Evaluation of dissociative experiences and the clinical utility of the Dissociative Experience Scale in patients with coexisting epilepsy and psychogenic nonepileptic seizures

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

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

Epilepsy in patients with schizophrenia: Pathophysiology and basic treatments

Schizophrenia is a chronic psychiatric disorder that may lead to epilepsy. However, there are limited findings on the issues. This narrative review aimed to provide a practical perspective on epilepsy in patients with schizophrenia using the current treatment systems for epilepsy. While there has been a debate on the relationship between epilepsy and schizophrenia, i.e., antagonism, affinity, and coincidence, recent large cohort studies have revealed a high frequency of epilepsy in patients with schizophrenia (4-5 times higher than that of general population). The high incidence observed is likely to be due to the bidirectionality between epilepsy and schizophrenia and additional schizophrenia-related conditions, e.g., antipsychotic drugs (APD), substance abuse, and head injury. As for symptomatology of epilepsy, only one small-size study showed that seizures of patients with schizophrenia are equivalent to those of patients without schizophrenia. Patients with schizophrenia exhibit the first seizure in their twenties or later, which are mostly focal seizures. Most of seizures in patients with schizophrenia can be controlled with conventional antiepileptic drugs. Few patients with schizophrenia develop treatment-resistant epilepsy. However, since drug interactions can be more complicated due to multiple conditions, such as pre-existing polypharmacy, heavy smoking, irregular eating, and comorbid metabolic disorders, cautious monitoring for clinical symptoms is required. To improve seizure control and adherence, non-pharmacological approaches are also recommended. Thus far, for seizure treatments in patients with schizophrenia, we have to use many empirical findings or substitute certain findings from population without schizophrenia because evidence is insufficient. The accumulation of clinical findings may contribute to the development of efficient treatment systems.

Validating Dissociative Experience Scale (DES) in a Greek sample

This study aimed to validate the Greek version of the Dissociative Experience Scale (DES). A sample of 340 psychiatric outpatients and controls was selected. Part of the sample went through a retest procedure after a two-week period. Due to the absence of equivalent tests, the Multiscale Dissociation Inventory (MDI), the Structured Clinical Interview for DSM-IV-Dissociative Disorders Revised (SCID-D-R), and the Zung Self-Rating Anxiety Scale were used. Explanatory factor analysis was performed, resulting in a 28-item scale; the analysis revealed four factors, explaining 61% of total variation: Depersonalization, Amnesia, Absorption, and Miscellaneous. Cronbach's alpha coefficient for the DES was 0.95. Intraclass correlation coefficient (ICC) of the total score between the first and second interview was 0.84. Concurrent and convergent validity, as assessed by correlations with clinical assessment used as a "gold standard," (0.77), MDI (0.96), and Zung scale (0.75) were satisfactory to excellent. The total score on the DES was significantly higher in the clinical sample than in the controls (17.8 ± 16.2 vs. 5.8 ± 7.2, p < .001), indicating high discriminant validity. After the ROC analysis was run, the best compromise between sensitivity/specificity was achieved at the value of 20. The Greek version of the DES is a reliable and valid tool suitable to assess dissociation in clinical and healthy populations.

Psychogenic non-epileptic seizures in children - psychophysiology & dissociative characteristics

The purpose of this study was to determine psychophysiology and dissociative characteristics of psychogenic non-epileptic seizures (PNES) in a clinical pediatric setting. A retrospective chart review was conducted over a 5-year period that included children meeting criteria for probable, clinically established or documented PNES. Of these, 33 patients (81%) underwent psychophysiology assessment as part of standardized care and were selected for study inclusion. Ages ranged from 10 to 17 years inclusive (70% female). The majority of patients were found to have some form of autonomic decompensation at baseline (82%) and lack of autonomic recovery from a cognitive stressor (58%). Inhibition of electrodermal skin response to laboratory stressor was associated with significantly longer duration of PNES illness (t=2.65, p=.013), while elevated heart rate (above 90^th percentile) was associated with significantly higher frequency of PNES events in the month preceding diagnosis (t=3.1, p=.004). High levels of dissociation and hyperventilation symptoms were self-reported by adolescent patients (n=19) with a moderate degree of positive association (r=0.35, p=.038). The majority of patients (n= 25, 89%) were taught to correct respiratory CO₂ levels during a single biofeedback training session. Conclusions: Child PNES populations appear to be characterized by chronic autonomic hyperarousal reflecting severity of their symptoms, which can feasibly be targeted for behavioral treatment.

