Long-term video EEG monitoring for diagnosis of psychogenic nonepileptic seizures

Efficacy of verbal suggestion, verbal suggestion with a tuning fork, and verbal suggestion with a cotton swab for inducing the paroxysmal event during video-EEG recording in children with suspected psychogenic nonepileptic seizures

INTRODUCTION

Video-electroencephalogram (EEG) with suggestion is widely considered the gold standard for diagnosing psychogenic nonepileptic seizures (PNES). However, ethical concerns and uncertainties persist regarding the most minimally invasive and least deceptive suggestion approach.

MATERIALS AND METHODS

In an open-label randomized controlled trial, we evaluated the effectiveness of three suggestion methods (verbal suggestion, verbal suggestion with a tuning fork, and verbal suggestion with a cotton swab) during short-term video-EEG (STVEEG) recordings to induce PNES in children aged 5-18 years. If the paroxysmal event couldn't be elicited with the assigned method, alternative techniques were employed.

RESULTS

Out of 97 initially screened children, 75 were enrolled, with 25 in each group. The efficacy of all three suggestion methods was comparable in reproducing paroxysmal events (success rate of 16/25, 17/25 and 17/25 in verbal suggestion only, verbal suggestion with tuning fork and sterile cotton swab group respectively, p = 0.83) and the time required for induction (median of 2, 3 and 3 min respectively, p = 0.21). After trying alternative methods, 20 %, 12 %, and 12 % more patients in these three groups, respectively, were able to reproduce the paroxysmal event, with the differences not reaching statistical significance (p = 0.74). The assigned induction method or the success/failure of event reproduction did not significantly impact clinical outcomes at 12 weeks, and none of the patients in whom PNES could not be reproduced during STVEEG were later found to have an organic cause. Only the presence of psychiatric comorbidity independently predicted successful event reproduction during STVEEG, with statistical significance even after adjusting for other variables (p = 0.03).

CONCLUSION

The efficacy of verbal suggestion alone in inducing paroxysmal nonepileptic seizures is on par with using a tuning fork or cotton swab in conjunction with verbal suggestion during STVEEG.

An unusual presentation of severe obstructive sleep apnea with nocturnal seizure-like movements: A case report

Key Clinical Message

This study suggests that severe obstructive sleep apnea can present as sleep-related epileptic or non-epileptic seizures. A detailed history and physical examination, along with polysomnography and video electroencephalography findings can lead to the correct diagnosis.

Abstract

Obstructive sleep apnea (OSA) is defined by recurrent episodes of the upper airway complete or partial collapse while sleeping. The obstructive episodes result in gradual suffocation that increases breathing attempts till the person is awakened. The main manifestations are excessive daytime sleepiness, snoring, observed episodes of stopped breathing, and abrupt awakenings accompanied by gasping or choking. Nevertheless, there are very few reports of patients with OSA, manifesting other symptoms such as seizure-like movements. Differentiating OSA with nocturnal seizures could be challenging due to their overlapping features. A 53-year-old man presented to the clinic, experiencing seizure-like involuntary movements during nocturnal sleep for the past 2 years with a frequency of 2-3 times per night. Neurologic examinations were normal. Further evaluation with polysomnography revealed impaired arousal followed by seizure-like movements during sleep. Video electroencephalography (EEG) did not show any epileptiform discharges, ruling out the nocturnal seizure diagnosis. The patient was diagnosed with OSA. Subsequently, continuous positive airway pressure (CPAP) treatment resolved all symptoms.

Computer vision for automated seizure detection and classification: A systematic review

Computer vision (CV) shows increasing promise as an efficient, low-cost tool for video seizure detection and classification. Here, we provide an overview of the fundamental concepts needed to understand CV and summarize the structure and performance of various model architectures used in video seizure analysis. We conduct a systematic literature review of the PubMed, Embase, and Web of Science databases from January 1, 2000 to September 15, 2023, to identify the strengths and limitations of CV seizure analysis methods and discuss the utility of these models when applied to different clinical seizure phenotypes. Reviews, nonhuman studies, and those with insufficient or poor quality data are excluded from the review. Of the 1942 records identified, 45 meet inclusion criteria and are analyzed. We conclude that the field has shown tremendous growth over the past 2 decades, leading to several model architectures with impressive accuracy and efficiency. The rapid and scalable detection offered by CV models holds the potential to reduce sudden unexpected death in epilepsy and help alleviate resource limitations in epilepsy monitoring units. However, a lack of standardized, thorough validation measures and concerns about patient privacy remain important obstacles for widespread acceptance and adoption. Investigation into the performance of models across varied datasets from clinical and nonclinical environments is an essential area for further research.

