Are there physical risk factors for psychogenic non-epileptic seizures in patients with epilepsy?

Patients with epilepsy may have additional psychogenic non-epileptic seizures (PNES). It has been suggested that PNES are more common if patients with epilepsy are female, develop epilepsy later in life and have right-sided brain lesions. We examine whether these or other physical factors affect the risk of PNES in patients with epilepsy in a controlled study. METHODS: Ninety consecutive patients with PNES and concurrent epilepsy (PNES+E group) and 90 consecutive patients with epilepsy alone (epilepsy group) were compared with regard to the variables sex, age at onset of epilepsy, epilepsy type (focal/generalised), location and lateralisation of epileptogenic zone, aetiology of epilepsy, interictal epileptiform potentials, magnetic resonance imaging (MRI) abnormalities, neuropsychological (NPS) deficits and intelligence quotient (IQ). RESULTS: Female sex (P<0.001), abnormal visual memory (P=0.012), global NPS impairment (P=0.029), and low IQ category (P=0.005) were associated with a higher risk of PNES. Other variables did not differ between the groups. CONCLUSIONS: In patients with epilepsy, female sex, poor visual memory or global neuropsychological underperformance and low IQ are associated with an increased risk of PNES. MRI changes, epileptiform EEG abnormalities and location of epileptogenic zone do not show a predilection for one hemisphere.     

Pseudosleep events in patients with psychogenic non-epileptic seizures: prevalence and associations

OBJECTIVES: To determine the prevalence and clinical associations of a history of events during sleep in patients with psychogenic non-epileptic seizures (PNES, pseudoseizures), and to compare the prevalence of a history of sleep events with that in poorly controlled epilepsy. METHODS: Prospective study by semistructured interview of the history of event patterns and their clinical associations in 142 patients with video EEG confirmed PNES, and 100 patients with poorly controlled epilepsy. RESULTS: 84/142 patients with PNES (59%) and 47/100 with epilepsy (47%) gave a history of events during sleep (p = 0.062). In patients with PNES, significant associations were found between a history of sleep events and: convulsive clinical semiology, antiepileptic drug treatment, fatigue, suicide attempts, mood disorder, and physical abuse. A particularly strong association with social security benefit was also found (odds ratio 4.0, p<0.001). CONCLUSIONS: The prevalence of a history of sleep events is similar in PNES and epilepsy, and is of no value in discriminating between the two, although a history of events occurring exclusively during sleep does suggest epileptic seizures. The clinical associations found indicate that a combination of psychopathological and external influences may be important in determining whether or not a patient with PNES gives a history of events during sleep.     

Weeping During Psychogenic Nonepileptic Seizures

Ictal weeping may help distinguish psychogenic nonepileptic seizures (PNES) from epileptic seizures. However, the prevalence of weeping during PNES or epileptic seizures is unknown. We reviewed videotapes of recorded events in 84 consecutive patients with PNES or epilepsy. Weeping was observed during 14% of PNES in 31% of patients with PNES. Ictal weeping was not observed in any epileptic seizures occurring in 48 patients. The differences were highly significant. One patient with epileptic seizures originating in the right temporal lobe wept soon after the end of a seizure. Depression was not more common in PNES patients with than without ictal weeping. Weeping during an apparent seizure strongly argues that the event is not epileptic.     

Physically traumatic events in patients with epilepsy compared with non-epileptic subjects

To determine the incidence of traumatic events among epileptic patients compared with non-epileptic individuals, we distributed a questionnaire on physically traumatic events occurring during the preceding three months to consecutive epileptic patients and to age- and sex-matched controls. There were 145 epileptic patients, 121 with seizures (age 36 +/- 15 y, 60 males) and 24 who were seizure free during this period (age 39 +/- 17 y, 13 males), and 145 controls (age 36 +/- 15 y, 73 males). There was no significant difference in the duration of epilepsy between the two groups of patients with epilepsy. Traumatic events (n= 27, three of them unrelated to seizure) were most common in patients with seizures, followed by controls (n= 20), and absent in seizure-free patients (P< 0.001). Patients with epilepsy most commonly injured the head while the extremities were more usually involved in controls. Patients with epilepsy had significantly more traumatic events at home, whereas controls underwent most traumatic events at work and in public areas. There was no significant difference in the type and severity of trauma between the two groups. We conclude that physically traumatic events not related to seizures are fewer among patients with epilepsy with and without seizures compared with controls, probably because of increased cautiousness.     

