Psychogenic non-epileptic seizures in children - psychophysiology & dissociative characteristics

Recent advances in understanding the neurobiology of pediatric functional neurological disorder

INTRODUCTION

Functional neurological disorder (FND) is a neuropsychiatric disorder that manifests in a broad array of functional motor, sensory, or cognitive symptoms, which arise from complex interactions between brain, mind, body, and context. Children with FND make up 10%-20% of presentations to neurology services in children's hospitals and up to 20% of adolescents admitted to hospital for the management of intractable seizures.

AREAS COVERED

The current review focuses on the neurobiology of pediatric FND. The authors present an overview of the small but growing body of research pertaining to the biological, emotion-processing, cognitive, mental health, physical health, and social system levels.

EXPERT OPINION

Emerging research suggests that pediatric FND is underpinned by aberrant changes within and between neuron-glial (brain) networks, with a variety of factors - on multiple system levels - contributing to brain network changes. In pediatric practice, adverse childhood experiences (ACEs) are commonly reported, and activation or dysregulation of stress-system components is a frequent finding. Our growing understanding of the neurobiology of pediatric FND has yielded important flow-on effects for assessing and diagnosing FND, for developing targeted treatment interventions, and for improving the treatment outcomes of children and adolescents with FND.

Neurometabolic alterations in children and adolescents with functional neurological disorder

OBJECTIVES

In vivo magnetic resonance spectroscopy (MRS) was used to investigate neurometabolic homeostasis in children with functional neurological disorder (FND) in three regions of interest: supplementary motor area (SMA), anterior default mode network (aDMN), and posterior default mode network (dDMN). Metabolites assessed included N-acetyl aspartate (NAA), a marker of neuron function; myo-inositol (mI), a glial-cell marker; choline (Cho), a membrane marker; glutamate plus glutamine (Glx), a marker of excitatory neurotransmission; γ-aminobutyric acid (GABA), a marker of inhibitor neurotransmission; and creatine (Cr), an energy marker. The relationship between excitatory (glutamate and glutamine) and inhibitory (GABA) neurotransmitter (E/I) balance was also examined.

METHODS

MRS data were acquired for 32 children with mixed FND (25 girls, 7 boys, aged 10.00 to 16.08 years) and 41 healthy controls of similar age using both short echo point-resolved spectroscopy (PRESS) and Mescher-Garwood point-resolved spectroscopy (MEGAPRESS) sequences in the three regions of interest.

RESULTS

In the SMA, children with FND had lower NAA/Cr, mI/Cr (trend level), and GABA/Cr ratios. In the aDMN, no group differences in metabolite ratios were found. In the pDMN, children with FND had lower NAA/Cr and mI/Cr (trend level) ratios. While no group differences in E/I balance were found (FND vs. controls), E/I balance in the aDMN was lower in children with functional seizures-a subgroup within the FND group. Pearson correlations found that increased arousal (indexed by higher heart rate) was associated with lower mI/Cr in the SMA and pDMN.

CONCLUSIONS

Our findings of multiple differences in neurometabolites in children with FND suggest dysfunction on multiple levels of the biological system: the neuron (lower NAA), the glial cell (lower mI), and inhibitory neurotransmission (lower GABA), as well as dysfunction in energy regulation in the subgroup with functional seizures.

Scoping review and expert-based consensus recommendations for assessment and management of psychogenic non-epileptic (functional) seizures (PNES) in children: A report from the Pediatric Psychiatric Issues Task Force of the International League Against Epilepsy

Limited guidance exists regarding the assessment and management of psychogenic non-epileptic seizures (PNES) in children. Our aim was to develop consensus-based recommendations to fill this gap. The members of the International League Against Epilepsy (ILAE) Task Force on Pediatric Psychiatric Issues conducted a scoping review adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-SR) standards. This was supplemented with a Delphi process sent to pediatric PNES experts. Consensus was defined as ≥80% agreement. The systematic search identified 77 studies, the majority (55%) of which were retrospective (only one randomized clinical trial). The primary means of PNES identification was video electroencephalography (vEEG) in 84% of studies. Better outcome was associated with access to counseling/psychological intervention. Children with PNES have more frequent psychiatric disorders than controls. The Delphi resulted in 22 recommendations: Assessment-There was consensus on the importance of (1) taking a comprehensive developmental history; (2) obtaining a description of the events; (3) asking about potential stressors; (4) the need to use vEEG if available parent, self, and school reports and video recordings can contribute to a "probable" diagnosis; and (5) that invasive provocation techniques or deceit should not be employed. Management-There was consensus about the (1) need for a professional with expertise in epilepsy to remain involved for a period after PNES diagnosis; (2) provision of appropriate educational materials to the child and caregivers; and (3) that the decision on treatment modality for PNES in children should consider the child's age, cognitive ability, and family factors. Comorbidities-There was consensus that all children with PNES should be screened for mental health and neurodevelopmental difficulties. Recommendations to facilitate the assessment and management of PNES in children were developed. Future directions to fill knowledge gaps were proposed.

