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Epilepsy Surgery in Patients With Additional Psychogenic Seizures
Markus Reuber, MD;
Martin Kurthen, PhD;
Guillén Fernández, MD;
Johannes Schramm, MD;
Christian E. Elger, MD, FRCP
Arch Neurol. 2002;59:82-86.
ABSTRACT
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Objective To assess whether surgery to reduce or control epileptic seizures is
safe and effective in patients known to have additional psychogenic seizures.
Design We reviewed our computerized database of 1342 patients examined for
epilepsy surgery and identified 13 patients with both epileptic and psychogenic
seizures on whom postoperative outcome data were available. Data were gathered
from the patients' records. Mean postoperative follow-up was 56 months.
Results Epilepsy surgery led to clinically relevant improvements in 11 of 13
patients. Seven patients became free of epileptic and psychogenic seizures,
2 patients became free of epileptic seizures but continued to have infrequent
psychogenic seizures, 1 patient reported more than an 80% improvement in epileptic
seizure frequency and an abolishment of psychogenic attacks, and in 1 patient
nondisabling epileptic seizures persisted at lower frequency but psychogenic
seizures stopped. In 2 of 13 patients, epilepsy surgery failed to produce
notable improvements. Although 1 patient became free of epileptic attacks
and the other had fewer than 3 epileptic seizures per year, the severity or
frequency of psychogenic seizures and pseudo–status epilepticus increased
postoperatively. One of these patients had a preoperative diagnosis of somatization
disorder; in the other, pathological illness behavior had been noted.
Conclusion A diagnosis of additional psychogenic seizures should not be considered
an absolute contraindication to epilepsy surgery, although patients should
undergo careful preoperative psychiatric evaluation.
INTRODUCTION
IN PATIENTS with medically refractory focal seizure disorders, seizure
freedom can be achieved only by epilepsy surgery. Complete control of seizures
is the most potent determinant of health-related quality of life in patients
with epilepsy.1 Seizure freedom is attained
in up to 78% of patients who undergo surgery for temporal lobe epilepsy and
in up to 82% of patients with lesions who have extratemporal operations.2-4 However, many neurologists
are reluctant to refer patients with refractory epileptic seizures for presurgical
evaluation if they have additional psychogenic seizures. Some epilepsy surgery
programs exclude such patients. Although other centers consider the additional
diagnosis of psychogenic seizure only a relative contraindication to epilepsy
surgery, to our knowledge, no center has reported the postoperative outcome
in this patient group. This study examines whether epilepsy surgery is safe
and effective in patients with mixed (epileptic and psychogenic) seizure disorders.
PATIENTS AND METHODS
PATIENTS
We searched the computerized epilepsy surgery database for the period
April 1, 1991, through December 31, 2000, for patients in whom an additional
preoperative diagnosis of psychogenic seizures was recorded. Patient characteristics
and seizure, medical, and psychiatric histories as well as details of diagnostic
workup, surgical treatment, and follow-up were retrieved from the clinical
records. The postsurgical follow-up program consisted of outpatient visits
3, 6, and 12 months after the operation and yearly after that. Patients who
did not benefit from surgery were reexamined on an inpatient basis.
DIAGNOSES
In all patients, the diagnosis of epileptic seizures was confirmed during
the preoperative workup by ictal video electroencephalogram (EEG) recordings,
and in 7 with implanted electrodes. The technique used in the implantation
of EEG electrodes has been described elsewhere.5
The diagnosis of psychogenic seizures was based on a combination of observations:
a clearly situational character of events, typical semiologic features (gradual
onset, waxing and waning of motor activity, side-to-side head movements, closed
eyes, resistance to eye opening, maintained ictal pupillary reaction to light,
ictal verbalization, ictal crying, pelvic thrusting, back arching, asynchronous
limb movements, semipurposeful movements, prolonged atonia, responsiveness
during apparent unconsciousness, and sudden postictal reorientation), the
incompatibility of the semiologic features with recognized epileptic seizure
patterns (including those seen in frontal lobe seizures), the absence of ictal
EEG changes in surface or invasive recordings, normal postictal prolactin
levels, or the induction of attacks with the suggestive injection of 0.9%
sodium chloride during video EEG recording. In 12 patients, psychogenic seizures
were documented at our center (spontaneous attacks on the ward were observed
in 2 patients, during prolonged video EEG in 4, and during video EEG after
suggestive injection in 6). In 1 patient, the diagnosis of psychogenic seizures
was based on the documentation of nonepileptic attacks with video EEG at another
hospital. All video recordings of psychogenic attacks were discussed with
patients and previous seizure witnesses to ensure that the observed episodes
were typical of habitual events. We confirmed the persistence of postoperative
psychogenic seizures by ictal video EEG recording in patient 7, and the persistence
of psychogenic as well as rare epileptic attacks in patient 5. In patients
1, 3, 4, and 12, the postoperative persistence of psychogenic or epileptic
seizures was diagnosed by an experienced epileptologist at the time of routine
follow-up on the basis of seizure descriptions from patients and relatives
and our preoperative investigations.
