Subgroup classification in patients with psychogenic non-epileptic seizures

Anger regulation in patients with functional neurological disorder: A systematic review

BACKGROUND

Functional neurological disorder (FND) has been associated with predisposing psychological factors, including dysregulation of anger-related processes. This paper provides a systematic review of the literature on anger regulation in FND. We evaluated anger-related research on patient self-report, observational, and laboratory based measures in FND. The review also addresses adverse childhood experiences and their relation with anger regulation, and the effects of therapies targeting anger regulation in FND.

METHODS

MEDLINE, EMBASE, and PsycINFO were searched for both quantitative and qualitative research, published in a peer-reviewed journal with a sample size of at least 5 (registered under Prospero protocol CRD42022314340).

RESULTS

A total of 2200 articles were identified. After screening, 54 studies were included in this review (k = 20 questionnaire-based studies, k = 12 laboratory studies, k = 21 using other methods, and k = 1 used both questionnaires and other methods) representing data of 2502 patients with FND. Questionnaire-based studies indicated elevated levels of state anger and trait hostility in patients with FND. Laboratory studies showed a higher tendency to avoid social threat cues, attentional bias towards angry faces, difficulties reliving anger, and preoccupation with frustrating barriers among FND patients versus controls. No specific childhood experiences were identified related to anger regulation in FND, and too few small and uncontrolled studies were available (k = 2) to assess the effects of anger-related interventions in FND. The overall quality of the studies was fair (k = 31) to poor (k = 18). Five studies (k = 5) were rated as having a good quality.

CONCLUSIONS

This review suggests that patients with FND have maladaptive anger regulation compared to individuals without FND. The findings also highlight the need for further research on the prevalence and consequences of anger-related processes in the development, diagnosis and treatment of FND.

Medication use in patients with functional seizures from a public and a private hospital

PURPOSE

Currently, we have limited knowledge of any potential differences among patients with functional seizures (FS), otherwise known as psychogenic non-epileptic seizures (PNES), from different socioeconomic backgrounds. Investigating medication use among these patients may provide insight into the quality and intensity of medical care they receive. Thus, we aimed to assess and compare the frequency and quantity of antiseizure medications (ASMs), and psychiatric and other medications used among patients with FS from a private and public epilepsy monitoring units (EMUs) in Cape Town, South Africa.

METHODS

Only video-electroencephalographically (video-EEG) confirmed patients with FS with no comorbid epilepsy were eligible for the study. For this retrospective case-control study we collected data on patients' medication-taking histories using digital patient records, starting with the earliest available digital patient record for each hospital.

RESULTS

A total of 305 patients from a private hospital and 67 patients from a public hospital were included in the study (N = 372). Patients with FS attending the public hospital had lower odds of taking any ASMs at presentation (aOR=0.39, 95% CI [0.20, 0.75]) and ever taking psychiatric medications (aOR=0.41, 95% CI [0.22, 0.78]) compared to FS patients from the private hospital. They did, however, have higher odds of being discharged with an ASM (aOR=6.60, 95% CI [3.27, 13.35]) and ever taking cardiovascular medication (aOR=2.69, 95% CI [1.22, 5.90]) when compared to the private hospital patients. With every additional presenting ASM (aOR=0.63, 95% CI [0.45, 0.89]) and psychiatric medication (aOR=0.58, 95% CI [0.40, 0.84]) the odds of being from the public hospital decreased. However, they increased with every additional discharge ASM (aOR=3.63, 95% CI [2.30, 5.72]) and cardiovascular medication (aOR=1.26, 95% CI [1.02, 1.55]).

CONCLUSION

Standard approaches to pharmacological treatment for patients with FS differed between the public and private hospitals and may indicate a gap in quality of care.

Psychiatric and psychological assessment of patients with drug-resistant epilepsy and psychogenic nonepileptic seizures (PNES) with no response to previous treatments

OBJECTIVE

Psychogenic nonepileptic seizures (PNES) are common imitators of epileptic seizures. Refractoriness to antiseizure medication hinders the differential diagnosis between ES and PNES, carrying deleterious consequences in patients with PNES. Psychiatric and psychological characteristics may assist in the differential diagnosis between drug-resistant epilepsy (DRE) and PNES. Nevertheless, current comprehensive psychiatric and psychological descriptive studies on both patient groups are scarce and with several study limitations. This study provides a comprehensive psychiatric and psychological characterization of Spanish patients with DRE and PNES.