Movement disorders in sleep: guidelines for differentiating epileptic from non-epileptic motor phenomena arising from sleep

Seizures, namely in certain epileptic conditions, may be precipitated by sleep. Nocturnal frontal lobe epilepsy seizures, characterized by bizarre motor behaviour and autonomic activation, appear almost exclusively during sleep. The differential diagnosis between this condition and sleep-related non-epileptic paroxysmal motor phenomena, in particular the parasomnias, is arduous. Moreover, accepted criteria for the diagnosis of nocturnal frontal lobe seizures are lacking and even ictal scalp EEG recording could fail to disclose paroxysmal abnormalities. The clinical and polygraphic features of the different types of seizures in nocturnal frontal lobe epilepsy and of the more common non-epileptic paroxysmal events during sleep are described. The main differentiating features characterizing nocturnal frontal seizures are: onset at any age, several attacks per night at any time during the night, brief duration (s) with stereotyped motor pattern. As video-polysomnographic recordings of the attack, the gold-standard for diagnosis, are expensive and not readily available everywhere, home-made video recordings may be helpful. Further investigations on pathophysiology, genetics and epidemiology are needed to clarify the relationship between epileptic and non-epileptic sleep related paroxysmal phenomena.     

Efficacy of safety signals in the epilepsy monitoring unit (EMU): should we worry?

There is little consensus regarding the critical safety measures to prevent harm in epilepsy monitoring units (EMUs). We sought to determine whether the safety signals (SS) triggered during EMU events differed by seizure type and the efficacy of SS in alerting responders. We screened 468 consecutive EMU admissions from January 2008 until April 2011 for definitive events to evaluate the first 50 events of complex partial seizures (CPS), generalized tonic-clonic seizures (GTC), and psychogenic non-epileptic seizures (PNES). Response to telemetry signal was slower than to push button (PB). When there was PB alarm, response time was slower in patients with PNES. A higher proportion of PNES were triggered by PB. A greater percentage of epileptic seizures were missed compared with PNES. Future studies investigating more effective techniques to capture every epileptic seizure are warranted as 24/7 monitoring by healthcare professionals is not feasible in many settings.     

Comparison of heart rate variability parameters during complex partial seizures and psychogenic nonepileptic seizures

Purpose: Psychogenic nonepileptic seizures (PNES) superficially resemble epileptic seizures. Little is known about ictal autonomic nervous system (ANS) activity changes in epilepsy and PNES. This study compares ictal heart rate variability (HRV) parameters as a reflection of ANS tone in epileptic seizures and PNES, and explores differences between interictal and ictal ANS tone in both patient groups. Methods: Ictal HRV parameters were extracted from single‐lead electrocardiography (ECG) data collected during video–electroencephalography (EEG) recordings of 26 patients with medically refractory temporal lobe epilepsy and 24 age‐ and sex‐matched patients with PNES. One seizure per patient in a resting, wake, supine state was analyzed. Interictal ECG data were available for comparison from 14 patients in both groups. HRV parameters in time and frequency domains were analyzed (low frequency [LF], high frequency [HF], standard deviation of all consecutive normal R wave intervals [SDNN], square root of the mean of the sum of the squares of differences between adjacent normal R wave intervals [RMSSD]). CVI (cardiovagal index), CSI (cardiosympathetic index), and ApEn (approximate entropy) were calculated from Lorenz plots. Key Findings: There were significant differences between ictal HRV measures during epileptic and nonepileptic seizures in the time and frequency domains. CSI (p < 0.001) was higher in epileptic seizures. Time interval between two consecutive R waves in the ECG (RR interval) (p = 0.002), LF (p = 0.02), HF (p = 0.003), and RMSSD (p = 0.003) were significantly lower during epileptic seizures. Binary logistic regression yielded a significant model based on the differences in CSI classifying 88% of patients with epilepsy and 73% of patients with PNES correctly. The comparison between resting and ictal states in both seizure disorders revealed significant differences in RR interval (epilepsy p < 0.001, PNES p = 0.01), CSI (epilepsy p < 0.001, PNES p = 0.02), HF (epilepsy p = 0.002, PNES p = 0.03), and RMSSD (epilepsy p = 0.004, PNES p = 0.04). In patients with epilepsy there were also significant differences in ictal versus interictal mean values of ApEn (p = 0.03) and LF (p = 0.04). Although CSI was significantly higher, the other parameters were lower during the seizures. Stepwise binary regression in the 14 patients with epilepsy produced a significant model differentiating resting state from seizures in 100% of cases. The same statistical approach did not yield a significant model in the PNES group. Significance: Our results show greater ANS activation in epileptic seizures than in PNES. The biggest ictal HRV changes associated with epileptic seizures (CSI, HF, and RMSSD) reflect high sympathetic system activation and reduced vagal tone. The reduced ApEn also reflects a high sympathetic tone. The observed ictal alterations of HRV patterns may be a more specific marker of epileptic seizures than heart rate changes alone. These altered HRV patterns could be used to detect seizures and also to differentiate epileptic seizures from PNES. Larger studies are justified with intergroup and intragroup comparisons between ictal and resting states.     