Illness-Promoting Psychological Processes in Children and Adolescents with Functional Neurological Disorder

Previous studies suggest that subjective distress in children with functional neurological disorder (FND) is associated with stress-system dysregulation and modulates aberrant changes in neural networks. The current study documents illness-promoting psychological processes in 76 children with FND (60 girls and 16 boys, aged 10.00-17.08 years) admitted to the Mind-Body Program. The children completed a comprehensive family assessment and self-report measures, and they worked with the clinical team to identify psychological processes during their inpatient admission. A total of 47 healthy controls (35 girls and 12 boys, aged 8.58-17.92 years) also completed self-report measures, but were not assessed for illness-promoting psychological processes. Children with FND (vs. controls) reported higher levels of subjective distress (total DASS score, t(104.24) = 12.18; p ˂ 0.001) and more adverse childhood experiences across their lifespans (total ELSQ score, t(88.57) = 9.38; p ˂ 0.001). Illness-promoting psychological processes were identified in all children with FND. Most common were the following: chronic worries about schoolwork, friendships, or parental wellbeing (n = 64; 84.2%); attention to symptoms (n = 61; 80.3%); feeling sad (n = 58; 76.3%); experiencing a low sense of control (helplessness) in relation to symptoms (n = 44; 57.9%); pushing difficult thoughts out of mind (n = 44; 57.9%); self-critical rumination (n = 42; 55.3%); negative/catastrophic-symptom expectations (n = 40; 52.6%); avoidance of activities (n = 38; 50%); intrusive thoughts/feelings/memories associated with adverse events (n = 38, 50%); and pushing difficult feelings out of mind (n = 37; 48.7%). In children with FND-disabled enough to be admitted for inpatient treatment-illness-promoting psychological processes are part of the clinical presentation. They contribute to the child's ongoing sense of subjective distress, and if not addressed can maintain the illness process. A range of clinical interventions used to address illness-promoting psychological processes are discussed, along with illustrative vignettes.

The neurobiology of functional neurological disorders characterised by impaired awareness

We review the neurobiology of Functional Neurological Disorders (FND), i.e., neurological disorders not explained by currently identifiable histopathological processes, in order to focus on those characterised by impaired awareness (functionally impaired awareness disorders, FIAD), and especially, on the paradigmatic case of Resignation Syndrome (RS). We thus provide an improved more integrated theory of FIAD, able to guide both research priorities and the diagnostic formulation of FIAD. We systematically address the diverse spectrum of clinical presentations of FND with impaired awareness, and offer a new framework for understanding FIAD. We find that unraveling the historical development of neurobiological theory of FIAD is of paramount importance for its current understanding. Then, we integrate contemporary clinical material in order to contextualise the neurobiology of FIAD within social, cultural, and psychological perspectives. We thus review neuro-computational insights in FND in general, to arrive at a more coherent account of FIAD. FIAD may be based on maladaptive predictive coding, shaped by stress, attention, uncertainty, and, ultimately, neurally encoded beliefs and their updates. We also critically appraise arguments in support of and against such Bayesian models. Finally, we discuss implications of our theoretical account and provide pointers towards an improved clinical diagnostic formulation of FIAD. We suggest directions for future research towards a more unified theory on which future interventions and management strategies could be based, as effective treatments and clinical trial evidence remain limited.

Evidence-Based Mind-Body Interventions for Children and Adolescents with Functional Neurological Disorder

LEARNING OBJECTIVES

• Develop and implement treatment plans for children and adolescents with functional neurological disorder (FND)• Outline a plan to increase awareness and standardize the care for patients with FND using evidence-based interventions.