Improving the treatment of functional seizures through a public specialist outpatient clinic

OBJECTIVES

We performed an audit of the first 12 months of clinical operations to assess the feasibility of a newly established public outpatient clinic for the assessment and treatment of functional (psychogenic nonepileptic) seizures (FS).

METHOD

Clinical notes for the first 12 months of the FSclinic weresystematicallyreviewed with data compiled onreferral pathways, clinic attendance, clinical features, treatments, and outcomes.

RESULTS

Of eighty-two new FS patients referred to the clinic, over 90% attended. Patients were diagnosed with FS after comprehensive epileptological and neuropsychiatric review, mostly with typical seizure-like episodes captured during video-EEG monitoring, and most accepted the diagnosis. Most had FS at least weekly, with little sense of control and significant impairment. The majority of individuals had significant psychiatric and medical comorbidity. Predisposing, precipitating, and perpetuating factors were readily identified in >90% of cases. Of 52 patients with follow-up data within12 months, 88% were either stable or improved in terms of the control of their FS.

CONCLUSION

The Alfred functional seizure clinic model, the first dedicated public outpatient clinic for FS in Australia, provides a feasible and potentially effective treatment pathway for this underserved and disabled patient group.

The Neuropsychiatric Approach to the Assessment of Patients in Neurology

Neuropsychiatry is a clinical neuroscience specialty focused on the evaluation and treatment of patients who present with symptoms at the intersection of neurology and psychiatry. Neuropsychiatrists assess and manage the cognitive, affective, behavioral, and perceptual manifestations of disorders of the central nervous system. Although fellowship training in behavioral neurology-neuropsychiatry exists in the United States and several other countries internationally, the need for neuropsychiatric expertise greatly outweighs the number of specialists in practice or training. This article serves as a primer for both neurologists and psychiatrists seeking to improve or refresh their knowledge of the neuropsychiatric assessment, including detailing aspects of the history-taking, physical exam, psychometric testing, and associated diagnostic work-up. In doing so, we urge the next generation of neurologists and psychiatrists to take on both the opportunity and challenge to work at the intersection of both clinical neuroscience specialties using an integrated neuropsychiatric perspective.

Diagnostic Yield of 8-Hour Video-EEG in Detecting Psychogenic Non-Epileptic Seizures (PNES)

To evaluate the diagnostic yield of the first 8 hours of video-EEG (vEEG) monitoring in detecting Psychogenic Non-Epileptic Seizures (PNES) during the Epilepsy Monitoring Unit (EMU) admission. We performed a retrospective chart review of patients ages ≥4 years who were admitted to the EMU between 2011 and 2018 (n = 616). We calculated the proportion of patients diagnosed with PNES within the first 8 hours of EEG recording and studied the associated risk factors for patients diagnosed with PNES and patients with epileptic seizures (ES). Out of the total 616 patients, 24% (149) patients had an EMU diagnosis of PNES. Of these, 44.3% had at least one typical event within the first 8 hours of vEEG monitoring. A higher incidence was seen within the pediatric subgroup (54.8% had an event within 8 hours). A diagnosis of chronic pain disorder was more common with PNES compared to ES (48.3% versus 16.5%, p < 0.001). A suspicion for PNES documented during an office visit was noted in a high proportion of patients (68.5%) who eventually had a PNES event during EMU. Our study suggests that in a well-selected group of patients (such as a high suspicion of PNES during a physician/neurology office visit), an outpatient 8-hour vEEG could open new avenues for a prompt diagnosis. This could especially be beneficial in hospital settings where there is either a lack of an EMU or a delay in admission to the EMU.

Functional Movement Disorder and Functional Seizures: What have we learned from different subtypes of functional neurological disorders?

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Functional seizures (FS) and functional movement disorders (FMD) are the most common manifestations of functional neurological disorders.

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FMD and FS may have similarities in etiology and pathophysiology.

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FMD and FS share disabling comorbidities of chronic pain, fatigue, and cognitive symptoms.

