Evidence of brain abnormality in patients with psychogenic nonepileptic seizures

Dissimilar Changes in Serum Cortisol after Epileptic and Psychogenic Non-Epileptic Seizures: A Promising Biomarker in the Differential Diagnosis of Paroxysmal Events?

The hypothalamic-pituitary-adrenal axis is known to be involved in the pathogenesis of epilepsy and psychiatric disorders. Epileptic seizures (ESs) and psychogenic non-epileptic seizures (PNESs) are frequently differentially misdiagnosed. This study aimed to evaluate changes in serum cortisol and prolactin levels after ESs and PNESs as possible differential diagnostic biomarkers. Patients over 18 years with ESs (n = 29) and PNESs with motor manifestations (n = 45), captured on video-EEG monitoring, were included. Serum cortisol and prolactin levels as well as hemograms were assessed in blood samples taken at admission, during the first hour after the seizure, and after 6, 12, and 24 h. Cortisol and prolactine response were evident in the ES group (but not the PNES group) as an acute significant increase within the first hour after seizure. The occurrence of seizures in patients with ESs and PNESs demonstrated different circadian patterns. ROC analysis confirmed the accuracy of discrimination between paroxysmal events based on cortisol response: the AUC equals 0.865, with a prediction accuracy at the cutoff point of 376.5 nmol/L 0.811 (sensitivity 86.7%, specificity 72.4%). Thus, assessments of acute serum cortisol response to a paroxysmal event may be regarded as a simple, fast, and minimally invasive laboratory test contributing to differential diagnosis of ESs and PNESs.

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

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

Amygdala subfield and prefrontal cortex abnormalities in patients with functional seizures

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Are brain MRI abnormalities associated with the semiology of functional seizures?

PURPOSE

To investigate whether radiologically apparent brain magnetic resonance imaging (MRI) abnormalities are associated with the functional seizure (FS) semiology.

METHODS

All patients with a diagnosis of FS at the epilepsy centers at Shiraz University of Medical Sciences, Iran; Aichi Medical University Hospital, Japan; University of Michigan, USA; University of California, Los Angeles, USA; Emory University School of Medicine, USA; and Hospital el Cruce, Argentina, were studied.

RESULTS

One hundred patients were included; 77 (77%) had motor functional seizures. Lobar location of brain abnormality did not have an association with the semiology (p = .83). There was no significant difference between ictal behaviors in patients with frontal or parietal lesions compared to those with temporal or occipital lesions.

CONCLUSION

There were no associations between functional seizure ictal behaviors and locations of the radiologically apparent brain MRI abnormalities. Further studies are needed to evaluate the underpinnings of varying behaviors in FS.

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

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Machine Learning Approach Involving Functional Connectivity Features to Classify Rest-EEG Psychogenic Non-Epileptic Seizures from Healthy Controls

Until now, clinicians are not able to evaluate the Psychogenic Non-Epileptic Seizures (PNES) from the rest-electroencephalography (EEG) readout. No EEG marker can help differentiate PNES cases from healthy subjects. In this paper, we have investigated the power spectrum density (PSD), in resting-state EEGs, to evaluate the abnormalities in PNES affected brains. Additionally, we have used functional connectivity tools, such as phase lag index (PLI), and graph-derived metrics to better observe the integration of distributed information of regular and synchronized multi-scale communication within and across inter-regional brain areas. We proved the utility of our method after enrolling a cohort study of 20 age- and gender-matched PNES and 19 healthy control (HC) subjects. In this work, three classification models, namely support vector machine (SVM), linear discriminant analysis (LDA), and Multilayer perceptron (MLP), have been employed to model the relationship between the functional connectivity features (rest-HC versus rest-PNES). The best performance for the discrimination of participants was obtained using the MLP classifier, reporting a precision of 85.73%, a recall of 86.57%, an F1-score of 78.98%, and, finally, an accuracy of 91.02%. In conclusion, our results hypothesized two main aspects. The first is an intrinsic organization of functional brain networks that reflects a dysfunctional level of integration across brain regions, which can provide new insights into the pathophysiological mechanisms of PNES. The second is that functional connectivity features and MLP could be a promising method to classify rest-EEG data of PNES form healthy controls subjects.

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.

A minority of patients with functional seizures have abnormalities on neuroimaging

OBJECTIVE

Functional seizures often are managed incorrectly as a diagnosis of exclusion. However, a significant minority of patients with functional seizures may have abnormalities on neuroimaging that typically are associated with epilepsy, leading to diagnostic confusion. We evaluated the rate of epilepsy-associated findings on MRI, FDG-PET, and CT in patients with functional seizures.

METHODS

We studied radiologists' reports from neuroimages at our comprehensive epilepsy center from a consecutive series of patients diagnosed with functional seizures without comorbid epilepsy from 2006 to 2019. We summarized the MRI, FDG-PET, and CT results as follows: within normal limits, incidental findings, unrelated findings, non-specific abnormalities, post-operative study, epilepsy risk factors (ERF), borderline epilepsy-associated findings (EAF), and definitive EAF.

RESULTS

Of the 256 MRIs, 23% demonstrated ERF (5%), borderline EAF (8%), or definitive EAF (10%). The most common EAF was hippocampal sclerosis, with the majority of borderline EAF comprising hippocampal atrophy without T2 hyperintensity or vice versa. Of the 87 FDG-PETs, 26% demonstrated borderline EAF (17%) or definitive EAF (8%). Epilepsy-associated findings primarily included focal hypometabolism, especially of the temporal lobes, with borderline findings including subtle or questionable hypometabolism. Of the 51 CTs, only 2% had definitive EAF.

