Regional brain atrophy and aberrant cortical folding relate to anxiety and depression in patients with traumatic brain injury and psychogenic nonepileptic seizures

One-year follow-up of neurobehavioral therapy in functional seizures or epilepsy with traumatic brain injury: A nonrandomized controlled trial

OBJECTIVE

Patients with traumatic brain injury (TBI) often present with seizures (functional and/or epileptic), but treatments for patients with TBI and seizures are limited. We examined treatment phase and 1-year post-enrollment outcomes following neurobehavioral therapy (NBT) for patients with TBI + functional seizures (FS) and TBI + epilepsy.

METHODS

In this multicenter, prospective, three-group, nonrandomized, controlled trial, with 1-year post-enrollment follow-up, three cohorts of adults were recruited: TBI + video-electroencephalography (EEG)-confirmed FS (n = 89), TBI + EEG-confirmed epilepsy (n = 29), and chart/history-confirmed TBI without seizures (n = 75). Exclusion criteria were recent psychotic or self-injurious behavior, current suicidal ideation, pending litigation or long-term disability, active substance use disorder, and inability to participate in study procedures. TBI + FS and TBI + epilepsy groups completed NBT for seizures, an evidence-based, 12-session, multimodal psychotherapy, whereas TBI without seizures participants received standard medical care. The primary outcome was change in seizure frequency; secondary outcomes were changes in mental health, TBI-related symptoms, disability, and quality of life.

RESULTS

Reductions in average monthly seizures occurred during treatment in TBI + FS participants (p = .002) and were significant from baseline (mean = 16.75; 95% confidence interval [CI] = 11.44-24.53) to 12 months post-enrollment (mean = 7.28, 95% CI = 4.37-12.13, p = .002, d = .38). Monthly seizures decreased during treatment in TBI + epilepsy participants (p = .002); reductions were not statistically significant from baseline (mean = 2.38, 95% CI = 1.12-5.04) to 12-month postenrollment (mean = .98, 95% CI = .40-2.42, p = .07, d = .22). Regarding treatment-phase changes in secondary outcome measures, TBI + FS participants improved significantly on 10 of 19 variables (52.6%), TBI + epilepsy participants improved on five of 19 (26.3%), and TBI-only comparisons improved on only one of 19 (5.3%).

SIGNIFICANCE

NBT benefited patients with TBI + FS and TBI + epilepsy. Improvements were demonstrated at 1 year post-enrollment in those with TBI + FS. NBT may be a clinically useful treatment for patients with seizures.

The imprint of dissociative seizures on the brain

BACKGROUND

Increased resting state functional connectivity between regions involved in emotion control with regions with other specializations, e.g. motor control (emotional hyperconnectivity) is one of the most consistent imaging findings in persons suffering from dissociative seizures (DS). The overall goal of this study was to better characterize DS-related emotional hyperconnectivity using dynamic resting state analysis combined with brainstem volumetry to investigate 1. If emotional hyperconnectivity is restricted to a single state. 2. How volume losses within the modulatory and emotional motor subnetworks of the neuromodulatory system influence the expression of the emotional hyperconnectivity.

METHODS

13 persons with dissociative seizures (PDS) (f/m:10/3, mean age (SD) 44.6 (11.5)) and 15 controls (CON) (f/m:10/5, mean age (SD) 41.7 (13.0)) underwent a mental health test battery and structural and functional imaging at 3 T. Deformation based morphometry was used to assess brain volume loss by extracting the mean Jacobian determinants from 457 brain, forebrain and brainstem structures. The bold signals from 445 brainstem and brain rois were extracted with CONN and a dynamic fMRI analysis combined with graph and hierarchical analysis was used to identify and characterize 9 different brain states. Welch's t tests and Kendall tau tests were used for group comparisons and correlation analyses.