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Neuroimaging has demonstrated structural and functional changes in emotional and motor planning pathways in FND.

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A multidisciplinary approach and psychotherapy are the treatments for FMD and FS, respectively.

The objective of this paper is to compare and contrast FMD and FS, and highlight important differences in etiology and the clinical approach towards these two entities. While patients with FMD often experience abnormal movements on a daily basis, FS is characterized by paroxysmal events. Both patient populations share psychiatric and environmental comorbidities, but patients with FS may have increased anxiety and neuroticism and a higher percentage of childhood trauma. Functional MRI scans have demonstrated impaired executive control over motor behavior in both groups. FMD responds well to multidisciplinary rehabilitation-oriented treatment, while psychotherapy remains the mainstay of treatment for FS. For practicing clinicians, recognizing commonalities and differences in patients with FMD and FS is important to develop the most appropriate treatment plan.

Evaluation and Management of Seizures and Status Epilepticus

Seizures are frequently triggered by an inciting event and result from uninhibited excitation and/or decreased inhibition of a pool of neurons. If physiologic seizure abortive mechanisms fail, the ensuing unrestrained synchronization of neurons-status epilepticus-can be life-threatening and is associated with the potential for marked morbidity in survivors and high medical care costs. Prognosis is intimately related to etiology and its response to therapeutic measures. Timely implementation of pharmacologic therapy while concurrently performing a stepwise workup for etiology are paramount. Neurodiagnostic testing should guide titration of pharmacologic therapies, and help determine if there is a role for immune modulation.

Video quality using outpatient smartphone videos in epilepsy: Results from the OSmartViE study

BACKGROUND AND PURPOSE

The aim of this study was to evaluate the quality of smartphone videos (SVs) of neurologic events in adult epilepsy outpatients. The use of home video recording in patients with neurological disease states is increasing. Experts interpretation of outpatient smartphone videos of seizures and neurological events has demonstrated similar diagnostic accuracy to inpatient video-electroencephalography (EEG) monitoring.

METHODS

A prospective, multicenter cohort study was conducted to evaluate SV quality in patients with paroxysmal neurologic events from August 15, 2015 through August 31, 2018. Epileptic seizures (ESs), psychogenic nonepileptic attacks (PNEAs), and physiologic nonepileptic events (PhysNEEs) were confirmed by video-EEG monitoring. Experts and senior neurology residents blindly viewed cloud-based SVs without clinical information. Quality ratings with regard to technical and operator-driven metrics were provided in responses to a survey.

RESULTS

Forty-four patients (31 women, age 45.1 years [r = 20-82]) were included and 530 SVs were viewed by a mean of seven experts and six residents; one video per patient was reviewed for a mean of 133.8 s (r = 9-543). In all, 30 patients had PNEAs, 11 had ESs, and three had PhysNEEs. Quality was suitable in 70.8% of SVs (375/530 total views), with 36/44 (81.8%) patient SVs rated as adequate by the majority of reviewers. Accuracy improved with the presence of convulsive features from 72.4% to 98.2% in ESs and from 71.1% to 95.7% in PNEAs. An accurate diagnosis was given by all reviewers (100%) in 11/44 SVs (all PNEAs). Audio was rated as good by 86.2% of reviewers for these SVs compared with 75.4% for the remaining SVs (p = 0.01). Lighting was better in SVs associated with high accuracy (p = 0.06), but clarity was not (p = 0.59). Poor video quality yielded unknown diagnoses in 24.2% of the SVs reviewed. Features hindering diagnosis were limited interactivity, restricted field of view and short video duration.

CONCLUSIONS

Smartphone video quality is adequate for clinical interpretation in the majority of patients with paroxysmal neurologic events. Quality can be optimized by encouraging interactivity with the patient, adequate duration of the SV, and enlarged field of view during videography. Quality limitations were primarily operational though accuracy remained for SV review of ESs and PNEAs.

Clinical differentiation of psychogenic non-epileptic seizure: a practical diagnostic approach

Background

Psychogenic non-epileptic seizure (PNES) has long been the counterpart of epileptic seizure (ES). Despite ample of evidence differentiating the two, PNES mistakenly diagnosed as ES was still common, resulting in unnecessary exposure to long-term antiepileptic medications and reduced patient’s and caregiver’s quality of life, not to mention the burgeoning financial costs.