SIGNIFICANCE

This large case series provides further evidence that, while uncommon, EAF are seen in patients with functional seizures. A significant portion of these abnormal findings are borderline. The moderately high rate of these abnormalities may represent framing bias from the indication of the study being "seizures," the relative subtlety of EAF, or effects of antiseizure medications.

DDESVSFS: A simple, rapid and comprehensive screening tool for the Differential Diagnosis of Epileptic Seizures VS Functional Seizures

OBJECTIVE

Functional seizures (FS) are often misclassified as epileptic seizures (ES). This study aimed to create an easy to use but comprehensive screening tool to guide further evaluation of patients presenting with this diagnostic dilemma.

MATERIALS AND METHODS

Demographic, clinical and diagnostic data were collected on patients admitted for video-EEG monitoring for clarification of their diagnosis. Upon discharge, patients were classified as having ES vs FS. Using the collected characteristics and video-EEG diagnosis, we created a multivariable logistic regression model to identify predictors of ES. Then, we trained an integer-coefficient model with the most frequently selected predictors, creating a pointing system coined DDESVSFS, with scores ranging from -17 to +8 points.

RESULTS

43 patients with FS and 165 patients with ES were recruited. In the final integer-coefficient model, 8 predictors were identified as significant in differentiating ES from FS: normal electroencephalogram (-3 points), predisposing factors for FS (-3 points), increased number of comorbidities (-3 points), semiology suggestive of FS (-4 points), increased seizure frequency (-4 points), longer disease duration (+3 points), antiepileptic polypharmacy (+2 points) and compliance with antiepileptic drugs (+3 points). Cumulative scores of ≤ -9 points carried <5% predictive value for ES, while cumulative scores of ≥ -1 points carried >95% predictive value. The model performed well (AUC: 0.923, sensitivity: 0.945, specificity: 0.698).

CONCLUSIONS

We propose DDESVSFS as a simple, rapid and comprehensive prediction score for the Differential Diagnosis of Epileptic Seizures VS Functional Seizures. Large prospective studies are needed to evaluate its utility in clinical practice.

Unexpected brain imaging findings in patients with seizures

New imaging technologies have advanced our ability to localize the epileptogenic zone in patients with epilepsy. As a result of the constant improvement of the image quality, magnetic resonance imaging (MRI) has become the most important ancillary tool in the management of patients with epilepsy. Magnetic resonance imaging for the evaluation of patients with epilepsy should be done using a special temporal lobe protocol and read by physicians experienced with the findings in patients with epilepsy. On the other hand, in the healthy populations, incidental structural brain abnormalities have been reported in 18% of people. Incidental, subtle, or unexpected structural brain abnormalities have also been reported in many patients who were investigated because of having seizures. In the current narrative review, we will discuss some of these instances, where structural brain abnormalities are discovered unexpectedly, are subtle (but important) and/or may be considered as incidental.

Memory and motor control in patients with psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (PNES) are of the most elusive phenomena in epileptology. Patients with PNES present episodes resembling epileptic seizures in their semiology yet lacking the underlying epileptic brain activity. These episodes are assumed to be related to psychological distress from past trauma, yet the underlying mechanism of this manifestation is still unknown. Using resting-state functional magnetic resonance imaging (fMRI), we investigated functional connectivity changes within and between large-scale brain networks in 9 patients with PNES, compared with a group of 13 age- and gender-matched healthy controls. Functional magnetic resonance imaging analyses identified functional connectivity disturbances between the medial temporal lobe (MTL) and the sensorimotor cortex and between the MTL and ventral attention networks in patients with PNES. Within network connectivity reduction was found within the visual network. Our findings suggest that PNES relate to changes in connectivity in between areas that are involved in memory processing and motor activity and attention control. These results may shed new light on the way by which traumatic memories may relate to PNES.

Preliminary Evidence for Limbic-Frontal Hyperexcitability in Psychogenic Nonepileptic Seizure Patients

OBJECTIVES

The goal of the current pilot project was to probe the resting-state magnetoencephalography (MEG) in individuals with psychogenic nonepileptic seizures (PNES) and ascertain if there is evidence for frontal temporal cortical hyperexcitability, as evidenced by increased focal coherence in these regions.

METHODS

Six patients with PNES and without any evidence of epilepsy were included. Nine healthy control (HC) subjects (age matched as a group) were also included. Subjects underwent 10 minutes of eyes open and 10 minutes of eyes closed MEG recording without any specific cognitive tasks (ie, resting state).

RESULTS

Analysis shows posterior-occipital alpha power to be decreased but fronto-temporal delta/theta power increased in people with PNES compared with HC subjects. Analyses of mean interregional functional connectivity of 54 brain regions, patients with PNES tended to have reduced mean coherence in extra-fronto-temporal regions (ex-FTRs) while increased mean coherence in fronto-temporal regions (FTRs) compared with HC. Furthermore, all 6 patients with PNES had their highest coherence structure within the FTRs. This is in contrast to the HC subjects where only 3 of the 9 subjects had their highest coherence value structure in the FTRs (χ² = 6.67, P = .010).

CONCLUSIONS

The above findings are consistent with a disbalance between frontotemporal and posterior brain regions in this population with possible increased excitability in the FTRs. The data support the need for further investigations of the pathophysiology of PNES. The identification of a biomarker for PNES would not only provide for more informed therapeutic approaches, but it could also eliminate the stigma associated with the diagnosis of PNES.

