Psychogenic movement disorders: past developments, current status, and future directions

Factors Influencing Triage to Rehabilitation in Functional Movement Disorder

BACKGROUND

Treatment of functional movement disorder (FMD) should be individualized, yet factors determining rehabilitation engagement have not been evaluated. Subspecialty FMD clinics are uniquely poised to explore factors influencing treatment suitability and triage.

OBJECTIVES

To describe our approach and explore factors associated with triage to FMD rehabilitation.

METHODS

We conducted a retrospective chart review of 158 consecutive patients with FMD seen for integrated assessment by movement disorders neurology and psychiatry, with the purpose of triage to rehabilitation. Demographic and clinical variables were compared between patients triaged to therapy versus no therapy, and logistic regression was used to explore factors predictive of triage outcome. Change in primary outcome scores were analyzed.

RESULTS

Sixty-six patients (42%) were triaged to FMD therapy from July 2019 to December 2021. Patients triaged to therapy were more likely to have a constant movement disorder, gait disorder and/or tremor, hyperarousal, readiness for change, and people pleasing traits. Patients triaged to no therapy demonstrated persistent diagnostic disagreement, an inability to appreciate motor symptom inconsistency, low self-agency, a propensity to dissociate, and cluster B traits. 90% of patients triaged to rehabilitation had improved outcomes.

CONCLUSIONS

The ability to "opt-in" to FMD rehabilitation relies on different factors than those relevant to establishing a diagnosis. Unlike many other neurological disorders, a triage and treatment planning step is recommended to identify those likely to meaningfully engage at that time. Holistic assessment through a transdisciplinary lens, and working collaboratively with the patient is essential to prioritize symptoms, determine engagement, and identify treatment targets.

Functional Dystonia: Differentiation From Primary Dystonia and Multidisciplinary Treatments

Dystonia is a common movement disorder, involving sustained muscle contractions, often resulting in twisting and repetitive movements and abnormal postures. Dystonia may be primary, as the sole feature (isolated) or in combination with other movement disorders (combined dystonia), or as one feature of another neurological process (secondary dystonia). The current hypothesis is that dystonia is a disorder of distributed brain networks, including the basal ganglia, cerebellum, thalamus and the cortex resulting in abnormal neural motor programs. In comparison, functional dystonia (FD) may resemble other forms of dystonia (OD) but has a different pathophysiology, as a subtype of functional movement disorders (FMD). FD is the second most common FMD and amongst the most diagnostically challenging FMD subtypes. Therefore, distinguishing between FD and OD is important, as the management of these disorders is distinct. There are also different pathophysiological underpinnings in FD, with for example evidence of involvement of the right temporoparietal junction in functional movement disorders that is believed to serve as a general comparator of internal predictions/motor intentions with actual motor events resulting in disturbances in self-agency. In this article, we present a comprehensive review across the spectrum of FD, including oromandibular and vocal forms and discuss the history, clinical clues, evidence for adjunctive "laboratory-based" testing, pathophysiological research and prognosis data. We also provide the approach used at the Massachusetts General Hospital Dystonia Center toward the diagnosis, management and treatment of FD. A multidisciplinary approach, including neurology, psychiatry, physical, occupational therapy and speech therapy, and cognitive behavioral psychotherapy approaches are frequently required; pharmacological approaches, including possible targeted use of botulinum toxin injections and inpatient programs are considerations in some patients. Early diagnosis and treatment may help prevent unnecessary investigations and procedures, while facilitating the appropriate management of these highly complex patients, which may help to mitigate frequently poor clinical outcomes.

Motor Retraining (MoRe) for Functional Movement Disorders: Outcomes From a 1-Week Multidisciplinary Rehabilitation Program

BACKGROUND

Functional movement disorders (FMDs) are conditions of abnormal motor control thought to be caused by psychological factors. These disorders are commonly seen in neurologic practice, and prognosis is often poor. No consensus treatment guidelines have been established; however, the role of physical therapy in addition to psychotherapy has increasingly been recognized. This study reports patient outcomes from a multidisciplinary FMD treatment program using motor retraining (MoRe) strategies.

