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

One-year follow-up of neurobehavioral therapy in functional seizures or epilepsy with traumatic brain injury: A nonrandomized controlled trial

OBJECTIVE

Patients with traumatic brain injury (TBI) often present with seizures (functional and/or epileptic), but treatments for patients with TBI and seizures are limited. We examined treatment phase and 1-year post-enrollment outcomes following neurobehavioral therapy (NBT) for patients with TBI + functional seizures (FS) and TBI + epilepsy.

METHODS

In this multicenter, prospective, three-group, nonrandomized, controlled trial, with 1-year post-enrollment follow-up, three cohorts of adults were recruited: TBI + video-electroencephalography (EEG)-confirmed FS (n = 89), TBI + EEG-confirmed epilepsy (n = 29), and chart/history-confirmed TBI without seizures (n = 75). Exclusion criteria were recent psychotic or self-injurious behavior, current suicidal ideation, pending litigation or long-term disability, active substance use disorder, and inability to participate in study procedures. TBI + FS and TBI + epilepsy groups completed NBT for seizures, an evidence-based, 12-session, multimodal psychotherapy, whereas TBI without seizures participants received standard medical care. The primary outcome was change in seizure frequency; secondary outcomes were changes in mental health, TBI-related symptoms, disability, and quality of life.

RESULTS

Reductions in average monthly seizures occurred during treatment in TBI + FS participants (p = .002) and were significant from baseline (mean = 16.75; 95% confidence interval [CI] = 11.44-24.53) to 12 months post-enrollment (mean = 7.28, 95% CI = 4.37-12.13, p = .002, d = .38). Monthly seizures decreased during treatment in TBI + epilepsy participants (p = .002); reductions were not statistically significant from baseline (mean = 2.38, 95% CI = 1.12-5.04) to 12-month postenrollment (mean = .98, 95% CI = .40-2.42, p = .07, d = .22). Regarding treatment-phase changes in secondary outcome measures, TBI + FS participants improved significantly on 10 of 19 variables (52.6%), TBI + epilepsy participants improved on five of 19 (26.3%), and TBI-only comparisons improved on only one of 19 (5.3%).

SIGNIFICANCE

NBT benefited patients with TBI + FS and TBI + epilepsy. Improvements were demonstrated at 1 year post-enrollment in those with TBI + FS. NBT may be a clinically useful treatment for patients with seizures.

Pain and functional neurological disorder: a systematic review and meta-analysis

BACKGROUND

Functional neurological disorder (FND) is characterised by neurological symptoms, such as seizures and abnormal movements. Despite its significance to patients, the clinical features of chronic pain in people with FND, and of FND in people with chronic pain, have not been comprehensively studied.

METHODS

We systematically reviewed PubMed, Embase and PsycINFO for studies of chronic pain in adults with FND and FND in patients with chronic pain. We described the proportions of patients reporting pain, pain rating and timing, pain-related diagnoses and responsiveness to treatment. We performed random effects meta-analyses of the proportions of patients with FND who reported pain or were diagnosed with pain-related disorders.

RESULTS

Seven hundred and fifteen articles were screened and 64 were included in the analysis. Eight case-control studies of 3476 patients described pain symptoms in a higher proportion of patients with FND than controls with other neurological disorders. A random effects model of 30 cohorts found that an estimated 55% (95% CI 46% to 64%) of 4272 patients with FND reported pain. Random effects models estimated diagnoses of complex regional pain syndrome in 22% (95% CI 6% to 39%) of patients, irritable bowel syndrome in 16% (95% CI 9% to 24%) and fibromyalgia in 10% (95% CI 8% to 13%). Five studies of FND diagnoses among 361 patients with chronic pain were identified. Most interventions for FND did not ameliorate pain, even when other symptoms improved.

CONCLUSIONS

Pain symptoms and pain-related diagnoses are common in FND. Classification systems and treatments should routinely consider pain as a comorbidity in patients with FND.