RESULTS

The duration of Brain state 6 was longer in PDS than in CON (93.1(88.3) vs. 23.4(31.2), p = 0.01) and positively correlated with higher degrees of somatization, depression, PTSD severity and dissociation. Its global connectivity was higher in PDS than CON (90.4(3.2) vs 86.5(4.2) p = 0.01) which was caused by an increased connectivity between regions involved in emotion control and regions involved in sense of agency/body control. The brainstem and brainstem-forebrain modulatory and emotional motor subnetworks of the neuromodulatory system were atrophied in PDS. Atrophy severity within the brainstem-forebrain subnetworks was correlated with state 6 dwell time (modulatory: tau = -0.295, p = 0.03; emotional motor: tau = -0.343, p = 0.015) and atrophy severity within the brainstem subnetwork with somatization severity (modulatory: tau = -0.25, p = 0.036; emotional motor: tau = -0.256, p = 0.033).

CONCLUSION

DS-related emotional hyperconnectivity was restricted to state 6 episodes. The remaining states were not different between PDS and CON. The modulatory subnetwork synchronizes brain activity across brain regions. Atrophy and dysfunction within that subnetwork could facilitate the abnormal interaction between regions involved in emotion control with those controlling sense of agency/body ownership during state 6 and contribute to the tendency for somatization in PDS. The emotional motor subnetwork controls the activity of spinal motoneurons. Atrophy and dysfunction within this subnetwork could impair that control resulting in motor symptoms during DS. Taken together, these findings indicate that DS have a neurophysiological underpinning.

Altered fronto-limbic-motor response to stress differs between functional and epileptic seizures in a TBI model

BACKGROUND AND OBJECTIVES

Psychogenic nonepileptic (functional) seizures (FS) clinically resemble epileptic seizures (ES) with both often preceded by traumatic brain injury (TBI). FS and ES emergence and occurrence after TBI may be linked to aberrant neurobehavioral stress responses. We hypothesized that neural activity signatures in response to a psychosocial stress task would differ between TBI + FS and TBI + ES after controlling for TBI status (TBI-only).

METHODS

In the current multicenter study, participants were recruited prospectively from Rhode Island Hospital, Providence Rhode Island Veterans Administration Medical Center, and the University of Alabama at Birmingham Medical Center. Previous diagnoses of TBI, ES, and FS were verified based on data collected from participants, medical chart and record review, and, where indicated, results of EEG and/or video-EEG confirmatory diagnosis. TBI + ES (N = 21) and TBI + FS (N = 21) were matched for age and sex and combined into an initial group (TBI + SZ; N = 42). A TBI-only group (N = 42) was age and sex matched to the TBI with seizures (TBI + SZ) group. All participants completed an fMRI control math task (CMT) and stress math task (SMT) based on the Montreal Imaging Stress Task (MIST).

RESULTS

The TBI + SZ group (n = 24 female) did not differ in mood or anxiety severity compared to TBI-only group (n = 24 female). However, TBI + FS group (n = 11 female) reported greater severity of these symptoms compared to TBI + ES (n = 13 female). The linear mixed effects analysis identified neural responses that differed between TBI-only and TBI + SZ during math performance within the left premotor cortex and during auditory feedback within bilateral prefrontal cortex and hippocampus/amygdala regions. Additionally, neural responses differed between TBI + ES and TBI + FS during math performance within the right dorsolateral prefrontal cortex and bilateral amygdala during auditory feedback within the supplementary motor area. All tests comparing neural stress responses to psychiatric symptom severity failed to reach significance.

DISCUSSION

Controlling for TBI and seizure status, these findings implicate specific nodes within frontal, limbic, and sensorimotor networks that may maintain functional neurological symptoms and possibly distinguish FS from ES. This study provides class II evidence of differences in neural responses to psychosocial stress between ES and FS after TBI.

An update on psychogenic nonepileptic seizures

PURPOSE OF REVIEW

The understanding of psychogenic nonepileptic seizures (PNES) has advanced steadily over recent decades. This update summarizes new insights from the last three years.

RECENT FINDINGS

The process of diagnosing PNES has shifted from the exclusion of epilepsy to one based on the recognition of typical clinical features. While the diagnosis cannot rely on any single feature in isolation, a range of semiological features characterising PNES are now recognised and a number of studies hint at the potential for machine learning and AI to improve the diagnostic process. Advances in data processing and analysis may also help to make sense of the heterogeneity of PNES populations demonstrated by recent studies focussing on aetiology and patient subgroups. It is now clear that PNES are associated with high rates of mental and physical comorbidities and premature death, highlighting that they are only one manifestation of a complex disorder extending beyond the nervous system and the seizures themselves.

