Download Psychogenic movement disorders

Review
Psychogenic movement disorders
Vanessa K Hinson, W Blake Haren
Diagnosis and treatment of psychogenic movement disorders are challenging for both neurologists and psychiatrists.
Symptoms can mimic the full range of organic abnormal involuntary movements, affect gait and speech, or present
as unusual undifferentiated movements. Typical clinical characteristics of these disorders are acute onset, fast
progression, movement patterns incongruent with organic movement disorders, distractibility, variability, and
simultaneous occurrence of various abnormal movements and dysfunctions. Avoidance of iatrogenic damage by
unnecessary invasive tests or inappropriate medication, as well as use of appropriate psychiatric treatments are pivotal
steps in the management of these disorders. The few clinical trials specific to psychogenic movement disorders focus
on antidepressants and psychotherapy. Presence of a comorbid psychiatric diagnosis of depression or an anxiety
disorder is a positive prognostic factor, whereas long-standing symptoms, insidious onset of movements, and a
psychiatric diagnosis of hypochondriasis, factitious disorder, or malingering are associated with poor outcome.
Introduction
Psychogenic movement disorders are substantial
diagnostic and management challenges for both
neurologists and psychiatrists. The term psychogenic is
traditionally used to describe disorders that cannot be
attributed to any known structural or neurochemical
disease but that result from an underlying psychiatric
illness or malingering. The disorders commonly present
with various complex movements. Symptoms can mimic
the full range of organic abnormal involuntary
movements, affect gait and speech, or present as unusual
undifferentiated movements that do not fit into a known
category. The disorders most commonly fulfil psychiatric
criteria for a conversion disorder, a form of somatoform
disorder,
along
with
somatisation
disorder,
hypochondriasis, body dysmorphic disorder, and pain
disorder. Psychogenic movement disorders can be
disabling and the health-care cost associated with
somatoform disorders in general is substantial,
amounting to an estimated cost of US$20 billion per
year.1 Many physicians are reluctant to make the diagnosis
of psychogenic movement disorder for fear of missing an
underlying organic and potentially treatable disorder or
because of the general reluctance of the patient to accept
the diagnosis. In this review we discuss the epidemiology,
diagnosis, and current treatment options for these
disorders.
Epidemiology
Neurological dysfunction of psychogenic origin occurs in
1–9% of all neurological diagnoses,2,3 depending on the
applied clinical definitions and methods for case
ascertainment. Abnormal movements are among the
most common psychogenic signs,2,4 and patients with
psychogenic movement disorders are estimated to
account for 2–3% of those in movement disorder
clinics.5
The mean age at onset described in several case series
on these disorders ranges between 37 years and 50 years
and women are predominantly affected (range 61–87%).5–7
There are no data on racial distribution in the published
research, but a transcultural comparison between
http://neurology.thelancet.com Vol 5 August 2006
Lancet Neurol 2006; 5: 695–700
Department of Neurosciences,
Murray Center for Research on
Parkinson’s Disease and
Related Disorders, Medical
University of South Carolina,
Charleston Memorial Hospital,
Charleston, SC 29425, USA
(V K Hinson MD, W B Haren MD)
Correspondence to:
Dr Vanessa K Hinson
[email protected]
patients with these disorders in Spain and in the USA
showed essentially similar demographic and clinical
characteristics by ethnic origin.8
Psychogenic movement disorders usually occur as a
single neurological diagnosis, but are associated with
organic neurological disorders in 10–15% of patients.9
More commonly, these disorders are encountered in the
context of a second coexisting psychiatric illness.
Feinstein and colleagues10 assessed psychiatric
comorbidities in 88 patients with psychogenic movement
disorders by use of structured clinical interviews for the
fourth edition of the diagnosistic and statistical manual
of the American Psychiatric Association (DSM-IV).11 They
reported a coexisting axis I diagnosis (most commonly
major depression and anxiety disorders) in addition to
the diagnosis of conversion disorder in 38% of patients,
and an axis II diagnosis (personality disorder) in 42%.
Several risk factors for psychogenic movement disorders
have been identified. These include history of sexual
abuse or rape, previous surgery or other physical trauma,
and major emotionally stressful life events, such as
divorce or death of a family member.3,6,10
Diagnosis
Diagnosis of psychogenic movement disorders was
typically viewed as a “diagnosis of exclusion”,12 but a
recent increase in clinical and research interest has led to
improved understanding of the clinical characteristics
and the role of ancillary testing. As a result, diagnostic
criteria have been established that enable clinicians to
make a positive diagnosis and a specific treatment plan.