Objectives

In this review, we aimed to elucidate various differences between PNES and epileptic seizure with respect to baseline characteristics, seizure semiology, EEG pattern, and other key hallmark features.

Methods

An unstructured search was carried out in PubMed, MEDLINE, and EMBASE using keywords pertinent to PNES and ES differentiation. Relevant information was subsequently summarized herein.

Results

PNES differs significantly with ES in terms of baseline characteristics, prodromal symptoms, seizure semiology, presence of pseudosleep, and other hallmark features (for instance provoking seizure with suggestion). The combined approach, if applied appropriately, can yield high diagnostic yield.

Conclusions

PNES can be clearly differentiated from ES via careful adherence to a set of valid clinical cues. The summarized clinical hallmarks is highly useful to prevent unnecessary ES diagnosis and treatment with AEDs.

Clinical utility of home videos for diagnosing epileptic seizures: a systematic review and practical recommendations for optimal and safe recording

Background

The aim of the present systematic revision is to analyze existing published reports about the use of home-videos recordings (HVRs) to support physicians in the differential diagnosis of paroxysmal seizure-like episodes (PSLE). We also developed practical recommendations in order to ensure adequate quality standards and safety advice for HVRs.

Material and methods

A comprehensive search of PubMed, Medline, Scopus, and Google Scholar was performed, and results were included up to July 2020. All studies concerning the use of HVRs as a diagnostic tool for patients presenting PSLE were included.

Results

Seventeen studies satisfied all inclusion and exclusion criteria and were considered for the review. A consistent boost in diagnostic and clinical decision-making was reported across all studies in the literature. One study found that HVRs decreased the stress level in many families and improved their quality of life. Training in performing good-quality videos is necessary and increases the diagnostic value of HVRs.

Conclusions

HVRs can be of diagnostic value in epilepsy diagnosis and management. HVRs are low cost, widespread, and may provide great support for neurologists. It is important to train patients and caregivers in performing good quality videos to optimize this useful tool and to guarantee safety standards during the recording.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05040-5.

Identification of Serum Biomarkers for Differentiating Epileptic Seizures from Psychogenic Attacks Using a Proteomic Approach; a Comparative study

INTRODUCTION

Differentiating actual epileptic seizures (ESs) from psychogenic non-epileptic seizures (PNES) is of great interest. This study compares the serum proteomics of patients diagnosed with ESs and PNES.

METHODS

Eight patients with seizure (4 with PNES and 4 with TLE (temporal lope epilepsy)) were enrolled in this comparative study. Venous blood samples were drawn during the first hour following the seizure. Standard protein purification technique was employed and proteins were subsequently separated via 2-D electrophoresis. After comparison of the serum proteomes from the two groups, protein expression was analyzed. The differentially expressed bands were determined using both matrix-assisted laser ionization time-of-flight (MALDI/TOF) and electrospray ionization quadruple mass spectrometry (MS).

RESULTS

This study identified 361 proteins, the expression of 110 proteins increased, and 87 proteins decreased in the PNES group compared with TLE group. Four separate proteins were finally identified with MALDI/TOF MS analysis. Compared with PNES group, alpha 1-acid glycoprotein, ceruloplasmin, and S100-β were down-regulated and malate dehydrogenase 2 was up-regulated in the serum of TLE patients.

CONCLUSION

Our results indicated that changes in serum levels of S100-β, ceruloplasmin, alpha 1-acid glycoprotein 1, and malate dehydrogenase 2 after seizure could be introduced as potential markers to differentiate ES from PNES; however, more advanced studies are required to reach a better understanding of the underlying mechanisms.

EEG-based classification of epilepsy and PNES: EEG microstate and functional brain network features

Epilepsy and psychogenic non-epileptic seizures (PNES) often show over-lap in symptoms, especially at an early disease stage. During a PNES, the electrical activity of the brain remains normal but in case of an epileptic seizure the brain will show epileptiform discharges on the electroencephalogram (EEG). In many cases an accurate diagnosis can only be achieved after a long-term video monitoring combined with EEG recording which is quite expensive and time-consuming. In this paper using short-term EEG data, the classification of epilepsy and PNES subjects is analyzed based on signal, functional network and EEG microstate features. Our results showed that the beta-band is the most useful EEG frequency sub-band as it performs best for classifying subjects. Also the results depicted that when the coverage feature of the EEG microstate analysis is calculated in beta-band, the classification shows fairly high accuracy and precision. Hence, the beta-band and the coverage are the most important features for classification of epilepsy and PNES patients.