A review of functional neurological symptom disorder etiology and the integrated etiological summary model

Functional neurological symptom disorder (FNSD) is characterized by neurological symptoms that are unexplained by other traditional neurological or medical conditions. Both physicians and patients have limited understanding of FNSD, which is often explained as a physical manifestation of psychological distress. Recently, diagnostic criteria have shifted from requiring a preceding stressor to relying on positive symptoms. Given this shift, we have provided a review of the etiology of FNSD. Predisposing factors include trauma or psychiatric symptoms, somatic symptoms, illness exposure, symptom monitoring and neurobiological factors. Neurobiological research has indicated that patients with FNSD have a decreased sense of agency and abnormal attentional focus on the affected area, both of which are modulated by beliefs and expectations about illness. Sick role and secondary gain may reinforce and maintain FNSD. The integrated etiological summary model combines research from various fields and other recent etiological models to represent the current understanding of FNSD etiology. It discusses a potential causal mechanism and informs future research and treatment.

Dual diagnosis of epilepsy and psychogenic nonepileptic seizures: Systematic review and meta-analysis of frequency, correlates, and outcomes

Comorbid epilepsy and psychogenic nonepileptic seizures (PNES) represent a serious challenge for the clinicians. However, the frequency, associations, and outcomes of dual diagnosis of epilepsy and PNES are unclear. The aim of the review was to determine the frequency, correlates, and outcomes of a dual diagnosis. A systematic review of all published observational studies (from inception to Dec. 2016) was conducted to determine the frequency, correlates, and outcomes of dual diagnosis. We included studies of individuals of any age reporting a dual diagnosis of epilepsy and PNES. All observational study designs were included with the exception of case reports and case series with fewer than 10 participants. The mean frequency of epilepsy in patients with PNES across all studies was 22% (95% confidence intervals [CI] 20 to 25%, range: 0% to 90%) while the mean frequency of PNES in patients with epilepsy was 12% (95% CI 10 to 14%, range: 1% to 62%). High heterogeneity means that these pooled estimates should be viewed with caution. A number of correlates of dual diagnosis were reported. Some studies delineated differences in semiology of seizures in patients with dual diagnosis vs. PNES or epilepsy only. However, most of the correlates were inconclusive. Only a few studies examined outcome in patients with dual diagnosis. Dual diagnosis is common in clinical practice, especially among patients referred to specialized services, and requires careful diagnosis and management.

A unifying theory for cognitive abnormalities in functional neurological disorders, fibromyalgia and chronic fatigue syndrome: systematic review

BACKGROUND

Functional cognitive disorder (FCD) describes cognitive dysfunction in the absence of an organic cause. It is increasingly prevalent in healthcare settings yet its key neuropsychological features have not been reported in large patient cohorts. We hypothesised that cognitive profiles in fibromyalgia (FM), chronic fatigue syndrome (CFS) and functional neurological disorders (FNDs) would provide a template for characterising FCD.

METHODS

We conducted a systematic review of studies with cognition-related outcomes in FM, CFS and FND.

RESULTS

We selected 52 studies on FM, 95 on CFS and 39 on FND. We found a general discordance between high rates of subjective cognitive symptoms, including forgetfulness, distractibility and word-finding difficulties, and inconsistent objective neuropsychological deficits. Objective deficits were reported, including poor selective and divided attention, slow information processing and vulnerability to distraction. In some studies, cognitive performance was inversely correlated with pain, exertion and fatigue. Performance validity testing demonstrated poor effort in only a minority of subjects, and patients with CFS showed a heightened perception of effort.

DISCUSSION

The cognitive profiles of FM, CFS and non-cognitive FND are similar to the proposed features of FCD, suggesting common mechanistic underpinnings. Similar findings have been reported in patients with mild traumatic brain injury and whiplash. We hypothesise that pain, fatigue and excessive interoceptive monitoring produce a decrease in externally directed attention. This increases susceptibility to distraction and slows information processing, interfering with cognitive function, in particular multitasking. Routine cognitive processes are experienced as unduly effortful. This may reflect a switch from an automatic to a less efficient controlled or explicit cognitive mode, a mechanism that has also been proposed for impaired motor control in FND. These experiences might then be overinterpreted due to memory perfectionism and heightened self-monitoring of cognitive performance.

Paediatricians' attitudes to and management of functional seizures in children

OBJECTIVE

To explore paediatricians' attitudes to and treatment practice for children with functional seizures (FS).

METHODS

In a nationwide survey, all 64 Danish neuro-paediatricians and social paediatricians were invited to complete a structured questionnaire encompassing FS-related issues that included beliefs and attitudes about aetiology and diagnostic assessment, current strategies for management, experienced need for clinical guidelines and better treatment options.

RESULTS

A total of 61 paediatricians (95%) participated in the study. Nearly half (46%) had seen more than 30 children with FS during their career. Most (65%) believed in a primarily psychogenic aetiology. More than half (57%) stated that they could make the diagnosis by solely observing a seizure, and 18% indicated the children faked their symptoms. The paediatricians' responses to these issues did not significantly vary according to their level of clinical experience. Furthermore, the majority (78%) expressed a need for clinical guidelines, and only 13% rated existing treatment options as sufficient. Collaborative care between different specialties or management in a child and adolescent mental health services (CAMHS) setting was seen as the best model for treatment. However, only 23% reported often referring these children to CAMHS after making the diagnosis.