ABSTRACT

Functional neurological disorder (FND) in children and adolescents involves the biological embedding of lived experience in the body and brain. This embedding culminates in stress-system activation or dysregulation and in aberrant changes in neural network function. In pediatric neurology clinics, FND represents up to one-fifth of patients. Current research shows good outcomes with prompt diagnosis and treatment using a biopsychosocial, stepped-care approach. At present, however-and worldwide-FND services are scarce, the result of long-standing stigma and ingrained belief that patients with FND do not suffer from a real ("organic") disorder and that they therefore do not require, or even deserve, treatment. Since 1994, the Mind-Body Program for children and adolescents with FND at The Children's Hospital at Westmead in Sydney, Australia-run by a consultation-liaison team-has delivered inpatient care to hundreds of patients with FND and outpatient care to hundreds of others. For less-disabled patients, the program enables community-based clinicians to implement biopsychosocial interventions locally by providing a positive diagnosis (by a neurologist or pediatrician), a biopsychosocial assessment and formulation (by clinicians from the consultation-liaison team), a physical therapy assessment, and clinical support (from the consultation-liaison team and the physiotherapist). In this Perspective we describe the elements of a biopsychosocial mind-body program intervention capable of providing, as needed, effective treatment to children and adolescents with FND. Our aim is to communicate to clinicians and institutions around the world what is needed to establish effective community treatment programs, as well as hospital inpatient and outpatient interventions, in their own health care settings.

Psychogenic non-epileptic seizures and functional motor disorders in developmental age: A comparison of clinical and psychopathological features

BACKGROUND

Psychogenic Non-Epileptic Seizures (PNES) and Functional Motor Disorders (FMDs) commonly represent the main clinical manifestations of Functional Neurological Disorders (FNDs). Despite their high prevalence in pediatric neurological services, literature on this topic is still spare for this population. The present study aimed to deepen the clinical knowledge of a pediatric FNDs sample through a demographic and clinical characterization of the most recurrent clinical patterns during the pediatric age. Moreover, a comparison of neuropsychological and psychopathological profiles of PNES and FMD patients was carried out to identify specific vulnerabilities and therapeutic targets linked with these different clinical manifestations.

MATERIALS AND METHODS

A total of 43 FNDs patients (age range 7-17 years old) were retrospectively included in our study, enrolled in two subgroups: 20 with FMDs and 23 with PNES diagnosis. They were inpatients and outpatients referred over a period of 5 years and a standardized neurological, neuropsychological (WISC-IV/WAIS-IV), and psychiatric (CDI-2, MASC-2, ADES, DIS-Q, PID-5) evaluation was assessed.

RESULTS

In PNES patients the most common clinical phenotypes were functional tonic-clonic (52%) and atonic (32%) manifestations while in the FMDs group were gait alterations (60%), functional myoclonus (35%), and tremor (35%). A higher frequency of cognitive impairment was reported in PNES patients with higher anxiety-depressive symptom rates than FMDs patients.

CONCLUSIONS

Notably, specific neurocognitive and psychopathological profiles were described in PNES and FMDs, highlighting higher cognitive and psychiatric vulnerabilities in PNES, suggesting as well different strategy for therapeutic approaches.

Cortisol and α-amylase awakening response in children and adolescents with functional neurological (conversion) disorder

OBJECTIVE

Stress system dysregulation is considered to have an important role in the aetiology of paediatric functional neurological (conversion) disorder. This study examined salivary cortisol and α-amylase awakening responses in children with functional neurological disorder to determine activation patterns of the hypothalamic-pituitary-adrenal axis and sympathetic system. A healthy cortisol awakening response involves a robust increase in cortisol within 30 minutes of awakening. Alpha-amylase awakening response is variable in children.

METHODS

Cortisol and α-amylase were measured in saliva from 32 patients with functional neurological disorder (26 girls and 6 boys, aged 11.3-16.1 years) and 31 healthy controls (23 girls and 8 boys, aged 8.6-17.7 years). Saliva samples were collected using a Salivette sampling device at two time points - upon awakening and 30 minutes after awakening.

RESULTS

Patients with functional neurological disorder showed a decrease in cortisol awakening response (-4 nmol.min/L) and controls showed an increase (107 nmol.min/L), t(55) = -.4.6, p < 0.001. Within the functional neurological disorder group, 57% showed an attenuated cortisol awakening response and 43% showed an obliterated/reversed cortisol awakening response: Cortisol awakening response was negatively correlated with adverse childhood experiences, r(58) = -0.6, p = 0.002, and subjective distress (total Depression Anxiety and Stress Scales score), r(58) = -0.4, p = 0.050. In controls, cortisol awakening response showed no correlation with adverse childhood experiences and a positive correlation with subjective distress, r(56) = 0.4, p = 0.023. Total cortisol remained similar between the functional neurological disorder and control group. No significant differences were observed between the functional neurological disorder and control group in any of the α-amylase analyses.

