Differentiating psychogenic nonepileptic from epileptic seizures: A mixed-methods, content analysis study

Prevalence of ictal injuries in functional (psychogenic nonepileptic) seizures: A systematic review and meta-analysis

OBJECTIVE

Ictal injuries have long been considered typical signs of epileptic seizures. However, studies have shown that patients with functional seizures (FS)-also named psychogenic nonepileptic seizures-can also present these signs, misleading physicians and delaying a correct diagnosis. This systematic review aimed to assess the prevalence of injuries from FS.

METHODS

A literature search was performed in PubMed, Embase, LILACS (Latin American and Caribbean Health Sciences Literature), Scopus, Web of Science, PsycINFO, Google Scholar, OpenGrey, and ProQuest. Observational studies were included. The risk of bias was assessed using the Joanna Briggs Institute (JBI) checklist for studies reporting prevalence data. RStudio was used for meta-analyses. Cumulative evidence was evaluated according to Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) criteria.

RESULTS

From the 2607 identified records, 41 studies were included in the qualitative synthesis, and 28 were included in meta-analyses. A meta-analysis of 13 studies, including 1673 individuals, resulted in an overall lifetime prevalence of injuries due to FS per person of 25% (95% confidence interval [CI] = 19%-32%, I2  = 88%). Considering a limited period (video-electroencephalographic [VEEG] monitoring days), a meta-analysis of 13 studies, including 848 individuals, resulted in an injury prevalence due to FS per person of .7% (95% CI = 0%-3%, I2  = 73%). Also, a meta-analysis of eight studies, including 1000 individuals, resulted in a prevalence of injuries per FS of .1% (95% CI = 0%-.98%, I2  = 49%). The certainty in cumulative evidence assessed by GRADE was rated "very low" for lifetime prevalence of injuries per person, "low" for prevalence per person during VEEG monitoring, and "moderate" for prevalence per number of FS.

SIGNIFICANCE

Overall pooled lifetime prevalence of injuries due to FS per person was 25%. In comparison, the prevalence of injuries per person during VEEG monitoring and per functional seizure was .7% and .1%, respectively. [Correction added on 07 October 2023, after first online publication: In the preceding sentence, 'consecutively' was corrected to 'respectively'.] The evidence of the occurrence of injuries due to FS breaks the paradigm that epileptic seizures can cause injuries but FS cannot.

Differentiation of epilepsy and psychogenic nonepileptic events based on body fluid characteristics

OBJECTIVE

Differential diagnosis between epileptic seizures and psychogenic nonepileptic events (PNEEs) is a worldwide problem for neurologists. The present study aims to identify important characteristics from body fluid tests and develop diagnostic models based on them.

METHODS

This is a register-based observational study in patients with a diagnosis of epilepsy or PNEEs at West China Hospital of Sichuan University. Data from body fluid tests between 2009 and 2019 were used as a training set. We constructed models with a random forest approach in eight training subsets divided by sex and categories of tests, including electrolyte, blood cell, metabolism, and urine tests. Then, we collected data prospectively from patients between 2020 and 2022 to validate our models and calculated the relative importance of characteristics in robust models. Selected characteristics were finally analyzed with multiple logistic regression to establish nomograms.

RESULTS

A total of 388 patients, including 218 with epilepsy and 170 with PNEEs, were studied. The AUROCs of random forest models of electrolyte and urine tests in the validation phase achieved 80.0% and 79.0%, respectively. Carbon dioxide combining power, anion gap, potassium, calcium, and chlorine in electrolyte tests and specific gravity, pH, and conductivity in urine tests were selected for the logistic regression analysis. C (ROC) of the electrolyte and urine diagnostic nomograms achieved 0.79 and 0.85, respectively.

SIGNIFICANCE

The application of routine indicators of serum and urine may help in the more accurate identification of epileptic and PNEEs.

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.

