many emotion-related brain regions, such as the medial anterior cingulate cortex (MACC), dorsolateral prefrontal cortex (DLPFC), insular (IC), middle temporal gyrus (MTG), and ventral posterior cingulate cortex (VPCC). Interestingly this is the first report of a hyperactive visual cortex (V1/V2) during resting-state in treatment-naïve PTSD patients. There were significant positive correlations between ALFF values in the bilateral visual cortex and re-experiencing or avoidance in PTSD. Negative correlation was observed between ALFF values in MACC and avoidance.

CONCLUSION

This study suggested that the visual cortex and the MACC may be involved in the characteristic symptoms of chronic PTSD, such as re-experiencing and avoidance. Future studies that focus on these areas of the brain are required, as alteration of these areas may act as a biomarker and could be targeted in future treatments for PTSD.

Anatomical deficits in adult posttraumatic stress disorder: a meta-analysis of voxel-based morphometry studies

Evidence from previous anatomical studies indicate that widespread brain regions are involved in the pathogenesis of posttraumatic stress disorder (PTSD). The aim of the present study was to quantitatively integrate the literature on structural abnormalities seen on individuals with PTSD. Twenty voxel-based analysis studies were analysed through a comprehensive series of meta-analyses. Compared with healthy controls, PTSD patients showed a significant reduction in grey matter (GM) in the left anterior cingulate gyrus (ACC) at the whole-brain level. Several brain regions, including the left ACC, the left insula and the right parahippocampal gyrus were significantly smaller in individuals with PTSD than in trauma-exposed healthy subjects. Furthermore, the clinician-administered PTSD scale scores were negatively correlated with GM in the left ACC and positively correlated with GM in the left insula. In addition, PTSD patients who experienced accidental or non-accidental trauma had anatomical changes in different brain regions. These results suggest that the smaller ACC and insular cortex within the limbic-prefrontal circuit contribute to the pathogenesis of PTSD. Moreover, the PTSD patients with different types of trauma may have different cerebral deficits.

Quantitative prediction of individual psychopathology in trauma survivors using resting-state FMRI

Neuroimaging techniques hold the promise that they may one day aid the clinical assessment of individual psychiatric patients. However, the vast majority of studies published so far have been based on average differences between groups. This study employed a multivariate approach to examine the potential of resting-state functional magnetic resonance imaging (MRI) data for making accurate predictions about psychopathology in survivors of the 2008 Sichuan earthquake at an individual level. Resting-state functional MRI data was acquired for 121 survivors of the 2008 Sichuan earthquake each of whom was assessed for symptoms of post-traumatic stress disorder (PTSD) using the 17-item PTSD Checklist (PCL). Using a multivariate analytical method known as relevance vector regression (RVR), we examined the relationship between resting-state functional MRI data and symptom scores. We found that the use of RVR allowed quantitative prediction of clinical scores with statistically significant accuracy (correlation=0.32, P=0.006; mean squared error=176.88, P=0.001). Accurate prediction was based on functional activation in a number of prefrontal, parietal, and occipital regions. This is the first evidence that neuroimaging techniques may inform the clinical assessment of trauma-exposed individuals by providing an accurate and objective quantitative estimation of psychopathology. Furthermore, the significant contribution of parietal and occipital regions to such estimation challenges the traditional view of PTSD as a disorder specific to the fronto-limbic network.

Vestibular insights into cognition and psychiatry

The vestibular system has traditionally been thought of as a balance apparatus; however, accumulating research suggests an association between vestibular function and psychiatric and cognitive symptoms, even when balance is measurably unaffected. There are several brain regions that are implicated in both vestibular pathways and psychiatric disorders. The present review examines the anatomical associations between the vestibular system and various psychiatric disorders. Despite the lack of direct evidence for vestibular pathology in the key psychiatric disorders selected for this review, there is a substantial body of literature implicating the vestibular system in each of the selected psychiatric disorders. The second part of this review provides complimentary evidence showing the link between vestibular dysfunction and vestibular stimulation upon cognitive and psychiatric symptoms. In summary, emerging research suggests the vestibular system can be considered a potential window for exploring brain function beyond that of maintenance of balance, and into areas of cognitive, affective and psychiatric symptomology. Given the paucity of biological and diagnostic markers in psychiatry, novel avenues to explore brain function in psychiatric disorders are of particular interest and warrant further exploration.