Medical and psychiatric comorbidities, somatic and cognitive symptoms, injuries and medical procedure history in patients with functional seizures from a public and a private hospital

PURPOSE

Patients with functional seizures (FS), otherwise known as psychogenic non-epileptic seizures (PNES), from different socioeconomic backgrounds may differ, however, this remains a gap in current literature. Comorbidities can play both a precipitating and a perpetuating role in FS and are important in the planning of individual treatment for this condition. With this study, we aimed to describe and compare the reported medical and psychiatric comorbidities, injuries, somatic and cognitive symptoms, and medical procedures among patients with FS from a private and a public epilepsy monitoring unit (EMU) in Cape Town, South Africa.

METHODS

This is a retrospective case-control study. We collected data on the comorbidity and medical procedure histories, as well as symptoms and clinical signs reported by patients with video-electroencephalographically (video-EEG) confirmed FS without comorbid epilepsy. We used digital patient records starting with the earliest available digital record for each hospital until the year 2022.

RESULTS

A total of 305 patients from a private hospital and 67 patients from a public hospital were included in the study (N = 372). Public hospital patients had higher odds of reporting intellectual disability (aOR=15.58, 95% CI [1.80, 134.95]), circulatory system disease (aOR=2.63, 95% CI [1.02, 6.78]) and gait disturbance (aOR=8.52, 95% CI [1.96, 37.08]) compared to patients with FS attending the private hospital. They did, however, have fewer odds of reporting a history of an infectious or parasitic disease (aOR=0.31, 95% CI [0.11, 0.87]), respiratory system disease (aOR=0.23, 95% CI [0.06, 0.82]), or medical procedures in the past (aOR=0.32, 95% CI [0.16, 0.63]).

CONCLUSION

The study presents prevalence and comparative data on the medical profiles of patients with FS from different socioeconomic backgrounds which may inform future considerations in FS diagnosis and treatment.

The role of neuropsychology in the care of patients with functional neurological symptom disorder

OBJECTIVE

Functional neurological symptom disorder (FNSD) is a neuropsychiatric condition characterized by signs/symptoms associated with brain network dysfunction. FNSDs are common and are associated with high healthcare costs. FNSDs are relevant to neuropsychologists, as they frequently present with chronic neuropsychiatric symptoms, subjective cognitive concerns, and/or low neuropsychological test scores, with associated disability and reduced quality of life. However, neuropsychologists in some settings are not involved in care of patients with FNSDs. This review summarizes relevant FNSD literature with a focus on the role of neuropsychologists.

METHODS

A brief review of the literature is provided with respect to epidemiology, public health impact, symptomatology, pathophysiology, and treatment.

RESULTS

Two primary areas of focus for this review are the following: (1) increasing neuropsychologists' training in FNSDs, and (2) increasing neuropsychologists' role in assessment and treatment of FNSD patients.

CONCLUSIONS

Patients with FNSD would benefit from increased involvement of neuropsychologists in their care.

Elevated Mortality Rate in Patients With Functional Seizures After Diagnosis and Referral

Background and Objectives

To evaluate the standardized mortality ratio (SMR) of patients in the United States referred to a multidisciplinary clinic for treatment of functional seizures.

Methods

We identified patients who had or had not died based on automated retrospective review of electronic health records from a registry of patients referred to a single-center multidisciplinary functional seizures treatment clinic. We calculated an SMR by comparing the number of observed deaths with the expected number of deaths in an age-matched, sex-matched, and race-matched population within the same state, and year records were available.

Results

A total of 700 patients with functional seizures (mean age 37 years, 78% female) were followed up for 1,329 patient-years for a median of 15 months per patient (interquartile range 6-37 months). We observed 11 deaths, corresponding to a mortality rate of 8.2 per 1,000 patient-years and an SMR of 2.4 (95% confidence interval: 1.17-4.22). Five of 9 patients with identified circumstances around their death were in hospice care when they passed. None of the identified causes of death were related to seizures directly.

Discussion

These data provide further evidence of elevated mortality in functional seizures soon after diagnosis and referral to treatment. These data from the decentralized health care system of the United States build on the findings from other countries with large-scale health registries.

