Comparison of clinical characteristics of ES and PNES.
Psychogenic nonepileptic seizure (PNES) is one of the most common clinical conditions in which the diagnostic complexity is experienced. Misdiagnosis leads to many years of wrong treatment regimens, side effects of drugs, additional financial burdens and adverse effects on social life. Differential diagnosis with epileptic seizures (ES) is one of the most common problems in neurology clinics as well as other health centers. A careful history from the patient and his relatives, detailed neurological and psychiatric examination are very important in reaching the correct diagnosis and treatment. Although imaging advances such as video electroencephalography (vEEG) have improved the ability of physicians to accurately identify these disorders, the diagnosis and treatment of PNES is still a challenging issue. Early diagnosis, young age, less psychiatric comorbidity have a positive effect on prognosis. Psychiatric evaluation of patients with PNES may be particularly helpful in elucidating the etiology and detecting comorbid diseases and may be helpful in the long-term treatment of these patients.
- psychogenic nonepileptic seizures
Psychogenic nonepileptic seizures (PNESs) are neuropsychiatric disorders caused by the combination of neurological findings and basic psychological conflicts [1, 2, 3]. Over a period of a century, medical community collects data and information about the phenomenology, epidemiology, risks, comorbidities and prognosis of PNES [4, 5, 6, 7, 8, 9]. However, information about PNES is insufficient. Video electroencephalography (vEEG) has become a gold standard in diagnostic examination to distinguish neurological seizures from PNES [10, 11, 12, 13, 14, 15]. For this reason, video electroencephalography is preferred for diagnosis. In this section, we systematically reviewed our current knowledge about diagnosis, differential diagnosis and treatment of PNES.
2. What is a psychogenic nonepileptic seizure?
PNESs, also referred to as hysteroepilepsy, pseudoseizure, hysterical seizures, psychogenic seizures, dissociative disorders, are sensory, motor or behavioral episodes similar to epileptic seizures (ES) without accompanying abnormal neuronal discharges [15, 16, 17, 18]. PNESs do not have neurological roots, on the contrary, they are concrete manifestations of psychological distress. The prevalence in the society ranges from 1/3000 to 1/5000 . Although the prevalence is lower than the epilepsy, it causes serious workload in the emergency departments and neurology clinics due to the tendency to frequent repetition. About 10–30% of patients admitted to epilepsy centers with the history of treatment-resistant seizure are created by patients with PNES [19, 20]. ES have also been reported in 5–40% of patients with PNES at the same time. In other words, both types of seizures can be seen together in the same patient [5, 6, 9, 20, 21, 22]. Although ESs and PNESs are seen in both sexes and ages, PNESs often affect young adult women. Lesser reviewed 21 studies investigating gender differences (734 women and 250 men diagnosed with PNES) . It has been reported that 75–85% of the diagnosed PNES patients are female, it is 10 times more likely to be seen than men, and the majority of patients are 30–40 years old [24, 25]. There are also cases of PNES diagnosed in childhood and adolescence . Two studies have reported sexual abuse in female patients and work-related problems in males more frequently [26, 27]. However, traumatic experiences such as warfare and captivity are higher in male patients . About 5–10% of patients followed up with a diagnosis of epilepsy and 20–40% of patients with epileptic patients receiving inpatient treatment experienced PNES [24, 29]. These patients often have accompanying psychiatric illnesses (mostly depression, posttraumatic stress disorder, other dissociative and somatoform disorders and personality pathology), especially borderline personality types . In most cases, it is reported that there is a story of childhood trauma (story of sexual or physical abuse) [31, 32, 33, 34, 35]. In one study, it was suggested that childhood traumatic experience may be a predisposing factor for PNES . Patients with PNES followed up with the diagnosis of ES are diagnosed at an average of 7.2 years . This situation led those patients with PNES to be exposed to incorrect treatment regimens for many years with the diagnosis of epilepsy, additional financial burdens, drug side effects and adverse social life [29, 36]. Considering that the cases were exposed to aggressive interventions such as intubation, considering status epilepticus by the emergency department, the importance of early differential diagnosis with epilepsy is once again emerging .