OBJECTIVE

To assess outcomes of FMD patients undergoing a multidisciplinary treatment program and determine factors predictive of treatment success.

DESIGN

Retrospective chart review.

SETTING

University-affiliated rehabilitation institute.

PATIENTS

Thirty-two consecutive FMD patients admitted to the MoRe program from July 2014-July 2016.

INTERVENTION

Patients participated in a 1-week, multidisciplinary inpatient treatment program with daily physical, occupational, speech therapy, and psychotherapy interventions.

MAIN OUTCOME MEASUREMENTS

Primary outcome measures were changes in the patient-rated Clinical Global Impression Scale (CGI) and the physician-rated Psychogenic Movement Disorder Rating Scale (PMDRS) based on review of standardized patient videos. Measurements were taken as part of the clinical evaluation of the program.

RESULTS

Twenty-four of the 32 patients were female with a mean age of 49.1 (±14.2) years and mean symptom duration of 7.4 (±10.8) years. Most common movement phenomenologies were abnormal gait (31.2%), hyperkinetic movements (31.2%), and dystonia (31.2%). At discharge, 86.7% of patients reported symptom improvement on the CGI, and self-reported improvement was maintained in 69.2% at the 6-month follow-up. PMDRS scores improved by 59.1% from baseline to discharge. Longer duration of symptoms, history of abuse, and comorbid psychiatric disorders were not significant predictors of treatment outcomes.

CONCLUSIONS

The majority of FMD patients experienced improvement from a 1-week multidisciplinary inpatient rehabilitation program. Treatment outcomes were not negatively correlated with longer disease duration or psychiatric comorbidities. The results from our study are encouraging, although further long-term prospective randomized studies are needed.

LEVEL OF EVIDENCE

III.

The Inpatient Assessment and Management of Motor Functional Neurological Disorders: An Interdisciplinary Perspective

BACKGROUND

Motor functional neurologic disorders (FND)-previously termed "hysteria" and later "conversion disorder"-are exceedingly common and frequently encountered in the acute hospital setting. Despite their high prevalence, patients with motor FND can be challenging to diagnose accurately and manage effectively. To date, there is limited guidance on the inpatient approach to the neuropsychiatric evaluation of patients with functional (psychogenic) neurologic symptoms.

OBJECTIVE

The authors outline an inpatient multidisciplinary approach, involving neurology, psychiatry, and physical therapy, for the assessment and acute inpatient management of motor FND.

METHODS

A vignette of a patient with motor FND is presented followed by a discussion of general assessment principles. Thereafter, a detailed description of the neurologic and psychiatric assessments is outlined. Delivery of a "rule-in" diagnosis is emphasized and specific guidance for what can be accomplished postdiagnosis in the hospital is suggested.

DISCUSSION

We encourage an interdisciplinary approach beginning at the early stages of the diagnostic assessment once an individual is suspected of having motor FND.

CONCLUSIONS

Practical suggestions for the inpatient assessment of motor FND are presented. It is also important to individualize the diagnostic assessment. Future research should be conducted to test best practices for motor FND management in the acute inpatient hospital setting.

Neurophysiologic studies of functional neurologic disorders

Functional neurologic disorders are largely genuine and represent conversion disorders, where the dysfunction is unconscious, but there are some that are factitious, where the abnormality is feigned and conscious. Malingering, which can have the same manifestations, is similarly feigned, but not considered a genuine disease. There are no good methods for differentiating these three entities at the present time. Physiologic studies of functional weakness and sensory loss reveal normal functioning of primary motor and sensory cortex, but abnormalities of premotor cortex and association cortices. This suggests a top-down influence creating the dysfunction. Studies of functional tremor and myoclonus show that these disorders utilize normal voluntary motor structures to produce the involuntary movements, again suggesting a higher-level abnormality. Agency is abnormal and studies shows that dysfunction of the temporoparietal junction may be a correlate. The limbic system is overactive and might initiate involuntary movements, but the mechanism for this is not known. The limbic system would then be the source of top-down dysfunction. It can be speculated that the involuntary movements are involuntary due to lack of proper feedforward signaling.

