NEST
Information about
non-epileptic
seizures (NES)
for health
professionals
NEST Group 2009
NEST GROUP
The Non-Epileptic Seizure Treatment (NEST) group was formed in 2005 as interdisciplinary
collaboration of clinicians and academics working in Sheffield, Leeds and Manchester. The aim of the
group is to develop and evaluate new treatments for non-epileptic seizures (NES).
The group includes professionals from the fields of neurology, psychiatry, clinical psychology and
psychotherapy.
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Contents
NEST
1
Some General Remarks about NES
4
Definition
5
Epidemiology
5
Diagnosis
6
Predisposing, Precipitating and Maintaining Factors
7
Treatment
11
Outcome
11
Model of NES
12
Further Reading
13
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Some general remarks about NES
Many different names are used for non-epileptic seizures (NES). Terms such as psychogenic,
dissociative, conversion, functional and hysterical seizures, pseudoseizures, non-epileptic attacks,
non-epileptic events or medically unexplained transient loss of consciousness (TLOC) describe the
same problem. None of these labels is perfect. Most can be misunderstood and some are likely to
offend patients. The term “pseudoseizure” seems to question the true nature of the events. The
expressions “dissociative” and “conversion” seizures imply a particular aetiology and a relationship
with trauma or distress which may not be relevant in all patients.
The NEST group and materials use the terms non-epileptic seizures, non-epileptic attacks and
non-epileptic attack disorder. These labels are used interchangeably. They describe the same
condition.
One reason why it is difficult to find a good name for NES is the fact that NES can occur in many
different clinical scenarios. NES can be the core symptom of a disorder or a relatively insignificant
aspect of a more complex problem – such as in patients with many different medically unexplained
symptoms or patients with medically explained conditions (for instance epilepsy) who also have
occasional NES. NES can occur in the context of time-limited adjustment problems or be the key
manifestation of a chronically disabling seizure disorder. In other words, there are many different
NES disorders.
This ‘heterogeneous’ nature of NES means that the readers of this booklet have to bear in mind
that it is unlikely that all parts of the booklet will apply to every patient they meet.
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Definition
Non-epileptic seizures (NES) are episodes of impairment of self-control associated with a range of
motor, sensory and cognitive symptoms, which superficially resemble epileptic seizures but are not
associated with abnormal electrical activity in the brain. NES are medically unexplained and
attributed to psychological causes. Most NES involve a period of impaired consciousness and
amnesia. Some patients with NES experience symptoms which also occur in panic attacks but panic
attacks do not cause loss of consciousness.
The overwhelming majority of NES are considered as beyond patients’ voluntary control. NES are
categorised under the dissociative or somatoform disorders in the current diagnostic manuals (ICD10, DSM IV).
Epidemiology
There are no studies which have accurately measured the incidence or prevalence of NES in the
general population. The highest quality epidemiological studies were based at tertiary epilepsy
referral centres and have only described the frequency of video-EEG proven NES. These studies are
likely to underestimate the true number of patients with NES. Bearing this in mind, the following
facts have been reported:

The incidence (the number of new cases) of video-EEG proven NES has been reported as
1.4/100,000, or 3/100,000/year.

The prevalence (the total number of cases of a disease in a given population at a specific
time) of NES has been estimated as between 2 and 33/100,000, illustrating the uncertainty
noted above.

In most patients, there is a delay of several years between the start of NES and the correct
diagnosis.

NES are more common in women; typically there is a 4:1 ratio of female to male patients
with the disorder.

NES typically start in the second or third decade of life, although a seizure onset in children
below age ten and adults above seventy has been described.
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Diagnosis
The diagnosis of NES and other seizure disorders is often a gradual process rather than a single
event. The information available to clinicians about a first seizure is often limited. The diagnosis may
become clearer as more events are observed and described. Most patients with NES are initially
misdiagnosed as having epilepsy. In many patients the diagnosis of NES is made on clinical grounds
alone (for instance because of a typical seizure history). Sometimes NES cannot be proven by videoEEG because seizures are too infrequent or fail to occur in hospital. Even if a NES has been recorded
by video-EEG, this does not prove that all previous seizures were also NES. However, studies using
prolonged video-EEG monitoring have found that only 5-10% of patients have NES and additional
concurrent epileptic seizures. Nevertheless the diagnosis is “very probable” rather than “completely
certain” in many cases. The following section briefly describes the most important diagnostic
methods.
Diagnostic methods