3.1. Epileptic seizure? Psychogenic nonepileptic seizure?
The main question to be answered in patients with seizure history is whether there is an epileptic seizure. When the patient is brought to the clinic, the seizure is usually terminated and the most important information is obtained in order to distinguish from the patient and the relatives who witnessed it during the seizure. Although any other diagnostic methods are available for diagnosis of epilepsy such as electroencephalogram (EEG), vEEG, cerebral magnetic resonance imaging (MRI), cerebral perfusion scintigraphy and, the most important first step in diagnosis is accurate history from patients and their relatives, and careful neurological examination, as well as semiologic recording of the seizure . In cases where anamnesis is not sufficient, the differential diagnosis of the patient becomes difficult. With good history, information can be obtained to suggest whether there is a nonepileptic seizure. For example, many reasons may be useful for differential diagnosis such as the onset and the duration of seizure, the appearance pattern, motor movements and reflex changes, the induction property of seizure [16, 39, 40]. If the seizures happen very often and repeat several times a day, this is a more common finding for PNES. Furthermore, while patients are normal in the period between the seizures due to the absence of postictal confusion in PNES, there may be consciousness disorders during the period between seizures in patients with ES due to prolonged confusion and sleepiness in frequent seizures. While epileptic seizures generally last a few minutes, PNESs tend to last much longer [41, 42]. Patients with epilepsy generally respond to treatment with one antiepileptic drug at around 50%, while patients with PNES do not respond to treatment with antiepileptic drugs . During examination, it is often learned that patients with PNESs received prior antiepileptic treatment and no response obtained to treatment. If the seizures are in a specific place, time and crowded environment, it is favorable for PNES. In ES, such a place and time difference is generally absent. While ES is seen in sleep and awake state, PNESs are seen awake state [17, 18]. A careful history can be used to determine that the patient is not asleep, although the patients report that they are asleep. vEEG can be used as an assistant method in cases where sleep and awake state cannot be distinguished . The type of seizure is generally the same with the reason that the discharge is in the same region in the brain in ES. In PNES, seizure types can be seen in different forms in the same patient . While seizures are usually sudden onset in epileptic patients, it starts gradually in patients with PNES. While there are complaints such as screaming, palpitations, hyperventilation, numbness in the hands and feet before the seizure in PNES, epigastric sensations, deja vu, swallowing, swallowing and automatisms in the hands may occur in ES [17, 18]. A complete loss of consciousness is observed according to type of seizure in ES, no loss of consciousness is seen in PNES, the patient hears around, and cannot respond. There may be physical injuries in ES due to fall. Even the patients with PNES fall, they usually have controlled falls and injuries are not often experienced [23, 42, 44]. In ES, contractions occurring in the extremities are tonic, clonic or tonic-clonic and rhythmic, whereas PNES is more tonic in contraction and not rhythmic. When the eyelids are attempted to open, patients with PNES show resistance, but this is not observed with ES. At ES, abnormal alignment of the eyes and unilateral clonic contractions in the eyelid can be seen . In patients with epilepsy, pupil dilatation and reflex changes are observed, however, these neurological findings are not seen in patients with PNES. In patients with PNES, pelvic pushing is a frequent finding, while it may be seen much less and lighter in epileptic patients . Urinary incontinence is a more common finding in ES, although it is rarely reported in patients with PNES . In the differential diagnosis, sudden onset of seizures, pupillary dilation during seizure and postictal confusion are semiologic findings in favor of ES, awareness of the environment, influencing the severity of seizures by the presence of people around and blinking of the eyes are semiologic findings in favor of PNES . At ES, there may be epileptic cries at the onset of the seizure and tonic-clonic contractions continue with wheezing. In patients with PNES, longer moaning during seizures, speech, which can be understood, can be observed with challenging hyperventilation, and generally last longer than ES . While postictal confusion is a frequent finding in ES, postictal confusion is not seen after PNES. EEG is the most important diagnostic method besides clinical information. Because it is a noninvasive and inexpensive method, it still maintains its importance as the most commonly used method in the orientation of diagnosis and treatment today. However, the normal EEG of the patient with seizure does not exclude the diagnosis of epilepsy, and many epileptic patients may have continuous normal EEG findings during the interictal period. Again, especially in cases where seizures with low frequency are difficult to get caught in the ictal period and take EEG recording, it often cannot help the diagnosis. In PNES cases, EEG taken during interictal and ictal period is normal. However, it should not be forgotten that EEG cannot be sufficient for the differential diagnosis of ES and PNES. Comparisons of clinical characteristics of ES and PNES are given in Table 1.
|Antiepileptic treatment response||No response||Usually present|
|Seizure duration||May be prolonged (10–15 min)||Short (1–2 min)|
|Onset of the seizure||Gradually||Sudden|
|Biting tongue, physical injury||Rare (tongue tip)||Common|
|Pupil dilatation, reflex changes||Absent||Present|
|Motor movements||Extended, uncoordinated||Automatism, coordinated, short|
|Seizure type||Variable||Usually the same|
|Interictal EEG||Normal||Frequently changed|
3.2. Video EEG imaging in psychogenic nonepileptic seizures
For the differentiation of PNES and epileptic seizures, when the decision cannot be taken with anamnesis, clinical examination and EEG, ‘