DISCUSSION

The results suggest dysregulation of the hypothalamic-pituitary-adrenal axis in children with functional neurological disorder. Hypothalamic-pituitary-adrenal dysregulation in children with functional neurological disorder may contribute to comorbid symptoms of fatigue, sleep disturbance and subjective loss of well-being because circadian rhythms and energy metabolism are disrupted. Hypothalamic-pituitary-adrenal dysregulation - and changes in glucocorticoid (cortisol) signalling at the molecular level - may also contribute to increased vulnerability for functional neurological disorder symptoms because of epigenetically mediated changes to neural networks implicated in functional neurological disorder.

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.

Autonomic, Endocrine, and Inflammation Profiles in Functional Neurological Disorder: A Systematic Review and Meta-Analysis

OBJECTIVE

Functional neurological disorder (FND) is a core neuropsychiatric condition. To date, promising yet inconsistently identified neural circuit profiles have been observed in patients with FND, suggesting that gaps remain in our systems-level neurobiological understanding. As such, other important physiological variables, including autonomic, endocrine, and inflammation findings, need to be contextualized for a more complete mechanistic picture.

METHODS

The investigators conducted a systematic review and meta-analysis of available case-control and cohort studies of FND. PubMed, PsycINFO, and Embase databases were searched for studies from January 1, 1900, to September 1, 2020, that investigated autonomic, endocrine, and inflammation markers in patients with FND. Sixty-six of 2,056 screened records were included in the review, representing 1,699 patients; data from 20 articles were used in the meta-analysis.

RESULTS

Findings revealed that children and adolescents with FND, compared with healthy control subjects (HCs), have increased resting heart rate (HR); there is also a tendency toward reduced resting HR variability in patients with FND across the lifespan compared with HCs. In adults, peri-ictal HR differentiated patients with functional seizures from those with epileptic seizures. Other autonomic and endocrine profiles for patients with FND were heterogeneous, with several studies highlighting the importance of individual differences.

CONCLUSIONS

Inflammation research in FND remains in its early stages. Moving forward, there is a need for the use of larger sample sizes to consider the complex interplay between functional neurological symptoms and behavioral, psychological, autonomic, endocrine, inflammation, neuroimaging, and epigenetic/genetic data. More research is also needed to determine whether FND is mechanistically (and etiologically) similar or distinct across phenotypes.

Non-epileptic paroxysmal events in paediatric patients: A single tertiary centre study in Egypt

PURPOSE

The misdiagnosis of non-epileptic seizures (NES) as epilepsy is one of the most common pitfalls in neuropsychiatric practice. This study aimed to describe the percentage and types of NES among children who were referred for a diagnosis of epilepsy in Upper Egypt.

METHODS

We recruited a total of 876 patients who were referred to Sohag University Hospital, a tertiary referral centre in Upper Egypt, for the evaluation of suspected epilepsy. Relevant methods for the diagnosis of epilepsy, including medical history and examination, EEG, video-EEG, laboratory investigations, and brain imaging, were performed for all study participants.

RESULTS

Among the 876 patients who were referred for the diagnosis of suspected epilepsy during the period from June 2017 to October 2018, 171 patients (19.5 %) were diagnosed as having NES. In general, we found that NES in the paediatric age groups did not differ from that reported in various studies across several different populations. The most prevalent NES in our study was breath-holding spells (32.2 %), followed by syncope (17.5 %), psychogenic nonepileptic seizures (12.3 %), motor tics (9.9 %), and benign sleep myoclonus (7.6 %). Other less frequent NES included infantile masturbation (7 %), spasmus nutans (5.3 %), migraine (2.9 %), benign paroxysmal torticollis (2.9 %), night terrors (1.8 %), and shuddering attacks (0.6 %).

CONCLUSION

Ideally, neurologists should not misdiagnose NES as epilepsy, and whenever the diagnosis of NES is uncertain, an accurate diagnosis should be made using long-term video-EEG monitoring, especially in younger paediatric patients.