CONCLUSION

The findings suggest that introduction of clinical guidelines in this area is highly needed. Such guidelines could promote more formal training of paediatricians in understanding and assessing FS and increased collaboration between paediatrics and CAMHS regarding care for children with this challenging and potentially costly and disabling disorder.

Utilization of brain imaging in evaluating patients with psychogenic nonepileptic spells

BACKGROUND

Psychogenic nonepileptic spells (PNES) are paroxysmal movements or sensory events that resemble epileptic seizures but lack corresponding ictal electrographic changes. A confirmed diagnosis of PNES is only accomplished via video electroencephalogram (vEEG) monitoring. Prior to diagnosis, patients are often assessed with neurodiagnostic imaging and their conditions treated with anticonvulsant medications, both of which are of limited clinical value and contribute to the higher cost of care. In this study, we assessed the relationship between the semiological features of PNES, medication regimen, or psychiatric comorbidities and the frequency of referrals for brain imaging tests prior to diagnosis of PNES.

METHODS

This is a retrospective chart review of 224 adult patients diagnosed as having PNES at a level 4 epilepsy care center from 2012 to 2017. Patients with coexisting epilepsy were excluded. The 882 segments of vEEG records were reviewed for semiology of spells, and patients were categorized into one of seven distinct phenotypic classes according to the accepted clinical classification. The frequency of neurodiagnostic tests completed for each patient prior to vEEG was correlated with PNES phenotype and other clinical characteristics.

RESULTS

There were 68 (30%) males and 156 (70%) females diagnosed as having PNES with a median age of 36 years. Seventy-four percent of patients were receiving one or several anticonvulsant medications, and 67% of patients were treated with psychotropic medications other than benzodiazepines. The most prevalent PNES events were characterized by semirhythmic small amplitude movements in the extremities (class 2; 34%) followed by those resembling tonic-clonic seizures (class 4; 28%). Neurodiagnostic imaging tests including computed tomography (CT) and magnetic resonance imaging (MRI) of the brain were performed at least once in 60% of patients and 4 times or more in 11% prior to vEEG. There was a significant association between the frequency of neurodiagnostic tests and the PNES phenotype (p = 0.02). Specifically, patients with sensory changes (class 6) had more imaging tests than those with primitive gesturing and truncal posturing (classes 1 and 5, respectively). Additionally, patients diagnosed with 3 or more psychiatric disorders underwent significantly more neurodiagnostic tests relative to patients diagnosed with two or fewer psychiatric disorders (p = 0.03). Furthermore, patients whose conditions were treated with anticonvulsant medications tended to undergo more imaging scans prior to vEEG as compared with the patients whose conditions were not being treated with anticonvulsants.

CONCLUSIONS

These findings suggest that the frequency of brain imaging obtained prior to the definitive diagnosis of PNES is influenced by semiology of spells and the psychiatric health of patients. Patients who demonstrate minimal paroxysmal movements in the settings of multiple psychiatric comorbidities represent a particularly challenging patient phenotype which is linked to more frequent referrals for brain imaging. These patients should be promptly referred for vEEG to improve diagnostic accuracy and prevent treatment with anticonvulsants as well as referrals for serial neurodiagnostic tests.

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.

Differentiating PNES from epileptic seizures using conversational analysis

We applied conversation analysis in an unselected continuous series of 70 patients to discriminate patients with psychogenic nonepileptic seizures (PNES) from patients with epilepsy. Two psychologists examined the patients' recorded reports. Patients were also submitted to an extensive neuropsychological battery in order to verify whether specific cognitive deficits or mental health problems are typical of patients with PNES and whether some cognitive deficits could prevent the correct diagnosis. The results showed a good percentage of correct diagnosis, with a sensitivity of 0.795 and a specificity of 0.83, while no difference in the cognitive profile was found between patients with PNES and patients with epilepsy. The results also suggest that psychologists can apply the conversation analysis as well as linguists, which is an important finding since psychologists are employed in specialized centers, while linguists in general are not part of the team.

Neuroimaging studies in patients with psychogenic non-epileptic seizures: A systematic meta-review

Psychogenic Non-epileptic Seizures (PNES) are ‘medically unexplained’ seizure-like episodes which superficially resemble epileptic seizures but which are not caused by epileptiform discharges in the brain. While many experts see PNES disorder as a multifactorial biopsychosocial condition, little is known about the neurobiological processes which may predispose, precipitate and/or perpetuate PNES symptomology. This systematic meta-review advances our knowledge and understanding of the neurobiological correlates of PNES by providing an up-to-date assessment of neuroimaging studies performed on individuals with PNES. Although the results presented appear inconclusive, they are consistent with an association between structural and functional brain abnormalities and PNES. These findings have implications for the way in which we think about this “medically unexplained” disorder and how we communicate the diagnosis to patients. However, it is also evident that neuroimaging studies in this area suffer from a number of significant limitations and future larger studies will need to better address these if we are to improve our understanding of the neurobiological correlates of predisposition to and/or manifestation of PNES.

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Neuroimaging results point to neurobiological correlates of PNES.

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Lack of convergent findings point to heterogeneous condition.

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Lack of high quality neuroimaging studies represents weak evidence base.

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Larger serial neuroimaging studies to assess state/trait characteristics required

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Future neuroimaging studies should use additional objective physiological measures.