Hypertension and other vascular risk factors in patients with functional seizures

OBJECTIVE

Recent literature has suggested that functional seizures are associated with an elevated risk for vascular disease and mortality. We investigated the prevalence of risk factors for vascular disease in patients who were admitted to the epilepsy monitoring unit.

METHODS

Patients who were admitted to the epilepsy monitoring unit and received a definitive diagnosis of either functional seizures or epilepsy were identified. Data collected included demographic, clinical characteristics, medication list, comorbidities, and scheduled blood pressure measurements that occurred every 12 h during the admission. The mean blood pressures were calculated and if they were above the American College of Cardiology and the American Heart Association guideline cutoff of 130/80 mm Hg or the patient had a documented history of hypertension the patient was counted as having the condition. A multiple logistic regression model was developed to evaluate the independent association of the patient's diagnosis (i.e., epilepsy or functional seizures) and vascular risk factors that controlled for the number of blood pressure measurements, age, sex, and if the patient was taking antihypertensive medications.

RESULTS

270 patients were included in this study of which 147 patients had epilepsy and 123 had functional seizures. Among those with functional seizures, 57.72 % had either a history of hypertension or a mean blood pressure above 130/80 compared to 38.78 % of those with epilepsy (p = 0.0022). In addition, 30.89 % of functional seizures patients had hyperlipidemia and 63.41 % were obese. The logistic regression model indicated that functional seizures were independently associated with high blood pressure (OR: 2.47, 95 % CI 1.10-5.69), hyperlipidemia (OR: 3.38, 95 % CI 1.35-8.86), and obesity (OR: 4.25, 95 % CI 2.22-8.36) compared to those with epilepsy. There was no significant difference in the prevalence of diabetes (OR: 0.81, 95 % CI 0.24-2.77) or current tobacco use (OR: 1.04, 95 % CI 0.48-2.25) between the groups.

SIGNIFICANCE

Patients with functional seizures had an elevated prevalence of several vascular risk factors. These findings may partially account for complications associated with functional seizures and have implications related to their pathophysiology.

'I just need to know what they are and if you can help me': Medicalization and the search for legitimacy in people diagnosed with non-epileptic attack disorder

This paper focuses on the struggles for legitimacy expressed by people with non-epileptic attack disorder (NEAD), one of the most common manifestations of functional neurological disorder presenting to emergency and secondary care services. Nonepileptic attacks are episodes of altered experience, awareness, and reduced self-control that superficially resemble epileptic seizures or other paroxysmal disorders but are not associated with physiological abnormalities sufficient to explain the semiological features. "Organic" or medicalized explanations are frequently sought by patients as the only legitimate explanation for symptoms, and consequently, a diagnosis of NEAD is often contested. Drawing on narrative interviews with patients from a small exploratory study and using a sociological perspective, we propose that a psychological account of NEAD does not provide a sufficiently legitimate path into a socially sanctioned sick role. This is a reflection of the dominance of biomedicine and the associated processes of medicalization. These processes are, we argue, the sole route to achieving legitimacy. The stress-based or psychologically oriented explanations offered to patients in contemporary medical models of the etiology of NEAD engender an uncertain identity and social position and fail to provide many patients with an account of the nature or origin of their symptoms that they find satisfactory or convincing. These struggles for legitimacy (shared by others with functional or somatoform conditions) are sharpened by key features of the contemporary healthcare landscape, such as the increasing framing of health through a lens of 'responsibilization'.

Changes in the heartbeat-evoked potential are associated with functional seizures

BACKGROUND

Patients with functional seizures (FS) can experience dissociation (depersonalisation) before their seizures. Depersonalisation reflects disembodiment, which may be related to changes in interoceptive processing. The heartbeat-evoked potential (HEP) is an electroencephalogram (EEG) marker of interoceptive processing.

AIM

To assess whether alterations in interoceptive processing indexed by HEP occur prior to FS and compare this with epileptic seizures (ES).