Although NES resemble epileptic seizures there are small but important differences in how
patients and witnesses describe these different seizure types. Experts can make a correct
diagnosis on the basis of factual and conversational features in at least 80% of patients.
Factual features are observations such as the duration of seizures, the situations in which
seizures have occurred, the precise nature of movements during seizures or whether the
eyes and mouth were open or closed. Conversational features include the observation
whether patients focus on their symptoms during the seizures or the situations in which
seizures occur and seizure consequences when they talk to their doctor.

Seizure experts can accurately differentiate between NES and other causes of attacks if they
have access to a video recording of a seizure. They would also be expected to diagnose NES
correctly if they had observed a seizure directly and examined the patient during the seizure.

Video-EEG involves the simultaneous observation of the patient’s behaviour and their EEG.
This test is highly reliable in the distinction of epilepsy and NES if the recording is analysed
by an expert and if the recorded seizure involved impairment of consciousness. This test can
only be considered diagnostic if the observed seizures were like the seizures which have
happened spontaneously before the test. For this reason, the patient and a seizure witness
should confirm that the recorded attack was typical. Seizure provocation techniques (such as
hyperventilation, photo stimulation or the injection of saline placebo) are sometimes used
to increase the yield of video-EEG.

A scalp EEG recording of an epileptic seizure can reliably exclude most types of epilepsy.
Normal ictal scalp EEG recordings cannot be considered diagnostic of NES if the seizure only
produced subjective symptoms (such as tingling or anxiety). Scalp EEG recordings are also
normal in some epileptic seizure of frontal lobe origin (for instance seizures with cycling
movements or bilateral posturing).
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
Blood tests immediately after a seizure (prolactin, creatine kinase) can provide some
indication of the diagnosis of NES or epilepsy, especially if the seizure looked like a tonicclonic (grand mal) seizure.
Predisposing, Precipitating and Maintaining Factors
A number of factors have been identified as possible causes of NES. The framework on page 12 gives
an overview.
Predisposing Factors
All studies of predisposing factors such as stressful experiences, childhood neglect or trauma in
patients with NES have been retrospective. Many were small and did not take clear account of the
base rates of such experiences in the general population, or control for gender differences between
NES and control groups. Studies of personality factors and of other psychopathology were typically
carried out in patients who had experienced NES for several years. This makes it difficult to
understand the relationship between NES and other emotional or behavioural symptoms. Like the
studies of childhood trauma or neglect, the results of these studies may have been affected by the
fact that more chronic or difficult seizure disorders were probably over-represented in the specialist
centres where the research was carried out. Most studies of cognitive factors used test batteries
designed for patients with epilepsy. The majority did not include tests of motivation, making the
results difficult to interpret. However, the following findings have been reported:
Stressful experience
Around 90% of patients with NES report significant traumatic experiences in their past.
 Around 90% of patients with NES report that they have experienced the kind of events in the
past which can be considered stressful enough to cause ongoing emotional problems.

The most widely studied form of traumatic experience is childhood sexual and physical
abuse.

The reported rates of sexual or physical abuse in patients with NES vary widely, but the best
quality studies have found that around 25% of women with NES report some form of early
life abuse. Abuse is reported much less commonly by men with NES.
Family dysfunction
 It has been argued that NES are not so much a direct consequence of childhood abuse, but
that both NES and childhood abuse are the result of family dysfunction.

Small studies suggest that patients with NES are more likely to have been exposed to
childhood neglect than control populations.
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
NES patients are also more likely than patients with epilepsy to report a family history of
psychiatric disorder or epilepsy.

Some studies have suggested that NES patients experience their families as less supportive
and communicative than patients with epilepsy or that their families are characterized by
high levels of criticism and stronger somatisation tendencies.
Personality Factors
 NES disorders are not associated with one particular personality profile.