3.3. Is there a biomarker and a test for a psychogenic nonepileptic seizure?
The search for biomarkers for the differentiation of ES and PNES has been a subject of interest to many authors. In the first studies in this area, changes in prolactin level after epileptic seizures and whether these changes were different in ES and PNES were examined. Ohman and colleagues found that plasma levels of prolactin increased after electroconvulsive therapy and it has been emphasized that an increase in prolactin level after epileptic seizures may be an important predictor of PNES differentiation . It has been revealed in eight of these studies that the postictal increase in serum prolactin level had a positive diagnostic value in terms of epilepsy but no increase did not exclude epilepsy and no significant increase was seen in PNES, whereas it has been revealed in the other two studies that there was a statistically significant increase in serum prolactin level in PNES, but this increase was significantly lower than in epilepsy . Shah et al. have indicated that there was an average increase of 17% in serum prolactin levels after PNES, therefore at least a two-fold increase may be considered significant for epilepsy . In one study, 69% sensitivity and 93% specificity were found for the prolactin level at the distinction of epileptic seizure and psychogenic nonepileptic seizure, in another study, 100% positive predictive value was reported for ES . However, the use of postictal prolactin level as a biomarker in EN/PNES differentiation was not supported in two studies [54, 55]. In addition, while a higher increase in prolactin was expected in generalized tonic-clonic seizures affecting the entire or most part of the brain, increase may not be seen after simple partial and frontal lobe seizures. Postictal serum prolactin level measurement is recommended to distinguish between epileptic and nonepileptic seizures, but it should be remembered that after half an hour following the seizure, it returns to normal level rapidly and is affected by stress, hypoglycemia, exercise, drug intake. Sundararajan et al. have evaluated 49 studies conducted between 1980 and 2015 on use of biomarkers in the diagnosis of psychogenic nonepileptic seizures. It has been indicated in this review study that neuroimaging (BT, fMRI, SPECT, etc.), autonomic nervous system, prolactin, postictal cortisol, creatine kinase, neuron specific enolase, brain-derived neurotropic factor, ghrelin, leptin, leukocytosis, heart rate have been studied as a biomarker to distinguish psychogenic nonepileptic seizures and epileptic seizures. However, it was reported that none of them could obtain sufficient evidence level. In addition, the authors noted that studies have significant limitations due to small sample and methodological differences and subtypes of psychogenic nonepileptic seizures have not been investigated .
Although there is no standardized protocol yet, it is thought that psychological tests may also be helpful for the differential diagnosis of ES-PNES in cases where necessary. It is reported that psychiatric disorders such as anxiety and depression are more frequent in patients with psychogenic seizures than epileptic patients, these patients have a higher incidence of suicide attempts and story of psychiatric treatment. In addition, researchers have also observed that patients with psychogenic seizures have a lower quality of life, more frequent long-term health problems and more dysfunctional family relationships than epileptic patients . Personality problems that occur in patients with psychogenic nonepileptic seizures have been the subject of many investigations. The Minnesota Multiphasic Personality Inventory (MMPI) is a very sensitive but nonspecific test in this area. There were statistically significant differences between the patients with epileptic seizures and psychogenic seizures with MMPI especially in hypochondriasis, depression, hysteria and schizophrenia scales, pathologic elevation (T-score ≥ 70) was detected in patients with psychogenic seizures . However, no significant difference was found in cases with ES and PNES in the other two studies [59, 60]. In other words, there are conflicting results about the clinical benefits of MMPI in the differential diagnosis of ES/PNES.
Alexithymia is a Greek term which is used to describe individuals who have difficulty to define and verbalize their emotions or which means “no words for emotions”, emerged in order to explain the symptoms of psychosomatic patients and gained a quick recognition among psychiatrists. It was first observed in psychosomatic patients who were also been seen on several psychiatric disorders such as depression, posttraumatic stress disorder, substance abuse and dependence . Patients exposed to trauma are reported to exhibit alexithymia more frequently than control group without trauma experience . A significant portion of PNES patients have a trauma history, so alexithymia is also common. On the other hand, alexithymia is not a common condition in patients with ES, so alexithymia can be helpful to distinguish ES/PNES.
Despite not being overworked, it is reported that the tendency of hypnosis is relatively increased in patients with PNES. High tendency of hypnosis has been found in a study conducted on 24 patients with ES and PNES by Kuyk et al. with Stanford Hypnotic Clinical Scale measurements in patients with PNES compared to general population and patients with ES .
On the other hand, it is necessary to evaluate whether the patients with psychogenic nonepileptic seizures are surely making symptoms consciously. Simulation is easier to notice as it is obviously benefit-oriented. In artificial disorder, the unconscious desire to ‘become ill’ is the motive that drives the patient. However, secondary gains can also be clearly identified .
As noted above, it is very clear that there have been many unanswered questions, even though there have been many studies to distinguish psychogenic nonepileptic seizures from epileptic seizures. It is seen that comparison was made with patients with generalized epileptic seizure, in a significant part of the studies and the heterogeneous structure of psychological nonepileptic seizures, subgroups and the effect of cultural characteristics were not addressed in studies. Moreover, although many studies point out that ictal vEEG is the ‘gold standard’ in diagnosis, it is still not certain. On the other hand, the place of psychogenic nonepileptic seizures in the classification diagnosis of epileptic seizures is also uncertain. At present, although there is a lot of information in the ES/PNES distinction, the diagnostic criteria of PNES disorders have not yet been established. The heterogeneous clinical appearance of the PNES causes this uncertainty. It is not clear whether it will be evaluated as multiple comorbid mental and personality disorders or neuropsychiatric syndromes in DSM classification system. Because it is not included in the diagnostic classifications, the development of appropriate treatment options and information and studies related to its prognosis are limited.