METHODS

HEP amplitudes were calculated from EEG during video-EEG monitoring in 25 patients with FS and 19 patients with ES, and were compared between interictal and preictal states. HEP amplitude difference was calculated as preictal HEP amplitude minus interictal HEP amplitude. A receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance of HEP amplitude difference in discriminating FS from ES.

RESULTS

The FS group demonstrated a significant reduction in HEP amplitude between interictal and preictal states at F8 (effect size rB=0.612, false discovery rate (FDR)-corrected q=0.030) and C4 (rB=0.600, FDR-corrected q=0.035). No differences in HEP amplitude were found between states in the ES group. Between diagnostic groups, HEP amplitude difference differed between the FS and ES groups at F8 (rB=0.423, FDR-corrected q=0.085) and C4 (rB=0.457, FDR-corrected q=0.085). Using HEP amplitude difference at frontal and central electrodes plus sex, we found that the ROC curve demonstrated an area under the curve of 0.893, with sensitivity=0.840 and specificity=0.842.

CONCLUSION

Our data support the notion that aberrant interoception occurs prior to FS. Changes in HEP amplitude may reflect a neurophysiological biomarker of FS and may have diagnostic utility in differentiating FS and ES.

Psychogenic Nonepileptic Seizures-High Mortality Rate Is a 'Wake-Up Call'

Patients with epilepsy have an elevated mortality rate compared to the general population and now studies are showing a comparable death ratio in patients diagnosed with psychogenic nonepileptic seizures. The latter is a top differential diagnosis for epilepsy and the unexpected mortality rate in these patients underscores the importance of an accurate diagnosis. Experts have called for more studies to elucidate this finding but the explanation is already available, embedded in the existing data. To illustrate, a review of the diagnostic practice in epilepsy monitoring units, of the studies examining mortality in PNES and epilepsy patients, and of the general clinical literature on the two populations was conducted. The analysis reveals that the scalp EEG test result, which distinguishes a psychogenic from an epileptic seizure, is highly fallible; that the clinical profiles of the PNES and epilepsy patient populations are virtually identical; and that both are dying of natural and non-natural causes including sudden unexpected death associated with confirmed or suspected seizure activity. The recent data showing a similar mortality rate simply constitutes more confirmatory evidence that the PNES population consists largely of patients with drug-resistant scalp EEG-negative epileptic seizures. To reduce the morbidity and mortality in these patients, they must be given access to treatments for epilepsy.

A systems biology approach for discovering the cellular and molecular aspects of psychogenic non-epileptic seizure

Objectives

Psychogenic non-epileptic seizure (PNES) is the most common non-epileptic disorder in patients referring to epilepsy centers. Contrary to common beliefs about the disease's harmlessness, the death rate of PNES patients is similar to drug-resistant epilepsy. Meanwhile, the molecular pathomechanism of PNES is unknown with very limited related research. Thus, the aim of this in silico study was to find different proteins and hormones associated with PNES via a systems biology approach.

Methods

Different bioinformatics databases and literature review were used to find proteins associated with PNES. The protein-hormone interaction network of PNES was constructed to discover its most influential compartments. The pathways associated with PNES pathomechanism were found by enrichment analysis of the identified proteins. Besides, the relationship between PNES-related molecules and psychiatric diseases was discovered, and the brain regions that could express altered levels of blood proteins were discovered.

Results

Eight genes and three hormones were found associated with PNES through the review process. Proopiomelanocortin (POMC), neuropeptide Y (NPY), cortisol, norepinephrine, and brain-derived neurotrophic factor (BDNF) were identified to have a high impact on the disease pathogenesis network. Moreover, activation of Janus kinase-signaling transducer and activator of transcription (JAK-STAT) and JAK, as well as signaling of growth hormone receptor, phosphatidylinositol 3-kinase /protein kinase B (PI3K/AKT), and neurotrophin were found associated with PNES molecular mechanism. Several psychiatric diseases such as depression, schizophrenia, and alcohol-related disorders were shown to be associated with PNES predominantly through signaling molecules.

Significance

This study was the first to gather the biochemicals associated with PNES. Multiple components and pathways and several psychiatric diseases associated with PNES, and some brain regions that could be altered during PNES were suggested, which should be confirmed in further studies. Altogether, these findings could be used in future molecular research on PNES patients.

