5
CHAPTER 1 :
PSYCHOGENIC NON-EPILEPTIC SEIZURES
1. Introduction
1.1. Definition
According to the recent literature, a psychogenic non-epileptic seizure (PNES)
can be defined as an observable abrupt paroxysmal change in behaviour and
consciousness (sometimes also defined as an episode of altered movement, sensation,
experience or internal psychic state) that resembles an epileptic seizure but is
characterized by the absence of typical electrophysiological changes that accompany an
epileptic seizure and for which no evidence is found for other somatic causes; there is
instead a positive evidence or a strong suspicion for psychogenic factors that may have
caused the seizure (Bodde et al., 2009). Current theories explain this illness invoking a
psychosocial etiology, but the conceptual and etiological understanding of PNES has
changed over the centuries. Historically, seizures in general were understood to carry
religious, spiritual, and even mythological meanings. Ancient populations, like the
Egyptians, the Greeks, the Romans and the Navajo, traced an association with sexual
abuse (Sharpe & Faye, 2006), whereas during the middle ages and the witch hunt in
Europe, seizures and convulsions were treated as a sign of demonic possession.
Between the 18
th
and the 20
th
century several clinics tried to understand the etiology and
the principal characteristics of psychogenic non-epileptic seizures (Dickinson & Looper,
2012): in the late 18
th
century Franz Mesmer (1734 – 1815) used his theory of the flow
of magnetic fluid in all living beings to explain, induce and cure seizures; at the end of
the 19
th
century Jean-Martin Charcot (1825 – 1893) was the first to describe hysteria as
an organic clinical disorder and classified PNES as “hysteroepilepsy” , an organic
disorder of the brain. Nevertheless, he continued to use the same treatments that
mesmerists and exorcists used centuries earlier, like hypnosis and seizure induction
6
(Ellenberger, 1970). Pierre Janet (1859 – 1947), conversely, rejected both the purely
neurological explanation and the suggestion that the symptoms were feigned. He
considered hysteria as a psychogenic disorder and proposed an important etiological
role of traumatic events (such as sexual abuse) in producing hysterical symptoms.
According to his view, this kind of symptoms arose when patients dissociated from their
memories of these events and, by reaction, focused their attention on bodily sensations
(Sharpe & Faye, 2006). In line with this, Sigmund Freud (1856 – 1939) and Joseph
Breuer (1842 – 1925) conceptualized such seizures as the repression of sexual abuse
converted into physical and somatic symptoms. Freud then revised his theory, when he
began to suspect that the stories of his patients’ sexual abuse were in fact fantasies,
concluding that seizures and other symptoms emerged from the suppression of sexual
urges, specifically oedipal fantasies, that were converted into physical manifestations.
Accordingly, he started to treat his hysterical patients using a purely discursive
approach (Ellenberger, 1970). Since then, theories of PNES etiology have been based
on the psychological constructs of dissociation and conversion (Dickinson & Looper,
2012).
According to the Diagnostic and Statistic Manual of Mental Disorders, fifth
edition (DSM-5; American Psychiatric Association, 2013) PNES are specifically a
conversion disorder and so they fall under the diagnostic category of somatic symptom
disorders. According to the DMS-5, PNES have to be distinguished from malingering
and factitious disorder even if some researchers suggest that at present there are no
definitive tests to identify simulated seizures (e.g. Reuber, 2008). Moreover, PNES have
to be distinguished from other paroxysmal non-epileptic episodes that have an organic
nature, like syncope, migraine and transient ischemic attacks. DSM-5 criteria for
conversion disorders are: a) presence of one or more symptoms of altered voluntary
motor or sensory function; b)clinical evidences of incompatibility between the
symptoms and recognized neurological or medical conditions; c)the evidence that
symptoms are not better explained by other medical or mental disorders; d) the evidence
that symptoms or deficits cause clinically significant distress or impairment in social,
occupational, or other important areas of functioning or warrants medical evaluation
(American Psychiatric Association, 2013).
In the International Classification of Diseases, tenth revision (ICD-10) (World
Health Organization, 1992) PNES is categorized under the label of dissociative
[conversion] disorders (F44). The main characteristic of these mental disorders is,
7
according to this classification, the partial or complete loss of the normal integration
between one’s sense of identity, memories of the past, immediate sensations and control
of bodily movements. Dissociative-conversion disorders are thought to be psychogenic
in origin: the symptoms often resemble the patient’s representation of how physical
illness would be manifested and might develop in close relationship to psychological
stress. PNES, under this label, are defined as “Dissociative convulsions” (F44.5) and are
described as episodes that “may mimic epileptic seizures very closely in terms of
movements, but tongue-biting, bruising due to falling, and urine incontinence are rare,
and consciousness is maintained or replaced by a state of stupor or trance” (ICD-10;
World Health Organization, 1992).
1.2. Terminology
The terms used to describe PNES have changed over the years. Moreover,
labeling this kind of condition could be difficult because it falls within the domain of
two medical specialities: neurology and psychiatry. As a result there are at least 15
synonyms for PNES that are often a cause of confusion for patients, doctors and
researchers (Scull, 1997). According to Scull (1997), the label pseudoseizures is the
most commonly used, but its flaw is that it may sound offensive to patients, because the
label implies that the seizures are not real, and can be counterproductive in term of
diagnosis delivering and treatment efficacy. He concluded that the favoured alternative
candidate was the term non-epileptic seizures (NES), because it does not imply any
specific causation and it is non-judgmental, non-offensive and therefore more
acceptable to patients (Scull, 1997). In a recent review, Bodde et al. (2009) suggest that,
as proposed by Scull, the terminology that avoids the term -pseudo- is preferable
because such term tends to imply that the seizures are unreal and can have a pejorative
and offensive meaning (Bodde et al., 2009). They conclude that a preferable term is
non-epilpetic seizure (NES), because it is non-judgmental, acceptable, and can be
descriptive and neutral at the same time; they finally suggest to add the term
‘psychogenic’ to help distinguish these seizures from other organic-based non-epileptic
spells (Bodde et al., 2009).