SUMMARY

PNES are now understood as a manifestation of dysfunction in interacting brain networks. This understanding provides an explanation for the psychopathological and semiological heterogeneity of PNES patient populations. New insights into medical comorbidities and increased rates of premature death call for more research into associated pathological processes outside the nervous system.

Resting state functional connectome in breast cancer patients with fear of cancer recurrence

This study aimed to investigate network-level brain functional changes in breast cancer patients and their relationship with fear of cancer recurrence (FCR). Resting-state functional MRI was collected from 43 patients with breast cancer and 40 healthy controls (HCs). Graph theory analyses, whole-brain voxel-wise functional connectivity strength (FCS) analyses and seed-based functional connectivity (FC) analyses were performed to identify connection alterations in breast cancer patients. Correlations between brain functional connections (i.e. FCS and FC) and FCR level were assessed to further reveal the neural mechanisms of FCR in breast cancer patients. Graph theory analyses indicated a decreased clustering coefficient in breast cancer patients compared to HCs (P = 0.04). Patients with breast cancer exhibited significantly higher FCS in both higher-order function networks (frontoparietal, default mode, and dorsal attention systems) and primary somatomotor networks. Among the hyperconnected regions in breast cancer, the left inferior frontal operculum demonstrated a significant positive correlation with FCR. Our findings suggest that breast cancer patients exhibit less segregation of brain function, and the left inferior frontal operculum is a key region associated with FCR. This study offers insights into the neural mechanisms of FCR in breast cancer patients at the level of brain connectome.

Peripheral and Central Nervous System Biomarkers of Inflammation in Functional Seizures: Assessment with Magnetic Resonance Spectroscopy

Purpose

Inflammation may link trauma to clinical symptoms in functional seizures (FS). We compared brain temperature and metabolites in FS, psychiatric (PCs) and healthy controls (HCs) and quantified their associations with serum biomarkers of inflammation and clinical symptoms.

Patients and Methods

Brain temperature and metabolites were measured with whole-brain magnetic resonance spectroscopic imaging (MRSI) and compared between groups in regions of interest and the whole brain. Relationships with inflammatory biomarkers and symptoms were assessed with Pearson correlations.

Results

Brain temperature was higher in FS than HCs in the orbitofrontal cortex (OFC) and anterior cingulate gyrus (ACG) and lower in the occipital cortex and frontal lobe. PCs showed lower temperatures than HCs in the frontal lobe including precentral gyrus and in the cerebellum. Myo-inositol (MINO) was higher in FS than HCs in the precentral gyrus, posterior temporal gyrus, ACG and OFC, and choline (CHO) was higher in the occipital lobe. CHO was higher in PCs than HCs in the ACG and OFC, and N-acetylaspartate (NAA) was higher in the ACG. There were no significant correlations with the serum inflammatory biomarkers. In FS, brain temperature correlated with depression, quality of life, psychological symptoms, and disability, CHO correlated with disability, and MINO correlated with hostility, disability, and quality of life.

Conclusion

Some of the previously identified neuroimaging abnormalities in FS may be related to comorbid psychiatric symptoms, while others, such as abnormalities in sensorimotor cortex, occipital regions, and the temporo-parietal junction may be specific to FS. Overlapping MINO and temperature increases in the ACG and OFC in FS suggest neuroinflammation.

Improvements in Montreal Cognitive Assessment scores after neurobehavioral therapy in adults with functional (nonepileptic) seizures and traumatic brain injury