Influence of comorbidity on mortality in patients with epilepsy and psychogenic nonepileptic seizures

OBJECTIVE

This study aims to determine the contribution of comorbidities to excess psychogenic nonepileptic seizures (PNES) mortality.

METHODS

A retrospective cohort study was conducted of tertiary epilepsy outpatients from St. Vincent's Hospital Melbourne, Australia with an 8:1 comparison cohort, matched by age, sex, and socioeconomic status (SES) to national administrative databases between 2007 and 2017. Privacy-preserving data linkage was undertaken with the national prescription, National Death Index, and National Coronial Information System. Forty-five comorbid disease classes were derived by applying the Australian validated RxRisk-V to all dispensed prescriptions. We fitted Cox proportional hazard models controlling for age, sex, SES, comorbidity, disease duration, and number of concomitant antiseizure medications, as a marker of disease severity. We also performed a parallel forward-selection change in estimate strategy to explore which specific comorbidities contributed to the largest changes in the hazard ratio.

RESULTS

A total of 13 488 participants were followed for a median 3.2 years (interquartile range = 2.4-4.0 years), including 1628 tertiary epilepsy outpatients, 1384 patients with epilepsy, 176 with PNES, and 59 with both. Eighty-two percent of epileptic seizures and 92% of typical PNES events were captured in an epilepsy monitoring unit. The age-/sex-/SES-adjusted hazard ratio was elevated for epilepsy (4.74, 95% confidence interval [CI] = 3.36-6.68) and PNES (3.46, 95% CI = 1.38-8.68) and remained elevated for epilepsy (3.21, 95% CI = 2.22-4.63) but not PNES (2.15, 95% CI = .77-6.04) after comorbidity adjustment. PNES had more pre-existing comorbidities (p = .0007), with a three times greater median weighted Rx-RiskV score. Psychotic illness, opioid analgesia, malignancies, and nonopioid analgesia had the greatest influence on PNES comorbid risk.

SIGNIFICANCE

Higher comorbidity appears to explain the excess PNES mortality and may represent either a wider underrecognized somatoform disorder or a psychological response to physical illness. Better understanding and management of the bidirectional relationship of these wider somatic treatments in PNES could potentially reduce the risk of death.

Nonpharmacologic Interventions and Seizure Frequency in Patients With Psychogenic Nonepileptic Seizures: An Integrative Review

BACKGROUND

Psychogenic nonepileptic seizures (PNES) pose a heavy burden on patients' lives and the health care system. The symptoms of PNES are often debilitating and cause high rates of disability and poor quality of life. Many treatment options are available, but there is no clear consensus on best practices.

AIM

To critique and synthesize the current literature on nonpharmacologic interventions and effects on seizure frequency in patients with PNES.

METHODS

An integrative review guided by the Whittemore and Knafl approach.

RESULTS

The review included 24 studies published from 2010 to 2020. Interventions for PNES included individualized psychotherapies, group therapies, multimodal psychotherapies, self-help therapies, and complementary and alternative medicine therapies. Individual psychotherapies such as cognitive behavioral therapy and psychoeducation were the most used treatment modalities. The most effective treatments for seizure frequency reduction were those that included multiple psychotherapy sessions with a health care provider and covered multiple domains (e.g., understanding of diagnosis, identifying triggers, and developing effective coping strategies).

CONCLUSIONS

Seizure frequency can be reduced in patients with PNES with multiple nonpharmacologic interventions. However, seizure frequency is not considered a comprehensive outcome measure and provides little insight into other important life domains. Further research is needed on nonpharmacologic interventions for PNES and effects on other areas of life such as sleep, employment status, global functioning, and self-efficacy.

Mortality in patients with psychogenic non-epileptic seizures a population-based cohort study

OBJECTIVES

To compare mortality, comorbidities and causes of death in people with psychogenic non-epileptic seizures (PNES), epilepsy and the general population.