Proposal for best practice in the use of video-EEG when psychogenic non-epileptic seizures are a possible diagnosis

The gold-standard for the diagnosis of psychogenic non-epileptic seizures (PNES) is capturing an attack with typical semiology and lack of epileptic ictal discharges on video-EEG. Despite the importance of this diagnostic test, lack of standardisation has resulted in a wide variety of protocols and reporting practices. The goal of this review is to provide an overview of research findings on the diagnostic video-EEG procedure, in both the adult and paediatric literature. We discuss how uncertainties about the ethical use of suggestion can be resolved, and consider what constitutes best clinical practice. We stress the importance of ictal observation and assessment and consider how diagnostically useful information is best obtained. We also discuss the optimal format of video-EEG reports; and of highlighting features with high sensitivity and specificity to reduce the risk of miscommunication. We suggest that over-interpretation of the interictal EEG, and the failure to recognise differences between typical epileptic and nonepileptic seizure manifestations are the greatest pitfalls in neurophysiological assessment of patients with PNES. Meanwhile, under-recognition of semiological pointers towards frontal lobe seizures and of the absence of epileptiform ictal EEG patterns during some epileptic seizure types (especially some seizures not associated with loss of awareness), may lead to erroneous PNES diagnoses. We propose that a standardised approach to the video-EEG examination and the subsequent written report will facilitate a clear communication of its import, improving diagnostic certainty and thereby promoting appropriate patient management.

Psychogenic Explanations of Physical Illness

In some patients with chronic physical complaints, detailed examination fails to reveal a well-recognized underlying disease process. In this situation, the physician may suspect a psychological cause. In this review, we critically evaluated the evidence for this causal claim, focusing on complaints presenting as neurological disorders. There were four main conclusions. First, patients with these complaints frequently exhibit psychopathology but not consistently more often than patients with a comparable “organic” diagnosis, so a causal role cannot be inferred. Second, these patients report a high incidence of adverse life experiences, but again, there is insufficient evidence to indicate a causal role for any particular type of experience. Third, although psychogenic illnesses are believed to be more responsive to psychological interventions than comparable “organic” illnesses, there is currently no evidence to support this claim. Finally, recent evidence suggests that biological and physical factors play a much greater causal role in these illnesses than previously believed. We conclude that there is currently little evidential support for psychogenic theories of illness in the neurological domain. In future research, researchers need to take a wider view concerning the etiology of these illnesses.

Which patients with epilepsy are at risk for psychogenic nonepileptic seizures (PNES)? A multicenter case-control study

OBJECTIVE

We sought to examine the clinical and electrographic differences between patients with combined epileptic (ES) and psychogenic nonepileptic seizures (PNES) and age- and gender-matched patients with ES-only and PNES-only.

METHODS

Data from 138 patients (105 women [77%]), including 46 with PNES/ES (39±12years), 46 with PNES-only (39±11years), and 46 with ES-only (39±11years), were compared using logistic regression analysis after adjusting for clustering effect.

RESULTS

In the cohort with PNES/ES, ES antedated PNES in 28 patients (70%) and occurred simultaneously in 11 (27.5%), while PNES were the initial presentation in only 1 case (2.5%); disease duration was undetermined in 6. Compared with those with ES-only, patients with PNES/ES had higher depression and anxiety scores, shorter-duration electrographic seizures, less ES absence/staring semiology (all p≤0.01), and more ES arising in the right hemisphere, both in isolation and in combination with contralateral brain regions (61% vs. 41%; p=0.024, adjusted for anxiety and depression) and tended to have less ES arising in the left temporal lobe (13% vs. 28%; p=0.054). Compared with those with PNES-only, patients with PNES/ES tended to show fewer right-hemibody PNES events (7% vs. 23%; p=0.054) and more myoclonic semiology (10% vs. 2%; p=0.073).

CONCLUSIONS

Right-hemispheric electrographic seizures may be more common among patients with ES who develop comorbid PNES, in agreement with prior neurobiological studies on functional neurological disorders.

Value of patient-reported symptoms in the diagnosis of transient loss of consciousness

OBJECTIVE

Epileptic seizures, syncope, and psychogenic nonepileptic seizures (PNES) account for over 90% of presentations with transient loss of consciousness (TLOC). The patient's history is crucial for the diagnosis, but the diagnostic value of individual semiologic features is limited. This study explores the diagnostic potential of a comprehensive questionnaire focusing on TLOC-associated symptoms.

METHODS

A total of 386 patients with proven epilepsy, 308 patients with proven PNES, and 371 patients with proven syncope were approached by post to recruit 100 patients in each diagnostic group. Symptoms were self-reported on an 86-item questionnaire (the Paroxysmal Event Profile [PEP]) using a 5-point Likert scale (always to never). Data were subjected to exploratory factor analysis (EFA) followed by confirmatory factor analysis (CFA). Factors were used to differentiate between diagnoses by pairwise and multinomial regression.

RESULTS

Patients with PNES reported more and more frequent TLOC-associated symptoms than those with epilepsy or syncope (p < 0.001). EFA/CFA identified a 5-factor structure based on 74/86 questionnaire items with loadings ≥0.4. Pairwise logistic regression analysis correctly classified 91% of patients with epilepsy vs those with syncope, 94% of those with PNES vs those with syncope, and 77% of those with epilepsy vs those with PNES. Multinomial logistic regression analysis yielded a similar pattern.

CONCLUSIONS

Clusters of self-reported TLOC symptoms can be used to direct patients to appropriate investigation and treatment pathways for syncope on the one hand and seizures on the other, although additional information is required for a reliable distinction, especially between epilepsy and PNES.