Historically, the use apomorphine, saline injection as a placebo, or mouth and nose closure for 20–30 s have been seen for the treatment of PNESs, defined as ‘hysterical seizures’. It is also known that Charcot tried different abdominal compressions that failed in PNES treatment . A more acceptable approach is to ensure that the patient speaks about seizures and distress created by seizures in order to provide self-control rather than strengthening their dependence on others . In this way, the patients experiencing seizures alerts generally learn how to control seizures using external focus and abdominal breathing techniques.
The results of treatment trials are contradictory because patients with PNES form a heterogeneous group. It has been reported in some studies that the psychogenic nonepileptic seizures of approximately one-third of the patients stopped after the diagnosis was told to them, better results were obtained for a group of patients who received psychotherapy than those who did not take, in some cases, 34–53% of patients recovered without treatment [66, 67, 68, 69]. One of the most important issues in treatment is to report the diagnosis to the patient, because the transmission of the diagnosis can cause some problems. Some patients evaluate the current situation as ‘no physical cause’ or ‘a mental illness’. At the same time, this can be unacceptable for them . On the other hand, seizures may discontinue with a successful communication in 10% patients who were informed about diagnosis . It is reported in a study that the patients were confronted first their diagnosis, then underwent psychotherapeutic approaches and early diagnosis and therapeutic interventions increased the chances of success of treatment . In another study, the health expenditure of the patient, health institution applications and the vEEG costs decreased within 6 months after the diagnosis .
The preliminary aim of treatment is to inform and educate the patient and his/her family about the diagnosis. Thus, it will be possible for the patient to be directed to psychiatric care. In addition, unnecessary admission to emergency services, unnecessary treatments and possible adverse effects will be avoided. Antiepileptic drugs may be useful to prevent return in patients with severe abuse or posttraumatic stress disorder, and sometimes it may be appropriate to continue antiepileptic drugs as a mood stabilizer. Although it will continue to be used, the intended use of the antiepileptic drug should be clearly explained to the patient and his/her family in order not to give a double message. It is necessary to cut the antiepileptic drugs gradually when diagnosed except for these conditions [73, 74]. In a prospective study, epileptic seizures were observed in only 3 of 64 patients that antiepileptic medication was discontinued and those informed that seizures were not due to a brain disorder . Especially for patients with dissociative features it is not possible to say that they will certainly not be harmed by seizures. There was no consensus on the recommendation of restrictions on certain activities (such as driving) until these patients had their seizures controlled . PNES treatment has been reviewed by various authors [29, 75, 76]. Most of the studies related to the subject are in the form of small sample case reports and there are few enough powerful or reliable controlled studies. In a study involving psychopharmacological treatment approaches in this area, inpatient group treated with psychological intervention (paradoxical intention) and outpatient group treated with diazepam (5–15 mg/day) were compared. It has been reported that the anxiety is reduced and the symptoms are controlled more effectively in the group treated with paradoxical intention . However, it should be noted that the control group was formed by 15 cases in the study and only 9 cases completed the study. Despite the fact that antidepressants may be effective in other medically unexplained symptoms, there is no adequate data and studies on the use of antidepressant drugs in patients with psychogenic nonepileptic episodes [29, 78, 79]. In all other studies, individual or group-specific psychological treatment methods were discussed . Especially in these studies, cognitive behavioral therapy (CBT), psychodynamic approaches, interpersonal therapy, operant conditioning, eye movement desensitization and reprocessing (EMDR), biofeedback, hypnotherapy, family therapy and multidisciplinary therapies are at the forefront [80, 81, 82, 83]. A significant decrease in seizure frequency, anxiety and depression levels, an increase in psychosocial functioning with CBT targeting fear and avoidance behavior have been reported in a 12-session prospective study which is one of the best study done up to this day .
Psychoanalytically, psychogenic nonepileptic seizures are an attempt to counteract/defend the traumatic experience of the patient, and at the same time to resolve conflicts related to this experience. At the same time, it is a defense that serves also in the control of the anger, instead of harming someone else, they prefer to hurt themselves. Therefore, it will be appropriate to shape treatment in the direction of these principles, especially in patients who have trauma or unresolved grievances in the past. In other words, patients diagnosed with PNES form a heterogeneous group, and psychodynamic psychotherapy may be a good treatment option for the patients with psychic trauma stories and those who could not mourn. The story of what happened to the patient needs to be formed and the meanings of it should be studied. At the outset of treatment, psychoeducation, prevention of secondary gains, raising awareness of the patient about the relation of psychic processes and seizures and developing a good therapeutic alliance is a priority. After that the meaning of the symptoms can be focused in depth . However, it should be remembered that psychotherapy may be beneficial for some patients and the same results cannot be achieved in all patients.