OUTCOME
The frequency of postoperative epileptic and psychogenic seizures was
gathered from patient records, including seizure charts. Postoperative seizure
outcome was interpreted on the basis of the Engel classification.6 The Engel classification is often used to express
epilepsy surgery outcome. Engel classes are based not only on epileptic seizure
control but also on lifestyle after surgery. For the purposes of this study,
psychogenic seizures were included in the tabulation. Classes I and II (no
or fewer than 3 disabling seizures, respectively) are considered to denote
surgical success. Class III represents limited improvement, and class IV,
no significant improvement in terms of seizures or lifestyle.
RESULTS
PATIENTS
Thirty-eight of 1342 patients who completed inpatient evaluation for
epilepsy surgery had a mixture of epileptic and psychogenic seizures. Of these,
25 did not go on to have an operation: 10 had almost exclusively psychogenic
seizures, 6 were thought to be inoperable, 5 did not want to go ahead with
invasive EEG recordings deemed necessary by the neurologic team, 2 were thought
to be good surgical candidates but decided against an operation, and 2 were
still awaiting surgery.
Thirteen patients with additional psychogenic seizures did undergo epilepsy
surgery (10 women and 3 men). The mean age at onset of unprovoked epileptic
seizures in these patients was 10 years, and that of psychogenic seizures,
21 years (we were unable to determine the age at onset of psychogenic seizures
in 4 cases). Even after discussion of the difference between epileptic and
psychogenic attacks with the physician in charge (using video recordings where
available), only 7 patients were able to distinguish between their 2 seizure
types. Additional preoperative behavioral, psychological, or psychiatric problems
were recorded in 10 patients (Table 1). Although 7 patients (patients 2 through 7 and 9) had had contact with a psychiatrist
before their assessment for epilepsy surgery, none had received psychiatric
treatment specifically directed toward the control of psychogenic seizures.
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Table 1. Patient Characteristics
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EPILEPSY SURGERY
The surgical techniques applied in this patient group have been described
elsewhere.2-3,5, 7-8
The epileptogenic lesions identified were hippocampal sclerosis (7 patients),
cortical or glioneuronal dysplasia (3 patients), benign tumor (2 patients),
and cerebral hemiatrophy (1 patient). Ten patients underwent temporal lobe
operations (6 had selective amygdala-hippocampectomies), 7 on the right side.
Two patients had extended extratemporal lesionectomies, 1 a functional hemispherectomy.
The mean age at the time of epilepsy surgery was 29 years. Mean postoperative
follow-up was 56 months (Table 2).
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Table 2. Details of Epileptogenic Lesions and Epilepsy Surgery*
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OUTCOME
Eleven of 13 patients improved overall after epilepsy surgery. Seven
became free of all epileptic and psychogenic seizures after surgery (patients
2, 6, 7, 9, 10, 11, and 13), although in 3 of these patients, anticonvulsant
medication had to be adjusted before freedom from epileptic seizures was attained.
Two patients (patients 3 and 12) reported seizure freedom for epileptic attacks
with persistence of infrequent psychogenic seizures. Two patients (patients
1 and 4) became free of psychogenic seizures and experienced a worthwhile
improvement of their epilepsy.
Two patients failed to benefit overall; whereas epileptic seizures were
abolished by surgery in patient 8, she developed less frequent but more violent
psychogenic seizures that could develop into pseudo–status epilepticus
and precipitate admissions to her local hospital. This patient had a preoperative
diagnosis of somatization disorder. Her medical history included an appendectomy,
cholecystectomy, hysterectomy, episodic monocular double vision, globus syndrome,
episodes of unexplained nondermatomal sensory loss, unexplained pyrexia, and
palpitations. The other patient (patient 5) had fewer than 3 epileptic seizures
per year after surgery but continued to be badly disabled by her devastating
psychogenic seizure disorder. She had spent a considerable part of her childhood
in the hospital with relapsing nephrotic syndrome and complications of immunosuppression.
Behavioral problems had been noted that a psychiatrist had characterized as
pathological illness behavior. She had taken a deliberate drug overdose. She
had a preoperative history of several episodes of "status epilepticus," which,
retrospectively, were likely to have been pseudo–status epilepticus.