Cognitive functioning impacts clinical symptoms, treatment response, and quality of life in adults with functional/nonepileptic seizures (FS/NES), but no study to date examines effects of behavioral FS/NES treatment on cognition in these patients. We hypothesized that there would be a reduction in cognitive symptoms in participants with FS/NES and traumatic brain injury (TBI) following neurobehavioral therapy (NBT). We also hypothesized that select seizure-related, medication, subjective cognitive, and mental health symptoms would be negatively correlated with improvements in cognitive performance after NBT. Participants were 37 adults with TBI + FS/NES and 35 adults with TBI only, recruited from medical centers in the northeastern or southeastern U.S. TBI + FS/NES participants completed a 12 session NBT intervention, and TBI without seizures participants were not treated. All participants completed pre-post assessments of cognition (Montreal Cognitive Assessment [MoCA]) and baseline sociodemographic factors and mental health symptoms. Pre-post MoCA scores increased significantly in TBI + FS/NES participants (28/37 [75.7%] improved) but not in TBI comparisons (10/35 [28.6%] improved). Language, memory, and visuospatial/executive functions, but not attention, improved over time in the TBI + FS/NES group. Gains in cognition were concentrated in those TBI + FS/NES participants with likely baseline cognitive impairments (MoCA total score <26), and 9/17 of these participants moved from the "impaired" range at baseline (<26) to the "intact" range at endpoint (≥26). Lastly, participants taking fewer medications and reporting lower subjective cognitive difficulties at baseline showed larger pre-post MoCA total score improvements. Overall, results from this study suggest the potential for positive change in cognition in FS/NES and co-occurring TBI using evidence-based psychotherapy.

Chemical composition and anticonvulsant activities of herb pair of Gastrodia elata Blume-Acorus tatarinowii Schott decoction on experimentally induced seizures in mice

Epilepsy is a serious public health problem in the world. At present, over 30% of affected patients remain refractory to currently available treatment. Medicinal plants as pharmaceuticals and healthcare treatments have been frequently used in the management of epilepsy in China for many centuries. Gastrodia elata-Acous tatarinowii (GEAT), as a classic and most commonly used herb pair in traditional Chinese medicine (TCM), has been employed to control seizures for thousands of years. However, the animal experiment data on its anticonvulsant effect is limited in the literature. Thus, this study aimed to reveal the therapeutic actions of GEAT decoction against seizures in mice. UHPLC-MS/MS was performed to analyze the chemical components of GEAT decoction. The mice were given GEAT decoction for 7 days, and MES, PTZ, and 3-MP injection was given 30 min after the last administration. Video monitoring was performed for comparisons. In addition, the PTZ-induced kindling models were conducted to investigate the seizure severity, anxiety and cognitive profile, inflammation, and oxidative stress parameters in mice. The results showed that GEAT decoction dose-dependently protected mice against MES, 3-MP, and PTZ-induced acute seizures. Furthermore, GEAT decoction significantly ameliorated seizure severity, decreased the accumulation of inflammatory mediators TNF-α, IL-1β, and IL-6, mitigated oxidative stress, as well as alleviated anxious-like behavior and cognitive deficits in PTZ-kindled mice. These results suggest that GEAT decoction possesses certain anticonvulsant properties, which might be clinically useful as phytotherapy alone or as an adjunct therapy for the prevention and treatment of seizures and epilepsy.

Amygdala subfield and prefrontal cortex abnormalities in patients with functional seizures

BACKGROUND

Functional seizures (FS) are paroxysmal episodes, resembling epileptic seizures, but without underlying epileptic abnormality. The aetiology and neuroanatomic associations are incompletely understood. Recent brain imaging data indicate cerebral changes, however, without clarifying possible pathophysiology. In the present study, we specifically investigated the neuroanatomic changes in subregions of the amygdala and hippocampus in FS.

METHODS

T1 MRI scans of 37 female patients with FS and 37 age-matched female seizure naïve controls (SNC) were analyzed retrospectively in FreeSurfer version 7.1. Seizure naïve controls included patients with depression and anxiety disorders. The analysis included whole-brain cortical thickness, subcortical volumes, and subfields of the amygdala and hippocampus. Group comparisons were carried out using multivariable linear models.

RESULTS

The FS and SNC groups did not differ in the whole hippocampus and amygdala volumes. However, patients had a significant reduction of the right lateral amygdala volume (p = 0.00041), an increase of the right central amygdala, (p = 0.037), and thinning of the left superior frontal gyrus (p = 0.024). Additional findings in patients were increased volumes of the right medial amygdala (p = 0.031), left anterior amygdala (p = 0.017), and left dentate gyrus of the hippocampus (p = 0.035).