Video-EEG Study of Psychogenic Nonepileptic Seizures: Differential Characteristics in Patients with and without Epilepsy

Summary:  Purpose: Psychogenic nonepileptic seizures (PNES) are episodes that may resemble epileptic seizures (ES) but are not associated with abnormal electrical discharges in the brain. Video-EEG recording of a typical episode is considered the best diagnostic tool available. PNES are, however, also documented in patients with epilepsy (PNES/ES). The purpose of this study was to assess this comorbid population, focusing on the differences between patients with PNES/ES and patients with PNES alone.
Methods: We reviewed 110 PNES episodes, occurring spontaneously or induced by means of suggestion techniques, recorded in our video-EEG laboratory over a period of eight years. We identified two subgroups of patients, consisting of 85 PNES cases and 25 PNES/ES cases, and assessed any differences in their characteristics by reviewing a number of variables (age, sex, clinical features, antiepileptic therapy, age of onset, time to diagnosis, pathological history, and length of follow-up).
Results: The comparison between the two subgroups revealed that PNES/ES patients displayed some statistically significant differences when compared with PNES alone patients, i.e., younger age, a higher percentage of spontaneously activated events, a shorter disease duration, a longer time to PNES diagnosis, and a lower percentage lost at follow-up.
Conclusions: This study confirms that PNES is a common, though probably underestimated, occurrence in epilepsy services. Our results shed light on some different characteristics between PNES and PNES/ES patients.     

Late-onset psychogenic nonepileptic seizures

Psychogenic non-epileptic seizures (PNES) are common, but have not been well studied in older patients. We retrospectively reviewed patients with PNES who were 60 years of age and above at the time of "seizure" onset. Over a 27-month period, nine (9.6%) of 94 patients diagnosed with PNES had onset at age 60 or above. None had evidence for coexisting epilepsy. Eight were women. Characteristics of the group were comparable to younger patients with PNES. We conclude that PNES should be considered as a diagnostic possibility in older patients.     

Psychiatric diagnoses of patients with psychogenic non-epileptic seizures.

OBJECTIVE: Our purpose was to present and discuss the psychiatric diagnoses of patients who presented psychogenic non-epileptic seizures (PNES) during video-electroencephalographic monitoring (VEEG). METHODS: Out of 98 patients, a total of 28 patients presented PNES during the diagnostic procedure. In those cases in which the PNES that occurred during VEEG were validated by clinical history (clinical validation), and by showing the recorded event on video to an observer close to the patient (observer validation), was defined psychogenic non-epileptic seizure disorder (PNESD). Psychiatric diagnoses were made according to DSM-IV. RESULTS: In 27, psychogenic non-epileptic seizures disorder was diagnosed. Fourteen patients presented only with psychogenic non-epileptic seizure disorder, 13 with both psychogenic non-epileptic seizures disorder and epilepsy, and one patient with epilepsy only. Psychiatric diagnoses were: 17 (63%) patients with conversion disorder, five (19%) with somatization disorder, two (7%) with dissociative disorder NOS, two (7%) with post-traumatic stress disorder and one (4%) with undifferentiated somatoform disorder. CONCLUSIONS: Dissociative-conversion non-epileptic seizures are the most frequent finding, representing the pseudoneurological manifestation of mental disorders that have these symptoms as a common feature. Provisionally, they may be defined as dissociative-conversion non-epileptic seizure disorders.     

Cognitive impairment profile differences in patients with psychogenic non-epileptic seizures and epilepsy patients with generalized seizures

ABSTRACT

Objective: This study aimed to compare cognitive skills in epilepsy patients and psychogenic non-epileptic seizures (PNES) patients who have no history of frequent seizures to those of a healthy control group.