As a result, epileptic and psychogenic nonepileptic seizures are two pathological conditions that should be evaluated separately in terms of both etiological, formation mechanism and treatment approach. Detailed history of seizures and careful neurological, psychiatric examination, as it provides for the correct diagnosis and treatment for the patients, it will also prevent many negative consequences that the wrong treatment may bring. Since it has been named as hysterical seizure, there has been considerable progress in the diagnosis of PNES with the use of EEG and vEEG in clinical practice. However, focusing on differential diagnosis for the PNES diagnosis by comparing with cases with epileptic seizure only, and the lack of comparison of the clinical appearance of the different subtypes of PNES are the shortcoming of the work done up to this day. Also, the effects of cultural differences on PNES are unknown. For a better understanding of treatment approaches, there is a need for studies with a large sample involving the control group.
I offer thanks to my patients for teaching me lot of things.
LaFrance WC Jr. Psychogenic nonepileptic seizures. Current Opinion in Neurology. 2008; 21(2):195-201. DOI: 10.1097/WCO.0b013e3282f7008f
Reuber M, Elger CE. Psychogenic nonepileptic seizures: Review and update. Epilepsy & Behavior. 2003; 4(3):205-216
Krebs PP. Psychogenic nonepileptic seizures. American Journal of Electroneurodiagnostic Technology. 2007; 47(1):20-28
Krumholz A. Nonepileptic seizures. Diagnosis and management. Neurology. 1999; 53(5 Suppl2):76-83
Bodde NMG, Brooks JL, Baker GA, Boon PA, Hendriksen JG, Mulder OG, et al. Psychogenic non-epileptic seizures—Definition, etiology, treatment and prognostic issues: A critical review. Seizure. 2009; 18(8):543-553. DOI: 10.1016/j.seizure.2009.06.006
Benbadis SR, Allen Hauser W. An estimate of the prevalance of psychogenic non-epileptic seizures. Seizure. 2000; 9(4):280-281
Szita B, Hidasi Z. Psychogenic non-epileptic seizures: Overview and implications for practice. Orvosi Hetilap. 2016; 157(20):767-775. DOI: 10.1556/650.2016.30428
Reuber M, Howlett S, Khan A, Grunewald RA. Non-epileptic seizures and other functional neurological symptoms: Predisposing, precipitating, and perpetuating factors. Psychosomatics. 2007; 48:230-238. DOI: 10.1176/appi.psy.48.3.230
Lancman ME, Brotherton TA, Asconape JJ, et al. Psychogenic seizures in adults: A longitudinal study. Seizure. 1993; 2:281-286
Martin RC, Gilliam FG, Kilgore M, Faught E, Kuzniecky R. Improved health care resource utilization following video-EEG confirmed diagnosis of nonepileptic psychogenic seizures. Seizure. 1998; 7:385-390
Benbadis SR. Nonepileptic behavioral disorders: Diagnosis and treatment. Continuum (Minneap Minn). 2013; 19(3 Epilepsy):715-729. DOI: 10.1212/01.CON.0000431399.69594.de
Gedzelman E, LaRoche MS. Long-term video EEG monitoring for diagnosis of psychogenic nonepileptic seizures. Neuropsychiatric Diseases and Treatment. 2014; 10:1979-1986. DOI: 10.2147/NDT.S49531
Krumholz A, Hopp J. Psychogenic (nonepileptic) seizures. Seminars in Neurology. 2006; 26(3):341-350. DOI: 10.1055/s-2006-945520
Mari F, Di Bonaventura C, Vanacore N, Fattouch J, Vaudano AE, Egeo G, et al. Video-EEG study of psychogenic nonepileptic seizures: Differential characteristics in patients with and without epilepsy. Epilepsia. 2006; 47(Suppl 5):64-67. DOI: 10.1111/j.1528-1167.2006.00880.x
Bodde NM, Brooks JL, Baker GA, Boon PA, Hendriksen JG, Aldenkamp AP. Psychogenic non-epileptic seizures—Diagnostic issues: A critical review. Clinical Neurology and Neurosurgery. 2009; 111(1):1-9. DOI: 10.1016/j.clineuro.2008.09.028
Çakıl D, Inanır S, Baykan H, Aygun H, Kozan R. Psychogenic nonepileptic seizures on differential diagnosis of epilepsy. Göztepe Tıp Dergisi. 2013; 28(1):41-47. DOI: 10.5222/J
Verrotti A, Agostinelli S, Mohn A, Manco R, Coppola G, Franzoni E, et al. Clinical features of psychogenic non-epileptic seizures in prepubertal and pubertal patients with idiopathic epilepsy. Neurological Sciences. 2009; 30(4):319-323. DOI: 10.1007/s10072-009-0107-x