METHODS

Using linkage of multiple Swedish national registers, we identified individuals with incident diagnosis of PNES, epilepsy and conversion disorder with motor symptoms or deficits, and 10 controls for each. Main outcome was all-cause mortality. Causes of death were categorised into non-natural (eg, suicide, injuries) and natural. Conditional Cox regression models were used to estimate HRs and 95% CIs for mortality. HRs were adjusted for socioeconomic factors and psychiatric comorbidities.

RESULTS

Included were 885 individuals with PNES, 50 663 with epilepsy and 1057 with conversion disorder and motor symptoms or deficits. We found 32 (3.6%) deaths among individuals with PNES, compared with 46 (0.5%) deaths in controls, giving an adjusted HR of 5.5 (95% CI 2.8 to 10.8). Patients with epilepsy had a 6.7 times higher risk of death (95% CI 6.4 to 7.0) compared with individuals without epilepsy. The association between conversion disorder with motor symptoms or deficits was non-significant after adjusting for psychiatric comorbidities. PNES carried a higher risk of natural (HR 8.1, 95% CI 4.0 to 16.4) and non-natural causes of death (HR 15.3, 95% CI 3.0 to 78.6). Suicide ranked high in patients with PNES (18.8%) and conversion disorder with motor symptoms and deficits. The association between PNES diagnosis and all-cause mortality varied with age and time since diagnosis.

CONCLUSION

Like epilepsy, PNES carries a higher than expected risk of both natural and non-natural causes of death. The high proportion of suicides requires further investigation.

Incidence and prevalence of psychogenic nonepileptic seizures (functional seizures): a systematic review and an analytical study

AIM

Psychogenic nonepileptic seizures (PNES) or functional seizures are universal phenomena. However, data on their epidemiology is limited. The aim of the current study was to review the literature on the epidemiology of PNES and to provide analytical estimates of its incidence and prevalence based on the direct data that are available from previous studies on PNES.

METHODS

The methods of this work had two parts: (1) MEDLINE, PsycINFO, and Scopus from inception to 19 October 2019 were systematically searched. (2) The analytical study of the incidence and prevalence of PNES was performed, based on the following data from previous studies: incidence of PNES, duration of PNES before making a diagnosis, outcome and mortality of PNES.

RESULTS

The search strategy yielded five articles; three were on the incidence and two on the prevalence. In the analytical part of the study, the incidence of PNES was calculated to be 3.1 (95% Confidence Interval: 1.1-5.1) per 100,000 population per year. The calculated prevalence rate of PNES in 2019 was 108.5 (95% Confidence Interval: 39.2-177.8) per 100,000 population, in the USA.

CONCLUSION

While, the generalizability of these calculated incidence and prevalence rates to other places in the world is limited, they give us a reasonable hint that PNES is a common condition and the prevalence is much more than that it was thought before.Supplemental data for this article is available online at https://doi.org/10.1080/00207454.2021.1942870.

Can Treating Patients With PNES Lower the Risk of Sudden Unexpected Death?

Mortality in Patients With Psychogenic Nonepileptic Seizures

Nightscales R, McCartney L, Auvrez C, et al. Neurology. 2020;95(6):e643-e652. doi:10.1212/WNL.0000000000009855

Objective:

To investigate the hypothesis that patients diagnosed with psychogenic nonepileptic seizures (PNES) on video-EEG monitoring (VEM) have increased mortality by comparison to the general population.

Methods:

This retrospective cohort study included patients evaluated in VEM units of 3 tertiary hospitals in Melbourne, Australia, between January 1, 1995, and December 31, 2015. Diagnosis was based on consensus opinion of experienced epileptologists and neuropsychiatrists at each hospital. Mortality was determined in patients diagnosed with PNES, epilepsy, or both conditions by linkage to the Australian National Death Index. Lifetime history of psychiatric disorders in PNES was determined from formal neuropsychiatric reports.