Methods: This prospective cross-sectional study was conducted between January 2017 and June 2019 and included 103 epilepsy patients, 100 PNES patients, and 101 healthy controls, aged 18 to 60 years. Patients with fewer than 12 annual seizure episodes and no history of seizures during the last 30 days were added to the study. A sociodemographic data form, the Beck Anxiety and Depression Scales, Montreal Cognitive Assessment, Digit Span test, and Stroop Color-Word Interference Test were used.

Results: Compared to the control group, sub-component scores were significantly lower in naming, attention, abstract thinking, and delayed recall for the epilepsy and PNES groups. Sub-component scores in orientation, executive functioning, and delayed recall were significantly lower in the epilepsy group compared to the PNES group. Digits Backward subtest scores and total Digit Span test scores were significantly lower in the epilepsy and PNES groups. Patients in the epilepsy and PNES groups took longer to complete the Stroop test and made more errors and corrections compared to the healthy controls. There was a negative correlation between the duration of the disease and the total Digit Span score in the epilepsy group.

Conclusion: These findings suggest that the epilepsy group showed reduced cognitive scores even though they did not suffer from frequent seizures and were not drug-resistant.     

Patients with epilepsy and patients with psychogenic non-epileptic seizures: Video-EEG, clinical and neuropsychological evaluation

Purpose

The incidence of psychogenic non-epileptic seizures (PNES) is 4.9/100,000/year and it is estimated that about 20–30% of patients referred to tertiary care epilepsy centers for refractory seizures have both epilepsy and PNES.The purpose of our study is to evaluate psychiatric disorders and neuropsychological functions among patients with PNES, patients with epilepsy associated with PNES and patients with epilepsy.

Methods

We evaluated 66 consecutive in-patients with video-EEG recordings: 21 patients with epilepsy, 22 patients with PNES and 10 patients with epilepsy associated with PNES; 13 patients were excluded (8 because of mental retardation and 5 because they did not present seizures or PNES during the recording period).

Results

All patients with PNES had a psychiatric diagnosis (100%) vs. 52% of patients with epilepsy. Cluster B personality disorders were more common in patients with PNES.We observed fewer mood and anxiety disorders in patients with PNES compared with those with epilepsy.We did not find statistically significant differences in neuropsychological profiles among the 3 patient groups.

Conclusion

This study can help to contribute to a better understanding of the impact of PNES manifestations, in addition to the occurrence of seizures, in order to provide patients with more appropriate clinical, psychological and social care.     

Psychogenic non-epileptic seizures—Diagnostic issues: A critical review

In this review we systematically assess our current knowledge about psychogenic non-epileptic seizures (PNES), epidemiology, etiology, with an emphasis on the diagnostic issues. Relevant studies were identified by searching the electronic databases. Case reports were not considered. Articles were included when published after 1980 up till 2005 (26 years). A total of 84 papers were identified; 60 of which were actual studies. Most studies have serious methodological limitations. An open non-randomized design, comparing patients with PNES to patients with epilepsy is the dominant design. The incidence of PNES in the general population is low. However, a relatively high prevalence is seen in patients referred to epilepsy centres (15–30%). Caution is needed in the clinical interpretation of ictal features suggested to be pathognomic for PNES. Video–EEG is widely considered to be the gold standard for diagnosing PNES. Still the differential diagnosis epileptic/non-epileptic seizures can be difficult. Despite the current available technical facilities, the mean latency between onset of PNES and final diagnosis as being non-epileptic and psychogenic is approximately 7 years. One of the reasons for diagnostic delay is that the diagnosis of PNES is often limited to a ‘negative’ process and consequently PNES is characterized as a ‘non-disease’ (i.e. ‘not epilepsy’). The psychological diagnosis is thus an important, although not a conclusive, ‘second phase’ aspect of medical decision making. Specific relations between seizure presentation and underlying psychological mechanisms are not conclusive. A classification between major motor manifestations and unresponsiveness is recognized. With respect to psychological etiology, a heterogeneous set of factors have been identified that may be involved in the causation, development and provocation of PNES.     

Juvenile and adult-onset psychogenic non-epileptic seizures

Purpose

Psychogenic non-epileptic seizures (PNES) tend to begin in adolescence and young adulthood, although the seizures can occur in a wide range of ages. In the current study, we investigated the age of onset in patients with PNES and tried to determine the correlation between the age of onset and the demographic and clinical characteristics and factors potentially predisposing to PNES.

