Psychogenic non-epileptic seizures
|Psychogenic non-epileptic seizures|
|Classification and external resources|
Psychogenic non-epileptic seizures (PNES), also known as non-epileptic attack disorders (NEAD), are events resembling an epileptic seizure, but without the characteristic electrical discharges associated with epilepsy.
There is no scientific consensus as to what causes PNES. However, many physicians believe the condition may be triggered by psychological problems (irrespective of whether the patient shows any obvious psychological distress or pathology). It is estimated that 20% of seizure patients seen at specialist epilepsy clinics have PNES.
The differential diagnosis of PNES firstly involves ruling out epilepsy as the cause of the seizure episodes, along with other organic causes of non-epileptic seizures, such as syncope, migraine, vertigo, and stroke. However, between 5-20% of patients with PNES also have epilepsy. Frontal lobe seizures can be mistaken for PNES, though these tend to have shorter duration, stereotyped patterns of movements and occurrence during sleep. Next, an exclusion of factitious disorder (a subconscious somatic symptom disorder, where seizures are caused by psychological reasons) and malingering (simulating seizures intentionally for conscious personal gain - such as monetary compensation or avoidance of criminal punishment) is conducted. Finally other psychiatric conditions that may superficially resemble seizures are eliminated, including panic disorder, schizophrenia, and depersonalisation disorder.
The most conclusive test to distinguish epilepsy from PNES is long term video-EEG monitoring, with the aim of capturing one or two episodes on both videotape and EEG simultaneously (some clinicians may use suggestion to attempt to trigger an episode). Conventional EEG may not be particularly helpful because of a high false-positive rate for abnormal findings in the general population, but also of abnormal findings in patients with some of the psychiatric disorders that can mimic PNES. Additional diagnostic criteria are usually considered when diagnosing PNES from long term video-EEG monitoring because frontal lobe epilepsy may be undetectable with surface EEGs.
Following most tonic-clonic or complex partial epileptic seizures, blood levels of serum prolactin rise, which can be detected by laboratory testing if a sample is taken in the right time window. However, due to false positives and variability in results this test is relied upon less frequently.
The use of older terms including pseudoseizures and hysterical seizures are discouraged. While it is correct that a non-epileptic seizure may resemble an epileptic seizure, pseudo can also connote "false, fraudulent, or pretending to be something that it is not." Non-epileptic seizures are not false, fraudulent, or produced under any sort of pretense.
The condition may also be referred to as non-epileptic attack disorder, functional seizures, or psychogenic non-epileptic seizures. Within DSM IV the attacks are classified as a somatoform disorder, whilst in ICD 10 the term dissociative convulsions is used, classed as a conversion disorder.
Some features are more or less likely to suggest PNES but they are not conclusive and should be considered within the broader clinical picture. Features that are common in PNES but rarer in epilepsy include: biting the tip of the tongue, seizures lasting more than 2 minutes (easiest factor to distinguish), seizures having a gradual onset, a fluctuating course of disease severity, the eyes being closed during a seizure, and side to side head movements. Features that are uncommon in PNES include automatisms (automatic complex movements during the seizure), severe tongue biting, biting the inside of the mouth, and incontinence.
If a patient with suspected PNES has an episode during a clinical examination, there are a number of signs that can be elicited to help support or refute the diagnosis of PNES. Compared to patients with epilepsy, patients with PNES will tend to resist having their eyes forced open (if they are closed during the seizure), will stop their hands from hitting their own face if the hand is dropped over the head, and will fixate their eyes in a way suggesting an absence of neurological interference. Mellers et al. warn that such tests are neither conclusive nor impossible for a determined patient with factitious disorder to "pass" through faking convincingly.
Most PNES patients (75%) are women, with onset in the late teens to early twenties being typical.
According to a study in 23 patients, there is an elevated frequency of childhood abuse, especially in those with motor involvement. Such findings have led to the proposal that PNES may be an expression of repressed psychological harm in response to trauma such as child abuse. However, the childhood abuse theory is by no means universally accepted, and several studies controlling for other demographic factors have failed to find a higher incidence of reported childhood abuse in PNES patients than in a comparable patient groups with organic disease (usually epilepsy).