Postoperatively, she developed a chronic factitious disorder. She had more
than 20 admissions with pseudo–status epilepticus to hospitals all over
Germany. On at least 10 occasions, pseudo–status epilepticus developed
during train journeys, causing emergency stops.
According to the modified Engel classification, epilepsy surgery was
considered successful in 9 of 13 patients with mixed (epileptic and psychogenic)
seizure disorders, useful in 2 patients, and a failure in 2 patients (Table 3).
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Table 3. Outcome of Epilepsy Surgery
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COMMENT
Up to 20% of patients referred to epilepsy surgery centers with presumed
refractory epileptic seizures prove to have purely psychogenic seizure disorders.9 Between 1991 and 2000, we diagnosed psychogenic seizures
in 233 patients admitted to our ward. In 10% to 30% of unselected patients,
psychogenic seizures coexist with epilepsy.10-11
We found additional epileptic seizures in 50% (116/233) of our inpatients
with psychogenic attacks. Patients with epilepsy who have additional psychogenic
seizures are excluded from some epilepsy surgery programs.12
We believed that we should not bar patients with medically refractory epileptic
seizure disorders from a proven, potentially curative form of treatment.13 However, epilepsy surgery was offered only to patients
predominantly disabled by epileptic rather than psychogenic seizures, and
patients were informed preoperatively that surgery was a recognized intervention
only for epileptic seizures and not for psychogenic seizures.
In total, 38 (2.8%) of 1342 patients examined for epilepsy surgery and
13 (1.3%) of 1001 patients operated on at our center during the past decade
were preoperatively known to have additional psychogenic seizures. There was
a preponderance of women in the group of surgically treated patients with
additional psychogenic seizures (76.9% vs 50.9% of all patients operated on).
Right-sided surgery was also more common in this group than in our whole surgical
cohort (76.9% vs 44.7%). The patients were representative of our whole group
in terms of onset or severity of epilepsy and age at the time of surgery.14 An association of psychogenic seizures and other
somatoform disorders with female sex and right-sided neurologic disease has
been described in previous studies of patients with mixed seizure disorders.15-16 The high number of patients with
additional psychogenic seizures (10 of 13) who had a recorded history of psychological,
behavioral, or psychiatric problems is also in accord with previous reports.17 That patients with additional psychogenic attacks
pose a particular diagnostic and therapeutic challenge was reflected by the
fact that 8 of 13 were investigated with ictal recordings from subdural or
depth EEG electrodes. However, the spectrum of epileptogenic zones identified
and the types of epilepsy surgery performed were typical of our whole surgical
program.
The good postoperative outcome in terms of epileptic seizure control
in patients with mixed seizures was in line with expectations.2-4,7-8
Patients 12 and 13 were included in this series for the sake of completeness
despite relatively short follow-up. Their exclusion from our analysis would
not have changed our conclusions. Ten patients became free of epileptic seizures
in the longer term, although in 3 of these patients, seizure freedom could
be achieved only by adjustments to their anticonvulsant therapy in the immediate
postoperative period.
We saw a "compensatory" increase in psychogenic seizure severity, as
suggested by some reports of patients who first developed psychogenic seizures
after epilepsy surgery,18-19 in
only 1 of 8 patients free of epileptic seizures postoperatively. Although
even in this patient (patient 8), the frequency of psychogenic seizures declined,
there were several episodes of pseudo–status epilepticus after the operation.
Psychogenic seizures could also disappear after epilepsy surgery. In
all, 9 patients became free of psychogenic attacks, 4 with a latency of 2
to 18 months. Seven of 9 patients who became free of psychogenic seizures
postoperatively were also free of epileptic attacks. However, the patient
with the worst postoperative outcome in terms of epileptic seizures (patient
4) also achieved freedom from psychogenic seizures, and 3 of 4 patients who
continued to have psychogenic seizures after surgery became free of disabling
epileptic seizures. There was therefore no definite link between the postoperative
outcome in terms of epileptic and psychogenic seizures.
That 7 of our patients became free of both seizure types does not necessarily
mean that psychogenic seizures were also caused by focal, organic disease,
which was cured by resection of the ictogenic part of the brain. Epilepsy
surgery, whether or not successful, represents a significant life event, and
the reasons for an improvement of psychogenic seizures could well be psychological.