Voxel-based morphometric gray matter correlates of posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is associated with functional abnormalities within a neurocircuitry that includes the hippocampus, amygdala, and medial prefrontal cortex. Evidence of structural abnormalities within these regions, and their association with PTSD severity and symptom burden is, however, sparse. The present study evaluated the relation between indices of gray matter volume and PTSD symptom severity using voxel-based morphometry. Fifteen individuals meeting DSM-IV criteria for PTSD completed the Clinician Administered PTSD Scale and underwent structural magnetic resonance imaging. Greater PTSD severity and avoidance/numbing were correlated with increased gray matter volume of the right amygdala-hippocampal complex. Greater hyper-arousal was associated with reduced gray matter volume in the left superior medial frontal gyrus. Findings are consistent with current neurocircuitry models of PTSD, which posit that the disorder is associated with structural and functional variance within this distributed network.

Reduced cortical thickness with increased lifetime burden of PTSD in OEF/OIF Veterans and the impact of comorbid TBI

Posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) in military personnel is increasing dramatically following the OEF/OIF conflicts and is associated with alterations to brain structure. The present study examined the relationship between PTSD and cortical thickness, and its possible modification by mTBI, in a 104-subject OEF/OIF veteran cohort ranging in age from 20 to 62 years. For each participant, two T1-weighted scans were averaged to create high-resolution images for calculation of regional cortical thickness. PTSD symptoms were assessed using the Clinician Administered PTSD Scale (CAPS) and scores were derived based on the previous month's symptoms (“current”) and a Cumulative Lifetime Burden of PTSD (CLB-P) reflecting the integral of CAPS scores across the lifetime. Mild TBI was diagnosed using the Boston Assessment of TBI-Lifetime (BAT-L). Results demonstrated a clear negative relationship between current PTSD severity and thickness in both postcentral gyri and middle temporal gyri. This relationship was stronger and more extensive when considering lifetime burden (CLB-P), demonstrating the importance of looking at trauma in the context of an individual's lifetime, rather than only at their current symptoms. Finally, interactions with current PTSD only and comorbid current PTSD and mTBI were found in several regions, implying an additive effect of lifetime PTSD and mTBI on cortical thickness.

Yoga meditation practitioners exhibit greater gray matter volume and fewer reported cognitive failures: results of a preliminary voxel-based morphometric analysis

Hatha yoga techniques, including physical postures (asanas), breathing exercises (pranayama), and meditation, involve the practice of mindfulness. In turn, yoga meditation practices may induce the state of mindfulness, which, when evoked recurrently through repeated practice, may accrue into trait or dispositional mindfulness. Putatively, these changes may be mediated by experience-dependent neuroplastic changes. Though prior studies have identified differences in gray matter volume (GMV) between long-term mindfulness practitioners and controls, no studies to date have reported on whether yoga meditation is associated with GMV differences. The present study investigated GMV differences between yoga meditation practitioners (YMP) and a matched control group (CG). The YMP group exhibited greater GM volume in frontal, limbic, temporal, occipital, and cerebellar regions; whereas the CG had no greater regional greater GMV. In addition, the YMP group reported significantly fewer cognitive failures on the Cognitive Failures Questionnaire (CFQ), the magnitude of which was positively correlated with GMV in numerous regions identified in the primary analysis. Lastly, GMV was positively correlated with the duration of yoga practice. Results from this preliminary study suggest that hatha yoga practice may be associated with the promotion of neuroplastic changes in executive brain systems, which may confer therapeutic benefits that accrue with repeated practice.