A number of studies have also reported a high incidence of abnormal personality traits or personality disorders in patients with PNES such as borderline personality. However, again, when an appropriate control group is used, the incidence of such characteristics it not always higher in PNES than in similar illnesses arising due to organic disease (e.g., epilepsy).
There are a number of recommended steps to explain to people their diagnosis in a sensitive and open manner. A negative diagnosis experience may cause frustration and could cause a person to reject any further attempts at treatment. Ten points to breaking the diagnosis to the person and their caregivers are:
- Reasons for concluding they do not have epilepsy
- What they do have (describe dissociation)
- Emphasise they are not suspected of "putting on" the attacks
- They are not "mad"
- Triggering "stresses" may not be immediately apparent.
- Relevance of aetiological factors in their case
- Maintaining factors
- May improve after correct diagnosis
- Caution that anticonvulsant drug withdrawal should be gradual
- Describe psychological treatment
Psychotherapy is the most frequently used treatment, which might include cognitive behavioral therapy, insight-orientated therapy, and/or group work. There is some tentative evidence supporting selective serotonin reuptake inhibitor antidepressants.
Though there is limited evidence, outcomes appear to be relatively poor with a review of outcome studies finding that two thirds of PNES patients continue to experience episodes and more than half are dependent on social security at three-year followup. This outcome data was obtained in a referral-based academic epilepsy center and loss to follow-up was considerable; the authors point out ways in which this may have biased their outcome data. Outcome was shown to be better in patients with higher IQ, social status, greater educational attainments, younger age of onset and diagnosis, attacks with less dramatic features, and fewer additional somatoform complaints.
Hystero-epilepsy is a historical term that refers to a condition described by 19th-century French neurologist Jean-Martin Charcot where patients with neuroses "acquired" symptoms resembling seizures as a result of being treated on the same ward as patients who genuinely had epilepsy.
- Devinsky, Orrin; Gazzola, Deana; LaFrance, W. Curt (2011-04-01). "Differentiating between nonepileptic and epileptic seizures". Nature Reviews. Neurology 7 (4): 210–220. doi:10.1038/nrneurol.2011.24. ISSN 1759-4766. PMID 21386814.
- Mellers JDC (2005). "The approach to patients with "non-epileptic seizures"". Postgrad Med J. 81 (958): 498–504. doi:10.1136/pgmj.2004.029785. PMC 1743326. PMID 16085740.
- Martin, R; J.G. Burneo, MD, A. Prasad, MD, T. Powell, MD, E. Faught, MD, R. Knowlton, MD, M. Mendez, MD and R. Kuzniecky, MD (23 December 2003). "Frequency of epilepsy in patients with psychogenic seizures monitored by video-EEG". Neurology 61 (12): 1791–1792. doi:10.1212/01. PMID 14694050. Cite uses deprecated parameter
- Bowman, E. S.; Coons, P. M. (2000). "The differential diagnosis of epilepsy, pseudoseizures, dissociative identity disorder, and dissociative disorder not otherwise specified". Bulletin of the Menninger Clinic 64 (2): 164–180. PMID 10842446.
- Diagnosis and management of dissociative seizures, John DC Mellers, The National Society for Epilepsy, September 2005.
- Abubakr A, Kablinger A, Caldito G (2003). "Psychogenic seizures: clinical features and psychological analysis". Epilepsy and Behavior 4 (3): 241–245. doi:10.1016/S1525-5050(03)00082-9. PMID 12791325.
- Salmon, Peter; Al-Marzooqi, Suad M.; Baker, Gus; Reilly, James (July 2003). "Childhood Family Dysfunction and Associated Abuse in Patients With Nonepileptic Seizures". Psychosomatic Medicine 65 (4): 695–700. doi:10.1097/01.PSY.0000075976.20244.D8.
- van Merode, T (1 August 2004). "Psychological characteristics of patients with newly developed psychogenic seizures". Journal of Neurology, Neurosurgery & Psychiatry 75 (8): 1175–1177. doi:10.1136/jnnp.2003.016923.