METHOD

A cross-sectional and comparative study was completed with 104 patients with DRE and 21 with PNES. Psychiatric and psychological characteristics were assessed with the HADS, SCL-90-R, NEO-FFI-R, PDQ-4+, COPE, and QOLIE-31 tests. Parametric and non-parametric tests were used, and regression models were fit to further explore factors affecting patients' life quality.

RESULTS

Patients with PNES had greater levels of somatization and extraversion and were associated with benzodiazepine intake. Patients with DRE showed greater narcissistic personality disorder symptoms than those with PNES. In patients with DRE, difficulty in performing basic needs-related tasks and greater psychological distress severity and seizure frequency were associated with poorer life quality. In contrast, being a woman, having a psychiatric disorder history, and greater psychiatric symptoms' intensity were associated with poorer life quality in patients with PNES.

CONCLUSION

Patients with DRE and PNES share similar psychiatric and psychological characteristics, with only very few being significantly different.

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.

Heterogeneity of patients with functional/dissociative seizures: Three multidimensional profiles

OBJECTIVE

Current concepts highlight the neurological and psychological heterogeneity of functional/dissociative seizures (FDS). However, it remains uncertain whether it is possible to distinguish between a limited number of subtypes of FDS disorders. We aimed to identify profiles of distinct FDS subtypes by cluster analysis of a multidimensional dataset without any a priori hypothesis.

METHODS

We conducted an exploratory, prospective multicenter study of 169 patients with FDS. We collected biographical, trauma (childhood and adulthood traumatic experiences), semiological (seizure characteristics), and psychopathological data (psychiatric comorbidities, dissociation, and alexithymia) through psychiatric interviews and standardized scales. Clusters were identified by the Partitioning Around Medoids method. The similarity of patients was computed using Gower distance. The clusters were compared using analysis of variance, chi-squared, or Fisher exact tests.

RESULTS

Three patient clusters were identified in this exploratory, hypothesis-generating study and named on the basis of their most prominent characteristics: A "No/Single Trauma" group (31.4%), with more male patients, intellectual disabilities, and nonhyperkinetic seizures, and a low level of psychopathology; A "Cumulative Lifetime Traumas" group (42.6%), with clear female predominance, hyperkinetic seizures, relatively common comorbid epilepsy, and a high level of psychopathology; and A "Childhood Traumas" group (26%), commonly with comorbid epilepsy, history of childhood sexual abuse (75%), and posttraumatic stress disorder, but also with a high level of anxiety and dissociation.

SIGNIFICANCE

Although our cluster analysis was undertaken without any a priori hypothesis, the nature of the trauma history emerged as the most important differentiator between three common FDS disorder subtypes. This subdifferentiation of FDS disorders may facilitate the development of more specific therapeutic programs for each patient profile.

Evaluating, Filtering and Clustering Genetic Disease Cohorts Based on Human Phenotype Ontology Data with Cohort Analyzer

Exhaustive and comprehensive analysis of pathological traits is essential to understanding genetic diseases, performing precise diagnosis and prescribing personalized treatments. It is particularly important for disease cohorts, as thoroughly detailed phenotypic profiles allow patients to be compared and contrasted. However, many disease cohorts contain patients that have been ascribed low numbers of very general and relatively uninformative phenotypes. We present Cohort Analyzer, a tool that measures the phenotyping quality of patient cohorts. It calculates multiple statistics to give a general overview of the cohort status in terms of the depth and breadth of phenotyping, allowing us to detect less well-phenotyped patients for re-examining or excluding from further analyses. In addition, it performs clustering analysis to find subgroups of patients that share similar phenotypic profiles. We used it to analyse three cohorts of genetic diseases patients with very different properties. We found that cohorts with the most specific and complete phenotypic characterization give more potential insights into the disease than those that were less deeply characterised by forming more informative clusters. For two of the cohorts, we also analysed genomic data related to the patients, and linked the genomic data to the patient-subgroups by mapping shared variants to genes and functions. The work highlights the need for improved phenotyping in this era of personalized medicine. The tool itself is freely available alongside a workflow to allow the analyses shown in this work to be applied to other datasets.

Interoception and stress in patients with Functional Neurological Symptom Disorder

INTRODUCTION

Research suggests that patients with Functional Neurological Symptom Disorder (pwFND) struggle to identify their own emotions and associated physiological cues (interoceptive sensitivity, IS). However, it is not known how this deficit interacts with stress. This study aimed to assess IS in pwFND at baseline and following stress induction, and relate the findings to self-reported emotion processing difficulties.