Dissociation in patients with epilepsy and functional seizures: A narrative review of the literature

Dissociation is a "disruption of the usually integrated functions of consciousness, memory, identity or perception of the environment" according to DSM-5.  It is commonly seen in psychiatric disorders including primary dissociative disorders, post-traumatic stress disorder, depression, and panic disorder. Dissociative phenomena are also described in the context of substance intoxication, sleep deprivation and medical illnesses including traumatic brain injury, migraines, and epilepsy. Patients with epilepsy have higher rates of dissociative experiences as measured on the Dissociative Experiences Scale compared to healthy controls. Ictal symptoms, especially in focal epilepsy of temporal lobe origin, may include dissociative-like experiences such as déjà vu/jamais vu, depersonalization, derealization and what has been described as a "dreamy state".  These descriptions are common in the setting of seizures that originate from mesial temporal lobe epilepsy and may involve the amygdala and hippocampus. Other ictal dissociative phenomena include autoscopy and out of body experiences, which are thought to be due to disruptions in networks responsible for the integration of one's own body and extra-personal space and involve the temporoparietal junction and posterior insula. In this narrative review, we will summarize the updated literature on dissociative experiences in epilepsy, as well as dissociative experiences in functional seizures. Using a case example, we will review the differential diagnosis of dissociative symptoms. We will also review neurobiological underpinnings of dissociative symptoms across different diagnostic entities and discuss how ictal symptoms may shed light on the neurobiology of complex mental processes including the subjective nature of consciousness and self-identity.

Beliefs and attitudes of traditional healers regarding epilepsy in Cameroon

INTRODUCTION

People living with epilepsy suffer from stigmatization, overprotection, or exclusion, thus, part of these population in developing countries uses traditional medicine as a first resort.

METHODS

We prospectively conducted a study to determine the knowledge, attitudes, and practices (KAP) of traditional healers (THs) concerning epilepsy. Over a 9-month period, we included 208 THs practicing in the Littoral, Center and West regions of Cameroon who agreed to participate in the study. The THs were interviewed using a standardized questionnaire. Data were analyzed using Epi Info version 7.2 software.

RESULTS

Two-hundred and eight THs were recruited, with a mean age ± standard deviation (SD) of 49.9 ± 11.4 years, and 169 (81.2%) were male. Primary 77(37.0%) and secondary 67(32.2%) levels of education were the most represented, and most of the THs had more than 10 years of professional experience. One hundred and forty-one TH (68,7%) had poor knowledge about epilepsy. The independent factors associated with poor knowledge were female sex, Muslim religion, and marital status of cohabitation. One hundred and eighty-four THs (88.4%) had a good attitude and practices toward people with seizures. Factors independently associated with poor practices and attitude were rural residence, Muslim religion, and education level.

CONCLUSION

Our result confirmed that THs had poor knowledge about epilepsy but good attitudes and practices about epilepsy. THs were in favor of future collaboration with modern medicine in the care of people living with epilepsy.

Differentiating between epileptic and functional/dissociative seizures using semantic content analysis of transcripts of routine clinic consultations

The common causes of Transient Loss of Consciousness (TLOC) are syncope, epilepsy, and functional/dissociative seizures (FDS). Simple, questionnaire-based decision-making tools for non-specialists who may have to deal with TLOC (such as clinicians working in primary or emergency care) reliably differentiate between patients who have experienced syncope and those who have had one or more seizures but are more limited in their ability to differentiate between epileptic seizures and FDS. Previous conversation analysis research has demonstrated that qualitative expert analysis of how people talk to clinicians about their seizures can help distinguish between these two TLOC causes. This paper investigates whether automated language analysis - using semantic categories measured by the Linguistic Inquiry and Word Count (LIWC) toolkit - can contribute to the distinction between epilepsy and FDS. Using patient-only talk manually transcribed from recordings of 58 routine doctor-patient clinic interactions, we compared the word frequencies for 21 semantic categories and explored the predictive performance of these categories using 5 different machine learning algorithms. Machine learning algorithms trained using the chosen semantic categories and leave-one-out cross-validation were able to predict the diagnosis with an accuracy of up to 81%. The results of this proof of principle study suggest that the analysis of semantic variables in seizure descriptions could improve clinical decision tools for patients presenting with TLOC.