Prevalence and distribution of MRI abnormalities in patients with psychogenic nonepileptic events

INTRODUCTION

Both structural and functional abnormalities have been reported in patients with psychogenic nonepileptic events (PNEEs), although no truly consistent abnormalities have been found.

METHODS

We retrospectively identified patients discharged from our EMU with video-EEG diagnoses of epileptic seizures, PNEEs, epileptic seizures plus PNEEs, interictal epileptiform abnormalities only, and nondiagnostic admissions. We then collected brain MRI results for analysis.

RESULTS

We found significant brain MRI abnormalities in 33.8% of patients with PNEEs, clearly higher than the rate of brain MRI abnormalities in the healthy population. In addition, we found statistically significant differences in the locations of brain MRI abnormalities in patients with epileptic seizures (more frequently temporal) versus PNEEs (more frequently multifocal).

CONCLUSION

This multifocal nature of abnormalities in patients with psychogenic nonepileptic events may help to explain the underlying pathophysiology as it relates to psychiatric disorders which are so frequently comorbid with PNEEs.

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.

Emotion and dissociative seizures: A phenomenological analysis of patients' perspectives

Quantitative research has indicated that patients with dissociative seizures (DS) show altered responses to emotional stimuli, in addition to considerable emotional distress and dysregulation. The present study sought to further explore emotional processes in this population, to extend previous findings, and to provide a phenomenological insight into patients' perspectives on these issues. Semistructured interviews were carried out with 15 patients with DS, and the principles of interpretative phenomenological analysis (IPA) were adopted in data analysis. Key themes elicited included: i) general emotional functioning; ii) adverse (stressful/traumatic) life experiences; iii) the role of emotions in DS; iv) relating to others; and v) resilience, protective factors, and coping mechanisms. The clinical and theoretical implications of the findings are discussed.

Biomarkers in the diagnosis and study of psychogenic nonepileptic seizures: A systematic review

OBJECTIVE

Video electroencephalography (vEEG) is the gold-standard method for diagnosing psychogenic nonepileptic seizures (PNES), but such assessment is expensive, unavailable in many centers, requires prolonged hospitalization, and many times is unable to capture an actual seizure episode. This paper systematically reviews other non-vEEG candidate biomarkers that may facilitate both diagnosis and study of PNES as differentiated from epileptic seizures (ES).

METHODS

PubMed database was searched to identify articles between 1980 and 2015 (inclusion: adult PNES population with or without controls, English language; exclusion: review articles, meta-analyses, single case reports).

RESULTS

A total of 49 studies were examined, including neuroimaging, autonomic nervous system, prolactin, other (non-prolactin) hormonal, enzyme, and miscellaneous marker studies. Functional MRI studies have shown PNES is hyperlinked with dissociation and emotional dysregulation centers in the brain, although conflicting findings are seen across studies and none used psychiatric comparators. Heart rate variability suggests increased vagal tone in PNES when compared to ES. Prolactin is elevated in ES but not PNES, although shows low diagnostic sensitivity. Postictal cortisol and creatine kinase are nonspecific. Other miscellaneous biomarkers (neuron specific enolase, brain derived neurotropic factor, ghrelin, leptin, leukocytosis) showed no conclusive evidence of utility. Many studies are limited by lack of psychiatric comparators, size, and other methodological issues.

CONCLUSION

No single biomarker successfully differentiates PNES from ES; in fact, PNES is only diagnosed via the negation of ES. Clinical assessment and rigorous investigation of psychosocial variables specific to PNES remain critical, and subtyping of PNES is warranted. Future investigational and clinical imperatives are discussed.

Neurobiological origin of psychogenic nonepileptic seizures: A review of imaging studies

Psychogenic nonepileptic seizures (PNES) are relatively common occurrences in epilepsy centers. Pathophysiology of PNES is still poorly understood. In this paper, the evidence for a neurobiological origin of PNES will be reviewed. Recent evidence suggests altered functional and structural brain connectivity as an underlying pathophysiological mechanism in patients with PNES. Pursuing the concept of connectome in patients with PNES and comparing the findings with healthy individuals may result in a breakthrough in identifying the exact neurobiological origin of PNES. Finding the neurobiological bases and identification of biomarkers of PNES will potentially have important clinical implications in formulating better diagnostic and therapeutic approaches for affected patients.

Resting cortical PET metabolic changes in psychogenic non-epileptic seizures (PNES)

BACKGROUND

The pathophysiology of psychogenic non-epileptic seizures (PNES) is poorly understood. Functional neuroimaging data in various functional neurological disorders increasingly support specific neurobiological dysfunction. However, to date, no studies have been reported of positron emission tomography (PET) in patients presenting with PNES.

METHODS

Sixteen patients being evaluated in a specialist epilepsy centre underwent PET with 2-deoxy-2-[fluorine-18]fluoro-d-glucose ((18)FDG-PET) because of suspected intractable epileptic seizures. However, in all patients, the diagnosis was subsequently confirmed to be PNES with no coexisting epilepsy. (18)FDG-PET was also performed in 16 healthy controls. A voxel by voxel intergroup analysis was performed to look for significant differences in interictal (resting state) cerebral metabolism. In addition, metabolic connectivity was studied using voxel-wise inter-regional correlation analysis.