METHODS

Twenty-six pwFND and 27 healthy controls performed the Heart Beat Detection Task pre- and post-stress induction with the Cold Pressor Test. Participants also completed questionnaires assessing anxiety (GAD-7) and depressive symptomology (PHQ-9), as well as emotion processing (EPS-25).

RESULTS

Patients reported deficits in emotion processing (p < . 001) and had lower IS (p = .032) than healthy controls. IS improved following stress induction across both groups (p = .003) but patients' IS was lower than that of healthy controls' pre-and post-stress induction. Exploratory analyses revealed that patients reporting sensory symptoms had lower IS at baseline than patients who did not.

CONCLUSION

Our findings suggest that pwFND are relatively impaired in the identification of their emotions at baseline and following stress induction. This may be related to the experience of functional sensory symptoms and has implications for the psychological treatment of emotion dysregulation in this population.

The impact of sexual abuse on psychopathology of patients with psychogenic nonepileptic seizures

OBJECTIVES

In the present study, we evaluated if the presence of sexual abuse in the clinical history of patients with psychogenic non-epileptic seizures (PNES) is associated with a different psychopathological profile.

MATERIALS AND METHODS

In a consecutive population of 63 PNES patients, we compared two demographically and clinically matched groups of patients with (no. 15) and without (no. 48) a history of sexual abuse using a comprehensive psychopathological assessment (Beck Depression Inventory, Hamilton Anxiety Rating Scale, Dissociative Experience Scale, Somatoform Dissociation Questionnaire, and Toronto Alexithymia Scale).

RESULTS

We found that the group of patients reporting sexual abuse is characterized by higher scores on Dissociative Experience Scale (p = 0.003) and Beck Depression Inventory (p = 0.001) with respect to the other group. No significant statistical differences in Hamilton Anxiety Rating Scale (p = 0.103), Toronto Alexithymia Scale (p = 0.137), and Somatoform Dissociation Questionnaire (p = 0.486) were captured. Moreover, we found that the negative effect on dissociate symptoms was also hampered by the increasing of seizure frequency.

CONCLUSIONS

This study reinforces the importance of traumatic screening in the clinical spectrum of PNES in order to implement and improve specific therapeutic strategies.

Quantitative analysis of phenotypic elements augments traditional electroclinical classification of common familial epilepsies

OBJECTIVE

Classification of epilepsy into types and subtypes is important for both clinical care and research into underlying disease mechanisms. A quantitative, data-driven approach may augment traditional electroclinical classification and shed new light on existing classification frameworks.

METHODS

We used latent class analysis, a statistical method that assigns subjects into groups called latent classes based on phenotypic elements, to classify individuals with common familial epilepsies from the Epi4K Multiplex Families study. Phenotypic elements included seizure types, seizure symptoms, and other elements of the medical history. We compared class assignments to traditional electroclinical classifications and assessed familial aggregation of latent classes.

RESULTS

A total of 1120 subjects with epilepsy were assigned to five latent classes. Classes 1 and 2 contained subjects with generalized epilepsy, largely reflecting the distinction between absence epilepsies and younger onset (class 1) versus myoclonic epilepsies and older onset (class 2). Classes 3 and 4 contained subjects with focal epilepsies, and in contrast to classes 1 and 2, these did not adhere as closely to clinically defined focal epilepsy subtypes. Class 5 contained nearly all subjects with febrile seizures plus or unknown epilepsy type, as well as a few subjects with generalized epilepsy and a few with focal epilepsy. Family concordance of latent classes was similar to or greater than concordance of clinically defined epilepsy types.

SIGNIFICANCE

Quantitative classification of epilepsy has the potential to augment traditional electroclinical classification by (1) combining some syndromes into a single class, (2) splitting some syndromes into different classes, (3) helping to classify subjects who could not be classified clinically, and (4) defining the boundaries of clinically defined classifications. This approach can guide future research, including molecular genetic studies, by identifying homogeneous sets of individuals that may share underlying disease mechanisms.