CONCLUSIONS

The observations from the amygdala and hippocampus segmentation affirm that there are neuroanatomic associations of FS. The pattern of these changes aligned with some of the cerebral changes described in chronic stress conditions and depression. The pattern of detected changes further study, and may, after validation, provide biomarkers for diagnosis and treatment.

Sense of control, selective attention, cognitive inhibition, and psychosocial outcomes after Retraining and Control Therapy (ReACT) in pediatric functional seizures

BACKGROUND

Differences in sense of control, cognitive inhibition, and selective attention in pediatric functional seizures (FS) versus matched controls implicate these as potential novel treatment targets. Retraining and Control Therapy (ReACT), which targets these factors, has been shown in a randomized controlled trial to be effective in improving pediatric FS with 82% of patients having complete symptom remission at 60 days following treatment. However, post-intervention data on sense of control, cognitive inhibition, and selective attention are not yet available. In this study, we assess changes in these and other psychosocial factors after ReACT.

METHODS

Children with FS (N = 14, Mage = 15.00, 64.3% female, 64.3% White) completed 8 weeks of ReACT and reported FS frequency at pre and post-1 (7 days before and after ReACT). At pre, post-1, and post-2 (60 days after ReACT), all 14 children completed the Pediatric Quality of Life Inventory Generic Core Scales, Behavior Assessment System (BASC2), and Children's Somatic Symptoms Inventory-24 (CSSI-24), and 8 children completed a modified Stroop task with seizure symptoms condition in which participants are presented with a word and respond to the ink color (e.g., "unconscious" in red) to assess selective attention and cognitive inhibition. At pre and post-1, ten children completed the magic and turbulence task (MAT) which assesses sense of control via 3 conditions (magic, lag, turbulence). In this computer-based task, participants attempt to catch falling X's while avoiding falling O's while their control over the task is manipulated in different ways. ANCOVAs controlling for change in FS from pre- to post-1 compared Stroop reaction time (RT) across all time points and MAT conditions between pre and post-1. Correlations assessed the relationships between changes in Stroop and MAT performance and change in FS from pre- to post-1. Paired samples t-tests assessed changes in quality of life (QOL), somatic symptoms, and mood pre to post-2.

RESULTS

Awareness that control was manipulated in the turbulence condition of the MAT increased at post-1 vs. pre- (p = 0.02, η2 = 0.57). This change correlated with a reduction in FS frequency after ReACT (r = 0.84, p < 0.01). Reaction time significantly improved for the seizure symptoms Stroop condition at post-2 compared to pre- (p = 0.02, η2 = 0.50), while the congruent and incongruent conditions were not different across time points. Quality of life was significantly improved at post-2, but the improvement was not significant when controlling for change in FS. Somatic symptom measures were significantly lower at post-2 vs. pre (BASC2: t(12) = 2.25, p = 0.04; CSSI-24: t(11) = 4.17, p < 0.01). No differences were observed regarding mood.

CONCLUSION

Sense of control improved after ReACT, and this improvement was proportional to a decrease in FS, suggesting this as a possible mechanism by which ReACT treats pediatric FS. Selective attention and cognitive inhibition were significantly increased 60 days after ReACT. The lack of improvement in QOL after controlling for change in FS suggests QOL changes may be mediated by decreases in FS. ReACT also improved general somatic symptoms independent of FS changes.

Morphometric correlates in patients with functional seizures with and without comorbid epilepsy

OBJECTIVE

Functional seizures (FS) or psychogenic, non-epileptic seizures (PNES) are episodic alterations of behaviour with similar semiology to epileptic seizures but which are not caused by epileptic brain activity. Epilepsy patients show a high risk in developing FS; therefore, the purpose of this study is to examine morphometric correlates in patients with FS as well as in epilepsy patients with FS by comparing them separately to healthy controls (HC).

METHODS

Twenty-one clinical three-dimensional (3D) T1-magnetic resonance imaging (MRI) scans of patients with FS (FS group) and 15 patients with FS and epilepsy (EFS group) were retrospectively compared with one control group of 21 age- and gender-matched HC. Two separate general linear model analyses were conducted via FreeSurfer version 6.0.