RESULTS

In comparison to group analysis of healthy participants, the group analysis of patients with PNES exhibited significant PET hypometabolism within the right inferior parietal and central region, and within the bilateral anterior cingulate cortex. A significant increase in metabolic correlation was found in patients with PNES, in comparison to healthy participants, between the right inferior parietal/central region and the bilateral cerebellum, and between the bilateral anterior cingulate cortex and the left parahippocampal gyrus.

CONCLUSIONS

To the best of our knowledge, this is the first study describing FDG-PET alterations in patients with PNES. Although we cannot exclude that our data reflect changes due to comorbidities, they may indicate a dysfunction of neural systems in patients with PNES. Hypometabolism regions might relate to two of the pathophysiological mechanisms that may be involved in PNES, that is, emotional dysregulation (anterior cingulate hypometabolism) and dysfunctional processes underlying the consciousness of the self and the environment (right parietal hypometabolism).

TRIAL REGISTRATION NUMBER

NCT00484523.

Uncinate fasciculus connectivity in patients with psychogenic nonepileptic seizures: A preliminary diffusion tensor tractography study

The amygdala, hippocampus, and medial prefrontal cortex are limbic brain regions connected by the uncinate fasciculus (UF) and implicated in emotion regulation. The aim of this study was to assess the connectivity characteristics of the UF in patients with psychogenic nonepileptic seizures (PNES) and matched healthy controls. We hypothesized that white matter connectivity of the UF in patients with PNES would differ from that in healthy controls. Eight patients with PNES and eight age- and sex-matched healthy controls underwent 3T MRI and 32-direction diffusion tensor imaging (DTI). Computation of DTI indices including fractional anisotropy (FA) and diffusion tensor tractography was performed. Two regions of interest were defined to manually trace the UF in each hemisphere for each subject. Fractional anisotropy and the number of reconstructed streamlines for the left and right hemispheres of the UF and the degree of asymmetry for each measure were compared between groups. Correlations between UF measures and clinical variables were also performed. Patients with PNES exhibited a significantly greater number of UF streamlines in the right hemisphere tract than in the left hemisphere (p=0.031), with such difference not observed in controls (p=0.81). This was reflected in a significant group difference in the asymmetry index (AI) for the number of streamlines, with more rightward asymmetry in patients with PNES (p=0.021). Average FA of the UF was similar between groups and between hemispheres for each group (all p>0.05). Age at illness onset was correlated with the AI for FA (r=-0.87; p=0.0045). Previously observed differences in emotion processing between controls and patients with PNES may be related to the differences in the rightward asymmetry in the number of UF streamlines in patients with PNES. Age at PNES onset appears to also have a role in the FA asymmetry of the UF. This is the first study to investigate the structural connectivity in these regions involved in emotional regulation in patients with PNES; further research is necessary to clarify the complex relationships between clinical measures and DTI characteristics.

An integrative neurocircuit perspective on psychogenic nonepileptic seizures and functional movement disorders: neural functional unawareness

Functional neurological disorder (conversion disorder) is a neurobehavioral condition frequently encountered by neurologists. Psychogenic nonepileptic seizure (PNES) and functional movement disorder (FMD) patients present to epileptologists and movement disorder specialists respectively, yet neurologists lack a neurobiological perspective through which to understand these enigmatic groups. Observational research studies suggest that PNES and FMD may represent variants of similar (or the same) conditions given that both groups exhibit a female predominance, have increased prevalence of mood-anxiety disorders, frequently endorse prior abuse, and share phenotypic characteristics. In this perspective article, neuroimaging studies in PNES and FMD are reviewed, and discussed using studies of emotional dysregulation, dissociation and psychological trauma in the context of motor control. Convergent neuroimaging findings implicate alterations in brain circuits mediating emotional expression, regulation and awareness (anterior cingulate and ventromedial prefrontal cortices, insula, amygdala, vermis), cognitive control and motor inhibition (dorsal anterior cingulate, dorsolateral prefrontal, inferior frontal cortices), self-referential processing and perceptual awareness (posterior parietal cortex, temporoparietal junction), and motor planning and coordination (supplementary motor area, cerebellum). Striatal-thalamic components of prefrontal-parietal networks may also play a role in pathophysiology. Aberrant medial prefrontal and amygdalar neuroplastic changes mediated by chronic stress may facilitate the development of functional neurological symptoms in a subset of patients. Improved biological understanding of PNES and FMD will likely reduce stigma and aid the identification of neuroimaging biomarkers guiding treatment development, selection, and prognosis. Additional research should investigate neurocircuit abnormalities within and across functional neurological disorder subtypes, as well as compare PNES and FMD with mood-anxiety-dissociative disorders.

Cognitive impairment and evaluation in psychogenic nonepileptic seizures: an integrated cognitive-emotional approach

Neuropsychological studies comparing patients with psychogenic nonepileptic seizures (PNES) to those with epilepsy have been largely equivocal. The variability in the neuropsychological literature highlights the heterogeneity of the PNES population across a number of psychiatric and neurologic factors. Phenotypic presentations in PNES arise from complex interactions between vulnerable cognitive and emotional systems. We propose that variability in neuropsychological findings in PNES emerge in the context of diverse psychiatric, neurologic, and clinical factors. Traditional assessments that fail to integrate cognitive and emotional/behavioral profiles sufficiently would fall short in characterizing the complexity of brain-behavior relationships in this population. To advance the neuropsychology of PNES, we propose a systematic approach to measure a number of factors that influence cognitive impairment in this population. We begin by reviewing the current neuropsychological literature in PNES and discussing a number of factors that influence cognitive deficits. We then present a comprehensive neuropsychological battery designed to capture elements (cognitive dysfunction, psychopathology, emotion processing deficits) underlying the proposed vulnerable cognitive-emotional system in PNES. It is our hope that the proposed battery will facilitate the aggregation of data across neuropsychological investigations, to allow more advanced statistical analyses, and ultimately enhance our understanding of PNES and the development of effective management and treatment options.