Psychiatric disorders and trauma history in patients with pure PNES and patients with PNES and coexisting epilepsy

Several studies found high prevalence rates of psychiatric disorders in patients with pure psychogenic nonepileptic seizures (PNES). Traumatic experiences were also reported to be elevated in patients with PNES and were discussed as a crucial risk factor for the development of PNES. Much less is known about psychiatric comorbidities and specifically, about trauma history in patients with PNES and coexisting epilepsy. Here, we aimed at directly comparing psychiatric disorders and traumatic life experiences in patients with pure PNES and in patients with PNES and coexisting epilepsy. We assessed the presence of current axes I and II disorders in 109 patients with either pure PNES (n = 67) or with PNES + epilepsy (n = 42) by using structured clinical interviews. We also compared the trauma histories by using the posttraumatic diagnostic scale (PDS) as an interview and the extent of physical, sexual, and emotional childhood maltreatment measured with the Childhood Trauma Questionnaire (CTQ). Patients of both groups had very high rates of psychiatric disorders: 79.1% of the patients with pure PNES and 76.2% of the patients with PNES + epilepsy had at least one psychiatric disorder. The frequencies of psychiatric disorders did not differ between groups. However, there was a trend towards higher rates of posttraumatic stress disorder (PTSD) in patients with PNES (32.9%) compared with patients with PNES + epilepsy (16.7%). In both groups, the proportion of patients who recalled traumatic events in the PDS was high (72.6% in the patients with pure PNES, 64.3% in the patients with PNES + epilepsy) and did not differ significantly between groups. The age at first traumatization, the types of trauma events experienced, the number of patients with single traumatization, and those with repeated traumatic experiences also did not differ between groups. We found high frequencies of childhood maltreatment in both groups. Our findings show that patients with PNES and patients with PNES and coexisting epilepsy could neither be differentiated by the amount of psychiatric additional disorders nor by the nature and extent of trauma and maltreatment experiences. Our results suggest that patients with PNES + epilepsy rather resemble patients with pure PNES than patients with epilepsy in respect to psychopathological characteristics and adverse life experiences. Trauma and maltreatment history are therefore assumed to be predisposing factors to PNES in both patients with pure PNES and patients with PNES and coexisting epilepsy.

Emotion dysregulation in patients with psychogenic nonepileptic seizures: A systematic review based on the extended process model

Psychogenic nonepileptic seizures (PNES) are characterized by paroxysmal alterations in motor and sensory functions resembling epileptic seizures, but are not caused by epileptiform activity. In recent years, there has been increasing scientific interest in emotion dysregulation in patients with PNES (pwPNES), but the literature has not yet been interpreted within a broader model of emotion dysregulation. The aim of this review was therefore to synthesize the existing literature on emotion dysregulation in pwPNES within the extended process model (EPM) of emotion regulation.

METHODS

PubMed and Web of Science were searched for studies relevant to emotion dysregulation as defined by the EPM. These studies were subjected to a bespoke quality appraisal tool. Studies of acceptable quality were categorized to the different stages of the EPM and critically appraised.

RESULTS

Studies of emotion regulation in pwPNES were generally of low quality - a finding largely driven by small sample sizes. However, there was evidence of emotion dysregulation characterized by deficits in the identification of patients' own emotional states, as well as the selection and implementation of maladaptive regulatory strategies, and altered exteroceptive emotional processing. However, heterogeneity in findings suggests that emotion dysregulation is likely linked to other psychological factors and not common to all pwPNES.

SIGNIFICANCE

This review suggests that while pwPNES are likely to experience emotion dysregulation as defined by the EPM, there is variability in the distribution of regulatory deficits in this patient population, and a person-centered approach should be taken when working with these patients. There is a need for more high quality and better-powered studies in this area.

Implicit attentional bias for facial emotion in dissociative seizures: Additional evidence

This study sought to extend knowledge about the previously reported preconscious attentional bias (AB) for facial emotion in patients with dissociative seizures (DS) by exploring whether the finding could be replicated, while controlling for concurrent anxiety, depression, and potentially relevant cognitive impairments. Patients diagnosed with DS (n=38) were compared with healthy controls (n=43) on a pictorial emotional Stroop test, in which backwardly masked emotional faces (angry, happy, neutral) were processed implicitly. The group with DS displayed a significantly greater AB to facial emotion relative to controls; however, the bias was not specific to negative or positive emotions. The group effect could not be explained by performance on standardized cognitive tests or self-reported depression/anxiety. The study provides additional evidence of a disproportionate and automatic allocation of attention to facial affect in patients with DS, including both positive and negative facial expressions. Such a tendency could act as a predisposing factor for developing DS initially, or may contribute to triggering individuals' seizures on an ongoing basis. Psychological interventions such as Cognitive Behavioral Therapy (CBT) or AB modification might be suitable approaches to target this bias in clinical practice.

