Transcript Psychogenic Non-Epileptic Seizures (PNES): Clinical

A Brief Structured Questionnaire to Discriminate Between
Psychogenic & Neurogenic Movement Disorders
Glosser, DS, Karoscik, K, Liang, TW, Kremens, D
Department of Neurology, Jefferson Medical College, Philadelphia, PA, USA [email protected]
METHODS
A PMD is a persistent behavioral event that has been interpreted to
be a neurogenic movement disorder when, in fact, it is not. The
epidemiology of PMD is difficult to establish since no population
based surveys have been done, and other estimates have been derived
from opportunity samples of tertiary care neurology clinics or
psychiatric populations, and selection biases are inherent in both
settings. Published estimates have ranged from 9%-60% of
movement disorders patients. What is clear is that the phenomenon is
not rare, is predominantly found among women, occasions lower
quality of life, greater risk of morbidity and mortality, disability, and
expensive unproductive medical care. While the propensity to emit
these behaviors is probably influenced by inherent constitutional
factors, once it has been labeled as neurologic disease, potent
culturally determined responses to it emerge which shape its further
course through processes of modeling and reinforcement in the same
way as other behaviors (Glosser & Stern, 2000). If the social learning
hypothesis is true, then early diagnosis and contingency management
are vital to mitigate harm.
Given the great heterogeneity of both PMD and NMD symptoms, an
economical, selective instrument to identify PMD patients would be
valuable. In the related phenomenon of psychogenic non-epileptic
seizures, we have developed such an instrument (Glosser, et al., 2003
& 2008), but until now no similar instrument has been developed to
discriminate between PMD and NMD. Accordingly, 34 new
Movement Disorder Center patients were evaluated clinically and
enrolled in a study to determine the ability of the “PMD Risk Factor
Interview” to discriminate PMD from NMD patients.
NMD
M
Years of Age
54
Modal Time Since
Onset of
Symptoms
Number x Gender
Total
SD
19.6
Days 50%
Weeks 20%
Months 10%
Years 20%
M=0
F=10
M
80
NMD
62.5*
PMD
70
24*
60
60
36*
60*
50
50
40
37.5
40
33.3
76*
29.2
30
25
20.8
16.6
20
12.5
8.3
10
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Di
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M
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is k
0
66.25 10.7
t=2.36, p<.01
Days 0%
Weeks 8%
Months 17%
Years 75%
M=16
10
Number of Risk Factors x % PMD Specificity
# of Risks
Male + Female
S’s
Female S’s
0
25%
13%
1
50%
25%
2
71%
38%
3
17%
38%
4
88%
75%
5
96%
88%
6
100%
100%
7
100%
100%
8
100%
100%
9
100%
100%
SD
F=8
24
PMD RISK FACTORS
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80
PMD Risk Factor
Diagnoses of the NMD subjects included: idiopathic PD,
vascular PD, cervical dystonia, & NPH. The presenting
symptoms of both PMD and NMD included various
combinations of dyskinesia, head drop, gait disorder, tremor,
rigidity, spasm, weakness, and vertigo.
BACKGROUND
90
Su
dd
en
SUBJECTS
PMD
Proportion of Patients with PMD Risk Factors
Sa
m
• Thirty four sequential patients of the Jefferson Movement
Disorders Center were enrolled in accordance with IRB
standards. Through conventional neurological exam, testing,
history, imaging, and video review, a consensus diagnosis was
achieved by the center’s two fellowship trained movement
disorders neurologists; 24 with NMD and 10 with PMD. All
subjects also independently underwent administration of the
“PMD Risk Factor Interview” by a trained research technician.
Six patients were asked to enroll but refused; all of whom had
been diagnosed with PMD. No NMD patients refused
participation.
• The test instrument, “PMD Risk Factor Interview (PMD-RFI)”
is a structured interview requiring approximately 10-15 minutes
to administer and which samples 15 risk factors; 9 of which
proved to be discriminative.
Variable
DISCUSSION/CONCLUSIONS
RESULTS
Percent
ABSTRACT (revised)
•A brief structured interview to discriminate between psychogenic & neurogenic
movement disorders.
•Objective: Diagnosis of psychogenic movement disorders (PMD) is principally based
on exam and history and can be challenging for specialists and bewildering for
generalists. We present data regarding the utility of a brief structured questionnaire to
identify risk factors that discriminate between neurogenic versus psychogenic
movement disorder patients.