Zincir SB, Yenel A, Semiz ÜB. Approach to patients with ‘psychogenic non-epileptic seizures’: A review düşünen adam. The Journal of Psychiatry and Neurological Sciences. 2012; 25:170-178. DOI: 10.5350/DAJPN2012250210 (Turkish)
Benbadis SR, O’Neill E, Tatum WO, Heriaud L. Outcome of prolonged video-EEG monitoring at a typical referral epilepsy center. Epilepsia. 2004; 45(9):1150-1153. DOI: 10.1111/j.0013-9580.2004.14504.x
Martin R, Burneo JG, Prasad A, Powell T, Faught E, Knowlton R. Frequency of epilepsy in patients with psychogenic seizures monitored by video-EEG. Neurology. 2003; 61(12):1791-1792
Iriarte J, Parra J, Urrestarazu E, Kuyk J. Controversies in the diagnosis and management of psychogenic pseudoseizures. Epilepsy & Behavior. 2003; 4(3):354-359
Benbadis SR, Agrawal V, Tatum WO. How many patients with psychogenic nonepileptic seizures also have epilepsy? Neurology. 2001; 57(5):915-917
Lesser RP. Psychogenic seizures. Neurology. 1996; 46:1499-1507
Alsaadi TM, Marquez AV. Psychogenic nonepileptic seizures. American Family Physician. 2005; 72(5):849-856
Carson AJ, Ringbauer B, MacKenzie L, Warlow C, Sharpe M. Neurological disease, emotional disorder and disability: They are related. A study of 300 consecutive new referrals to a neurology outpatient department. Journal of Neurology, Neurosurgery, and Psychiatry. 2000; 68:202-206
Oto M, Conway P, McGonigal A, Russell AJ, Duncan R. Gender differences in psychogenic non-epileptic seizures. Seizure. 2005; 14:33-39. DOI: 10.1016/j.seizure.2004.02.008
Bowman E. Relationship of remote and recent life events to the onset and course of non-epileptic seizures. In: Gates JR, Rowan AJ, editors. Non-Epileptic Seizures. Boston: Butterworth–Heinemann; 2000. p. 269-283
Dworetzky BA, Strahonja-Packard A, Shanahan CW, Paz J, Schauble B, Bromfield EB. Characteristics of male veterans with psychogenic nonepileptic seizures. Epilepsia. 2005; 46(9):1418-1422. DOI: 10.1111/j.1528-1167.2005.13004.x
Reuber M. Psychogenic nonepileptic seizures: Answers and questions. Epilepsy & Behavior. 2008; 12(4):622-635. DOI: 10.1016/j.yebeh
Auxéméry Y, Hubsch C, Fidelle G. Psychogenic nonepileptic seizures: A review. Encephale. 2011 Apr; 37(2):153-158. DOI: 10.1016/j.encep.2010.04.009
Bowman ES. Etiology and clinical course of pseudoseizures: Relationship to trauma, depression, and dissociation. Psychosomatics. 1993; 34:333-342
Rosenberg HJ, Rosenberg SD, Williamson PD, Wolford GLA. Comparative study of trauma and posttraumatic stress disorder prevalence in epilepsy patients and psychogenic nonepileptic seizure patients. Epilepsia. 2000; 41:447-452
Alper K, Devinsky O, Perrine K, Vazquez B, Luciano D. Nonepileptic seizures and childhood sexual and physical abuse. Neurology. 1993; 43:1950-1953
Ristić AJ, Petrović I, Vojvodić N, Janković S, Sokić D. Phenomenology and psychiatric origins of psychogenic non-epileptic seizures. Srpski Arhiv za Celokupno Lekarstvo. 2004; 132(1-2):22-27
Hoerth MT, Wellik KE, Demaerschalk BM, Drazkowski JF, Noe KH, Sirven JI, et al. Clinical predictors of psychogenic nonepileptic seizures: A critically appraised topic. The Neurologist. 2008; 14(4):266-270. DOI: 10.1097/NRL.0b013e31817acee4
Karakis I, Montouris GD, Piperidou C, Luciano MS, Meador KJ, Cole AJ. Patient and caregiver quality of life in psychogenic non-epileptic seizures compared to epileptic seizures. Seizure. 2014; 23:47-54. DOI: 10.1016/j.seizure.2013.09.011
Leiss AA, Ross MA, Summers AK. Psychogenic seizures; ictal characteristics and diagnostic pitfalls. Neurology. 1992; 42:95-99
Testa SM, Schefft BK, Szaflarski JP, Yeh HS, Privitera MD. Mood, personality, and health-related quality of life in epileptic and psychogenic seizure disorders. Epilepsia. 2007; 48(5):973-982. DOI: 10.1111/j.1528-1167.2006.00965.x
Genç F, Yılmaz N, Biçer GY, Özen KH, Kurtuluş F, Yaman A, et al. The diagnostic and prognostic value of induction methods in patients with psychogenic nonepileptic seizures. Epilepsia. 2013; 19(3):114-120. DOI: 10.5505/epilepsi.2013.30306. (Turkish)