An Overview of Psychogenic Non-Epileptic Seizures: Etiology, Diagnosis and Management

The purpose of this review is to provide an update of the research regarding the etiology, diagnosis and management of psychogenic non-epileptic seizures (PNES). A literature search using Pubmed, Ovid MEDLINE and EMBASE database was performed from 2000 up to August 2017. We have evaluated the different factors leading to PNES as well as the diagnostic approach and management of this disorder which continue to be very difficult. The coexistence of epilepsy and PNES poses special challenges and requires the coordinated efforts of the family physicians, psychiatrists, psychologists and neurologists. Although this condition has an overall poor prognosis, a multidisciplinary approach in the diagnosis and management of this disorder would likely improve the outcomes. We have proposed a diagnostic and treatment algorithm for PNES and suggested a national registry of patients suffering from this condition. The registry would contain data regarding treatment and outcomes to aid in the understanding of this entity.

Increased odds and predictive rates of MMPI-2-RF scale elevations in patients with psychogenic non-epileptic seizures and observed sex differences

OBJECTIVE

The Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) is a self-report instrument, previously shown to differentiate patients with epileptic seizures (ES) and psychogenic non-epileptic seizures (PNES). At present, the odds of MMPI-2-RF scale elevations in PNES patients, as well as the diagnostic predictive value of such scale elevations, remain largely unexplored. This can be of clinical utility, particularly when a diagnosis is uncertain.

METHOD

After looking at mean group differences, we applied contingency table derived odds ratios to a sample of ES (n=92) and PNES (n=77) patients from a video EEG (vEEG) monitoring unit. We also looked at the positive and negative predictive values (PPV, NPV), as well as the false discovery rate (FDR) and false omission rate (FOR) for scales found to have increased odds of elevation in PNES patients. This was completed for the overall sample, as well as the sample stratified by sex.

RESULTS

The odds of elevations related to somatic concerns, negative mood, and suicidal ideation in the PNES sample ranged from 2 to 5 times more likely. Female PNES patients had 3-6 times greater odds of such scale elevations, while male PNES patients had odds of 5-15 times more likely. PPV rates ranged from 53.66% to 84.62%, while NPV rates ranged from 47.52% to 90.91%. FDR across scales ranged from 15.38% to 50%, while the FOR ranged from 9.09% to 52.47%.

CONCLUSIONS

Consistent with prior research, PNES patients have greater odds of MMPI-2-RF scale elevations, particularly related to somatic concerns and mood disturbance. Female PNES patients endorsed greater emotional distress, including endorsement of suicide related items. Elevations of these scales could aid in differentiating PNES from ES patients, although caution is warranted due to the possibility of both false positives and the incorrect omissions of PNES cases.

Dissociation in patients with dissociative seizures: relationships with trauma and seizure symptoms

BACKGROUND

This study aimed to extend the current understanding of dissociative symptoms experienced by patients with dissociative (psychogenic, non-epileptic) seizures (DS), including psychological and somatoform types of symptomatology. An additional aim was to assess possible relationships between dissociation, traumatic experiences, post-traumatic symptoms and seizure manifestations in this group.

METHOD

A total of 40 patients with DS were compared with a healthy control group (n = 43), matched on relevant demographic characteristics. Participants completed several self-report questionnaires, including the Multiscale Dissociation Inventory (MDI), Somatoform Dissociation Questionnaire-20, Traumatic Experiences Checklist and the Post-Traumatic Diagnostic Scale. Measures of seizure symptoms and current emotional distress (Hospital Anxiety and Depression Scale) were also administered.

RESULTS

The clinical group reported significantly more psychological and somatoform dissociative symptoms, trauma, perceived impact of trauma, and post-traumatic symptoms than controls. Some dissociative symptoms (i.e. MDI disengagement, MDI depersonalization, MDI derealization, MDI memory disturbance, and somatoform dissociation scores) were elevated even after controlling for emotional distress; MDI depersonalization scores correlated positively with trauma scores while seizure symptoms correlated with MDI depersonalization, derealization and identity dissociation scores. Exploratory analyses indicated that somatoform dissociation specifically mediated the relationship between reported sexual abuse and DS diagnosis, along with depressive symptoms.