Some NES patients have a personality profile resembling that of patients with borderline
personality disorder.

A further subgroup has a personality profile characterised by an unusually tight control of
emotional regulation.
Psychopathology
 NES are associated with high levels of psychiatric co-morbidity. Common co-morbid
disorders include;

o
Somatoform disorders
o
Dissociative disorders
o
Post-traumatic stress disorder
o
Depressive disorders
o
Anxiety disorders
The severity of psychopathology measured by self-report questionnaires correlates
positively with the severity of the NES disorder.
Illness perceptions
 An important subgroup of patients with NES has difficulty recognising psychological
influences on their disorder.

They are less likely than patients with epilepsy to endorse stress or emotional factors as a
possible cause of seizures.

Many patients score as alexithymic (deficiency in understanding, processing, or describing
emotions) on a self-report instrument.
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Cognitive factors
 Many studies show that patients with NES tend to perform below expectation in tests of
memory, attention and mental processing.
 However, most researchers have failed to identify a characteristic pattern of deficits in
patients with NES.
Precipitating factors and seizure triggers
All studies of stress, life events or dilemmas as precipitants of NES are retrospective. Most do not
compare the findings in NES patients with those in controls. Many patients report that (some of) their
seizures are triggered by particular stimuli. However, there are no high quality studies of trigger
factors. Bearing these limitations in mind, the following observations have been made.
Stress and dilemmas
 Many NES patients experience stress, or unresolvable dilemmas in their home environment.
 NES have been reported as developing after a whole range of life events: rape, injury,
”symbolic“ traumatic experience in adulthood after childhood abuse, surgical procedures,
giving birth and undergoing anesthetics, death of or separation from family members or
friends, job loss, road traffic and other accidents, earthquakes, relationship difficulties, and
legal action.
 Many NES disorders do not start soon after a particular negative life event or experience.
One small study in which patients were interviewed soon after seizures had first started,
showed that (whilst patients with NES reported more negative life events over all than
patients with epilepsy) there was no higher incidence of such events within the three
months before seizure manifestation, although patients did report more negative life events
overall.
Triggers for seizure recurrence
 Some recurrent seizures can be triggered by much less significant events or stimuli, for
instance visits to the doctor, sudden noise or flashing light.

In around two thirds of patients, NES can be provoked during (video-) EEG monitoring by a
range of suggestion or provocation techniques.

NES have also been reported from EEG-documented sleep, although NES from
“pseudosleep” (apparent sleep with EEG appearances of wakefulness) are much more
common.

Very rarely, NES can be triggered by simple partial epileptic seizures.
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Maintaining factors
Several studies have examined the healthcare use of patients with NES. Although it may be likely that
suboptimal communication between patients and healthcare providers can contribute to bad
treatment outcomes, the role of healthcare contacts as an aetiological factor remains unproven.
Existing work in this area may have been influenced by the fact that most studies have been carried
out in patients with relatively chronic seizure disorders presenting to specialist centres. Other possible
maintaining factors such as financial illness benefits are very difficult to study. Nevertheless the
following findings have been published:
Healthcare contacts
 Many patients with NES are frequent users of healthcare services.

Patients with NES often have other medically unexplained physical symptoms including
chronic pain, fibromyalgia, irritable bowel syndrome or menstrual problems.

Frequent healthcare contacts mean that some patients are being repetitively investigated
and hear different explanations from the many doctors they encounter.
Social / financial illness gain
 It is possible that financial or social benefits related to the seizures play a perpetuating role
in some cases.

Some patients may acquire a “sick role“ and off-load unpleasant responsibilities onto others.
However, there is no systematic evidence suggesting that this is more common in NES
patients than in those with other medical or psychological conditions.

There is no evidence that malingering or the exaggeration of symptoms is seen more
commonly in patients with NES than in patients with medically explained disorders.
Behaviour Change/Avoidance
 Avoidance is common in NES. Patients often stop doing activities they previously enjoyed or
took part in because of the fear of having a seizure. This might be related to anxiety about
what others might think, or fears about injury.