Balal M, Demir T, Bozdemir H. Epileptic seizure and nonepileptic psychogenic seizure differential diagnosis in primary health care. Turkish Journal of Family Medicine and Primary Care. 2016; 10(2):105-108. DOI: 10.5455/tjfmpc.217587. (Turkish)
Abubakr A, Kablinger A, Caldito G. Psychogenic seizures: Clinical features and psychological analysis. Epilepsy & Behavior. 2003; 4(3):241-245
Brodie MJ, Kwan P. Staged approach to epilepsy management. Neurology. 2002; 58:2-8
Avbersek A, Sisodiya S. Does the primary literature provide support for clinical signs used to distinguish psychogenic nonepileptic seizures from epileptic seizures? J Neurol Neorosurg Psychiatry. 2010; 81(7):719-725. DOI: 10.1136/jnnp.2009.197996
Baslet G. Psychogenic non-epileptic seizures: A model of their pathogenic mechanism. Seizure. 2001; 20:1-13
Chung SS, Gerber P, Kirlin KA. Ictal eye closure is a reliable indicator for psychogenic nonepileptic seizures. Neurology. 2006; 66:1730-1731. DOI: 10.1212/01.wnl.0000218160.31537.87
Benbadis SR, LaFrance WC Jr, Papandonatos GD, Korabathina K, Lin K, Kraemer HC et al. Interrater reliability of EEG-video monitoring. Neurology. 2009 Sep 15; 73(11):843-846. DOI: 10.1212/WNL.0b013e3181b78425
Al-Quadah AA, Abu-Sheik S, Tamimi AF. Diagnostic value of short duration of outpatient video electroencephalographic monitoring. Pediatric Neurology. 1999; 21:622-625
Foley CM, Legido A, Miles DK, Grover WD. Diagnostic value of pediatric outpatient video-EEG. Pediatric Neurology. 1995; 12:120-124
McGonigal A, Russell AJ, Mallik AK, Oto M, Duncan R. Use of short term video EEG in the diagnosis of attack disorders. Journal of Neurology, Neurosurgery, and Psychiatry. 2004; 75(5):771-772
Ohman R, Walinder J, Balldin J, Wallin L. Prolactin response to electroconvulsive therapy. Lancet. 1976; 2(7992):936-937
Chen DK, So YT, Fisher RS. Use of serum prolactin in diagnosing epileptic seizures: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2005; 65:668-675. DOI: 10.1212/01.wnl.0000178391.96957.d0
Shah AK, Shein N, Fuerst D, Yangala R, Shah J, Watson C, Peripheral WBC. Count and serum prolactin level in various seizure types and nonepileptic events. Epilepsia. 2001; 42:1472-1475
Fisher RS, Chan DW, Bare M, Lesser RP. Capillary prolactin measurement for diagnosis of seizures. Annals of Neurology. 1991; 29(2):187-190
Alving J. Serum prolactin levels are elevated also after pseudoepileptic seizures. Seizure. 1998; 7(2):85-89
Shukla G, Bhatia M, Vivekanandhan S, Gupta N, Tripathi M, Srivastava A, et al. Serum prolactin levels for differentiation of nonepileptic versus true seizures: Limited utility. Epilepsy & Behavior. 2004; 5(4):517-521. DOI: 10.1016/j.yebeh.2004.03.004
Sundararajan T, Tesar GE, Jimenez XF. Biomarkers in the diagnosis and study of psychogenic nonepileptic seizures: A systematic review. Seizure. 2016; 35:11-22. DOI: 10.1016/j.seizure.2015.12.011
Moore PM, Baker GA, McDade G, Chadwick D, Brown S. Epilepsy, pseudoseizures and perceived family characteristics: A controlled study. Epilepsy Research. 1994; 18:75-83
Wilkus RJ, Dodrill CB. Factors affecting the outcome of MMPI and neuropsychological assessments of psychogenic and epileptic seizure patients. Epilepsia. 1989; 30(3):339-347
Cuthill FM, Espie CA. Sensitivity and specificity of procedures for the differential diagnosis of epileptic and non-epileptic seizures: A systematic review. Seizure. 2005; 14(5):293-303. DOI: 10.1016/j.seizure.2005.04.006
Cragar DE, Berry DT, Fakhoury TA, Cibula JE, Schmitt FA. A review of diagnostic techniques in the differential diagnosis of epileptic and nonepileptic seizures. Neuropsychology Review. 2002; 12(1):31-64
Sasıoglu M, Gulol C, Tosun A. The concept of alexithymia. Current Approaches in Psychiatry. 2013; 5:507-527. DOI: 10.5455/cap.20130531
Zeitlin SB, McNally RJ, Cassidy KL. Alexithymia in victims of sexual assault: An effect of repeated traumatization? The American Journal of Psychiatry. 1993; 150:661-663
Kuyk J, Dunki JL, Spinhoven P. Use of a dissociation questionnaire and a hypnotizability scale in a population with pseudo- and epileptic seizures. Epilepsia. 1995; 36:173