CONCLUSIONS

A range of psychological and somatoform dissociative symptoms, traumatic experiences and post-traumatic symptoms are elevated in patients with DS relative to healthy controls, and seem related to seizure manifestations. Further studies are needed to explore peri-ictal dissociative experiences in more detail.

A comparative retrospective exploration of the profiles of patients in South Africa diagnosed with epileptic and psychogenic non-epileptic seizures

Psychogenic non-epileptic seizures (PNES) have a high prevalence globally but the accurate diagnosis of this condition still remains a challenge. This is particularly the case in countries where there is scarce expertise and insufficient affordable medical facilities to which patients have access. The rate of PNES diagnosis in epilepsy units is typically within the range of 20 to 30%. In the context of developing countries, this rate tends to be higher and increases demand on the existing scarce health care capacities. Although the profiling of patients with different seizure presentations is essential for informing appropriate treatment, to date there has been no comparative analysis of the profiles of patients with PNES and epilepsy in South Africa. The aim of the present study was to explore retrospectively the demographic and medication characteristics of these patients and to compare these characteristics to those reported in patient populations from other countries and regions. The total sample of 246 participants included 85 (35%) male and 161 (65%) female patients who were admitted to the Epilepsy Monitoring Unit (EMU) at Milpark Hospital, South Africa. Following the video-EEG monitoring assessment, 123 patients (50%) were diagnosed with PNES, and for 123 patients (50%) the diagnosis of epilepsy was confirmed. The results indicated that the demographic profiles of the groups of patients with epilepsy and PNES were similar with reference to age and self-ascribed ethnicity. In both groups, the majority of the patients were females, but proportionally their prevalence was higher in the PNES patient group than in the epilepsy patient group, which is compatible with the trends found in the PNES patient populations internationally. Pre-diagnostically, the type and the number of medications prescribed to patients with PNES and epilepsy were comparable. Subsequent to the diagnosis at the EMU, there was a significant reduction of overall medications in each group, but this reducton was more pronounced in the group with PNES. It is concluded that the rate of misdiagnosis of PNES in South Africa surpasses the rates reported for the patient populations in other countries and is one of the highest documented worldwide. Considering that post-diagnostically, there was reduction in central nervous system (CNS) medications as well as anti-epileptic drugs (AEDs) in both patients with epilepsy and those with PNES, it is likely that pre-diagnostically a significant proportion of all patients were over medicated. Compared to the epilepsy diagnosis, the PNES diagnosis resulted in a more substantial reduction of medication. These findings outline important dimensions of the diagnostic and medication treatment practices of epilepsy and PNES and point to the urgent need to improve these practices in South Africa and the African continent.

Psychological and psychiatric aspects of psychogenic non-epileptic seizures (PNES): A systematic review

Psychogenic non-epileptic seizures (PNES) are common in neurological settings and often associated with considerable distress and disability. The psychological mechanisms underlying PNES are poorly understood and there is a lack of well-established, evidence-based treatments. This paper advances our understanding of PNES by providing a comprehensive systematic review of the evidence pertaining to the main theoretical models of this phenomenon. Methodological quality appraisal and effect size calculation were conducted on one hundred forty empirical studies on the following aspects of PNES: life adversity, dissociation, anxiety, suggestibility, attentional dysfunction, family/relationship problems, insecure attachment, defence mechanisms, somatization/conversion, coping, emotion regulation, alexithymia, emotional processing, symptom modelling, learning and expectancy. Although most of the studies were only of low to moderate quality, some findings are sufficiently consistent to warrant tentative conclusions: (i) physical symptom reporting is elevated in patients with PNES; (ii) trait dissociation and exposure to traumatic events are common but not inevitable correlates of PNES; (iii) there is a mismatch between subjective reports of anxiety and physical arousal during PNES; and (iv) inconsistent findings in this area are likely to be attributable to the heterogeneity of patients with PNES. Empirical, theoretical and clinical implications are discussed.

