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

Predictive Processing and the Pathophysiology of Functional Neurological Disorder

The contemporary neuroscience understanding of the brain as an active inference organ supports that our conscious experiences, including sensorimotor perceptions, depend on the integration of probabilistic predictions with incoming sensory input across hierarchically organized levels. As in other systems, these complex processes are prone to error under certain circumstances, which may lead to alterations in their outcomes (i.e., variations in sensations and movements). Such variations are an important aspect of functional neurological disorder, a complex disorder at the interface of brain-mind-body interactions. Thus, predictive processing frameworks offer fundamental mechanistic insights into the pathophysiology of functional neurological disorder. In recent years, many of the aspects relevant to the neurobiology of functional neurological disorder - e.g., aberrant motor and sensory processes, symptom expectation, self-agency, and illness beliefs, as well as interoception, allostasis, and emotion - have been investigated through the lens of predictive processing frameworks. Here, we provide an overview of the current state of research on predictive processing and the pathophysiology of functional neurological disorder.

Dissociative seizures in the emergency room: room for improvement

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Psychogenic non-epileptic seizures: Chronology of multidisciplinary team approach to diagnosis and management

While the diagnosis and management of psychogenic non-epileptic seizures (PNES) remain challenging, certain evidence-based guidelines exist, which can help to optimize patient care. A multidisciplinary team approach appears to have many benefits. Current recommendations exist for some aspects of diagnosis and management of PNES, including levels of diagnostic certainty as proposed by the International League Against Epilepsy's expert Task Force on PNES. Other aspects of clinical still care lack clear consensus, including use of suggestion techniques for recording PNES and optimal terminology, since the term "functional seizures" has recently been proposed as a possible term to replace "PNES". The present article aims to (1) review current recommendations and (2) discuss our own team's experience in managing patients with PNES. This is organized chronologically in terms of the roles of the neurologist, psychiatrist and psychologist, and discusses diagnostic issues, psychiatric assessment and treatment, and psychotherapeutic approaches.

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.

Suggestibility in functional neurological disorder: a meta-analysis

OBJECTIVE

Responsiveness to direct verbal suggestions (suggestibility) has long been hypothesised to represent a predisposing factor for functional neurological disorder (FND) but previous research has yielded conflicting results. The aim of this study was to quantitatively evaluate whether patients with FND display elevated suggestibility relative to controls via meta-analysis.

METHODS

Four electronic databases were searched in November 2019, with the search updated in April 2020, for original studies assessing suggestibility using standardised behavioural scales or suggestive symptom induction protocols in patients with FND (including somatisation disorder) and controls. The meta-analysis followed Cochrane, Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analyses Of Observational Studies in Epidemiology (MOOSE) guidelines. Data extraction and study quality coding were performed by two independent reviewers. Standardised suggestibility scores and responsiveness to symptom induction protocols were used to calculate standardised mean differences (SMDs) between groups.

RESULTS

Of 26 643 search results, 19 articles presenting 11 standardised suggestibility data sets (FND: n=316; control: n=360) and 11 symptom suggestibility data sets (FND: n=1285; control: n=1409) were included in random-effect meta-analyses. Meta-analyses revealed that patients with FND displayed greater suggestibility than controls on standardised behavioural scales (SMD, 0.48 (95% C, 0.15 to 0.81)) and greater responsiveness to suggestive symptom induction (SMD, 1.39 (95% CI 0.92 to 1.86)). Moderation analyses presented mixed evidence regarding the extent to which effect sizes covaried with methodological differences across studies. No evidence of publication bias was found.

CONCLUSIONS

These results corroborate the hypothesis that FND is characterised by heightened responsiveness to verbal suggestion. Atypical suggestibility may confer risk for FND and be a cognitive marker that can inform diagnosis and treatment of this condition.

Impaired emotional and behavioural awareness and control in patients with dissociative seizures

BACKGROUND

Dissociative seizures (DS) are brief episodes of disrupted awareness and behavioural control that may resemble epileptic seizures. They are thought to arise in the context of impaired emotion processing and disinhibition. In a multi-perspective neuropsychological study, we aim to assess specific metacognitive traits and behavioural features involved in the affective and cognitive underpinnings of DS (emotion recognition and regulation, inhibition, interoception and sense of agency).

METHODS

Twenty prospectively recruited patients with video-EEG-confirmed DS and 20 healthy controls underwent comprehensive neuropsychological and psychiatric testing using validated questionnaires and structured interviews. Behavioural experimental data was obtained using a custom-made emotional go/no-go task, a digital Libet clock setup and a heartbeat counting paradigm.