Proteomic Analysis of patients with Epileptic Seizure and Psychogenic Non-epileptic Seizure; a Cross-Sectional Study

INTRODUCTION

There is an increasing interest in the use of different biomarkers to help distinguish psychogenic non-epileptic seizure (PNES) from epileptic seizures (ES). This study aimed to evaluate the patterns of differentially expressed serum proteins in ES and PNES cases.

METHODS

In this cross-sectional study, 4 patients with mesial temporal lobe epilepsy and 4 patients with PNES were selected from patients with history of recurrent seizures. Venous blood samples were obtained within 1 hour after seizure and serum proteomes as well as the extent of protein expression were analyzed.

RESULTS

361 proteins were identified; of these, expression of 197 proteins had altered. 110 (55.9%) proteins were down-regulated and 87 (44.1%) were up-regulated in the PNES samples compared to ES samples. The mean pI for deregulated proteins with 1.5 to 3 fold changes were 6.69 ± 1.68 in proteins with increasing expression in ES group and 5.88 ± 1.39 in proteins with increasing expression in PNES group (p = 0.008). The median and interquartile range (IQR) of molecular weight changes in proteins with 1.5 to 3 fold changes were 64 (22.0-86.0) in proteins whose expression had increased in ES group and 39.5 (26.0-61.5) in proteins whose expression had increased in PNES cases (p = 0.05).

CONCLUSION

Several spots with differential expression were observed by comparing patients with ES against the PNES groups, which could be potential biomarkers of the disease. Damage to the blood-brain barrier is the most important difference between the two groups, thus identifying total protein changes offers a key to the future of differentiating ES and PNES patients.

Clinical Classifications of Children With Psychogenic Non-epileptic Seizure

Objective: To analyze the clinical features of children with psychogenic non-epileptic seizures in one tertiary center in China. Methods: Clinical data including medical records and video- electroencephalograph (video-EEG) monitoring records of 88 pediatric PNES patients hospitalized in the pediatric department of Xuanwu Hospital, Beijing, China from April, 2012 to April, 2018 were collected in this study. Demographic information of patients, semiological classification, duration, and frequency of symptoms, risk factors as well as comorbidity were summarized and analyzed. Results: For semiological classification, all PNES related symptoms were divided into different categories: motor symptoms, unresponsiveness, sensory symptoms, visceral symptoms, and abnormal behaviors, among which motor symptoms were the most prevalent form. Risk factors were reviewed and categorized into two groups: persistent factors and predisposing factors, and patients were most frequently affected by the influences of families. The duration and frequency of symptoms varied substantially within PNES patients while the average time of duration was relatively longer than epilepsy as reported previously. Epilepsy was considered as the most frequent comorbidity of PNES and PNES patients misdiagnosed as epilepsy often mistreated with antiseizure medication. Significance: Our study showed that motor PNES are the most frequent seizure type. Family issues were a risk factor for PNES. Epilepsy was the most frequent co-existing neurological comorbidity.

Use of noninvasive induction techniques in the diagnosis of PNES

The diagnosis of psychogenic nonepileptic seizures (PNES) remains challenging. In the correct clinical setting with prolonged electroencephalography (EEG) monitoring, the specificity of provocative techniques to distinguish induced epileptic event from a nonepileptic event approaches 90%. We report our epilepsy monitoring unit (EMU) experience with the use of noninvasive verbal suggestion (VS) during hyperventilation (HV), photic stimulation (PS) as induction technique in making the diagnosis of PNES. In total, 189/423 patients were diagnosed with PNES during the EMU evaluation. Of the 189, 20 had mixed disorder and 169 patients had only PNES, 80 patients (47.3%) had a PNES with induction, and the remaining 89 of 169 patients (52.7%) had a spontaneous PNES episode that did not require induction. Verbal suggestion during HV and PS confirmed the diagnosis of PNES in 47% of the patients who otherwise did not have spontaneous events. Within the group who was diagnosed with PNES following induction, antiepileptic drugs (AEDs) were stopped in 53% of the patients. We believe that this is a large proportion of patients that would possibly remain undiagnosed if no induction were performed.

