Peri‐ictal responsiveness to the social environment is greater in psychogenic nonepileptic than epileptic seizures

Dissociative seizures in the emergency room: room for improvement

BACKGROUND

Dissociative seizures, also known as functional or psychogenic non-epileptic seizures, account for 11%-27% of all emergency seizure presentations. Misdiagnosis as epileptic seizures is common and leads to ineffective and potentially harmful treatment escalations. We assess the potential for diagnostic improvement at different stages of emergency workup and estimate the utility of benzodiazepines.

METHODS

A retrospective study of all emergency presentations with a discharge diagnosis of acute dissociative seizures seen at a university hospital 2010-2022 was performed to assess clinical characteristics and emergency decision-making.

RESULTS

Among 156 patients (73% female, median 29 years), 15% presented more than once for a total of 203 presentations. Half of seizures were ongoing at first medical contact; prolonged seizures and clusters were common (23% and 24%). Diagnostic accuracy differed between on-site emergency physicians and emergency department neurologists (12% vs 52%). Typical features such as eye closure, discontinuous course and asynchronous movements were common. Benzodiazepines were given in two-thirds of ongoing seizures, often in high doses and preferentially for major hyperkinetic semiology. Clinical response to benzodiazepines was mixed, with a minority of patients remaining either unaffected (16%) or becoming critically sedated (13%). A quarter of patients given benzodiazepines by emergency medical services were admitted to a monitoring unit, 9% were intubated.

CONCLUSIONS

Improved semiological assessment could reduce early misdiagnosis of dissociative seizures. Although some seizures seem to respond to benzodiazepines, critical sedation is common, and further studies are needed to assess the therapeutic ratio.

Functional neurological disorder is a feminist issue

Functional neurological disorder (FND) is a common and disabling disorder, often misunderstood by clinicians. Although viewed sceptically by some, FND is a diagnosis that can be made accurately, based on positive clinical signs, with clinical features that have remained stable for over 100 years. Despite some progress in the last decade, people with FND continue to suffer subtle and overt forms of discrimination by clinicians, researchers and the public. There is abundant evidence that disorders perceived as primarily affecting women are neglected in healthcare and medical research, and the course of FND mirrors this neglect. We outline the reasons why FND is a feminist issue, incorporating historical and contemporary clinical, research and social perspectives. We call for parity for FND in medical education, research and clinical service development so that people affected by FND can receive the care they need.

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.

The A to F of functional status in the acute setting: A scoping review

Functional status (FSt) describes the phenomenon of prolonged non-epileptic attacks that may be misidentified as Status Epilepticus (SE). The early differentiation between epileptic and functional status is crucial in order to avoid unnecessarily invasive and costly medical escalation in the latter group, including the hazards of overmedication, intubation and intensive care admission. The authors conducted a literature review of available studies describing cases of functional status to extract the common aspects of FSt seizure semiology, investigations used to differentiate from SE, and guidance for managing FSt. A search was carried out using Medline, Embase and PsychInfo databases and 3909 papers were extracted for review. 30 papers were found relevant for inclusion, describing 260 cases of FSt. FSt was found to occur more commonly in younger, female patients with a family history of epilepsy, co-morbid psychiatric diagnosis and following a recent traumatic event. Common clinical features of FSt during and after, the events were identified. While video-EEG remains the gold standard investigation for differentiating FSt from SE, many of the included studies considered the utility of other investigation modalities including serum markers and neuroimaging. One key shortcoming identified within the literature reviewed was a lack of well-defined guidance on the acute management of FSt. We offer an A-F step management plan for the immediate and longer term assessment and treatment of FSt.

Functional neurological disorder: new subtypes and shared mechanisms

Functional neurological disorder is common in neurological practice. A new approach to the positive diagnosis of this disorder focuses on recognisable patterns of genuinely experienced symptoms and signs that show variability within the same task and between different tasks over time. Psychological stressors are common risk factors for functional neurological disorder, but are often absent. Four entities-functional seizures, functional movement disorders, persistent perceptual postural dizziness, and functional cognitive disorder-show similarities in aetiology and pathophysiology and are variants of a disorder at the interface between neurology and psychiatry. All four entities have distinctive features and can be diagnosed with the support of clinical neurophysiological studies and other biomarkers. The pathophysiology of functional neurological disorder includes overactivity of the limbic system, the development of an internal symptom model as part of a predictive coding framework, and dysfunction of brain networks that gives movement the sense of voluntariness. Evidence supports tailored multidisciplinary treatment that can involve physical and psychological therapy approaches.

Psychogenic nonepileptic seizures: Are they a freeze reaction?

Psychogenic nonepileptic seizures (PNES) clinically resemble epileptic seizures (ES) but lack epileptic activity at the time of the seizure and are also not due to any other pathophysiological disorder. The integrative cognitive model (ICM) suggests that PNES is an automatic reaction generated from distorted memory and is perceived as uncontrollable and unwanted. Furthermore, the ICM model implies that a PNES event occurs due to an external or internal cue. Intrigued by this assumption, we wanted to examine why a PNES event occurs at a particular moment by investigating the pre-ictal behavior. This study is a retrospective study. We included all patients diagnosed with PNES or ES admitted to our long-term video-EEG monitoring unit (LTVEM) between 01/01/2018 and 30/08/2020. Using thorough video analysis, we checked the patient's state at the onset of the event and looked back to see what the patient was doing before the event onset. We defined 4 types of pre-ictal behavior A. Inactivity. B. Environment arrangement c. Other. D. No apparent pre-ictal behavior. Thirty patients with PNES and 30 patients with ES were included in the study. In total, 46 PNES events and 56 ES events were recorded and analyzed. In 33 /46 PNES seizures (72%), a type A, A + B or C pre-ictal behavior was observed compared to 1/56 ES (1.78%) with type A pre-ictal behavior. All other pre-ictal behavior in the ES group were of type D. Patients with PNES have a unique pre-ictal behavior before most PNES events with motor manifestations. Since the pre-ictal behavior consists mainly of inactivity, we believe it may imply that PNES represents a freeze reaction or a reconstruction of a freeze reaction.

