Disruptions in cortico-subcortical covariance networks associated with anxiety in new-onset childhood epilepsy

Shared and distinct morphometric similarity network abnormalities in generalized anxiety disorder, posttraumatic stress disorder and social anxiety disorder

BACKGROUND

The high comorbidity and symptom overlap of generalized anxiety disorder (GAD), posttraumatic stress disorder (PTSD), and social anxiety disorder (SAD), has led to the study of their shared and disorder-specific neural substrates. However, the morphometric similarity network (MSN) differences among these disorders remain unknown.

METHODS

MSN derived from T1-weighted images in patients of GAD, PTSD, and SAD, and health controls (HC) using a Siemens 3T magnetic resonance imaging system. Covariance analysis and post hoc tests were used to investigate group differences. In addition, the relationship between MSN and clinical characteristics was analyzed.

RESULTS

Increased morphometric similarity (MS) between left bankssts (BA22, superior temporal cortex, STC) and right precentral gyrus, and decreased MS between left precentral gyrus and right cuneus_part1/part2, and between right rostral middle frontal cortex (rMFC) and right STC were common in GAD and PTSD relative to HC and SAD. Compared to the other three groups, SAD exhibited disorder-specific alterations of increased MS between right rMFC and right STC, and between left cuneus and right inferior parietal cortex. Additionally, increased regional MSN in left precentral gyrus was found in PTSD compared to HC and SAD. A mild positive correlation of the MS value between left bankssts and right precentral gyrus and the Hamilton Anxiety Rating Scale scores (uncorrected p = 0.041) was found in PTSD.

CONCLUSIONS

Our study provides the first evidence for common and distinct brain MSN abnormalities underlying the pathophysiology of GAD, PTSD, and SAD, which may aid in differential diagnosis and determining potential disorder-specific intervention targets.

Progressive Brain Structural Impairment Assessed via Network and Causal Analysis in Patients With Hepatitis B Virus-Related Cirrhosis

Objectives

This research amid to elucidate the disease stage-specific spatial patterns and the probable sequences of gray matter (GM) deterioration as well as the causal relationship among structural network components in hepatitis B virus-related cirrhosis (HBV-RC) patients.

Methods

Totally 30 HBV-RC patients and 38 healthy controls (HC) were recruited for this study. High-resolution T1-weighted magnetic resonance imaging and psychometric hepatic encephalopathy score (PHES) were evaluated in all participants. Voxel-based morphometry (VBM), structural covariance network (SCN), and causal SCN (CaSCN) were applied to identify the disease stage-specific GM abnormalities in morphology and network, as well as their causal relationship.

Results

Compared to HC (0.443 ± 0.073 cm3), the thalamus swelled significantly in the no minimal hepatic encephalopathy (NMHE) stage (0.607 ± 0.154 cm3, p <0.05, corrected) and further progressed and expanded to the bilateral basal ganglia, the cortices, and the cerebellum in the MHE stage (p < 0.05, corrected). Furthermore, the thalamus swelling had a causal effect on other parts of cortex-basal ganglia-thalamus circuits (p < 0.05, corrected), which was negatively correlated with cognitive performance (r = −0.422, p < 0.05). Moreover, the thalamus-related SCN also displayed progressive deterioration as the disease advanced in HBV-RC patients (p < 0.05, corrected).

Conclusion

Progressive deterioration of GM morphology and SCN exists in HBV-RC patients during advanced disease, displaying thalamus-related causal effects. These findings indicate that bilateral thalamus morphology as well as the thalamus-related network may serve as an in vivo biomarker for monitoring the progression of the disease in HBV-RC patients.

An updated systematic review and meta-analysis of brain network organization in focal epilepsy: Looking back and forth

Abnormalities of the brain network organization in focal epilepsy have been extensively quantified. However, the extent and directionality of abnormalities are highly variable and subtype insensitive. We conducted meta-analyses to obtain a more accurate and epilepsy type-specific quantification of the interictal global brain network organization in focal epilepsy. By using random-effects models, we estimated differences in average clustering coefficient, average path length, and modularity between patients with focal epilepsy and controls, based on 45 studies with a total sample size of 1,468 patients and 1,021 controls. Structural networks had a significant lower level of integration in patients with epilepsy as compared to controls, with a standardized mean difference of -0.334 (95 % confidence interval -0.631 to -0.038; p-value 0.027). Functional networks did not differ between patients and controls, except for the beta band clustering coefficient. Our meta-analyses show that differences in the brain network organization are not as well defined as individual studies often propose. We discuss potential pitfalls and suggestions to enhance the yield and clinical value of network studies.