White matter and neurite morphology differ in psychogenic nonepileptic seizures

OBJECTIVE

To further evaluate the relationship between the clinical profiles and limbic and motor brain regions and their connecting pathways in psychogenic nonepileptic seizures (PNES). Neurite Orientation Dispersion and Density Indices (NODDI) multicompartment modeling was used to test the relationships between tissue alterations in patients with traumatic brain injury (TBI) and multiple psychiatric symptoms.

METHODS

The sample included participants with prior TBI (TBI; N = 37) but no PNES, and with TBI and PNES (TBI + PNES; N = 34). Participants completed 3T Siemens Prisma MRI high angular resolution imaging diffusion protocol. Statistical maps, including fractional anisotropy (FA), mean diffusivity (MD), neurite dispersion [orientation dispersion index (ODI)] and density [intracellular volume fraction (ICVF), and free water (i.e., isotropic) volume fraction (V-ISO)] signal intensity, were generated for each participant. Linear mixed-effects models identified clusters of between-group differences in indices of white matter changes. Pearson's r correlation tests assessed any relationship between signal intensity and psychiatric symptoms.

RESULTS

Compared to TBI, TBI + PNES revealed decreases in FA, ICVF, and V-ISO and increases in MD for clusters within cingulum bundle, uncinate fasciculus, fornix/stria terminalis, and corticospinal tract pathways (cluster threshold α = 0.05). Indices of white matter changes for these clusters correlated with depressive, anxiety, PTSD, psychoticism, and somatization symptom severity (FDR threshold α = 0.05). A follow-up within-group analysis revealed that these correlations failed to reach the criteria for significance in the TBI + PNES group alone.

INTERPRETATION

The results expand support for the hypothesis that alterations in pathways comprising the specific PNES network correspond to patient profiles. These findings implicate myelin-specific changes as possible contributors to PNES, thus introducing novel potential treatment targets.

Psychological trauma, somatization, dissociation, and psychiatric comorbidities in patients with psychogenic nonepileptic seizures compared with those in patients with intractable partial epilepsy

OBJECTIVE

The objective of this study was to compare patients with intractable epilepsy with patients with psychogenic nonepileptic seizures (PNES) on the presence of psychological traumas, clinical factors, and psychological measures of somatization and dissociation.

BACKGROUND

Several studies have reported a high prevalence of psychological trauma in patients with PNES, while less have examined the prevalence of psychological trauma in patients with epilepsy and compared both groups. Reports have been somewhat divergent with some describing significantly higher prevalence in physical abuse, others, in emotional abuse/neglect, and others, in sexual abuse in patients with PNES compared with those in patients with epilepsy.

METHODS

This is a retrospective study of 96 patients (61 women, 35 men) with intractable epilepsy (2009 to 2017) and 161 patients (107 women, 54 men) with PNES (2008 to 2018). Demographic and clinical (psychological trauma, depression, anxiety, seizure frequency, and number of antiepileptic drugs) data were collected. The Trauma Symptom Inventory II and the Minnesota Multiphasic Personality Inventory 2RF were administered.