Number of patient-reported allergies helps distinguish epilepsy from psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (PNES) are relatively common, accounting for 5-40% of visits to tertiary epilepsy centers. Inpatient video-electroencephalogram (vEEG) monitoring is the gold standard for diagnosis, but additional positive predictive tools are necessary given vEEG's relatively scarce availability. In this study, we investigated if the number of patient-reported allergies distinguishes between PNES and epilepsy. Excessive allergy-reporting, like PNES, may reflect somatization. Using electronic medical records, ICD-9 codes, and text-identification algorithms to search EEG reports, we identified 905 cases of confirmed PNES and 5187 controls with epilepsy but no PNES. Patients with PNES averaged more self-reported allergies than patients with epilepsy alone (1.93 vs. 1.00, p<0.001). Compared to those with no allergies, each additional allergy linearly increased the percentage of patients with PNES by 2.98% (R(2)=0.71) such that with ≥12 allergies, 12/28 patients (42.8%) had PNES compared to 349/3368 (11.6%) of the population with no allergies (odds ratio=6.49). This relationship remained unchanged with logistic regression analysis. We conclude that long allergy lists may help identify patients with PNES. We hypothesize that a tendency to inaccurately self-report allergies reflects a maladaptive externalization of psychologic distress and that a similar mechanism may be responsible for PNES in some patients with somatic symptom disorder.

Number of patient-reported allergies helps distinguish epilepsy from psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (PNES) are relatively common, accounting for 5-40% of visits to tertiary epilepsy centers. Inpatient video-electroencephalogram (vEEG) monitoring is the gold standard for diagnosis, but additional positive predictive tools are necessary given vEEG's relatively scarce availability. In this study, we investigated if the number of patient-reported allergies distinguishes between PNES and epilepsy. Excessive allergy-reporting, like PNES, may reflect somatization. Using electronic medical records, ICD-9 codes, and text-identification algorithms to search EEG reports, we identified 905 cases of confirmed PNES and 5187 controls with epilepsy but no PNES. Patients with PNES averaged more self-reported allergies than patients with epilepsy alone (1.93 vs. 1.00, p<0.001). Compared to those with no allergies, each additional allergy linearly increased the percentage of patients with PNES by 2.98% (R(2)=0.71) such that with ≥12 allergies, 12/28 patients (42.8%) had PNES compared to 349/3368 (11.6%) of the population with no allergies (odds ratio=6.49). This relationship remained unchanged with logistic regression analysis. We conclude that long allergy lists may help identify patients with PNES. We hypothesize that a tendency to inaccurately self-report allergies reflects a maladaptive externalization of psychologic distress and that a similar mechanism may be responsible for PNES in some patients with somatic symptom disorder.

Childhood trauma and psychogenic nonepileptic seizures: A review of findings with speculations on the underlying mechanisms

OBJECTIVE

The objective of this review was to examine the possible link between psychological trauma in a patient's medical history and the onset of psychogenic nonepileptic seizures (PNES).

METHODOLOGY

An electronic search of published reports was made using the search engines PubMed-MedLine, EBSCO, PsycINFO, SFX, and Embase and the keywords "PNES", "psychogenic seizures", "sexual abuse", and "trauma".

RESULTS

A correlation emerged between history of childhood trauma and the presence of PNES. Antecedent trauma was more frequent in females than in males and in patients exhibiting psychiatric disorders but was inversely correlated with cognitive impairment.

CONCLUSIONS

In the presence of PNES, it is important to accurately investigate the patient's medical history in search of psychological trauma, particularly in women and in patients with psychiatric disorders.

Psychogenic non-epileptic seizures: so-called psychiatric comorbidity and underlying defense mechanisms

In Diagnostic and Statistical Manual of Mental Disorders, fifth edition, psychogenic non-epileptic seizures (PNES) do not have a unique classification as they can be found within different categories: conversion, dissociative, and somatization disorders. The ICD-10, instead, considers PNES within dissociative disorders, merging the dissociative disorders and conversion disorders, although the underlying defense mechanisms are different. The literature data show that PNES are associated with cluster B (mainly borderline) personality disorders and/or to people with depressive or anxiety disorders. Defense mechanisms in patients with PNES with a prevalence of anxious/depressive symptoms are of "neurotic" type; their goal is to lead to a "split", either vertical (dissociation) or horizontal (repression). The majority of patients with this type of PNES have alexithymia traits, meaning that they had difficulties in feeling or perceiving emotions. In subjects where PNES are associated with a borderline personality, in which the symbolic function is lost, the defense mechanisms are of a more archaic nature (denial). PNES with different underlying defense mechanisms have different prognoses (despite similar severity of PNES) and need usually a different treatment (pharmacological or psychological). Thus, it appears superfluous to talk about psychiatric comorbidity, since PNES are a different symptomatic expression of specific psychiatric disorders.