Factors associated with comorbid epilepsy in patients with psychogenic nonepileptic seizures: A large cohort study

OBJECTIVE

Comorbid epilepsy and psychogenic nonepileptic seizures (PNES) occur in 12-22% of cases and the diagnosis of both simultaneous disorders is challenging. We aimed to identify baseline characteristics that may help distinguish patients with PNES-only from those with comorbid epilepsy.

METHODS

We performed a longitudinal cohort study on those patients diagnosed with PNES in our epilepsy monitoring unit (EMU) between May 2001 and February 2011, prospectively followed up until September 2016. Patients were classified into PNES-only, PNES + possible or probable epilepsy, and PNES + definite epilepsy based on the clinical, vEEG, and neuroimaging data. Demographic and basal clinical data were obtained from chart review. Multiple regression models were performed to identify significant predictors of PNES + definite epilepsy, excluding patients with only possible or probable epilepsy for this specific analysis.

RESULTS

One-hundred and ninety four patients with PNES-only, 30 with PNES + possible or probable epilepsy and 47 with PNES + definite epilepsy were included. 73.8% were female and the mean age at EMU admission was 37.4 ± standard deviation 13.5 years. Patients with PNES + definite epilepsy most likely had never worked, had history of febrile seizures, structural brain lesions, developmental disabilities, and maximum reported seizure duration between 0.5 and 2 min. Patients with PNES-only were on fewer anti-seizure medications (ASM), reported more frequently an initial minor head trauma, seizures longer than 10 min, and a higher number of neurological and medical illnesses - being migraine (18.1%), other types of headaches (18.5%), and asthma (15.5%) the most prevalent ones. All p < 0.05. On the hierarchical regression analysis, history of febrile seizures, developmental disabilities, brain lesions, longest reported seizure duration between 0.5 and 2 min, and lack of neurological comorbidity, remained as significant predictors of PNES + epilepsy. The model's performance of a 5-fold cross-validation analysis showed an overall accuracy of 84.7% to classify patients correctly.

CONCLUSIONS

Some demographic and clinical characteristics may support the presence of comorbid epilepsy in patients with PNES, being unemployment, the presence of brain lesions, developmental disabilities, history of febrile seizures, seizure duration and lack of comorbid headaches the most relevant ones.

The Comparison Between Neuropsychological Features of Psychogenic Non-epileptic Seizures and Epileptic Seizures

Background: Both epileptic seizures (ES) and psychogenic non-epileptic seizures (PNES) are often associated with some degree of cognitive impairment. Video electroencephalography (EEG) monitoring is the gold standard for diagnosing PNES. This diagnostic procedure is costly and available in specific tertiary centers. Neuropsychological assessment can provide clues for the differential diagnosis of PNES and ES and help clarify the nature and etiology of these two disorders. Objectives: Therefore, this study aimed to compare the neuropsychological profiles of PNES and ES patients. Methods: In this analytical cross-sectional study, 30 patients with ES and 31 patients with PNES were compared by neuropsychiatric tests, such as the Wechsler Adult Intelligence scale (WAIS), Addenbrooke’s Cognitive examination (ACE), and California Verbal Learning test (CVLT). Results: There was a female predominance in the PNES group (female-to-male ratio = 4.16/1, P = 0.003). In the PNES group, 77.4% of the patients had a psychiatric disorder versus 66.7% of the patients in the ES group; however, the difference was not statistically significant (P = 0.34). The mean score of total intelligence was higher in the PNES group (84.77 ± 16.94), compared to the ES group (83.63 ± 10.04); however, the difference was not significant (P = 0.75). Based on the mean subscale scores, the digit symbol score (WAIS-IV subscale) and memory score (ACE subscale) were significantly higher in the PNES group compared to the ES group (P = 0.037 and 0.032, respectively). Conclusions: This study showed that neuropsychological assessments might not differentiate ES from non-epileptic seizures.