Avoidance will typically lead to restrictions on the patient’s life over and above the level
explained by physical disability.
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Treatment
There is no high quality evidence for effective treatments for NES. A number of case reports, large
uncontrolled studies and small controlled studies have been published. Many treatment suggestions
are based on experience from the treatment of similar conditions such as somatoform disorder,
dissociative disorder, or panic. The following statements can be made.

Most experts consider psychological intervention the treatment of choice, although there is
currently limited proof that this is effective.

There is evidence that a clear presentation of the diagnosis in itself can be followed by a
cessation or reduction of seizure activity, in about a third of patients.

Conversely, the failure to accept the psychological nature of NES is associated with poor long
term outcome.

There is no proof that drug treatment is effective. However, antidepressant drugs are
sometimes used. They may help patients with additional symptoms of anxiety or depression.

Antiepileptic drugs have never been shown to work for NES. NES have been reported to be
made worse by antiepileptic drugs.
Outcome
Only short term outcome after the communication of the diagnosis of NES has been studied in
prospective studies. In view of their limited size these studies could not take full account of the
clinical differences between the various types of NES disorders. All long term outcome studies are
retrospective and describe the outcome of patients diagnosed with NES at tertiary referral centres. It
is possible that these studies make the longer term outlook worse than it is for patients presenting
earlier to less specialised centres. Current knowledge is summarised below.
Short and long term prognosis

Within weeks of the diagnosis of NES, some 1/6 of patients have been found to have had no
further seizures.

Three months after the communication of the diagnosis about 1/3 of patients have been
reported to be seizure-free (with no specific further treatment).
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
Longer term outcome studies suggest a poorer prognosis: In one study, two thirds of
patients remained disabled, continued to experience seizures or both, years after onset and
diagnosis.

In the same study, 40% of patients diagnosed as having only NES were taking antiepileptic
drugs (again) four years after the diagnosis. It is likely that most of these patients were
inaccurately re-diagnosed as having epilepsy after their assessment in a specialist centre.
Factors affecting outcome

Several studies indicate that seizures presenting in children and younger adults are
associated with a better prognosis.

Outcome has been shown to be better in patients with higher educational achievements.

Longer duration of seizures before diagnosis is also associated with poorer outcome; the
early and non-threatening communication of the diagnosis would therefore seem an
important starting point for successful longer term management.
Model of NES
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Further Reading
Brooks, J. L., Baker, G. A., Goodfellow, L., Bodde, N. & Aldenkamp, A. (2007) Behavioural treatments
for non-epileptic attack disorder. Cochrane Database of Systematic Reviews DOI:
10.1002/14651858.CD006370.
Brown, R (2004) Psychological mechanisms of medically unexplained symptoms: an integrative
conceptual model. Psychological Bulletin. 130: 793-812.
Lafrance, C. W. & Devinsky, O. (2002) Treatment of nonepileptic seizures. Epilepsy and Behavior, 3:
19-23.
LaFrance, WC & Barry, JJ (2005) Update on treatments of psychological nonepileptic seizures.
Epilepsy and Behavior. 7: 364-3.
Reuber, M & House, AO (2002) Treating patients with psychogenic non-epileptic seizures. Current
Opinion in Neurology. 15: 207-211.
Reuber, M, Pukrop, R, Bauer, J, Helmstaedter, C, Tessendorf, N & Elger, CE (2003) Outcome in
psychogenic nonepileptic seizures: 1 to 10 year follow-up in 164 patients. Annas of Neurology. 53:
305-311.
Reuber, M & Elger, CE (2003) Psychogenic nonepileptic seizures: review and update. Epilepsy and
Behavior. 4: 205-216.
Reuber, M, Howlett, S & Kemp, S (2005) Psychologic treatment for patients with psychogenic
nonepileptic seizures. Expert Opinion in Neurotherapeutics. 5: 737-752.
Reuber, M., Howlett, S., Khan, A. & Grunewald, R. A. (2007) Non-epileptic seizures and other
functional neurological symptoms: predisposing, precipitating, and perpetuating factors.
Psychosomatics, 48: 230-8.
Reuber M. (2008) Psychogenic nonepileptic seizures: answers and questions. Epilepsy and Behavior.
12: 622-635.
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