Results:

A total of 5508 patients underwent VEM. A total of 674 (12.2%) were diagnosed with PNES, 3064 (55.6%) with epilepsy, 175 (3.2%) with both conditions, and 1595 (29.0%) received other diagnoses or had no diagnosis made. The standardized mortality ratio (SMR) of patients diagnosed with PNES was 2.5 (95% CI: 2.0-3.3). Those younger than 30 had an 8-fold higher risk of death (95% CI: 3.4-19.8). Direct comparison revealed no significant difference in mortality rate between diagnostic groups. Among deaths in patients diagnosed with PNES (n = 55), external causes contributed 18%, with 20% of deaths in those younger than 50 years attributed to suicide, and “epilepsy” was recorded as the cause of death in 24%.

Conclusions:

Patients diagnosed with PNES have a SMR 2.5 times above the general population, dying at a rate comparable to those with drug-resistant epilepsy. This emphasizes the importance of prompt diagnosis, identification of risk factors, and implementation of appropriate strategies to prevent potential avoidable deaths.

Heart Rate Variability Parameters During Psychogenic Non-epileptic Seizures: Comparison Between Patients With Pure PNES and Comorbid Epilepsy

Introduction: Psychogenic non-epileptic seizures (PNES) may resemble epileptic seizures. There are few data about ictal ANS activity alterations induced by PNES in patients with pure PNES (pPNES) compared to PNES with comorbid epilepsy (PNES/ES). We aimed to compare heart rate variability (HRV) parameters and hence autonomic regulation in PNES in epileptic and non-epileptic patients.

Methods: We obtained HRV data from video-electroencephalography recordings in 22 patients presenting PNES (11 pPNES and 11 PNES/ES) in awake, and supine states. We calculated HRV parameters in both time and frequency domains including low frequency (LF) power, high frequency power (HF), LF/HF ratio, square root of the mean of the sum of the squares of differences between adjacent R wave intervals (RMSSD) and the standard deviation of all consecutive R wave intervals (SDNN). We also evaluated approximate entropy (ApEn), cardiosympathetic index (CSI), and cardiovagal index (CVI). Four conditions were considered: basal condition (BAS), before PNES (PRE), during PNES (ICT) and after PNES (POST).

Results: HRV analysis showed significantly higher ICT LF and LF/HF ratio vs. each condition. We also found higher POST HF vs. PRE and BAS, lower RRI in ICT vs. each condition and PRE vs. BAS. POST RMSSD was significantly higher compared to all other states. ICT CSI was significantly higher compared to all other states, whereas CSI was significantly lower in POST vs. PRE and PRE CVI lower than ICT and higher in POST vs. BAS and PRE. Also, ICT ApEn was lower than in all other states. Higher LF in pPNES vs. PNES/ES was also evident when compared across groups.

Significance: A few studies examined HRV alterations in PNES, reporting high sympathetic tone (although less evident than in epileptic seizures). Our data suggest a sympathetic overdrive before and during PNES followed by a post-PNES increase in vagal tone. A sympathovagal imbalance was more evident in pPNES as compared to PNES/ES.

Mortality in patients with psychogenic nonepileptic seizures

Objective

To investigate the hypothesis that patients diagnosed with psychogenic nonepileptic seizures (PNES) on video-EEG monitoring (VEM) have increased mortality by comparison to the general population.

Methods

This retrospective cohort study included patients evaluated in VEM units of 3 tertiary hospitals in Melbourne, Australia, between January 1, 1995, and December 31, 2015. Diagnosis was based on consensus opinion of experienced epileptologists and neuropsychiatrists at each hospital. Mortality was determined in patients diagnosed with PNES, epilepsy, or both conditions by linkage to the Australian National Death Index. Lifetime history of psychiatric disorders in PNES was determined from formal neuropsychiatric reports.

Results

A total of 5,508 patients underwent VEM. A total of 674 (12.2%) were diagnosed with PNES, 3064 (55.6%) with epilepsy, 175 (3.2%) with both conditions, and 1,595 (29.0%) received other diagnoses or had no diagnosis made. The standardized mortality ratio (SMR) of patients diagnosed with PNES was 2.5 (95% confidence interval [CI] 2.0–3.3). Those younger than 30 had an 8-fold higher risk of death (95% CI 3.4–19.8). Direct comparison revealed no significant difference in mortality rate between diagnostic groups. Among deaths in patients diagnosed with PNES (n = 55), external causes contributed 18%, with 20% of deaths in those younger than 50 years attributed to suicide, and “epilepsy” was recorded as the cause of death in 24%.