In general, these disorders can present with the whole
variety of movements seen in movement disorders of
organic origin (tremor, dystonia, chorea, bradykinesia,
myoclonus, tics, athetosis, ballism, incoordination) and
can affect speech and gait. The disorders commonly
present with complex movements that affect several body
regions. Hinson and colleagues7 analysed a sample of
88 patients with psychogenic movement disorders at a
tertiary referral centre by means of a rating scale designed
to reflect the complex clinical signs in these disorders.7
Action tremor (42%) was the most commonly observed
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sign, followed by resting tremor (39%), dystonia (32%),
bradykinesia (23%), myoclonus (19%), incoordination
resembling cerebellar dysfunction (11%), tics (8%),
chorea (7%), athetosis (3%), and ballism (2%). 60% had a
gait disorder and 28% had speech dysfunction. Most
patients (74%) exhibited two or more signs. The upper
hands and arms were most frequently affected, followed
by the legs and feet, the neck, trunk, head, face, and
shoulders.
The mode of onset typifies the clinical presentation of
psychogenic movement disorders: symptoms begin
abruptly, sometimes in the context of a minor injury or
another precipitating event, and maximum symptom
severity and disability are reached quickly.10 Disabilities
might be selective and only affect specific functions, such
as walking, whereas movement of the extremities is
normal when engaged in other motor tasks (rapid
alternating movements, strength testing).5,13 Other signs
that implicate psychogenicity are abnormal movements
incongruent with an organic movement disorder,
deliberate slowness of movement, distractibility,
variability, and simultaneous occurrence of various
abnormal movements and dysfunctions (eg, tremor
associated with myoclonus and gait dysfunction).
Movements may resolve when a patient is unaware of
being observed and increase when the affected body part
is being examined. Distractibility and variability are
especially common in psychogenic tremor (80% of
cases14) and commonly coexist with entrainment and
coactivation signs.15 Entrainment is tested by having the
patient make voluntary movements at a given frequency
Panel 1: Clinical characteristics of psychogenic movement disorders
Mode of onset
Abrupt
Precipitating event
Fast progression to maximum symptom severity and disability
Clinical signs
Signs incongruent with organic disease
Distractibility and variability
Multiple abnormal movements
Increased movement with attention to the affected body part
Deliberate slowness of movement
Entrainment, coactivation
Association with false weakness, sensory loss, and pain
Unresponsiveness to drugs for organic movement disorders, response to placebo drugs
and suggestion
Ancillary tests
Electromyography based tremor analysis
Variable frequency and amplitude, entrainment, coactivation, abnormal response to
weight loading
Electromyographic analysis of myoclonus
Variable and prolonged latencies and duration of myoclonic jerks, variable patterns of
muscle recruitment, habituation
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with the extremity contralateral to the side under
assessment. The psychogenic movement will assume the
frequency of the contralateral voluntary movement if
entrainment is positive. Coactivation is increased muscle
tone in the tremulous extremity that is inconsistent
during the examination and can be overcome with
passive movement. These characteristic features of
psychogenic tremors can also be seen in cases of
psychogenic parkinsonism, which is a rare syndrome
accounting for 0·17–0·5% of all parkinsonism cases.5,13
In psychogenic parkinsonism, atypical tremor occurs in
conjunction with extremely slow movements that are
often accompanied by grimacing, sighing, or whole-body
movements when patients do a simple motor task.16
Common characteristics of organic parkinsonism, such
as hypomimia, decreased blink rate, or axial rigidity,
are usually absent in psychogenic parkinsonism.16
Psychogenic dystonia often lacks the typical variability
and distractibility of other psychogenic movement
disorders and presents with fixed abnormal postures,17
which are often painful and can manifest in an atypical
distribution. Leg involvement, for example, is uncommon
in adult-onset organic dystonia, but quite common in
psychogenic dystonia.17,18
Abnormal gait is commonly associated with the
abnormal movements of psychogenic movement
disorders. Psychogenic gait disorders are characterised by
exaggerated effort and slowness, unusual uneconomic
postures, convulsive shaking episodes, sudden knee
buckling, and near falling.19,20 The movement disorder is
commonly accompanied by other psychogenic
neurological symptoms, such as false weakness or sensory
findings, or by excessive pain and tenderness.6,21 Response
to placebo drugs and suggestion22,23 are other important
characteristics of these disorders.24 Placebo administration
should be carefully planned and ideally given in a doubleblind fashion with the patient’s consent to avoid feelings
of deception or mistrust.6,25 Organic movement disorders,
however, can transiently improve with placebo therapy,
and a diagnosis of a psychogenic movement disorder
should not be made on the basis of the presence of a
placebo response alone.6,26 Typical clinical characteristics
of these disorders are summarised in panel 1.