Cognitive differences between patients who have psychogenic nonepileptic seizures (PNESs) and posttraumatic stress disorder (PTSD) and patients who have PNESs without PTSD

OBJECTIVES

The objective of this study was to examine cognitive and clinical differences among three groups of patients diagnosed with psychogenic nonepileptic seizures (PNESs): those with posttraumatic stress disorder (PTSD), those with a history of trauma but no PTSD, and those without a history of trauma.

METHODS

Seventeen patients who were confirmed to have PTSD based on the Trauma Symptom Inventory-2 (TSI-2) and clinical interview were compared with 29 patients without PTSD who had experienced trauma and 17 patients who denied experiencing trauma. We analyzed demographic data, psychiatric information, trauma characteristics, and neuropsychological variables in these groups.

RESULTS

Our study revealed that patients with PNESs with comorbid PTSD performed significantly worse on episodic verbal memory (narrative memory); had greater self-reported Total, Verbal, and Visual Memory impairments; and had higher substance abuse history and use of psychopharmacological agents compared with patients without PTSD regardless of a history of trauma.

CONCLUSION

The present study showed that patients with PNESs diagnosed with PTSD exhibited memory functions that were significantly different from those in patients with PNESs who do not carry a diagnosis of PTSD (regardless of history of trauma). Furthermore, these specific cognitive findings in narrative memory are consistent with those reported in patients with PTSD alone. The present findings contribute to further identifying discrete intragroup differences within PNESs. Identifying a specific psychopathological subgroup such as PTSD will allow clinicians to accurately select treatment.

Cognitive deficits and emotion regulation strategies in patients with psychogenic nonepileptic seizures: a task-switching study

This study examined the task-switching ability and emotion regulation strategies in 72 patients with psychogenic nonepileptic seizures (PNES) and 72 healthy individuals, where participants categorized emotion and age dimensions among faces. Results demonstrated cognitive impairment in terms of the interrupted ability to switch between emotion and nonemotion face categorizations in patients with PNES. In contrast, healthy individuals exhibited efficient switching between these face categorizations. In patients with PNES, there was an asymmetric relationship between emotion and age tasks, while this asymmetry was absent in the healthy group. The results demonstrated that patients with PNES used expressive suppression to regulate their emotions more frequently than the control group. On the other hand, patients with PNES less frequently reappraised their cognitions than healthy individuals. Switching deficits in patients with PNES were positively correlated with expressive suppression but were negatively correlated with cognitive reappraisal. This is the first study demonstrating the presence of switching deficits in terms of inferior cognitive control of emotion in patients with PNES as compared to healthy individuals. The switching deficits are associated with emotion regulation strategies. These findings suggest that emotion regulation strategies are significant markers of switching deficits in patients with PNES.

Understanding the perceived treatment needs of patients with psychogenic nonepileptic seizures

Psychological therapy is generally considered the treatment of choice for psychogenic nonepileptic seizures (PNES), but there is a paucity of research on patients' attitudes towards psychological referral. We conducted semistructured interviews with twelve patients with PNES awaiting psychological treatment in order to understand their perceived treatment needs. Data were analyzed inductively according to the principles of thematic analysis. The results indicated that our patients had clear ideas about their treatment needs and a desire to recover by 'returning to normality'. Many participants felt 'caught in limbo' following their PNES diagnosis, however, because of uncertainties about their condition and a lack of support from professionals. This linked with participants feeling unsure whether psychological treatment would meet their needs; there was also apprehension for some participants about the potential negative consequences of therapy. The clinical implications of these findings are discussed, and recommendations for future research are made.

Neurophysiological correlates of dissociative symptoms

OBJECTIVE

Dissociation is a mental process with psychological and somatoform manifestations, which is closely related to hypnotic suggestibility and essentially shows the ability to obtain distance from reality. An increased tendency to dissociate is a frequently reported characteristic of patients with functional neurological symptoms and syndromes (FNSS), which account for a substantial part of all neurological admissions. This review aims to investigate what heart rate variability (HRV), EEG and neuroimaging data (MRI) reveal about the nature of dissociation and related conditions.

METHODS

Studies reporting HRV, EEG and neuroimaging data related to hypnosis, dissociation and FNSS were identified by searching the electronic databases Pubmed and ScienceDirect.

RESULTS

The majority of the identified studies concerned the physiological characteristics of hypnosis; relatively few investigations on dissociation related FNSS were identified. General findings were increased parasympathetic functioning during hypnosis (as measured by HRV), and lower HRV in patients with FNSS. The large variety of EEG and functional MRI investigations with diverse results challenges definite conclusions, but evidence suggests that subcortical as well as (pre)frontal regions serve emotion regulation in dissociative conditions. Functional connectivity analyses suggest the presence of altered brain networks in patients with FNSS, in which limbic areas have an increased influence on motor preparatory regions.

CONCLUSIONS

HRV, EEG and (functional) MRI are sensitive methods to detect physiological changes related to dissociation and dissociative disorders such as FNSS, and can possibly provide more information about their aetiology. The use of such measures could eventually provide biomarkers for earlier identification of patients at risk and appropriate treatment of dissociative conditions.