RESULTS

Emotion recognition, as quantified in the emotional go/no-go task, was impaired in the DS group, and correlated with alexithymic traits. Behavioural inhibition, especially under conditions that would require emotion regulation, was also reduced in the emotional go/no-go task compared to controls and was correlated with neuropsychometric measures of emotion regulation. Data from the Libet clock experiment suggested impaired behavioural awareness in DS patients. No evidence of impaired interoceptive awareness was found in the heartbeat counting task.

CONCLUSION

These results represent comprehensive experimental evidence for alterations in emotional and behavioural awareness and control in patients with DS that yield empirical evidence for current psychopathological models. Our findings offer a more detailed understanding of key pathogenic factors in DS and provide theoretical support for recently developed cognitive-behavioural therapies for DS.

Incidence rates and characteristics of pediatric onset psychogenic nonepileptic seizures

BACKGROUND

Pediatric onset psychogenic nonepileptic seizures (PNES) is a highly disabling disorder and potentially misdiagnosed as epilepsy. Still, knowledge regarding PNES in children and adolescents is limited and data on both incidence and characteristics are scarce. This study investigated the incidence rate (IR) and clinical characteristics of pediatric onset PNES, including possible differences when having comorbid epilepsy.

METHODS

A population-based study of children and adolescents aged 5-17 years with an incident diagnosis of PNES in the Danish healthcare registries between 1996 and 2014. In total, 386 children and adolescents were included after assessment of diagnostic validity using medical record data.

RESULTS

The IR increased during the study period with the maximum IR observed in 2014 (7.4 per 100,000 person-years). A history of both neurologic and psychiatric problems as well as negative life events was identified. Comorbid epilepsy was confirmed for 55 cases (14.2%) and was associated with intellectual disabilities, school support and prolonged delay in PNES diagnosis.

CONCLUSIONS

PNES are increasingly diagnosed in children and adolescents, and the clinical profile of both neurologic and psychiatric health problems underscores the need for collaborative pediatric and mental healthcare. These findings provide important information for future healthcare planning in this area.

IMPACT

This nationwide study is the first to report population-based incidence rates of pediatric onset PNES documenting markedly increasing incidence rates between 1996 and 2014. A history of both neurologic and psychiatric problems as well as negative life events was identified for pediatric onset PNES. Comorbid epileptic seizures were associated with intellectual disabilities, school support and prolonged delay in PNES diagnosis. The clinical profile of both neurologic and psychiatric health problems underscores the need for collaborative pediatric and mental healthcare. The increasing number of children and adolescents diagnosed with PNES is important information for future healthcare planning in this area.

Suggestive seizure induction for inpatients with suspected psychogenic nonepileptic seizures

OBJECTIVE

To determine the utility of suggestive seizure induction for inpatient work-up of suspected psychogenic nonepileptic seizures (PNES).

METHODS

Prospective study of epilepsy center inpatient admissions with suspected PNES. Patients were randomized to undergo suggestive induction first (group A) and then, if necessary, long-term video-electroencephalography (EEG) monitoring, or vice versa (group B). Diagnostic pathways were compared. Potential clinical predictors for diagnostic success were evaluated.

RESULTS

Length of in-hospital stay did not significantly differ between groups. Suspicion of PNES was confirmed in 43 of 77 (56%) patients, evenly distributed between group A (22 of 39) and group B (21 of 38). In nine patients, recorded habitual seizures were epileptic and in 25 cases, no diagnostic event could be recorded. Diagnosis of PNES was ascertained primarily by recording a typical seizure through suggestive induction in 24 patients and through long-term monitoring in 19 patients. In group A (induction first), monitoring was not deemed necessary in 21% of cases. In group B (monitoring first), 13% would have remained inconclusive without suggestive induction. Patients who reported triggers to their habitual seizures were not more likely to have spontaneous or provoked PNES during monitoring or suggestive inducion, respectively. Patients with subjective seizure prodromes (auras) were significantly more likely to have a PNES during suggestive induction than those without (odds ratio [OR] 3.4, 95% confidence interval [CI] 1.1-10.4). There was no significant difference in seizure frequency between patients with spontaneous PNES during long-term monitoring and those with nondiagnostic monitoring sessions.

SIGNIFICANCE

Our results support the notion that suggestive seizure induction can reduce the number of inconclusive inpatient workups, and can obviate resource-intensive long-term monitoring in one fifth of cases. Patients who are aware of prodromes might have a higher chance of having seizures induced through suggestion.