RESULTS

Patients with PNES differed significantly from those with intractable epilepsy on sexual trauma (χ² (5df, N = 257) =9.787, p < .002) and "other" trauma (χ² (5df, N = 257) = 17.9076, p < .000). On psychological measures, there was a significant difference on Somatization scores in patients with PNES (M = 59.63, SD = 11.47) and patients with intractable epilepsy (M = 53.98, SD = 11.31); t(173) = 2.8396, p = .0051, but no difference was noted on a measure of Dissociation. Subsequent principal components analysis revealed that the first 3 principal components (sexual, physical, and other trauma) explained 74.19% of the variability, and that one principal component (dissociation, somatization, demoralization) explained 61.57% of the variability. However, after adjusting for the effects of covariates, only the presence of trauma discriminated between epilepsy and PNES.

CONCLUSIONS

Patients with PNES diagnoses differed from those with epilepsy on a Somatization scale but not on Dissociation or Intrusive Experiences and exhibited significantly higher rates of sexual and "other" trauma compared with those with intractable epilepsy. However, subsequent analyses revealed that a history of psychological trauma was the only condition found to discriminate between patients with PNES and those with epilepsy. These findings suggest that during initial workup and diagnosis, when patients report a history of psychological trauma (sexual or otherwise) a psychogenic nonepileptic etiology should be strongly considered in the differential diagnosis.

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.

Psychotic-Like Symptoms and the Temporal Lobe in Trauma-Related Disorders: Diagnosis, Treatment, and Assessment of Potential Malingering

Objective

To overview the phenomenology, etiology, assessment, and treatment of psychotic-like symptoms in trauma-related disorders focusing on the proposed role of temporal lobe dysfunction.

Method

We describe the literature pertaining to (i) psychotic-like symptoms and temporal lobe dysfunction in trauma-related disorders and (ii) psychological testing profiles in trauma-related disorders. We define trauma-related disorders as borderline personality disorder, post-traumatic stress disorder, and the dissociative disorders. Our search terms were dissociative disorders, temporal lobe, trauma, post-traumatic stress disorder, borderline personality disorder, psychosis, and malingering.

Results

Trauma-related psychotic-like symptoms are common and can differ in phenomenology from primary psychotic symptoms. Hallucinations consist of auditory and nonauditory content that may or may not relate to traumatic content. Child voices are highly suggestive of complex dissociative disorders. Critically, not only do these symptoms resemble those seen in temporal lobe epilepsy, but the temporal lobe is implicated in trauma-related disorders, thus providing a plausible neurobiological explanation. Despite such evidence, these symptoms are frequently considered atypical and misdiagnosed. Indeed, common structured psychological assessment tools categorize these symptoms as possible indicators of invalid testing profiles.

Conclusion

Psychotic-like symptoms are common in trauma-related disorders, may be related to temporal lobe dysfunction, and are frequently misinterpreted. This may lead to ineffective treatment and inappropriate determinations of malingering in the forensic system.

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.

Dissociative experiences in patients with epilepsy

A few studies have explored dissociative experiences in epilepsy patients. We investigated dissociative experiences in patients with epilepsy using the dissociative experiences scale (DES). Ninety-eight patients with epilepsy and sixty healthy controls were enrolled in this study. A sociodemographic questionnaire and the Dissociative Experiences Scale (DES), Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) were administered to the participants. The DES scores were significantly higher for the patients with epilepsy than the healthy individuals. The number of individuals with pathological dissociation (DES ≥ 30) was higher in the epilepsy group (n = 28) than in the control group (n = 8). Also, higher levels of dissociation were significantly associated with frequency of seizures, but were not associated with duration of epilepsy and age at onset of the disorder. These findings demonstrate that patients with epilepsy are more prone to dissociation than controls. The high rate of dissociative experiences among patients with epilepsy suggest that some epilepsy-related factors are present.