It has also been observed that psychogenic seizures can remit spontaneously
after a patient has been confronted with the diagnosis (eg, during the presurgical
workup).20 Whatever the mechanism of improvement,
the duration of follow-up suggests that freedom from psychogenic seizures
can be maintained long-term after epilepsy surgery. The relatively good outcome
in terms of psychogenic seizure control in our patients who underwent epilepsy
surgery is in contrast with the poor outcome described in a group of patients
with conservatively treated mixed seizure disorders.21
Epilepsy surgery can improve patients' lives only if candidates are
examined carefully before surgery and if operative intervention is offered
only to those who have a clearly demonstrable, surgically amenable seizure
onset zone. A diagnosis of additional psychogenic seizures adds a further
dimension to this evaluation. The "surgical failures" in our series were caused
by the persistence of their underlying psychological disorder, expressed by
psychogenic seizures and pseudo–status epilepticus. This suggests that
it is prudent to pay close attention to patients' psychological status and
to the cause of their psychogenic seizures before epilepsy surgery is undertaken.
Our limited experience indicates that frequent or recurrent unexplained neurologic
or medical symptoms and multiple operations may be a warning of poor surgical
outcome, although less frequent or severe unexplained symptoms were also recorded
in 2 of our patients who were successfully operated on. Other investigators
have identified female sex, neurologic abnormality of the right or nondominant
hemisphere, and seizure onset after puberty as risk factors for psychogenic
seizures after epilepsy surgery.15 The inability
of a patient to distinguish between psychogenic and epileptic attacks should
not necessarily be a bar to surgery; although none of the patients who failed
to improve overall could differentiate their epileptic from their psychogenic
attacks, 3 of those patients who were successfully operated on could not distinguish
their seizure types. In addition, frequent psychogenic seizures and a history
of pseudo–status epilepticus do not seem to be reliable predictors of
poor epilepsy surgery outcome.
Several potential limitations of our study deserve discussion. Patients
examined for epilepsy surgery at our center represent a highly selected population;
our results should thus be extrapolated with caution. In particular, the findings
should not be interpreted as showing that epilepsy surgery is a treatment
for psychogenic seizures. Furthermore, the retrospective nature of the study
introduces potential bias. The selection of patients with mixed seizure disorders
for surgery was not based on predefined rules, and our results may have been
different if more of the 116 patients with both epileptic and psychogenic
seizures studied on our ward had been operated on. In 2 patients, the preoperative
diagnosis of additional psychogenic seizures was not based on video EEG (the
mode of investigation that comes closest to representing a gold standard in
this setting) but on the observation of situational attacks that improved
with verbal reassurance. Although attacks were observed by experienced clinicians,
our diagnosis in these patients may have been incorrect. Likewise, we may
have been wrong in the classification of persistent epileptic seizures in
patients 1 and 4 and psychogenic seizures in patients 3 and 12 after surgery.
In view of the low frequency of these postoperative events, the diagnosis
was based on expert clinical assessment and preoperative seizure documentation
rather than direct seizure observation.
Despite these limitations, we feel justified in concluding that patients
with disabling, refractory epileptic and additional psychogenic seizures should
not be barred from epilepsy surgery, since this would deny a good outcome
to some patients. However, both epileptic and psychogenic seizures should
be clearly characterized before surgery. Although we have no proof of the
efficacy of a preoperative psychiatric contact, patients with additional psychogenic
seizures should be assessed by a psychiatrist before epilepsy surgery is undertaken
so that psychological intervention can be considered, a clear psychiatric
diagnosis formulated, and a prognosis recorded. Our findings should be confirmed
in future prospective studies.
AUTHOR INFORMATION
Accepted for publication September 7, 2001.
Author Contributions: Study concept and
design (Drs Reuber, Kurthen, and Elger); acquisition of data (Drs Reuber and Fernández); analysis and interpretation
of data (Drs Reuber, Kurthen, Fernández, and Schramm); drafting of the manuscript (Drs Reuber and Kurthen); critical
revision of the manuscript for important intellectual content (Drs
Reuber, Fernández, Schramm, and Elger); statistical expertise (Drs Reuber and Fernández); obtained funding (Drs
Reuber, Schramm, and Elger); administrative, technical, and material
support (Drs Reuber and Kurthen); study supervision (Drs
Schramm and Elger).
This study was supported by the St James' Trust for Nervous System Diseases
and the Special Trustees of the General Infirmary at Leeds, Leeds, England
(Dr Reuber), and grant SFB 400 from the Deutsche Forschungsgemeinschaft, Bonn,
Germany (Drs Schramm and Elger).
We thank Peter J. Goulding, MD, FRCP, and Allan O. House, MD, FRCPsych,
for their helpful comments.
Corresponding author: Markus Reuber, MD, Department of Epileptology,
University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn, Germany (e-mail: mreuber{at}doctors.org.uk).
From the Departments of Epileptology (Drs Reuber, Kurthen, Fernández,
and Elger) and Neurosurgery (Dr Schramm), University of Bonn, Bonn, Germany.
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