•Background: PMD’s are stereotyped behaviors attributed to one of the known
neurogenic movement disorders (NMD); when in fact this is not the case. PMD’s
represent diagnostic misattributions which have the social effect of transforming a
behavior pattern into a disease. They can best be regarded as distress displays, or
escape/avoidance behaviors which trigger culturally determined responses; including
extensive medical interventions and disability. The symptoms can mimic NMD’s
including: pathological gait, tremor, speech, speed, coordination, or atypical
undifferentiated movements. In the related area of Psychogenic Non-epileptic Seizures,
a risk factor model has shown excellent discriminative selectivity/sensitivity (Glosser,et
al., 2008), and a similar approach is tested for PMD’s.
•Design/Methods: Thirty four sequential referrals to the Movement Disorders Center,
enrolled under IRB approval, were independently diagnosed by consensus of 2
movement disorders specialists and categorized as either neurogenic (n=24) or
psychogenic (n=10). Subsequently, a 15 minute structured interview was administered
by a research technician assessing: symptom evolution, semiology, medico-legal,
substance use, other somatizations, psychiatric, and trauma risk factors.
•Results: NMD subjects’ mean # of risks =1.9; SD=1.8. PMD subjects’ mean # risks =4.8;
SD=1.8. t=4.4, df=32; p<.0001.
•Conclusions: The test instrument discriminated well between neurogenic and
psychogenic movement disorder patients. Early diagnosis may reduce the social
disability, psychiatric morbidity, and economic burden of the condition. Expansion to a
greater number of subjects, with follow-up may reveal factors associated with outcome
differences. Examination of subject variables may reveal etiological factors of relevance
to clinical management.
•Study Supported by: Departmental resources
A. Symptom Onset
1. “Sudden vs. Gradual” onset
2. Evolution in less than 14 days
B. Symptom Inconsistency
3. Complete remission with subsequent relapse
4. Movements not all the same
5. >3 Movement types
C. Psychiatric Risk
6. Any prior consultation with mental health professional
D. Abuse History Risk
7. Hx of sexual abuse
8. Hx of self-injurious behavior
E. Medicolegal Risk
9. Sued other for any reason, attorney referred, or hx of
arrest
•The nine described “PMD-RFI” risk factors discriminated
well between neurogenic and psychogenic movement disorders
patients. The test instrument had excellent selectivity and is
economical to administer. A diagnostic cutting point of > 4
risks seems to have the greatest utility with 88% specificity.
Five risk factors gave 96% specificity, and no subject with > 5
risks was falsely categorized as PMD. The mean number of
risks by group showed a highly significant difference (NMD
M=1.9; sd=1.9, and PMD M=4.8; sd=1.8, t=4.4, df=32;
p<.0001).
•Though we had expected a preponderance of female PMD
subjects, the serial admission protocol produced no male
subjects at all; which is a significant weakness of the study.
Accordingly, gender alone could be regarded as a risk factor;
though all of the senior investigators have diagnosed men with
PMD. The PMD S’s were also characterized by significantly
younger age as well as the other symptom and history-based
risks relative to NMD S’s. The high rate of participation
refusal among PMD patients was surprising as well; especially
in comparison of the 100% participation of NMD patients.
This may have been related to PMD patients’ resentment of
the clinical diagnosis.
•The PMD subject group bore several similarities to earlier
studied psychogenic non-epileptic seizure (PNES) patients, but
were older, more female, and had less frequent histories of
physical abuse. The data set is too small to make quantitative
characterizations of the factors which seemed to provoke the
onset of the PMD. Anecdotally, several of the subjects were
women who seemed entrapped in generally aversive social,
family, or work situations and had suffered one of a number of
unrelated illnesses immediately prior to PMD onset. The
antecedent illness may have produced temporary negative
reinforcement, via escape from noxious situations, or yielded
help and support. Some subjects sought disability status, and
yet others appeared mainly to have had anxiety and depressive
illnesses.
•The PMD-RFI is a useful diagnostic tool which helps to
systematize the collection of relevant clinical data and
discriminates between NMD and PMD, but it does not
delineate the etiology of the behavior. PMD may be regarded
as one variant of a wider class of evolved distress display
behaviors; which include pain display, certain deception
behaviors, and social subordination stress behaviors. PMD
patients may be those who have exaggerated constitutional or
learned vulnerabilities for the emergence of the behavior, but
whether it becomes persistent may be largely conditioned by
the social consequences that accrue to it once it does emerge. If
so, early diagnosis is important to modify those consequences
and redirect the patient towards more instrumental means of
meeting personal needs. An additional instrument that is
sensitive to etiological risk factors, and tapping those
consequences; such as family, employment, and legal factors
should be developed as well.