Weakened functional connectivity in patients with psychogenic non-epileptic seizures (PNES) converges on basal ganglia

BACKGROUND

Psychogenic non-epileptic seizures (PNES) are involuntary paroxysmal events that are unaccompanied by epileptiform EEG discharges. We hypothesised that PNES are a disorder of distributed brain networks resulting from their functional disconnection.The disconnection may underlie a dissociation mechanism that weakens the influence of unconsciously presented traumatising information but exerts maladaptive effects leading to episodic failures of behavioural control manifested by psychogenic 'seizures'.

METHODS

To test this hypothesis, we compared functional connectivity (FC) derived from resting state high-density EEGs of 18 patients with PNES and 18 age-matched and gender-matched controls. To this end, the EEGs were transformed into source space using the local autoregressive average inverse solution. FC was estimated with a multivariate measure of lagged synchronisation in the θ, α and β frequency bands for 66 brain sites clustered into 18 regions. A multiple comparison permutation test was applied to deduce significant between-group differences in inter-regional and intraregional FC.

RESULTS

The significant effect of PNES-a decrease in lagged FC between the basal ganglia and limbic, prefrontal, temporal, parietal and occipital regions-was found in the α band.

CONCLUSION

We believe that this finding reveals a possible neurobiological substrate of PNES, which explains both attenuation of the effect of potentially disturbing mental representations and the occurrence of PNES episodes. By improving understanding of the aetiology of this condition, our results suggest a potential refinement of diagnostic criteria and management principles.

Nonepileptic seizures - subjective phenomena

Psychogenic nonepileptic seizures (PNES) superficially resemble epileptic seizures or syncope and most patients with PNES are initially misdiagnosed as having one of the latter two types of transient loss of consciousness. However, evidence suggests that the subjective seizure experience of PNES and its main differential diagnoses are as different as the causes of these three disorders. In spite of this, and regardless of the fact that PNES are considered a mental disorder in the current nosologies, research has only given limited attention to the subjective symptomatology of PNES. Instead, most phenomenologic research has focused on the visible manifestations of PNES and on physiologic parameters, neglecting patients' symptoms and experiences. This chapter gives an overview of qualitative and quantitative studies providing insights into subjective symptoms associated with PNES, drawing on a wide range of methodologies (questionnaires, self-reports, physiologic measures, linguistic analyses, and neuropsychologic experiments). After discussing the scope and limitations of these approaches in the context of this dissociative phenomenon, we discuss ictal, peri-ictal and interictal symptoms described by patients with PNES. We particularly focus on impairment of consciousness. PNES emerges as a clinically heterogeneous condition. We conclude with a discussion of the clinical significance of particular subjective symptoms for the engagement of patients in treatment, the formulation of treatment, and prognosis.

Dissociation and functional neurologic disorders

Dissociation has been cited as a possible psychologic mechanism underpinning functional neurologic disorders (FND) since the 19th century. Since that time, changes in psychiatric classification have created confusion about what the term dissociation actually means. The available evidence suggests that it now refers to at least two qualitatively distinct types of phenomena: detachment (an altered state of consciousness characterized by a sense of separation from the self or world) and compartmentalization (a reversible loss of voluntary control over apparently intact processes and functions), as well as their underlying mechanisms. This chapter considers some of the problems with conflating these phenomena under a single heading as well as the relationship between detachment, compartmentalization, and FND. It is argued that FNDs are fundamentally compartmentalization disorders, but that detachment is often part of the clinical picture and may contribute to the development and maintenance of functional symptoms in many cases. By this view, understanding compartmentalization requires an appreciation of the mechanisms involved in controlling and accessing mental processes and contents. Two possible mechanisms in this regard are described and the evidence for these is considered, followed by a discussion of clinical and empiric implications.