Longitudinal changes in emotional functioning following pediatric resective epilepsy surgery: 2-Year follow-up

OBJECTIVE

To examine longitudinal changes and predictors of depression and anxiety 2 years following resective epilepsy surgery, compared to no surgery, in children with drug-resistant epilepsy (DRE).

METHOD

This multicenter cohort study involved 128 children and adolescents with DRE (48 surgical, 80 nonsurgical; 8-18 years) who completed self-report measures of depression and anxiety at baseline and follow-up (6-month, 1-year, 2-year). Child demographic (age, sex, IQ) and seizure (age at onset, duration, frequency, site and side) variables were collected.

RESULTS

Linear mixed-effects models controlling for age at enrolment found a time by treatment by seizure outcome interaction for depression. A negative linear trend across time (reduction in symptoms) was found for surgical patients, irrespective of seizure outcome. In contrast, the linear trend differed depending on seizure outcome in nonsurgical patients; a negative trend was found for those with continued seizures, whereas a positive trend (increase in symptoms) was found for those who achieved seizure freedom. Only a main effect of time was found for anxiety indicating a reduction in symptoms across patient groups. Multivariate regressions failed to find baseline predictors of depression or anxiety at 2-year follow-up in surgical patients. Older age, not baseline anxiety or depression, predicted greater symptoms of anxiety and depression at 2-year follow-up in nonsurgical patients.

CONCLUSION

Children with DRE reported improvement in anxiety and depression, irrespective of whether they achieve seizure control, across the 2 years following surgery. In contrast, children with DRE who did not undergo surgery, but achieved seizure freedom, reported worsening of depressive symptoms, which may indicate difficulty adjusting to life without seizures and highlight the potential need for ongoing medical and psychosocial follow-up and support.

Neural correlates of verbal working memory in children with epilepsy with centro-temporal spikes

BACKGROUND

Previous functional magnetic resonance imaging (fMRI) studies have identified brain systems underlying different components of working memory (WM) in healthy subjects. The aim of this study was to compare the functional integrity of these neural networks in children with self-limited childhood epilepsy with centro-temporal spikes (ECTS) as compared to healthy controls, using a verbal working memory task (WMT).

METHODS

Functional MRI of WM in seventeen 6-to-13 year-old children, diagnosed with ECTS, and 17 sex- and age-matched healthy controls were conducted at 3 T. To estimate BOLD responses during the maintenance of low, medium, and high WMT loads, we used a Sternberg verbal WMT. Neuropsychological testing prior to scanning and behavioral data during scanning were also acquired.

RESULTS

Behavioral performances during WMT, in particular accuracy and response time, were poorer in children with ECTS than in controls. Increased WM load was associated with increased BOLD signal in all subjects, with significant clusters detected in frontal and parietal regions, predominantly in the left hemisphere. However, under the high load condition, patients showed reduced activation in the frontal, temporal and parietal regions as compared to controls. In brain regions where WM-triggered BOLD activation differed between groups, this activation correlated with neuropsychological performances in healthy controls but not in patients with ECTS, further suggesting WM network dysfunction in the latter.

CONCLUSION

Children with ECTS differ from healthy controls in how they control WM processes during tasks with increasing difficulty level, notably for high WM load where patients demonstrate both reduced BOLD activation and behavioral performances.

Network, clinical and sociodemographic features of cognitive phenotypes in temporal lobe epilepsy