Supra-normal stimulation of dopamine D1 receptors in the prelimbic cortex blocks behavioral expression of both aversive and rewarding associative memories through a cyclic-AMP-dependent signaling pathway

Dopamine (DA) receptor transmission through either D(1) or D(2)-like subtypes is involved critically in the processing of emotional information within the medial prefrontal cortex (mPFC). However the functional role of specific DA D(1)-like receptor transmission in the expression of emotionally salient associative memories (either aversive or rewarding) is not currently understood. Here we demonstrate that specific activation of DA D(1) receptors in the prelimbic (PLC) division of the mPFC causes a transient block in the behavioral expression of both aversive and rewarding associative memories. We report that intra-PLC microinfusions of a selective D(1) receptor agonist block the spontaneous expression of an associative olfactory fear memory, without altering the stability of the original memory trace. Furthermore, using an unbiased place conditioning procedure (CPP), intra-PLC D(1) receptor activation blocks the spontaneous expression of an associative morphine (5 mg/kg; i.p.) reward memory, while leaving morphine-primed memory expression intact. Interestingly, both intra-PLC D(1)-receptor mediated block of either fear-related or reward-related associative memories were dependent upon downstream cyclic-AMP (cAMP) signaling as both effects were rescued by co-administration of a cAMP signaling inhibitor. The blockade of both rewarding and aversive associative memories is mediated through a D(1)-specific signaling pathway, as neither forms of spontaneous memory expression were blocked by intra-PLC microinfusions of a D(2)-like receptor agonist. Our results demonstrate that the spontaneous expression of either rewarding or aversive emotionally salient memories shares a common, D(1)-receptor mediated substrate within the mPFC.

White matter integrity in highly traumatized adults with and without post-traumatic stress disorder

Prior structural imaging studies of post-traumatic stress disorder (PTSD) have observed smaller volumes of the hippocampus and cingulate cortex, yet little is known about the integrity of white matter connections between these structures in PTSD samples. The few published studies using diffusion tensor imaging (DTI) to measure white matter integrity in PTSD have described individuals with focal trauma rather than chronically stressed individuals, which limits generalization of findings to this population; in addition, these studies have lacked traumatized comparison groups without PTSD. The present DTI study examined microstructural integrity of white matter tracts in a sample of highly traumatized African-American women with (n=25) and without (n=26) PTSD using a tract-based spatial statistical approach, with threshold-free cluster enhancement. Our findings indicated that, relative to comparably traumatized controls, decreased integrity (measured by fractional anisotropy) of the posterior cingulum was observed in participants with PTSD (p<0.05). These findings indicate that reduced microarchitectural integrity of the cingulum, a white matter fiber that connects the entorhinal and cingulate cortices, appears to be associated with PTSD symptomatology. The role of this pathway in problems that characterize PTSD, such as inadequate extinction of learned fear, as well as attention and explicit memory functions, are discussed.

Accuracy and reliability of automated gray matter segmentation pathways on real and simulated structural magnetic resonance images of the human brain

Automated gray matter segmentation of magnetic resonance imaging data is essential for morphometric analyses of the brain, particularly when large sample sizes are investigated. However, although detection of small structural brain differences may fundamentally depend on the method used, both accuracy and reliability of different automated segmentation algorithms have rarely been compared. Here, performance of the segmentation algorithms provided by SPM8, VBM8, FSL and FreeSurfer was quantified on simulated and real magnetic resonance imaging data. First, accuracy was assessed by comparing segmentations of twenty simulated and 18 real T1 images with corresponding ground truth images. Second, reliability was determined in ten T1 images from the same subject and in ten T1 images of different subjects scanned twice. Third, the impact of preprocessing steps on segmentation accuracy was investigated. VBM8 showed a very high accuracy and a very high reliability. FSL achieved the highest accuracy but demonstrated poor reliability and FreeSurfer showed the lowest accuracy, but high reliability. An universally valid recommendation on how to implement morphometric analyses is not warranted due to the vast number of scanning and analysis parameters. However, our analysis suggests that researchers can optimize their individual processing procedures with respect to final segmentation quality and exemplifies adequate performance criteria.