In general, a discrepancy between the presenting
symptoms and the negative results of multiple
neurological investigations (eg, MRI, spinal-fluid
analysis, evoked potentials) exists. Nonetheless, ancillary
testing might be useful in some difficult-to-diagnose
cases to exclude organic movement disorders.27 Functional
neuroimaging with iodine-123-labelled β CIT singlephoton-emission CT and fluorine-18-labelled-dopa PET,
for example, has been used in the diagnosis of
psychogenic parkinsonism. Factor and co-workers28 and
Booij and colleagues29 confirmed cases of psychogenic
parkinsonism by use of 123I-β-CIT single-photon-emission
CT, which showed no striatonigral degeneration.
However, O’Sullivan and colleagues30 and Lang and
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Review
co-workers13 reported cases of suspected psychogenic
parkinsonism, but abnormal functional neuroimaging
was consistent with organic pathological changes.
Additionally, there are several neurophysiological tests
that positively reinforce the diagnosis of psychogenic
movement disorders. Tremor analysis based on
electromyography can identify entrainment and
coactivation,15,31 an increase of tremor amplitude and
frequency with weight loading of the tremulous extremity,
variability in tremor frequency, and coactivation of
antagonist muscles. Electromyographic assessment of
psychogenic myoclonus shows an abnormally long and
variable latency between the stimulus and the myoclonic
jerk, variable patterns of muscle recruitment within each
jerk, prolonged duration of myoclonic bursts, as well as
significant habituation with repeated stimulation.32
Psychogenic movement disorders are a diagnostic
challenge to the clinician, and diagnosis should be made
by an experienced movement-disorders neurologist
familiar with the various organic counterparts of the
disorders. The underlying psychiatric diagnosis and
associated secondary psychiatric disorders might not be
obvious and need expert assessment by a psychiatrist in
all cases. The DSM IV11 identifies three pertinent
diagnostic categories for these disorders: somatoform
disorders, factitious disorders, and malingering.
Somatoform disorders encompass conversion disorders
(physical symptoms that are brought on by psychological
stressors) and somatisation disorders (a multitude of
physical, non-organic symptoms). Factitious disorders
are associated with symptoms that are intentionally
produced with the purpose of achieving some
psychological gain, whereas malingering is intentional
symptom production for material (eg, financial) gain.
The most commonly encountered psychiatric diagnosis
for psychogenic movement disorders is conversion
disorder, then somatisation disorder, factitious disorder,
and malingering.6 Psychogenic movement disorders are
commonly associated with other axis I psychiatric
disorders, usually depression and anxiety.
Because individual clinical characteristics can be
difficult to interpret, Williams and colleagues6 defined
four levels of certainty for the diagnosis of psychogenic
movement disorders, which are currently being used in
clinical practice and research (panel 2).
Treatment
An important part of the management of these disorders
is the avoidance of iatrogenic damage by unnecessary
invasive tests or inappropriate medication, early and
precise diagnosis, and the use of the appropriate
psychiatric treatment. Since patients’ acceptance of the
diagnosis of psychogenicity is fundamental to treatment
success, delivery of the diagnosis becomes a pivotal step.