Dissociative experiences in epilepsy: effects of epilepsy-related factors on pathological dissociation

Psychogenic nonepileptic seizures (PNESs) in patients with epilepsy can be categorized as dissociative disorders. The prevalence of PNESs in patients with epilepsy appears to be much higher than that of dissociative experiences in nonclinical subjects. In order to clarify as to whether epilepsy-related factors were associated with pathological dissociation, we conducted a controlled study with 225 patients with epilepsy and 334 nonclinically matched individuals. All participants completed the Japanese version of the Dissociative Experiences Scale (DES). There was no significant difference in the DES score (DES-S) between the group with epilepsy and the control group. The group with epilepsy showed a significantly higher DES taxon (DES-T; a subset of DES-S and an index of pathological dissociation) than the control group. Thirty-one out of the 225 patients with epilepsy (13.8%) had PNESs. Because of its strong association with the DES-S and DES-T, PNESs can be regarded as a symptom of dissociation. With multiple regression analysis, the patients with a shorter duration of epilepsy, higher seizure frequency, or shorter period in education tend to suffer from pathological dissociation. These findings demonstrate that patients with epilepsy are more prone to experiencing pathological dissociation when having certain clinical factors.

Dissociative experiences in epilepsy--a neuropathological and sociodemographic study in a Chinese population

BACKGROUND

It is well known that dissociative experiences coexist with various epilepsy syndromes. However, the prevalence of dissociative experiences in different subtypes of epilepsy remains unknown. This is especially important because of the current prevalent view that the etiology of dissociation in seizures is neurobiological rather than psychosocial. The amygdala especially has been implicated in such dissociative features of epilepsy. This would indirectly imply that the patients with CPS have higher prevalence of dissociative symptoms compared with those with GTCS.

METHODOLOGY

We studied and compared the dissociative experiences as well as the depression and anxiety levels between 24 patients suffering from temporal lobe epilepsy and 26 patients suffering from generalized tonic-clonic seizures. We used the Dissociative Experiences Scale to evaluate the dissociative experiences. A third group of healthy individuals was included as the control group. The statistical significance was fixed at 0.05.

RESULTS

There were significant differences between the scores of DES-II of the healthy individuals and those of patients with epilepsy. However, there were no significant differences between the DES scores of different patients with epilepsy categorized according to neuropathology. There were also no significant differences between HAM-A and HAM-D scores between groups with epilepsy, but the scores were higher than those of the healthy individuals. There were significant differences between the DES scores in different sociodemographic groups such that higher scores were observed in groups with lower education (p<0.05). In addition, the scores on DES were higher in individuals with low socioeconomic status than in those with high socioeconomic status.

CONCLUSION

The patients with temporal lobe epilepsy and those with generalized tonic-clonic seizures have similar dissociative experiences which are both more than those found in individuals without epilepsy. However, these dissociative experiences may not be related to the neuropathological parameters as much as they are to the sociodemographic parameters like education, age, socioeconomic status, and sex. This shows that the psychopathology of dissociation in epilepsy is similar to that of the general population.

Resting-state networks and dissociation in psychogenic non-epileptic seizures

OBJECTIVE

Psychogenic non-epileptic seizures (PNES) are epilepsy-like episodes which have an emotional rather than organic origin. Although PNES have often been related to the process of dissociation, the psychopathology is still poorly understood. To elucidate underlying mechanisms, the current study applied independent component analysis (ICA) on resting-state fMRI to investigate alterations within four relevant networks, associated with executive, fronto-parietal, sensorimotor, and default mode activation, and within a visual network to examine specificity of between-group differences.

METHODS

Twenty-one patients with PNES without psychiatric or neurologic comorbidities and twenty-seven healthy controls underwent resting-state functional MR imaging at 3.0T (Philips Achieva). Additional neuropsychological testing included Raven's Matrices test and dissociation questionnaires. ICA with dual regression was used to identify resting-state networks in all participants, and spatial maps of the networks of interest were compared between patients and healthy controls.