Methods

In this cross-sectional study, all patients with a clinical diagnosis of PNES were recruited at the outpatient epilepsy clinic at Shiraz University of Medical Sciences from 2008 to 2012. We dichotomized the patients into two groups; those with age of onset below 18 years (juvenile), and those with age of onset at 18–55 years (adult-onset). We studied the demographic and clinical characteristics and factors potentially predisposing to PNES between these two groups. Statistical analyses were performed using Chi square and Fisher's Exact tests and Mann–Whitney U test.

Results

Fifty-seven patients with juvenile and 129 people with adult-onset PNES were studied. Demographic characteristics of these two groups were not different significantly. Seizure characteristics and semiology in these two groups were not significantly different either. However, factors potentially predisposing to PNES were significantly different between these two groups. History of being abused, academic failure, epilepsy or family history of epilepsy were more frequently observed in juvenile PNES, while medical comorbidities were more frequent among patients with adult-onset PNES.

Conclusion

Age of onset of PNES is not correlated with the clinical manifestations; however, factors potentially predisposing to PNES are significantly different in patients with juvenile compared to those with adult-onset PNES.     

Psychogenic non-epileptic seizures in Iran

PurposeWe investigated the demographic and clinical characteristics of psychogenic non-epileptic seizures (PNES) in patients in Iran.MethodsIn this prospective study, all patients with a clinical diagnosis of PNES (based on ictal recordings) were recruited at the outpatient epilepsy clinic at Shiraz University of Medical Sciences, from 2008 through 2013. The epileptologist interviewed all the patients. We investigated the demographic and clinical characteristics of PNES.ResultsTwo hundred and forty-nine patients were diagnosed as having PNES. Two hundred and eleven patients had video-EEG recordings available and included in the study. One hundred and forty-one (66.8%) were female and 70 (33.2%) were male. There were no significant differences between our patients and previous reports regarding the clinical and semiological characteristics of PNES.ConclusionPsychogenic non-epileptic seizures are relatively common at epilepsy clinics. It appears that an Islamic lifestyle (in Iran) has little influence on the clinical characteristics and manifestations of PNES, as we observed similar results as in most previous studies from other cultures.     

Differentiating frontal lobe epilepsy from psychogenic nonepileptic seizures

Patients with psychogenic nonepileptic seizures (PNES) remain one of the most challenging patient populations. The misdiagnosis of PNES is costly to patients, the health care system, and to society. The first step in treatment is proper diagnosis. Video electroencephalography remains the gold standard for PNES diagnosis. Differentiating frontal lobe epilepsy (FLE) from PNES can be difficult; however, clinical findings and laboratory advances are emerging that more clearly establish the diagnosis of PNES. This article provides clues to differentiating FLE from PNES so that neurologists and mental health providers are better equipped to offer treatments for PNES.     

Gender differences in psychogenic non-epileptic seizures.

PURPOSE: To determine whether male and female populations of patients with psychogenic non-epileptic seizures (PNES) are similar, in terms of demographic and social factors, aetiological factors, the clinical characteristics of events and path to diagnosis. METHODS: Prospective study by semi-structured interview of 160 consecutive patients (117 female and 43 male) with video EEG confirmed diagnosis of PNES + epileptic seizures (ES). RESULTS: Most parameters showed no significant differences. Males were, however, more likely to be unemployed (P = 0.028), and females were six times more likely to self-harm (P = 0.050), though the numbers were small in these categories. Men were more likely to attribute their PNES to a predisposing factor for epilepsy (P = 0.001), and women were over eight times more likely to report sexual abuse (P = 0.001). Event semiology was similar, but women were more likely to weep after events (P = 0.017). The carers and family of men with PNES were three times less likely to accept the diagnosis of PNES (P = 0.017). CONCLUSIONS: Our samples showed few significant gender differences, suggesting that other male and female populations of patients with PNES are likely to be similar also. Some of the differences we found may give insight into causation of PNES.     

Psychogenic non epileptic seizures: a review

Objective

This paper summarizes the recent literature on the phenomena of psychogenic non epileptic seizures (PNES).

Definition and epidemiology

PNES are, as altered movement, sensation or experience, similar to epilepsy, but caused by a psychological process. Although in the ICD-10, PNES belong to the group of dissociative disorders, they are classified as somatoform disorders in the DSM-IV. That represents a challenging diagnosis: the mean latency between manifestations and diagnosis remains as long as 7 years. It has been estimated that between 10 and 30% of patients referred to epilepsy centers have paroxysmal events that despite looking like epileptic episodes are in fact non-epileptic. Many pseudo epileptic seizures have received the wrong diagnosis of epilepsy being treated with anticonvulsants. The prevalence of epilepsy in PNES patients is higher than in the general population and epilepsy may be a risk factor for PNES. It has been considered that 65 to 80% of PNES patients are young females but a new old men subgroup has been recently described.