Williams and co-workers6 have called this the “diagnostic
debriefing”.6 Ideally involving the patient, the neurologist,
and the psychiatrist, this meeting allows the patient to
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Panel 2: Levels of certainty for diagnosis of psychogenic movement disorders6
Documented psychogenic movement disorders
Movements relieved by psychotherapy, suggestion, or placebo, or spontaneous symptom
resolution when the patient feels unobserved
Clinically established psychogenic movement disorders
Movements incongruent with organic disease or inconsistent symptoms, in addition to
the presence of other false neurological signs, multiple somatisations, or a documented
psychiatric illness
Probable psychogenic movement disorders
Movements are incongruent with organic disease or inconsistent, but no other supportive
features are present
Possible psychogenic movement disorders
Suspicion for disorder based on the patient’s obvious emotional disturbance alone
receive information from the preceding assessment and
to begin to understand the diagnosis and their own role
in the treatment plan. The specific movement-disorder
diagnosis based on the primary abnormal movements
(eg, tremor, dystonia, myoclonus) should be disclosed,
and the underlying psychiatric disorder clearly discussed
in layman’s terms. The interaction between body and
mind will often be mentioned, as will the good outcome
compared with organic neurodegenerative diseases. This
debriefing is also a time to remind the patient that the
process of treating these disorders is fluid and that the
participation of the neurologist will be ongoing. To
ensure patients’ confidence in the treatment plan,
agreement between the neurologist and the psychiatrist
on diagnosis and management is crucial. Effective
communication of the diagnosis to the treating mentalhealth professional is necessary to avoid misperception
of movement-disorder symptoms and doubt of the
diagnosis on the part of the non-neurological
consultant.33
The psychiatric treatment process will begin with a
structured clinical interview according to DSM IV11 to
establish the pertinent diagnostic category for the
psychogenic movement disorder (somatoform disorder,
factitious disorder, or malingering) and secondary
psychiatric illnesses. Eliciting the potential coexisting
psychiatric disorders is of great importance given that
proper treatment of masked depression can improve
physical symptoms.2
There have been several case reports of treatment for
psychogenic movement disorders, but clinical trials
specific to these disorders are rare. Voon and co-workers34
did an open-label trial of antidepressants (either
citalopram or paroxetine) in 15 patients who fulfilled
Fahn and Willams diagnostic criteria for a documented
or clinically established psychogenic movement disorder.
Three patients also received concurrent supportive
psychotherapy. Eight of ten patients with primary
conversion disorder had substantial improvements in
both motor and global outcomes (clinical global
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impression scale and depression and anxiety rating
scales), and seven had a complete remission. The
remaining five patients were diagnosed with primary
hypochondriasis, somatisation, and probable factitious
disorder or malingering and did not improve with the
intervention. All the patients with primary conversion
disorder had a current or previous anxiety or depression
diagnosis, whereas only 40% of the patients within the
somatoform group had these diagnoses.
Hinson and colleagues35 recruited ten patients with
psychogenic movement disorders for a single-blind
clinical trial to receive 12 weeks of treatment with
outpatient psychodynamic psychotherapy and use of
antidepressants or anxiolytic drugs. Psychotherapy was
given once weekly by the same study psychiatrist. This
treatment modality falls in the category of brief
psychotherapy and is based on psychoanalytic theories.
The psychiatrist also gave antidepressant or anxiolytic
drugs if indicated depending on comorbid psychiatric
diagnosis. The movement disorder was videotaped before
and after treatment. Tapes were rated in a random order
by a rater unaware of treatment allocation using the
psychogenic movement disorder rating scale (PMDRS).7
All patients were diagnosed with conversion disorder.
Psychiatric comorbidities were major depressive disorder
(five patients), post-traumatic stress disorder (two
patients), personality disorder (two patients), anxiety
disorder (one patient), and bipolar disorder (one patient).
Nine of ten recruited patients completed the study. Total
mean PMDRS and total mean PMDRS function scores
improved with psychotherapeutic intervention. There
were significant treatment effects in Hamilton depression
scores, Beck anxiety scores, and global assessment of
function.
Several other clinical trials, even though not specifically
designed for psychogenic movement disorders but for
other forms of conversion or somatoform disorders, are
worth mentioning here. An open-label trial of somatisation disorder studied the efficacy of nefazodone in
patients with and without comorbid depression and
showed improvement in clinical global impression and
functioning in 73% of patients.36 The efficacy of haloperidol
compared with sulpiride (a D2 blocking neuroleptic not
available in the USA) was assessed in a clinical trial of
18 patients with conversion disorder of the motor type.37
12 had tried previous medication (tricyclic antidepressants
and benzodiazepines) with no success. Patients were
randomly assigned to receive either haloperidol or
sulpiride for 16 weeks. Objective assessment with the
Middlesex Hospital questionnaire and the Hamilton
depression and anxiety rating scale showed that in the
haloperidol group one patient substantially improved,
three partly improved, and two did not improve. Whereas,
in the sulpiride group, eight patients remarkably
improved, two partly improved, and two did not improve.
This study concluded that there seems to be a positive
correlation between dopamine blockade, drug-induced
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plasma prolactin concentrations, and improvement in a
patient’s conversion symptoms. However, because of the
risk for drug-induced movement disorders and general
medical side-effects, the use of D2 blocking neuroleptics
in this population should be avoided.
Moene and colleagues38 did a randomised controlled
clinical trial of treatment for conversion disorder of the
motor type with hypnosis. They randomly assigned
48 patients to receive either hypnosis or a control
intervention consisting of generic elements of
psychotherapy. Outcome measures were a video rating
scale for motor conversion symptoms, the symptom
checklist-90, and elements of the international
classification of impairments, disabilities, and handicaps.