The clinical value of long - term electroencephalogram (EEG) in seizure - free populations: implications from a cross-sectional study

Backgroud

This study aimed to explore the clinical value of long - term electroencephalogram (LTM EEG) in seizure-free individuals taking antiepileptic drugs (AEDs) for more than 2 years. We try to look for clinical factors associated with epileptiform activity on LTM EEG in seizure free patients. We hope that the detection of epileptiform activity by the LTM EEG recording can develop the better treatment strategy.

Methods

The LTM EEG recordings of 770 individuals with a definite diagnosis of epilepsy were assessed. Two hundred sixty-two individuals accorded with the inclusion criteria and exclusion criteria. We collect the demographic and clinical information and LTM EEG data of these 262 individuals. We analysed the data by one-way analysis of variance and Cox proportional hazards models.

Results

We found that more epileptiform activity were found with LTM EEG recording than regular EEG recording in seizure-free individuals. We found several clinical factors could be associated with epileptiform activity on LTM EEG in seizure free patients by a one-way analysis: symptomatic or cryptogenic epilepsy [hazard ratio (HR) = 2.6], history of cerebral trauma (HR = 7.5), and abnormal imaging findings (HR = 3.1). The following factors suggested a correlation between history of cerebral trauma (HR = 2.4) and history of cerebral surgery (HR = 3.4) with epileptiform activity on LTM EEG presentation by multivariate logistic regression analysis.

Conclusions

The study indicated a correlation of a number of factors with abnormal LTM EEG presentation: symptomatic or cryptogenic epilepsy, history of cerebral trauma, history of cerebral surgery, and abnormal imaging findings. The LTM EEG recording may help find epileptiform activity in high risk seizure-free individuals. The individuals need be reevaluated the therapeutic strateagies, and increase the hope to reach real seizure-free.

Levels of diagnostic certainty for nonepileptic attack disorder in the neuropsychiatry setting

Nonepileptic attack disorder (NEAD) is a medical condition commonly seen in neuropsychiatry services, often as a differential diagnosis of other neuropsychiatric conditions. Recommendations by the International League Against Epilepsy (ILAE) Nonepileptic Seizures Task Force propose a four-level hierarchical approach to the diagnosis of NEAD, based on history, witnessed event, and electroencephalographic (EEG) investigation. We set out to provide the first description of the diagnostic levels of patients with NEAD at a specialist neuropsychiatry clinic. Comprehensive clinical data from 148 consecutive patients with NEAD attending the specialist Neuropsychiatry Clinic run by a single Consultant in Behavioral Neurology were retrospectively reviewed. Patients with NEAD were primarily referred to neuropsychiatry by Consultant Neurologists (n = 94; 63.5%). The majority of patients were female (n = 108; 73.0%), with a disease duration of 7.9 years (standard deviation: 10.4). Anxiety was the most common comorbidity (n = 43; 26.7%). Categorization of patients according to the ILAE Nonepileptic Seizures Task Force criteria was mainly based on clinical features and EEG findings, as only 7 (4.7%) patients had attacks witnessed by a specialist. The largest diagnostic categories were 'possible' (n = 54; 36.5%) and 'clinically established' (n = 40; 27.0%), followed by 'documented' (n = 12; 8.1%) and 'probable' (n = 5; 3.4%). In 125 patients (84.4%), EEGs were performed. Selective serotonin reuptake inhibitors were the most frequently prescribed psychotropic medications (n = 48; 32.4%); 89 patients (60.1%) received behavioral therapy. There were no differences in pharmacological or behavioral management strategies across the patients categorized under different diagnostic levels. Patients with NEAD seen within neuropsychiatry settings are mainly assigned 'possible' and 'clinically established' levels of diagnostic certainty. Difficulty in capturing typical clinical events witnessed by an experienced clinician while on video-EEG can limit the clinical application of the 'documented' diagnostic level. If appropriate, active interventions can be implemented irrespective of diagnostic levels to minimize delays in the neuropsychiatric care pathways.

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.

The epileptology of alternating hemiplegia of childhood

OBJECTIVE

To report our experience and investigate 5 original hypotheses: (1) multiple types of epileptic seizures occur in alternating hemiplegia of childhood (AHC), and these can be the initial presentation; (2) epileptiform abnormalities often appear well after clinical seizures; (3) nonepileptic reduced awareness spells (RAS) occur frequently; (4) epilepsy is commonly drug resistant but may respond to vagal nerve stimulation (VNS); and (5) status epilepticus (SE) is common and is usually refractory and recurrent.

METHODS

We analyzed a cohort of 51 consecutive patients with AHC.