In conclusion, given that the diagnosis itself is considered the first step in PNES
treatment, how the diagnosis is relayed could be a crucial factor in the transition to
longer-term treatment (Brown et al., 2011). The most used term, especially in the most
8
recent studies, remains psychogenic non-epileptic seizures (with the acronym PNES),
and therefore this label appears to be the most appropriate for the aims of this report.
1.3. Epidemiology
There is general agreement in the literature that patients with PNES represent
approximately the 10 - 20% of those referred to a specialized epilepsy clinic
(Lesser, 1996; Benbadis & Hauser, 2000). In contrast, with regard to the incidence and
prevalence of these manifestations in the general population results are often unclear
and characterized by a large variability. Using available date four parameters (epilepsy
prevalence, proportion of intractable epilepsy, percentage of referred to epilepsy centers
and percentage of epilepsy centers that are found to have PNES patients) Benbadis and
Hauser (2000) proposed an estimate of the prevalence of PNES that can vary from
1/50000 to 1/30000 (2 to 33 per 100000) which is comparable to the prevalence of
better known illnesses such as multiple sclerosis or trigeminal neuralgia (Benbadis &
Hauser,2000). Certainly, is the prevalence of conversion disorders of which PNES
represent a specific sub-type, is much higher, with some studies suggesting that 9% of
the neurologic inpatients have psychogenic rather than organic symptoms (e.g. Lempert
et al., 1990).
Studies of PNES incidence indicated that it varies from 1.4/100000/year
(Sigurdardottir & Olafsson, 1998) to 3/100000/year (Szaflarsky et al., 2000), but these
data are likely to be underestimated given that these studies have only considered
neurology centers and patients with video-EEG confirmed diagnoses (see paragraph
2.1) (Reuber, 2007).
Duncan et al. (2011) tried to obtain more precise estimates by collecting data from 843
patients of a first seizure clinic who had fast access to EEG, video-EEG and ambulatory
EEG. Of those patients, 300 had epilepsy, 68 had PNES and 475 had other symptoms or
diseases (vasovagal syncope, cardiac syncope, panic attack, sleep disorder, or other).
These diagnoses were made on the basis of short outpatient video/EEG and eyewitness
confirmation, ambulatory EEG and typical eyewitness description, inpatient video-EEG
recording and patient/eyewitness description. Based on these data, PNES with video-
EEG confirmed diagnoses is estimated to have an incidence of 4.90/100000/year,
roughly 1 case of PNES for every 5.6 cases of epilepsy (Duncan et al., 2011). A
complicating factor is that a large number of PNES patients (estimates vary from 3.6%
9
to 56%) has a concomitant diagnosis of epilepsy or has a past history of epileptic
seizures (Reuber et al., 2003d; Iriarte et al., 2003).
An important and remarkable finding in the PNES literature is the
approximately threefold incidence in women compared to men (Lesser, 1996;
Rosembaum,2000, Oto et al., 2005). Rosembaum (2000) suggested that the higher
incidence in women was the only consistent result reported in the PNES literature, in
contrast with other findings that exhibited much variability among different studies
(such as the incidence of childhood sexual abuse, the incidence of cerebral pathology,
the frequency of combined PNES/epilepsy) (Rosembaum, 2000). Different hypothesis
have been made to explain this gender difference in incidence of conversion disorders,
somatization disorders, psychogenic neurological disorders and, historically, hysteria.
Some researchers suggest that the higher prevalence in women may reflect a higher
prevalence of sexual abuse (Van Merode et al., 1997; Betts & Boden, 1992), or greater
social acceptability of overt emotional expressions (Reuber & Elger,2003).
Important gender differences have been reported regarding with PNES
manifestations (Oto et al., 2005). The mean age at onset and the age of the first
presentation at the clinic were found to be higher for men than for women (35.73 vs
30.02 years and 40.98 vs 35.17 years, respectively), whereas women resulted six times
more likely than men to self-harm (12.8% vs 2.3%). Considering potential etiological
factors, men were found to be significantly more likely than women to report possible
predisposing factor to epilepsy, such as mild or severe head injury, birth hypoxia,
central nervous system infection or cerebral vascular disease (48.5% vs 19.0%),
whereas women were more likely to report sexual abuse (47.0% vs 9.5%). Whit regard
to semiology, women were found to be more likely than men to weep during or after an
attack (42.6% versus 20.9%); this is an important result if we consider that weeping
during an epileptic seizure is rare, whereas in PNES is not uncommon (Oto et al., 2005).
According to Willie et al. (2001) and other researchers, the consistent female
predominance appears to be age-related: it seems that it first emerges during
adolescence, with no gender difference, or even male predominance, between 5 and 11
years of age (Willie et al., 2001). The same result has been found in older patients,
among whom no gender difference emerged. Importantly, it has been shown that PNES
in older age are less related to sexual abuse and more likely related to health-related
traumatic experiences (Duncan et al., 2006).
Ricevi informazioni sui nostri servizi, sulle offerte e non perdere news e consigli su università e lavoro.