- Galimberti, Carlo Andrea; Ratti, Maria Teresa; Murelli, Rosanna; Marchioni, Enrico; Manni, Raffaele; Tartara, Amelia (1 March 2003). "Patients with psychogenic nonepileptic seizures, alone or epilepsy-associated, share a psychological profile distinct from that of epilepsy patients". Journal of Neurology 250 (3): 338–346. doi:10.1007/s00415-003-1009-0.
- Brown, Richard J.; Bouska, Julia F.; Frow, Anna; Kirkby, Antonia; Baker, Gus A.; Kemp, Steven; Burness, Christine; Reuber, Markus (October 2013). "Emotional dysregulation, alexithymia, and attachment in psychogenic nonepileptic seizures". Epilepsy & Behavior 29 (1): 178–183. doi:10.1016/j.yebeh.2013.07.019.
- Dimaro, Lian V.; Dawson, David L.; Roberts, Nicole A.; Brown, Ian; Moghaddam, Nima G.; Reuber, Markus (April 2014). "Anxiety and avoidance in psychogenic nonepileptic seizures: The role of implicit and explicit anxiety". Epilepsy & Behavior 33: 77–86. doi:10.1016/j.yebeh.2014.02.016.
- Strutt, Adriana M.; Hill, Stacy W.; Scott, Bonnie M.; Uber-Zak, Lori; Fogel, Travis G. (October 2011). "Motivation, psychopathology, locus of control, and quality of life in women with epileptic and nonepileptic seizures". Epilepsy & Behavior 22 (2): 279–284. doi:10.1016/j.yebeh.2011.06.020.
- Thompson, Alexander W.; Hantke, Nathan; Phatak, Vaishali; Chaytor, Naomi (January 2010). "The Personality Assessment Inventory as a tool for diagnosing psychogenic nonepileptic seizures". Epilepsia 51 (1): 161–164. doi:10.1111/j.1528-1167.2009.02151.x.
- LaFrance WC, Jr; Reuber, M; Goldstein, LH (March 2013). "Management of psychogenic nonepileptic seizures.". Epilepsia. 54 Suppl 1: 53–67. doi:10.1111/epi.12106. PMID 23458467.
- Reuber M, Elger CE (2003). "Psychogenic nonepileptic seizures: review and update". Epilepsy and Behavior 4 (3): 205–216. doi:10.1016/S1525-5050(03)00104-5. PMID 12791321.
- McDade (1992). "Non-epileptic seizures: management and predictive factors of outcome". Seizure 1: 7–10. doi:10.1016/1059-1311(92)90047-5. PMID 1344323.
- Kanner (1999). "Psychiatric and neurologic predictors of psychogenic pseudoseizure outcome". Neurology 53: 933–938. doi:10.1212/wnl.53.5.933. PMID 10496249.
- Reuber, Markus (March 2003). "Outcome in psychogenic nonepileptic seizures: 1 to 10-year follow-up in 164 patients". Annals of Neurology 53 (3): 305–311. doi:10.1002/ana.3000. PMID 12601698.
- Gamgee, A (Oct 12, 1878). "An Account of a Demonstration on the Phenomena of Hystero-Epilepsy Given by Professor Charcot: And on the Modification which they Undergo under the Influence of Magnets and Solenoids.". British Medical Journal 2 (928): 545–8. doi:10.1136/bmj.2.928.545. PMC 2221928. PMID 20748992.
- Ahmad, S; Beckett, MW (March 2004). "Value of serum prolactin in the management of syncope". Emergency medicine journal : EMJ 21 (2): e3. doi:10.1136/emj.2003.008870. PMC 1726305. PMID 14988379.
- Betts, T (2008). "Conversion Disorders". In Engel, Jerome; Pedley, Timothy A.; Aicardi, Jean. Epilepsy: A Comprehensive Textbook. Lippincott Williams & Wilkins. ISBN 978-0-7817-5777-5.
- Epilepsy Foundation article about non-epileptic seizures
- Epilepsy.com article about non-epileptic seizures
- National Society for Epilepsy (UK) article on Non-epileptic attack disorder – a technical article aimed at health professionals