RESULTS

Thirty-two of 51 patients had epilepsy: 18 focal seizures, frontal more frequently than temporal, and then posterior. Eleven had primary generalized seizures (tonic-clonic, myoclonic, and/or absence). Epileptic seizures preceded other AHC paroxysmal events in 8 (lag 5.63 ± 6.55 months; p = 0.0365). In 7 of 32, initial EEGs were normal, with the first epileptiform EEG lagging behind by 3.53 ± 4.65 years (p = 0.0484). RAS occurred equally in patients with epilepsy (16 of 32) and patients without epilepsy (10 of 19, p = 1.0). Twenty-eight patients had video-EEG; captured RAS showed no concomitant EEG changes. Nineteen patients (59%) were drug resistant. VNS resulted in >50% reduction in seizures in 5 of 6 (p < 0.04). Twelve patients (38%) had SE (9 of 12 multiple episodes), refractory/superrefractory in all (p < 0.001), and 4 of 12 had regression after SE.

CONCLUSIONS

Epilepsy in AHC can be focal or generalized. Epileptic seizures may be the first paroxysmal symptom. EEG may become epileptiform only on follow-up. Epilepsy, although frequently drug resistant, can respond to VNS. RAS are frequent and nonepileptic. SE often recurs and is usually refractory/superrefractory. Our observations are consistent with current data on AHC-ATP1A3 pathophysiology.

Welfare consequences for people diagnosed with nonepileptic seizures: A matched nationwide study in Denmark

OBJECTIVE

We aimed to evaluate the excess direct and indirect costs associated with nonepileptic seizures.

METHODS

From the Danish National Patient Registry (2011-2016), we identified 1057 people of any age with a diagnosis of psychogenic nonepileptic seizures (PNESs) and matched them with 2113 control individuals. Additionally, 239 partners of patients with PNES aged ≥18 years were identified and compared with 471 control partners. Direct costs included frequencies and costs of hospitalizations and outpatient use weighted by diagnosis-related group, and specific outpatient costs based on data from the Danish Ministry of Health. The use and costs of drugs were based on data from the Danish Medicines Agency. The frequencies of visits and hospitalizations and costs of general practice were derived from National Health Security data. Indirect costs included labor supply-based income data, and all social transfer payments were obtained from Coherent Social Statistics.

RESULTS

A higher percentage of people with PNES and their partners compared with respective control subjects received welfare benefits (sick pay, disability pension, home care). Those with PNES had a lower employment rate than did controls for equivalent periods up to three years before the diagnosis was made. The additional direct and indirect annual costs for those aged ≥18 years, including transfers to patients with PNES, compared with controls, were €33,697 for people with PNES and €15,121 for their partners.

SIGNIFICANCE

Psychogenic nonepileptic seizures have substantial socioeconomic consequences for individual patients, their partners, and society.

Morbidity and mortality of nonepileptic seizures (NES): A controlled national study

Nonepileptic seizures (NES, psychogenic NES-PNES) are associated with significant morbidities. We evaluated the morbidities and mortality in a national group of children, adolescent, and adult patients before and after a first diagnosis of PNES.

METHODS

From the Danish National Patient Registry (1998-2013), we identified 1057 people of all ages with a diagnosis of NES and matched them with 2113 control individuals by age, gender, and geography. Comorbidities were calculated three years before and after diagnoses.

RESULTS

Patients with PNES showed increased comorbidities 3 years before and after diagnosis in almost all the diagnostic domains. The strongest associations were identified with other neurological diseases (after diagnosis, Hazard Ratio (HR): 38.63; 95% Confidence Interval (CI): 21.58-69.13; P < 0.001), abnormal clinical and laboratory findings (HR: 46.59; 95 CI: 27.30-79.52; P < 0.001), other health-related factors (HR: 12.83; 95%CI: 8.45-19.46; P < 0.001), and psychiatric comorbidities (HR: 15.45; 95% CI: 9.81-24.33). Epilepsy was identified in 8% of the patients with PNES. We found especially frequent comorbidity involving overweight, depression, anxiety, dissociative somatoform condition, other convulsions, lipothymias, reports of pain and other symptoms in several organ systems, and several reports of minimal traumas to the head, trunk, and extremities. Mortality was higher in patients with NES than in controls (HR: 3.21; 95% CI: 1.92-5.34; P < 0.001).

CONCLUSION

Morbidity is more frequent in several domains, including neurological, psychiatric, and other diseases, before and after a diagnosis of NES. Mortality is significantly higher in patients with PNES as compared to controls.