Long-term outcome in a sample of underprivileged patients with psychogenic nonepileptic seizures (PNES) living in Argentina

OBJECTIVE

The objective of the present study was to perform a long-term follow-up of economically disadvantaged Latin American patients diagnosed as having psychogenic nonepileptic seizures (PNES) and contribute to the field's understanding of outcome in this population.

BACKGROUND

A handful of studies have examined outcome of patients once the diagnosis of PNES has been communicated. However, the vast majority of these have been conducted in the first world countries with samples that were predominantly Caucasian. There is limited knowledge about outcome in economically disadvantaged Latin American patients diagnosed as having PNES.

METHODS

This is a study of 23 patients (20 women, 3 men) with PNES in which demographic data (age, education, nationality, presence of psychological trauma, age of onset) were retrospectively retrieved from medical files. Follow-up was done through a telephonic questionnaire in which investigators collected clinical information (seizure characteristics at follow-up, and treatments employed) and changes in demographic data.

RESULTS

Patients from this Argentinian PNES sample demonstrated having many similar demographic and clinical characteristics to samples from US and European studies. Long-term follow-up revealed, however, decreased seizure frequency and intensity as well as a substantial improvement in occupational status. A majority had engaged in psychotherapy as well as alternative and complementary approaches. A majority had also developed what are suspected to be other functional symptoms.

CONCLUSIONS

Argentinian patients from economically disadvantaged backgrounds, diagnosed as having PNES reported improvements in seizure frequency and occupational status during long-term follow-up. Future studies will need to focus on what (e.g., communication of diagnosis, psychotherapy, alternative treatments) may have contributed to these changes.

A Case of Dissociative Seizures Presented like Myoclonic Epilepsy

Psychogenic seizures are often underdiagnosed and epilepsy is very often over-treated which leads to multiple financial, social and stigma related difficulties. The myoclonic seizure itself is a rare phenomenon and when functional movement disorder presents like myoclonus then it's extremely difficult to pinpoint the exact cause. Here, we are presenting a case who was misdiagnosed as having a myoclonic seizure disorder and treated in multiple places without any improvement which ultimately turned out to be functional movement disorder of a rare variety.

The Inpatient Assessment and Management of Motor Functional Neurological Disorders: An Interdisciplinary Perspective

BACKGROUND

Motor functional neurologic disorders (FND)-previously termed "hysteria" and later "conversion disorder"-are exceedingly common and frequently encountered in the acute hospital setting. Despite their high prevalence, patients with motor FND can be challenging to diagnose accurately and manage effectively. To date, there is limited guidance on the inpatient approach to the neuropsychiatric evaluation of patients with functional (psychogenic) neurologic symptoms.

OBJECTIVE

The authors outline an inpatient multidisciplinary approach, involving neurology, psychiatry, and physical therapy, for the assessment and acute inpatient management of motor FND.

METHODS

A vignette of a patient with motor FND is presented followed by a discussion of general assessment principles. Thereafter, a detailed description of the neurologic and psychiatric assessments is outlined. Delivery of a "rule-in" diagnosis is emphasized and specific guidance for what can be accomplished postdiagnosis in the hospital is suggested.

DISCUSSION

We encourage an interdisciplinary approach beginning at the early stages of the diagnostic assessment once an individual is suspected of having motor FND.

CONCLUSIONS

Practical suggestions for the inpatient assessment of motor FND are presented. It is also important to individualize the diagnostic assessment. Future research should be conducted to test best practices for motor FND management in the acute inpatient hospital setting.

Simultaneous occurrence of nonepileptic and epileptic seizures during a single period of in-patient video-electroencephalographic monitoring

Epilepsy and psychogenic nonepileptic seizures (PNES) can coexist and may present in two forms: sequential and simultaneous. In sequential presentations, epileptic seizures (ES) are treated and PNES emerge later. Simultaneous recording of ES and PNES by video‐electroencephalogram (vEEG) is less well described. We retrospectively reviewed all patients diagnosed with PNES by vEEG following standard seizure induction practices over a 21‐month period. Within this cohort, we established the prevalence of coexisting epilepsy using clinical and electrographic data acquired from our epilepsy‐specific patient record. We identified patients with simultaneous PNES and ES recorded during a single vEEG admission, establishing the frequency and emergent timing of each type. Of our 262 monitored patients, 59 were diagnosed with PNES. Nineteen of the patients with PNES had coexisting epilepsy (prevalence rate of 7.3% or 32% of those with PNES). Sixteen patients had PNES and ES recorded during the same admission, and the remaining three patients had sequential PNES following successful treatment of ES. PNES occurred earlier (mean, within 1.21 days), with ES occurring later (mean, within 4.86 days). The simultaneous occurrence of PNES and ES recorded during a single admission is more common than previously reported. Identifying this group of patients may require a significantly longer period of vEEG monitoring and a detailed analysis of each individual's historical seizure events.

