Psychogenic non-epileptic seizures (PNES) are usually
differentiated from epileptic seizures on the basis of absence of tongue
biting, falling, incontinence, post ictal phenomena and concomitant
abnormalities on the electroencephalogram (EEG)(1,2). It is important to
make an early diagnosis of PNES as a delay in diagnosis leads to
overtreatment including polytherapy, repeated hospitalization, poor
response to treatment, and mechanical ventilation(3,4). However, PNES
are frequently misdiagnosed as epileptic seizures and delays in
diagnosis are common(1). This is mainly due to the presence of clinical
features thought to be typical of epileptic seizures among those with
PNES.
Case Reports
Case 1: A 12-year-old child was brought with
repeated episodes of "seizures" of four years duration. The episodes
were characterized by tonic-clonic movements of all four limbs
associated with blinking of eyes. The child was "unresponsive" and had
urinary incontinence during each of the episodes. There was no history
of tongue biting, falling or sustaining injuries. The child had 8-10
episodes per day and there were no episodes during nights. Though
majority of episodes occurred in front of others, a few occurred when
none was around. He was previously treated with various antiepileptic
drugs and was on maximum therapeutic doses of phenytoin, carbamazepine
and clobazam at presentation. Clinical examination was normal. MRI scan
of the brain and EEG were normal. Video-EEG monitoring showed that the
child’s attacks were non-epileptic in origin as during the attacks, he
would stand up and jerk his limbs in a bizarre fashion and pass urine.
He would maintain eye contact but would not answer questions. The
episode would last for about 5-30 minutes and concomitant EEG recording
was normal except for movement artifacts. A psychiatric evaluation
revealed the presence of learning disability and over-expectation from
parents. Both parents and the child were counseled and antiepileptic
drugs were gradually withdrawn. The child became seizure-free four weeks
after starting treatment and remains well at the last follow up after
two years.
Case 2: A seven-year-old boy presented with
episodic jerking movements of limbs associated with unresponsiveness of
two-year duration. During the attacks, the child would gradually slump
to the ground and start violent jerking of hands and legs with thrusting
movements. He would also produce bizarre incomprehensible sounds. These
would persist for 15-20 minutes and would occur 2-3 times per week.
Birth and development were normal. He was studying in second standard
and was doing well in studies. There was no family history of seizures.
Neurological examination was normal. MRI of the brain and EEG were
normal. He was referred to us as "seizures" were uncontrolled on maximum
therapeutic doses of sodium valproate and lamotrigine. Episodes were
witnessed during video-EEG monitoring and they were suggestive of
non-epileptic seizures as the child would avoid all possibilities of
getting hurt and he would hold his hands in air if they were lifted and
let drop by the examiner. Further questioning of parents revealed that
the child suffered from chronic constipation and would pass stools once
in 7-10 days. Extensive investigations by gastroenterologists for the
same were normal. At this stage, psychiatrist saw him and it was found
that the child felt extremely embarrassed to go to toilet and pass
stools, especially in school. He learnt to habitually constipate
himself. The urge to pass stools were constantly suppressed and resulted
in NES. He was adequately counseled and showed a marked improvement in
frequency of attacks.
Discussion
Psychogenic nonepileptic seizures (PNES) are episodes
of altered movement, sensation, or experience similar to those due to
epilepsy but caused by a psychogenic process and not associated with
abnormal electrical discharges in the brain(5). "Pseudoseizures" as a
term is better avoided as it attempts to deny the validity of the events
altogether. PNES are common in children and adolescents. The prevalence
of PNES has been estimated to be between 2-33 per 100, 000
population(6). Moreover, about 25% of neurologically normal patients and
upto 60% of children with mental retardation referred for evaluation of
seizures have PNES(7). PNES also accounts for about 20% of cases
referred for evaluation of refractory epilepsy(8).
Although PNES are common, a significant delay often
occurs prior to their diagnosis. The mean time-lapse between the first
attack and PNES diagnosis has been found to range from 7.2 years(9) to
8.7 years(1). In our cases, the diagnosis was made after a delay of four
and two years respectively. The reasons for a delayed diagnosis are
manifold. Presence of clinical signs typically associated with epileptic
seizures (such as tongue biting, falling, incontinence) is thought to be
against a diagnosis of PNES. However, in a recent study(1), at least one
of these signs was reported by 66% of patients finally diagnosed to have
PNES. One of our patients too had urinary incontinence during most of
the attacks. Interictal EEG abnormality is also thought to be a factor
supporting a diagnosis of epilepsy; however, about 16% of patients
finally diagnosed to have PNES had interictal EEG abnormalities(1).
Delayed diagnosis of PNES hampers child’s education and poses an undue
economic burden on families. A diagnosis of PNES should be suspected in
children with uncontrolled seizures, atypical clinical presentation,
learning disability, mental retardation and history of physical or
sexual abuse. Video-EEG monitoring is extremely useful in making an
early diagnosis(10). An encouraging point to note is that the outcome of
children with PNES after treatment is better than that of adults,
perhaps because causes are more likely to be external to the child, more
easily identified, and more amenable to prompt intervention(11).
Funding: None.
Competing interests: None.