RESULTS

Patients displayed higher dissociation scores, lower cognitive performance and increased contribution of the orbitofrontal, insular and subcallosal cortex in the fronto-parietal network; the cingulate and insular cortex in the executive control network; the cingulate gyrus, superior parietal lobe, pre- and postcentral gyri and supplemental motor cortex in the sensorimotor network; and the precuneus and (para-) cingulate gyri in the default-mode network. The connectivity strengths within these regions of interest significantly correlated with dissociation scores. No between-group differences were found within the visual network, which was examined to determine specificity of between-group differences.

CONCLUSIONS

PNES patients displayed abnormalities in several resting-state networks that provide neuronal correlates for an underlying dissociation mechanism.

Subgroup classification in patients with psychogenic non-epileptic seizures

INTRODUCTION

In this open non-controlled clinical cohort study, the applicability of a theoretical model for the diagnosis of psychogenic non-epileptic seizures (PNES) was studied in order to define a general psychological profile and to specify possible subgroups.

METHODS

Forty PNES patients were assessed with a PNES "test battery" consisting of eleven psychological instruments, e.g., a trauma checklist, the global cognitive level, mental flexibility, speed of information processing, personality factors, dissociation, daily hassles and stress and coping factors.

RESULTS

The total PNES group was characterized by multiple trauma, personality vulnerability (in a lesser extent, neuropsychological vulnerabilities), no increased dissociation, many complaints about daily hassles that may trigger seizures and negative coping strategies that may contribute to prolongation of the seizures. Using factor analysis, specific subgroups were revealed: a 'psychotrauma subgroup', a 'high vulnerability somatizing subgroup' (with high and low cognitive levels) and a 'high vulnerability sensitive personality problem subgroup'.

CONCLUSION

Using a theoretical model in PNES diagnosis, PNES seem to be a symptom of distinct underlying etiological factors with different accents in the model. Hence, describing a general profile seems to conceal specific subgroups with subsequent treatment implications. This study identified three factors, representing two dimensions of the model, that are essential for subgroup classification: psychological etiology (psychotrauma or not), vulnerability, e.g., the somatization tendency, and sensitive personality problems/characteristics ('novelty seeking'). For treatment, this means that interventions could be tailored to the main underlying etiological problem. Also, further research could focus on differentiating subgroups with subsequent treatment indications and possible different prognoses.

Psychogenic nonepileptic seizures and chronic pain: a retrospective case-controlled study

PURPOSE

Psychogenic nonepileptic seizures (PNES) can be challenging to diagnose, but certain clinical features can help to distinguish PNES from epileptic seizures. The purpose of this study is to assess chronic pain and prescribed pain medication use in PNES patients.

METHODS

A case-controlled, retrospective analysis was performed examining pain medication use in 85 PNES patients versus an active control group of 85 patients with idiopathic generalized epilepsy (IGE).

RESULTS

Chronic pain was more frequent among PNES patients (N=40) than active controls (N=10) (p<0.0001). Reported use of prescription pain medication was higher among PNES patients (N=20) versus active controls (N=6) (p=0.0048). The Positive Predictive Value of prescription pain medications for PNES patients was 76.9%. Opioid use in the PNES population was higher compared with active controls (p=0.0096). When excluding patients with a dual diagnosis of PNES and epilepsy from the latter two analyses and comparing these results to those that included this patient population, no statistically significant difference in results was found.

CONCLUSIONS

Patients with PNES are more likely than those with IGE to report chronic pain disorders. A history of chronic pain and opioid use among patients with seizures raises the possibility of PNES. Among patients with PNES and chronic pain, a psychogenic etiology for pain and non-opiate pain management strategies should be considered.

Epilepsy, mental health disorder, or both?

Temporal lobe epilepsy (TLE), a subset of the seizure disorder family, represents a complex neuropsychiatric illness, where the neurological presentation may be complemented by varying severity of affective, behavioral, psychotic, or personality abnormalities, which, in turn, may not only lead to misdiagnosis, but also affect the management. This paper outlines a spectrum of mental health presentations, including psychosis, mood, anxiety, panic, and dissociative states, associated with epilepsy that make the correct diagnosis a challenge.