RESULTS

The study population consisted of 21 FS patients (66.7% females, n = 14) with a median age at the time of the scan of 24 years (range 17-44 years); 15 EFS patients (80% females, n = 12) with a median age at the time of the scan of 27 years (range 16-43 years); and 21 healthy subjects (66.7% females, n = 14) with a median age at the time of the scan of 24 years (range 19-38 years). Both patient groups showed an increased Cth in the right prefrontal lobe: in the FS group in the right superior frontal, rostral middle frontal gyri and the right orbitofrontal cortex and, in the EFS group, in the right superior frontal gyrus and the right orbitofrontal cortex. Decreases in Cth were present in the right lateral occipital lobe in the FS group, while also in both hemispheres in the EFS group, namely the left paracentral, superior frontal, caudal middle frontal, lateral occipital and right superior frontal gyri. Neither group showed changes in curvature.

CONCLUSION

These results suggest alterations in regions of emotional processing and executive control in patients with FS regardless of the presence of epilepsy.

Relationship between intrinsic network connectivity and psychiatric symptom severity in functional seizures

BACKGROUND

Traumatic brain injury (TBI) may precipitate the onset of functional seizures (FSs). Many patients with FS report at least one prior TBI, and these patients typically present with more severe psychiatric comorbidities. TBI and psychopathology are linked to changes in neural network connectivity, but their combined effects on these networks and relationship to the effects of FS remain unclear. We hypothesised that resting-state functional connectivity (rsFC) would differ between patients with FS and TBI (FS+TBI) compared with TBI without FS (TBI only), with variability only partially explained by the presence of psychopathology.

METHODS

Patients with FS+TBI (n=52) and TBI only (n=54) were matched for age and sex. All participants completed psychiatric assessments prior to resting-state functional MRI at 3 T. Independent component analysis identified five canonical rsFC networks related to emotion and motor functions.

RESULTS

Five linear mixed-effects analyses identified clusters of connectivity coefficients that differed between groups within the posterior cingulate of the default mode network, insula and supramarginal gyrus of the executive control network and bilateral anterior cingulate of the salience network (all α=0.05, corrected). Cluster signal extractions revealed decreased contributions to each network for FS+TBI compared to TBI only. Planned secondary analyses demonstrated correlations between signal and severity of mood, anxiety, somatisation and global functioning symptoms.

CONCLUSIONS

These findings indicate the presence of aberrant connectivity in FS and extend the biopsychosocial network model by demonstrating that common aetiology is linked to both FS and comorbidities, but the overlap in affected networks varies by comorbid symptoms.

Structural Changes in Brain Magnetic Resonance Imaging Associated With Psychogenic Non-epileptic Seizures: An Analytical Cross-Sectional Study

Background Psychogenic non-epileptic seizures (PNES) are often seen as indicators of poor motor and sensory function caused by psychological responses to stressful experiences. A seizure might trigger these reactions. The aim of our study was to assess the structural changes in brain MRI associated with psychogenic non-epileptic seizures. Methodology A retrospective analytical cross-sectional study at the Department of Medicine and Neurology, Ayub Teaching Hospital, Abbottabad, was conducted from October 2020 to September 2021. The medical records of patients with confirmed PNES were collected and retrospectively evaluated. Results Medical records and MRI scans were accessible for 52 patients with PNES; 10 patients were excluded from the study. The average age of the patients (standard deviation) was 34 (±9) years, and the average age at onset was 31.6 (±5.8) years. Based on the video-EEG recordings, 57.1% of patients (n=24) were classified as having broadly generalized motor seizures, 40% of patients (n=17) were classified as having predominantly akinetic seizures defined primarily by blank spells, and only one patient was classified as having focal motor seizures. Only three patients (7%) had a positive epilepsy family history. Twenty-four (47.6%) patients with brain MRI scans reported abnormal findings, while 22 (52.4%) had normal MRI findings. The majority of patients with abnormal MRIs had nonspecific white matter changes (50%), mesial temporal sclerosis (15%), and cysts (15%). In a statistical analysis, age at the beginning of PNES (p = 0.04), duration of PNES (p=0.01), concomitant epilepsy (p = 0.05), generalized motor seizures (p= 0.03), and focal motor seizures (p= 0.02) were strongly associated with abnormal brain MRI findings. Conclusion Research reveals that persons with PNES have a higher-than-average prevalence of anatomical brain abnormalities. The main takeaway is that these findings lend credence to the growing body of data suggesting that PNES may not be a medical mystery but rather a disorder with physical foundations in the brain. Important implications for diagnosing and treating PNES patients are discussed, as are the outcomes of earlier neuroimaging investigations of PNES. Studying the involvement of structural brain anomalies in the etiology of psychogenic non-epileptic seizures requires further well-designed multicenter studies with larger sample sizes and a consistent imaging approach (PNES). It is crucial to consider any confounding variables, such as co-occurring mental diseases, while designing this study.