Research on dissociative seizures: A bibliometric analysis and visualization of the scientific landscape

Dissociative seizures are a common and often elusive differential diagnosis in epilepsy centers. Considering their high prevalence, long diagnostic delays, and disappointing rates of treatment response, scientific research dedicated to dissociative seizures is surprisingly scarce. In order to chart the scientific landscape of dissociative seizures and to visualize thematic clusters and trends in research, a comprehensive bibliometric analysis was performed. The Web of Science database was examined to identify relevant English language documents from the last half-century. A total of 1751 documents with titles referring to dissociative seizures were identified. Automated textual analysis of all titles and abstracts revealed that research clusters around three major topics: differential diagnosis in epilepsy centers, management and treatment, and psychopathology. Time analysis of term networks revealed that the focus of clinical research has moved from diagnostic procedures to treatment approaches. Furthermore, interest within etiological research is shifting from an emphasis on early life trauma and personality traits to the role of anxiety and emotion regulation. With respect to individual contributing authors, a relatively small network of prolific scientists with a remarkable degree of collaboration emerges. By mapping relevant publications, it becomes evident that dissociative seizures still represent a subject mostly within the realm of neurology and epileptology, with a tendency to settle in the latter domain. This analysis sheds light on an important niche subject and highlights trends in research focus and output.

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

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

A simple clinical score for prediction of nonepileptic seizures

Psychogenic nonepileptic seizures (PNES), often mistaken for epilepsy in community practice, require inpatient video-EEG (VEEG) monitoring for diagnostic confirmation. We developed a simple score designed for use in an outpatient setting to predict the subsequent VEEG diagnosis of PNES. We retrospectively compared fifty-five consecutive patients with VEEG-proven PNES (N₁=55) with a group of randomly selected patients with VEEG-proven epilepsy (N₂=55). Patients were divided into two groups: I) a 'truly retrospective' group of 27 patients with PNES and 27 patients with epilepsy whose data served to develop the score, and II) a 'pseudoprospective' group of 28 patients each with PNES and epilepsy to whom the score was applied. Six features in the history of the Group I cohort appeared more prominent in patients with PNES than patients with epilepsy and were assigned escalating numerical values as follows: number of declared drug allergies (0, 0.5, 1), number of declared comorbidities (0, 0.5, 1), number of previous invasive medical interventions of any type (0, 0.5, 1), and a history of significant psychological or physical trauma (0 or 1). In addition, a score was assigned to verbal description of the seizures themselves as being consistent (=0), atypical (=1), or indeterminate (=0.5) for epilepsy. The values were added to yield an omnibus score ranging from 0 to 6. Scoring of Group II subjects in a blinded fashion revealed that in general patients with PNES had higher scores, and the majority obtained a score >2; most patients with epilepsy scored <1.5. Group difference in the mean between the PNES and epilepsy cohort was highly significant (p<0.0001, Wilcoxon rank-sum test). Our score is a simple clinical instrument based on the patient history that may find use in the triage of patients awaiting hospitalization for VEEG and in pre-VEEG counseling.

Patients' and caregivers' contributions for differentiating epileptic from psychogenic nonepileptic seizures. Value and limitations of self-reporting questionnaires: A pilot study

PURPOSE

Questionnaires investigating semiology and comorbidities of psychogenic non-epileptic seizures (PNES) have been used mainly to help physicians expedite referrals to epilepsy centres for confirmation of diagnosis rather than as alternative diagnostic tool when video-EEG monitoring (VEM), the current gold standard, is not available or is inconclusive.

METHODS

We developed one structured questionnaire for patients, exploring subjective experiences and vulnerabilities and one for eyewitnesses, focused on features observable during typical events to study prospectively 50 consecutive adult patients with PNES or epileptic seizures (ES) admitted for VEM. A list of variables representing specific signs, symptoms and risk factors was obtained from each question. Specificity (SP) and sensitivity (SE) of each variable were calculated analyzing patient's and witness' responses against the final diagnosis. Statistical significance was assessed using the Fisher's exact test.

RESULTS

Twenty-eight patients' questionnaires (17 PNES, 11 ES) were eligible for analysis. Seven variables with high SE and SP, of which 5 statistically significant, emerged as diagnostic predictors. They comprised three historical items: head injury, physical abuse and chronic fatigue; two warning signs: heart racing and tingling or numbness; one triggering sign: headache; one postictal symptom: physical pain. Sixteen witness questionnaires (6 PNES, 10 ES) were available. Side-to-side head movements and eyes closed were the statistically significant variables.

CONCLUSION

Pending further refinements, ad hoc questionnaires specifically designed for patients and eyewitnesses, may represent a practical tool for distinguishing ES from PNES in settings without sophisticated facilities or when VEM is inconclusive.