Positive diagnosis and psychiatric comorbidities

Even if clinical characteristics of seizures were defined as important in the diagnosis algorithm, this point of view could be inadequate because of its lack of sensitivity. Because neuron-specific enolase, prolactin and creatine kinase are not reliable and able to validate the diagnosis, video electroencephalography monitoring (with or without provocative techniques) is currently the gold standard for the differential diagnosis of ES, and PNES patients with pseudoseizures have high rates of psychiatric disorders such as depression, anxiety, somatoform symptoms, dissociative disorders and post-traumatic stress disorder. We found evidence for correlations between childhood trauma, history of childhood abuse, PTSD, and PNES diagnoses. PNES could also be hypothesized of a dissociative phenomena generated by childhood trauma.

Pathophysiology

Some authors report that PNES can be associated with a physical brain disorder playing a role in their development: head injury may contribute to the pathogenesis of PNES. New-onset psychogenic seizures after resective epilepsy surgery or other intracranial neurosurgery have been described. Recent studies found psychogenic seizure disorders associated with brain pathology in the right hemisphere, non specific interictal electroencephalography abnormalities, magnetic resonance imaging changes and neuropsychological deficits. However, complex partial seizures of frontal origin might present similar characteristics with PNES and could be confused with the latter.

Prognosis and treatment

There is actually no clear agreement as the best treatment plan for PNES patients. The PNES diagnosis has to be clearly communicated to the patient. Nevertheless, even after a correct diagnosis is made a high proportion of PNES patients continue to have seizures, serious disability and bad self-reported quality of life. Furthermore, seizure remission cannot be considered a comprehensive measure of medical or psychosocial outcome. Nearly half of the patients who become seizure free remain unproductive and many of these patients continue to have symptoms of psychopathology including other somatoform, depressive, and anxiety disorders. Even if psychiatric comorbidities have to be treated by a psychiatrist? who could also suggest a psychotherapy, in all cases the importance of a neurologist continuing to follow post-diagnosis PNES patients is essential.

Conclusions

PNES is a diagnostic and therapeutic challenge that is costly to patients and to society at large. Further studies are needed to understand this dissociative psychiatric disorder and to propose therapeutic guidelines.     

Frontal lobe epilepsy.

Frontal lobe epilepsy accounts for only 10-20% of the patients in surgical series, but the incidence in non-surgical patient cohorts seems to be much higher. The typical clinical presentation of the seizures includes contralateral clonic movements, uni- or bilateral tonic motor activity as well as complex automatism. The yield of surface EEG may be limited due to the difficulty in detection of mesial or basal foci, and the patient may be misdiagnosed as having non-epileptic events. In addition, in patients with mesial frontal foci the epileptiform discharges may be mislateralized ("paradoxical lateralization"). Therefore, epilepsy surgery has been commonly considered as less promising in patients with frontal lobe epilepsy. However, the advent of sophisticated neuroimaging techniques, particularly MRI with epilepsy-specific sequences, has made it possible to delineate the epileptogenic lesion and detect a specific etiology, in an increasing number of patients. Thus, the success rate of epilepsy surgery in frontal lobe epilepsy is currently comparable to temporal lobe epilepsy, if the candidates are carefully selected. Patients with frontal lobe epilepsy who do not respond to anticonvulsive medication, and who are not eligible for epilepsy surgery may benefit from alternative approaches such as electrical brain stimulation.     

Expanding the theory of symptom modeling in patents with psychogenic nonepileptic seizures

Symptom modeling has been used to explain the development of psychogenic nonepileptic seizures (PNES) in predisposed patients, but has been understood only in the context of individuals who have both PNES and epileptic seizures. Our aim in the study described here was to learn whether this concept applies to patients with PNES who do not have epileptic seizures, that is, to determine whether the prevalence of having personally witnessed a seizure prior to the occurrence of their event differs in patients with PNES and those with epileptic seizures. We interviewed 27 patients with PNES and 35 patients with epileptic seizures. A significantly larger number of patients with PNES (66%) admitted to having witnessed a seizure prior to their event compared with patients with epileptic seizures (11%) (P < 0.001). This suggests that symptom modeling plays a key role in the development of PNES, even among individuals without a coexisting history of epilepsy.