Clinical MRI morphological analysis of functional seizures compared to seizure-naïve and psychiatric controls

PURPOSE

Functional seizures (FS), also known as psychogenic nonepileptic seizures (PNES), are physical manifestations of acute or chronic psychological distress. Functional and structural neuroimaging have identified objective signs of this disorder. We evaluated whether magnetic resonance imaging (MRI) morphometry differed between patients with FS and clinically relevant comparison populations.

METHODS

Quality-screened clinical-grade MRIs were acquired from 666 patients from 2006 to 2020. Morphometric features were quantified with FreeSurfer v6. Mixed-effects linear regression compared the volume, thickness, and surface area within 201 regions-of-interest for 90 patients with FS, compared to seizure-naïve patients with depression (n = 243), anxiety (n = 68), and obsessive-compulsive disorder (OCD, n = 41), respectively, and to other seizure-naïve controls with similar quality MRIs, accounting for the influence of multiple confounds including depression and anxiety based on chart review. These comparison populations were obtained through review of clinical records plus research studies obtained on similar scanners.

RESULTS

After Bonferroni-Holm correction, patients with FS compared with seizure-naïve controls exhibited thinner bilateral superior temporal cortex (left 0.053 mm, p = 0.014; right 0.071 mm, p = 0.00006), thicker left lateral occipital cortex (0.052 mm, p = 0.0035), and greater left cerebellar white-matter volume (1085 mm³, p = 0.0065). These findings were not accounted for by lower MRI quality in patients with FS.

CONCLUSIONS

These results reinforce prior indications of structural neuroimaging correlates of FS and, in particular, distinguish brain morphology in FS from that in depression, anxiety, and OCD. Future work may entail comparisons with other psychiatric disorders including bipolar and schizophrenia, as well as exploration of brain structural heterogeneity within FS.

Diagnostic delay in functional seizures is associated with abnormal processing of facial emotions

PURPOSE

In patients with functional seizures (FS), delay in diagnosis (DD) may negatively affect outcomes. Altered brain responses to emotional stimuli have been shown in adults with FS. We hypothesized that DD would be associated with differential fMRI activation in emotion processing circuits.

METHODS

Fifty-two adults (38 females) with video-EEG confirmed FS prospectively completed assessments related to symptoms of depression (BDI-II), anxiety (BAI), post-traumatic stress disorder (PCL-S), a measure of how their symptoms affect day-to-day life (GAF), and fMRI at 3T with emotional faces task (EFT). During fMRI, subjects indicated "male" or "female" via button press while implicitly processing happy, sad, fearful, and neutral faces. Functional magnetic resonance imaging (FMRI) response to each emotion was modeled and group analyses were performed in AFNI within pre-specified regions-of-interest involved in emotion processing. A median split (507 days) defined short- (s-DD) and long-delay diagnosis (l-DD) groups. Voxelwise regression analyses were also performed to examine linear relationship between DD and emotion processing. FMRI signal was extracted from clusters showing group differences and Spearman's correlations assessed relationships with symptom scores.