This study explored the taxonomy of cognitive impairment within temporal lobe epilepsy and characterized the sociodemographic, clinical and neurobiological correlates of identified cognitive phenotypes. 111 temporal lobe epilepsy patients and 83 controls (mean ages 33 and 39, 57% and 61% female, respectively) from the Epilepsy Connectome Project underwent neuropsychological assessment, clinical interview, and high resolution 3T structural and resting-state functional MRI. A comprehensive neuropsychological test battery was reduced to core cognitive domains (language, memory, executive, visuospatial, motor speed) which were then subjected to cluster analysis. The resulting cognitive subgroups were compared in regard to sociodemographic and clinical epilepsy characteristics as well as variations in brain structure and functional connectivity. Three cognitive subgroups were identified (intact, language/memory/executive function impairment, generalized impairment) which differed significantly, in a systematic fashion, across multiple features. The generalized impairment group was characterized by an earlier age at medication initiation (P < 0.05), fewer patient (P < 0.001) and parental years of education (P < 0.05), greater racial diversity (P < 0.05), and greater number of lifetime generalized seizures (P < 0.001). The three groups also differed in an orderly manner across total intracranial (P < 0.001) and bilateral cerebellar cortex volumes (P < 0.01), and rate of bilateral hippocampal atrophy (P < 0.014), but minimally in regional measures of cortical volume or thickness. In contrast, large-scale patterns of cortical-subcortical covariance networks revealed significant differences across groups in global and local measures of community structure and distribution of hubs. Resting-state fMRI revealed stepwise anomalies as a function of cluster membership, with the most abnormal patterns of connectivity evident in the generalized impairment group and no significant differences from controls in the cognitively intact group. Overall, the distinct underlying cognitive phenotypes of temporal lobe epilepsy harbor systematic relationships with clinical, sociodemographic and neuroimaging correlates. Cognitive phenotype variations in patient and familial education and ethnicity, with linked variations in total intracranial volume, raise the question of an early and persisting socioeconomic-status related neurodevelopmental impact, with additional contributions of clinical epilepsy factors (e.g., lifetime generalized seizures). The neuroimaging features of cognitive phenotype membership are most notable for disrupted large scale cortical-subcortical networks and patterns of functional connectivity with bilateral hippocampal and cerebellar atrophy. The cognitive taxonomy of temporal lobe epilepsy appears influenced by features that reflect the combined influence of socioeconomic, neurodevelopmental and neurobiological risk factors.

Phenotype Network and Brain Structural Covariance Network of Anxiety

Network-based approach for psychological phenotypes assumes the dynamical interactions among the psychiatric symptoms, psychological characteristics, and neurocognitive performances arise, as they coexist, propagate, and inhibit other components within the network of mental phenomena. For differential types of dataset from which the phenotype network is to be estimated, a Gaussian graphical model, an Ising model, a directed acyclic graph, or an intraindividual covariance network could be used. Accordingly, these network-based approaches for anxiety-related psychological phenomena have been helpful in quantitative and pictorial understanding of qualitative dynamics among the diverse psychological phenomena as well as mind-environment interactions. Brain structural covariance refers to the correlative patterns of diverse brain morphological features among differential brain regions comprising the brain, as calculated per participant or across the participants. These covarying patterns of brain morphology partly overlap with longitudinal patterns of brain cortical maturation and also with propagating pattern of brain morphological changes such as cortical thinning and brain volume reduction in patients diagnosed with neurologic or psychiatric disorders along the trajectory of disease progression. Previous studies that used the brain structural covariance network could show neural correlates of specific anxiety disorder such as panic disorder and also elucidate the neural underpinning of anxiety symptom severity in diverse psychiatric and neurologic disorder patients.

Impact of resective surgery for pediatric drug-resistant epilepsy on emotional functioning

OBJECTIVE

The objective of the study was to evaluate emotional functioning following surgical and medical treatment in children with drug-resistant epilepsy (DRE; i.e., uncontrolled seizures despite treatment with ≥2 antiepileptic drugs [AED]).

METHOD

This prospective, longitudinal, multicenter study involved 128 children and adolescents (8-18 years) with DRE who were assessed for surgical candidacy; 48 went on to have surgery and 80 continued medical treatment. Participants completed child-validated self-report measures of anxiety and depression at baseline, 6, and 12 month follow-up. Standardized z-scores were calculated with higher scores indicative of greater symptoms.

RESULTS

At baseline, 16% and 22% of all patients reported elevated symptoms of depression and anxiety, respectively (i.e., z ≥ 1.00). Seizure freedom was higher in the surgical, compared with the medical, group at 6 (64 vs. 11%) and 12 month (77 vs. 24%) follow-up. Linear mixed effects models controlling for age found a main effect of time for both depression and anxiety; scores decreased over time for all patients. A main effect of seizure outcome was found for depression, but not anxiety; seizure freedom was associated with lower scores overall. There were no main effects of treatment or significant interactions. Multiple regression analyses found baseline mood predicted outcomes at 6 and 12 month follow-up; higher anxiety and depression scores at baseline were associated with higher scores at follow-up. Older age and greater number of AEDs at baseline was associated with higher depression scores at 12 month follow-up.

CONCLUSION

Overall, patients reported a reduction in anxiety and depressive symptoms over the first 12 months, irrespective of treatment, and baseline level of functioning was the best predictor of outcome. Despite more children achieving seizure freedom with surgery compared with medical treatment, surgery was not associated with better outcomes over time. It may be that changes in anxiety and depression require a longer time to emerge postsurgery; however, being seizure-free is associated with fewer depressive symptoms, irrespective of treatment type.