Using Semiology to Classify Epileptic Seizures vs Psychogenic Nonepileptic Seizures: A Meta-analysis

Background and objectives:

Misdiagnosis of psychogenic nonepileptic seizures (PNES) and epileptic seizures (ES) is common. In the absence of the diagnostic gold standard (video EEG), clinicians rely on semiology and clinical assessment. However, questions regarding the diagnostic accuracy of different signs remain. This meta-analysis aims to evaluate the diagnostic accuracy of semiology in PNES and ES.

Methods:

We systematically searched PubMed, PsycInfo and Medline for original research publications published before 8 February 2021 with no restriction on search dates to identify studies that compared semiology in ES and PNES in epilepsy monitoring units. Non-English publications, review articles, studies reporting on only PNES or ES and studies limited to patients with developmental delay were excluded. Study characteristics and proportions of ‘event groups’ and ‘patient groups’ demonstrating signs were extracted from each article. Bivariate analysis was conducted, and data were pooled in a random effects model for meta-analysis. The I2 statistic was calculated to assess statistical heterogeneity. The QUADAS-2 tool was utilized to assess risk of bias in included studies. The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were calculated. A PLR > 10 or an NLR < 0.1 has a large impact on the post-test probability of a diagnosis (ES or PNES) whereas a PLR between 5-10 or an NLR between 0.1- 0.2 has a moderate impact on the post-test probability of a diagnosis (ES or PNES).

Results:

The meta-analysis included 14 studies comprising of 800 patients with ES and 452 patients with PNES. For PNES, ictal eye closure (PLR 40.5 95%CI: 16.2-101.3; I2 = 0, from three studies) and asynchronous limb movements (PLR 10.2; 95%CI: 2.8-37.7; I2 = 0, from three studies) reached a PLR threshold > 5. No single sign reached a PLR threshold >5 for ES.

Conclusions:

While all signs require interpretation in the overall clinical context, the presence of ictal eye closure and asynchronous limb movements are reliable discriminative signs for PNES.

Misdiagnosis of prolonged psychogenic non-epileptic seizures as status epilepticus: epidemiology and associated risks

OBJECTIVE

To determine the epidemiology of prolonged psychogenic non-epileptic seizures (pPNES) misdiagnosed as status epilepticus, as well as the risks associated with non-indicated treatment.

METHODS

We performed an individual patient data analysis from the Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART) and the Established Status Epilepticus Treatment Trial (ESETT) to assess incidence, patient characteristics and clinical course of misdiagnosed pPNES.

RESULTS

Among 980 patients aged 8 years or older diagnosed and treated for status epilepticus in RAMPART and ESETT, 79 (8.1%) were discharged with a final diagnosis of pPNES. The relative incidence was highest in adolescents and young adults (20.1%). The typical female preponderance seen in that age bracket was not evident in children and older adults. Adverse effects, including respiratory depression and intubation, were documented in 26% of patients with pPNES receiving benzodiazepines in RAMPART and 33% of patients receiving additional second-line medication in ESETT. In ESETT, patients who were treated with benzodiazepines before hospital admission had higher rates of unresponsiveness and severe adverse effects than those treated after admission, suggesting cumulative effects of accelerated treatment momentum. Across trials, one in five patients with pPNES were admitted to an intensive care unit.

CONCLUSIONS

Misdiagnosis and treatment of pPNES as status epilepticus are a common and widespread problem with deleterious consequences. Mitigating it will require training of emergency staff in semiological diagnosis. Status epilepticus response protocols should incorporate appropriate diagnostic re-evaluations at each step of treatment escalation, especially in clinical trials.

What do we know about non-epileptic seizures in adults with intellectual disability: A narrative review

Psychogenic non-epileptic seizures (PNES) superficially resemble epileptic seizures, but are not associated with abnormal electrical activity in the brain. PNES are a heterogeneous entity and while there is increasing interest in the characterisation of PNES sub-groups, little is known about individuals with PNES who have an intellectual disability (ID). ID is a lifelong condition characterised by significant limitations in cognitive, social and practical skills. ID (commonly with comorbid epilepsy) has been identified as a risk factor for developing PNES. However, people with ID are often excluded from research in PNES. This has unfortunately resulted in a lack of evidence to help inform practice and policy for this population. This narrative review synthesises the currently available evidence in terms of the epidemiology, demographic and clinical profile of adults with PNES and ID. There is a particular focus on demographics, aetiological factors, PNES characteristics, diagnosis and treatment of the condition in this population. Throughout this article, we critique the existing evidence, discuss implications for clinical practice and highlight the need for further research and enquiry. What emerges from the evidence is that, even within the sub-group of those with ID, PNES are a heterogeneous condition. Individuals with ID and PNES are likely to present with diverse and complex needs requiring multidisciplinary care. This review is aimed at the broad range of healthcare professionals who may encounter this group. We hope that it will stimulate further discussion and research initiatives.