Conclusions

Patients diagnosed with PNES have a SMR 2.5 times above the general population, dying at a rate comparable to those with drug-resistant epilepsy. This emphasizes the importance of prompt diagnosis, identification of risk factors, and implementation of appropriate strategies to prevent potential avoidable deaths.

Trait and state interoceptive abnormalities are associated with dissociation and seizure frequency in patients with functional seizures

OBJECTIVE

Dissociative traits represent a disturbance in selfhood that may predispose to, and trigger, functional seizures (FSs). The predictive representation and control of the internal physiological state of the body (interoception) are proposed to underpin the integrity of the sense of self ("minimal selfhood"). Therefore, discrepancies between objective and subjective aspects of interoception may relate to symptom expression in patients with FSs. Here, we tested whether individual differences in trait measures of interoception relate to dissociative symptoms, and whether state interoceptive deficits predict FS occurrence.

METHODS

Forty-one participants with FSs and 30 controls completed questionnaire ratings of dissociation, and measures of (1) interoceptive accuracy (IA)-objective performance on heartbeat detection tasks; (2) trait interoceptive sensibility-subjective sensitivity to internal sensations (using the Porges Body Perception Questionnaire); and (3) state interoceptive sensibility-subjective trial-by-trial measures of confidence in heartbeat detection. Interoceptive trait prediction error (ITPE) was calculated from the discrepancy between IA and trait sensibility, and interoceptive state prediction error (ISPE) from the discrepancy between IA and state sensibility.

RESULTS

Patients with FSs had significantly lower IA and greater trait interoceptive sensibility than healthy controls. ITPE was the strongest predictor of dissociation after controlling for trait anxiety and depression in a regression model. ISPE correlated significantly with FS frequency after controlling for state anxiety.

SIGNIFICANCE

Patients with FSs have disturbances in interoceptive processing that predict both dissociative traits reflecting the disrupted integrity of self-representation, and the expression of FSs. These findings provide insight into the pathophysiology of functional neurological disorder, and could lead to novel diagnostic and therapeutic approaches.

Nonepileptic seizures in individuals attending neurological services in New Zealand

OBJECTIVES

This study examined the demographic, social, and clinical (neurological and psychiatric) characteristics of people with psychogenic nonepileptic seizures (PNES) presenting to tertiary neurological services at Auckland District Health Board, New Zealand.

METHODS

Electronic notes and video-electroencephalography (video-EEG) data gathered from the telemetry unit based on synchronized acquisition (motor activity and brain electrophysiology) over a five-year period (2011 to 2015 inclusive) were retrospectively examined. Two groups were compared: people with PNES only or people with combined PNES and epileptic seizures (ES) (the group with PNES) and a control group with ES only, matched 1:1 by age and gender.

RESULTS

Sixty-six people in the group with PNES were matched with an equivalent number of ES controls. As a cohort, there was high psychiatric and medical comorbidity in both groups, but overall, those with PNES experienced higher rates than their ES counterparts. An older age of onset, female gender, and history of abuse were more frequently seen in those with PNES. Compared with controls, people with PNES more commonly had daily seizures (rather than monthly) but presented less frequently to neurology services. A high proportion of people with PNES experienced historical traumas, ongoing stressors, and disability. Almost half of the people with PNES were on antiepileptic drugs (AEDs) and received limited psychiatric or psychological input. In contrast, people with ES were more likely to be on psychotropic medication.

CONCLUSION

Both PNES and ES are associated with high levels of psychiatric and medical comorbidity. Additionally, PNES were found to be associated with iatrogenic harm and disability. Though people with PNES and ES often have a range of associated needs, there is, however, limited access to appropriate services. The needs of these populations should be better met through enhanced integration across psychiatry, neurology, and multidisciplinary services.