RESULTS

Groups did not differ in FS age of onset, sex distribution, years of education, TBI characteristics, EFT in-scanner or post-test performance, or scores on the GAF, BDI-II, BAI, and PCL-S measures. The s-DD group was younger than l-DD (mean age 32.6 vs. 40.1; p = 0.022) at the time of study participation. After correcting for age, compared to s-DD, the l-DD group showed greater fMRI activation to sad faces in the bilateral posterior cingulate cortex (PCC) and to neutral faces in the right anterior insula. Within-group linear regression revealed that with increasing DD, there was increased fMRI activation to sad faces in the PCC and to happy faces in the right anterior insula/inferior frontal gyrus (AI/IFG). There were positive correlations between PCC response to sad faces and BDI-II scores in the l-DD group (rho = 0.48, p = 0.012) and the combined sample (rho = 0.30, p = 0.029). Increased PCC activation to sad faces in those in the l-DD group was associated with worse symptoms of depression (i.e. higher BDI-II score).

CONCLUSIONS

Delay in FS diagnosis is associated with fMRI changes in PCC and AI/IFG. As part of the default mode network, PCC is implicated in mood control, self-referencing, and other emotion-relevant processes. In our study, PCC changes are linked to depression. Future studies should assess the effects of interventions on these abnormalities.

Sense of control, selective attention and cognitive inhibition in pediatric functional seizures: A prospective case-control study

PURPOSE

To date, laboratory-based experimental behavioral methods have not been used to identify factors associated with pediatric functional seizures (FS), leaving a critical gap for effective treatment development.

METHODS

Children ages 13-18 with video-EEG-confirmed FS were matched to controls (MCs) based on income, sex, race, and age. A modified Stroop task which included a condition requiring participants to report the ink colors in which seizure symptom words were written (e.g., "shaking" in blue) measured selective attention and cognitive inhibition through response time. The magic and turbulence task assessed sense of control in three conditions (magic, lag, turbulence). Children with FS were asked to report premonitory symptoms predicting FS.

RESULTS

Participants included 26 children with FS and 26 MCs (Meanage=15.2, 74% female, 59% white). On Stroop, children with FS had a slower reaction time (Mean=1193.83) than MCs (Mean=949.26, p = 0.022) for seizure symptom words. Children with FS had significantly poorer sense of control in the turbulence condition of the magic and turbulence task (Mean=-3.99, SD=8.83) than MCs (Mean=-11.51, SD=7.87; t(20)=-2.61, p =0.017). Children with FS (Mean=-1.80, SD=6.54) also had significantly poorer sense of control in the magic condition than MCs (Mean=-5.57, SD=6.01; p =0.028). Ninety-eight percent of patients endorsed premonitory symptoms.

CONCLUSION

Compared with MCs, children with FS have (1) poorer selective attention and cognitive inhibition when presented with seizure-related information and (2) lower sense of control (i.e. poorer awareness that their control was manipulated). Premonitory symptoms were common. Sense of control, selective attention, and inhibition may be novel treatment targets for FS intervention.

Neuroinflammation as a pathophysiological factor in the development and maintenance of functional seizures: A hypothesis

•

Early-life stress may be a priming neuroinflammatory factor for later development of FS.

•

Secondary trauma has emerged as an important predisposing factor for FS initiation.

•

We propose an explanatory, two-hit hypothesis for FS development.

•

The proposed hypothesis is based on findings from neuroimaging and biomarker studies.

The neurobiological underpinnings of functional seizure (FS) development and maintenance represent an active research area. Recent work has focused on hardware (brain structure) and software (brain function and connectivity). However, understanding whether FS are an adaptive consequence of changes in brain structure, function, and/or connectivity is important for identifying a causative mechanism and for FS treatment and prevention. Further, investigation must also uncover what causes these structural and functional phenomena. Pioneering work in the field of psychoneuroimmunology has established a strong, consistent link between psychopathology, immune dysfunction, and brain structure/function. Based on this and recent FS biomarker findings, we propose a new etiologic model of FS pathophysiology. We hypothesize that early-life stressors cause neuroinflammatory and neuroendocrine changes that prime the brain for later FS development following secondary trauma (e.g., traumatic brain injury or psychological trauma). This framework coalesces existing knowledge regarding brain aberrations underlying FS and established neurobiological theories on the pathophysiology of underlying psychiatric disorders. We also propose brain temperature mapping as a way of indirectly visualizing neuroinflammation in patients with FS, particularly in emotion regulation, fear processing, and sensory-motor integration circuits. We offer a foundation on which future research can be built, with clear recommendations for future studies.