Kuyk J, Siffels MC, Bakvis P, Swinkels WA. Psychological treatment of patients with psychogenic non-epileptic seizures: An outcome study. Seizure. 2008; 17(7):595-603. DOI: 10.1016/j.seizure.2008.02.006
Bakvis P, Roelofs K, Kuyk J, Edelbroek PM, Swinkels WA, Spinhoven P. Trauma, stress, and preconscious threat processing in patients with psychogenic nonepileptic seizures. Epilepsia. 2009; 50(5):1001-1011. DOI: 10.1111/j.1528-1167.2008.01862.x
Kanner AM, Parra J, Frey M, Stebbins G, Pierre-Louis S, Iriarte J. Psychiatric and neurologic predictors of psychogenic pseudoseizure outcome. Neurology. 1999; 53(5):933-938
Berkhoff M, Briellmann RS, Radanov BP, Donati F, Hess CW. Developmental background and outcome in patients with nonepileptic versus epileptic seizures: A controlled study. Epilepsia. 1998; 39(5):463-469
Meierkord H, Will B, Fish D, Shorvon S. The clinical features and prognosis of pseudoseizures diagnosed using video-EEG telemetry. Neurology. 1991; 41(10):1643-1646
Storzbach D, Binder LM, Salinsky MC, Campbell BR, Mueller RM. Improved prediction of nonepileptic seizures with combined MMPI and EEG measures. Epilepsia. 2000; 41(3):332-337
Carton S, Thompson PJ, Duncan JS. Non-epileptic seizures: patients’ understanding and reaction to the diagnosis and impact on outcome. Seizure. 2003; 12(5):287-294
Aboukasm A, Mahr G, Gahry BR, Thomas A, Barkley GL. Retrospective analysis of the effects of psychotherapeutic interventions on outcomes of psychogenic nonepileptic seizures. Epilepsia. 1998; 39(5):470-473
Buchanan N, Snars J. Pseudoseizures (nonepileptic attack disorder)—clinical management and outcome in 50 patients. Seizure. 1993; 2(2):141-146
Kerr WT, Janio EA, Le JM, Hori JM, Patel AB, Gallardo NL, et al. Diagnostic delay in psychogenic seizures and the association with anti-seizure medication trials. Seizure. 2016; 40:123-126. DOI: 10.1016/j.seizure.2016.06.015
Duncan R. The withdrawal of antiepileptic drugs in patients with non-epileptic seizures: Safety considerations. Expert Opinion on Drug Safety. 2006; 5(5):609-613. DOI: 10.1517/14740322.214.171.1249
Chen DK, Sharma E, LaFrance WC Jr. Psychogenic non-epileptic seizures. Current Neurology and Neuroscience Reports. 2017; 17(9):71. DOI: 10.1007/s11910-017-0781-7
Perez DL, LaFrance WC Jr. Nonepileptic seizures: An updated review. CNS Spectrums. 2016; 21(3):239-246. DOI: 10.1017/S109285291600002X
Ataoglu A, Ozcetin A, Icmeli C, Ozbulut O. Paradoxical therapy in conversion reaction. Journal of Korean Medical Science. 2003; 18(4):581-584. DOI: 10.3346/jkms.2003.18.4.581
O’Malley PG, Jackson JL, Santoro J, Tomkins G, Balden E, Kroenke K. Antidepressant therapy for unexplained symptoms and symptom syndromes. The Journal of Family Practice. 1999; 48:980-990
Baird GL, Harlow LL, Machan JT, Curt LaFrance W Jr. Cluster reduction in patients in a pilot treatment trial for psychogenic nonepileptic seizures. Epilepsy & Behavior. 2017; 73:273-279. DOI: 10.1016/j.yebeh.2017.04.015
LaFrance WC, Reuber M, Goldstein LH. Management of psychogenic nonepileptic seizures. Epilepsia. 2013; 54(Suppl. 1):53-67
Baslet G, Dworetzky B, Perez DL, Oser M. Treatment of psychogenic nonepileptic seizures: Updated review and findings from a mindfulness-based intervention case series. Clinical EEG and Neuroscience. 2015; 46(1):54-64. DOI: 10.1177/1550059414557025
Reuber M, Mayor R. Recent progress in the understanding and treatment of nonepileptic seizures. Current Opinion in Psychiatry. 2012; 25(3):244-250. DOI: 10.1097/YCO.0b013e3283523db6
Goldstein LH, Mellers JD, Landau S, Stone J, Carson A, Medford N, et al. COgnitive behavioural therapy vs standardised medical care for adults with Dissociative non-Epileptic Seizures (CODES): A multicentre randomised controlled trial protocol. BMC Neurology. 2015; 15:98. DOI: 10.1186/s12883-015-0350-0
Goldstein LH, Deale A, Mitchell-O’Malley S, Toone BK, JDC M. An evaluation of cognitive behavioral therapy as a treatment for dissociative seizures. Cognitive and Behavioral Neurology. 2004; 17:41-49