Diagnosing psychogenic nonepileptic seizures: Video-EEG monitoring, suggestive seizure induction and diagnostic certainty

Psychogenic nonepileptic seizures (PNES) can remain undiagnosed for many years, leading to unnecessary medication and delayed treatment. A recent report by the International League Against Epilepsy Nonepileptic Seizures Task Force recommends a staged approach to the diagnosis of PNES (LaFrance, et al., 2013). We aimed to investigate its practical utility, and to apply the proposed classification to evaluate the role of long-term video-EEG monitoring (VEEG) and suggestive seizure induction (SSI) in PNES workup. Using electronic medical records, 122 inpatients (mean age 36.0±12.9years; 68% women) who received the diagnosis of PNES at our epilepsy center during a 4.3-year time period were included. There was an 82.8% agreement between diagnostic certainty documented at discharge and that assigned retroactively using the Task Force recommendations. In a minority of cases, having used the Task Force criteria could have encouraged the clinicians to give more certain diagnoses, exemplifying the Task Force report's utility. Both VEEG and SSI were effective at supporting high level diagnostic certainty. Interestingly, about one in four patients (26.2%) had a non-diagnostic ("negative") VEEG but a positive SSI. On average, this subgroup did not have significantly shorter mean VEEG recording times than VEEG-positive patients. However, VEEG-negative/SSI-positive patients had a significantly lower habitual seizure frequency than their counterparts. This finding emphasizes the utility of SSI in ascertaining the diagnosis of PNES in patients who do not have a spontaneous habitual event during VEEG due to, for example, low seizure frequency.

Neurophysiologic studies of functional neurologic disorders

Functional neurologic disorders are largely genuine and represent conversion disorders, where the dysfunction is unconscious, but there are some that are factitious, where the abnormality is feigned and conscious. Malingering, which can have the same manifestations, is similarly feigned, but not considered a genuine disease. There are no good methods for differentiating these three entities at the present time. Physiologic studies of functional weakness and sensory loss reveal normal functioning of primary motor and sensory cortex, but abnormalities of premotor cortex and association cortices. This suggests a top-down influence creating the dysfunction. Studies of functional tremor and myoclonus show that these disorders utilize normal voluntary motor structures to produce the involuntary movements, again suggesting a higher-level abnormality. Agency is abnormal and studies shows that dysfunction of the temporoparietal junction may be a correlate. The limbic system is overactive and might initiate involuntary movements, but the mechanism for this is not known. The limbic system would then be the source of top-down dysfunction. It can be speculated that the involuntary movements are involuntary due to lack of proper feedforward signaling.

Functional coma

Functional coma - here defined as a prolonged motionless dissociative attack with absent or reduced response to external stimuli - is a relatively rare presentation. In this chapter we examine a wide range of terms used to describe states of unresponsiveness in which psychologic factors are relevant to etiology, such as depressive stupor, catatonia, nonepileptic "pseudostatus," and factitious disorders, and discuss the place of functional or psychogenic coma among these. Historically, diagnosis of functional coma has sometimes been reached after prolonged investigation and exclusion of other diagnoses. However, as is the case with other functional disorders, diagnosis should preferably be made on the basis of positive findings that provide evidence of inconsistency between an apparent comatose state and normal waking nervous system functioning. In our review of physical signs, we find some evidence for the presence of firm resistance to eye opening as reasonably sensitive and specific for functional coma, as well as the eye gaze sign, in which patients tend to look to the ground when turned on to one side. Noxious stimuli such as Harvey's sign (application of high-frequency vibrating tuning fork to the nasal mucosa) can also be helpful, although patients with this disorder are often remarkably unresponsive to usually painful stimuli, particularly as more commonly applied using sternal or nail bed pressure. The use of repeated painful stimuli is therefore not recommended. We also discuss the role of general anesthesia and other physiologic triggers to functional coma.