Independent of the treatment condition, 65% of patients
showed substantial improvement at post-treatment
assessment and 84% at 6-month follow-up, which
suggests that both psychotherapy and hypnosis have a
role in the treatment of conversion disorder.
Psychotherapy has been an important treatment
modality of conversion disorders, depression, anxiety, and
somatoform disorders in general. Cognitive behavioural
therapy (CBT) is of value in the management of functional
somatic symptoms. The goal of CBT is to reduce
symptoms, perceived stress, and disability and to limit
the inappropriate use of medical care.39 A controlled trial
of the use of CBT for medically unexplained physical
symptoms40 enrolled 79 patients and randomly assigned
them to receive either CBT or optimum medical care. The
CBT intervention group had less impairment of sleep, a
lower mean intensity of physical symptoms, and a higher
recovery rate on follow-up measured with a general health
questionnaire and a checklist for somatic symptoms than
did the optimum medical care group. Kroenke and coworkers41 did a meta-analysis of studies of CBT for various
somatisation syndromes that showed a definite or possible
treatment effect of CBT in 71% of patients.
In summary, there are few data derived from controlled
clinical trials that could lead to specific treatment
guidelines for psychogenic movement disorders.
However, a recent round-table discussion among experts
led to a publication of treatment strategies based on their
cumulative personal experiences.33 There was consensus
a psychiatrist should explore the psychodynamic basis of
the individual psychogenic movement disorder and
define the underlying and secondary psychiatric
disorders. A psychiatrist will then develop a treatment
plan addressing the psychiatric pathologies, commonly
using a combination of psychotherapy (psychodynamic
psychotherapy or CBT), stress management, relaxation
techniques, and pharmacological treatment of associated
depression and anxiety. Additionally, referral to physical
or occupational therapy might help the patient reestablish a healthy pattern of motor function. The
ultimate goal of this therapeutic approach is to enable the
patient to give up the “sick role” and return to the previous
level of function as quickly as possible (panel 3).
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Panel 3: Commonly used treatment strategies
Search strategy and selection criteria
Psychotherapy
CBT
Psychodynamic psychotherapy
References for this review were identified by searches of
PubMed and MDconsult from 1966 to May 2006, with the
terms “psychogenic movement disorders”, “functional
movement disorders”, “conversion disorder”, “somatoform
disorder”, and “somatization disorder”. Articles and book
chapters were identified through searches of the authors’
own files. Abstracts and reports from meetings were also
included. Only articles published in English were reviewed.
The final reference list was generated on the basis of
originality and relevance to the topic.
Stress management and relaxation techniques
Biofeedback
Yoga
Meditation
Pharmacotherapy
Antidepressants
Anxiolytics
Rehabilitation
Physical therapy
Occupational therapy
Prognosis
The outcome of patients with psychogenic movement
disorders is variable, but several factors that affect
outcome have been described. In general, outlook for
patients with these disorders is better than for those with
other somatoform complaints, such as sensory
symptoms, weakness, or pain.2 The presence of a
comorbid psychiatric diagnosis of depression or anxiety
disorder is a positive prognostic factor for the outcome of
conversion disorders in general37 and also in psychogenic
movement disorders.10 Negative prognostic value has
been associated with long-standing symptoms (more
than 6 months),5 insidious onset of movements,5 and
primary psychiatric diagnosis of hypochondriasis,
factitious disorder, or malingering.34 Other common
obstacles to treatment success are patients’ resistance
towards the diagnosis of psychogenicity and lack of
willingness to engage in psychiatric treatment.42 However,
patients can be motivated successfully to engage in
psychiatric treatment when physicians take interest in
the condition and deliver an unambiguous diagnosis and
a clearly outlined treatment plan.35 Of 20 consecutively
identified patients with psychogenic movement disorders,
only one patient did not accept the diagnosis and was
opposed to psychiatric treatment.35 If left untreated,
psychogenic movement disorders tend to become
chronic, and follow-up data in several series show
persistent symptoms in 65–95% of patients,5,6,10,37 clearly
showing the need for effective early intervention
strategies and larger, carefully designed clinical trials
with long-term follow-up.
Conclusion
Psychogenic movement disorders are diagnostically and
therapeutically challenging to both neurologists and
psychiatrists. More research into the underlying
mechanisms of these disorders, as well as larger treatment
studies, are clearly needed to improve the understanding
and management of these complex disorders.
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Contributors
Both authors contributed to the selection of references and the writing
of the review.
Conflicts of interest
We have no conflicts of interest.
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