Functional dystonia

Although currently lacking a sensitive and specific electrophysiologic battery test, functional (psychogenic) dystonia can sometimes be diagnosed with clinically definite certainty using available criteria. Certain regional phenotypes have been recognized as distinctive, such as unilateral lip and jaw deviation, laterocollis with ipsilateral shoulder elevation and contralateral shoulder depression, fixed wrist and finger flexion with relative sparing of the thumb and index fingers, and fixed foot plantar flexion and inversion. The pathophysiologic abnormalities in functional dystonia overlap substantially with those of organic dystonia, with similar impairments in cortical and spinal inhibition and somatosensory processing, but with emerging data suggesting abnormalities in regional blood flow and activation patterns on positron emission tomography and functional magnetic resonance imaging, respectively. Management of functional dystonia begins with compassionate and assertive debriefing of the diagnosis to ensure full acceptance by the patient, a critical step in enhancing the likelihood of success with physical rehabilitation, and psychodynamic or cognitive therapy. Physical therapy, with or without cognitive behavioral therapy, appears to be of benefit but has not yet been examined in a controlled fashion. While the prognosis remains grim for a substantial majority of patients, partly stemming from restricted mobility, delayed diagnosis, and inappropriate pharmacotherapy, early recognition and initiation of therapy stand to minimize iatrogenic harm and unnecessary laboratory investigations, and potentially reduce the long-term neurologic disability.

Apollo's curse: neurological causes of motor impairments in musicians

Performing music at a professional level is probably one of the most complex human accomplishments. Extremely fast and complex, temporo-spatially predefined movement patterns have to be learned, memorized, and retrieved with high reliability in order to meet the expectations of listeners. Performing music requires not only the integration of multimodal sensory and motor information, and its precise monitoring via auditory and kinesthetic feedback, but also emotional communicative skills, which provide a "speaking" rendition of a musical masterpiece. To acquire these specialized auditory-sensory-motor and emotional skills, musicians must undergo extensive training periods over many years, which start in early childhood and continue on through stages of increasing physical and strategic complexities. Performance anxiety, linked to high societal pressures such as the fear of failure and heightened self-demands, frequently accompanies these learning processes. Motor disturbances in musicians are common and include mild forms, such as temporary motor fatigue with short-term reduction of motor skills, painful overuse injuries following prolonged practice, anxiety-related motor failures during performances (choking under pressure), as well as more persistent losses of motor control, here termed "dynamic stereotypes" (DSs). Musician's dystonia (MD), which is characterized by the permanent loss of control of highly skilled movements when playing a musical instrument, is the gravest manifestation of dysfunctional motor programs, frequently linked to a genetic susceptibility to develop such motor disturbances. In this review chapter, we focus on different types of motor failures in musicians. We argue that motor failures in musicians develop along a continuum, starting with subtle transient degradations due to fatigue, overuse, or performance stress, which transform by and by into more permanent, still fluctuating motor degradations, the DSs, until a more irreversible condition, MD manifests. We will review the epidemiology and the principles of medical treatment of MD and discuss prevention strategies.

Caloric vestibular stimulation as a treatment for conversion disorder: a case report and medical hypothesis

Conversion disorder is a medical condition in which a person has paralysis, blindness, or other neurological symptoms that cannot be clearly explained physiologically. To date, there is neither specific nor conclusive treatment. In this paper, we draw together a number of disparate pieces of knowledge to propose a novel intervention to provide transient alleviation for this condition. As caloric vestibular stimulation has been demonstrated to modulate a variety of cognitive functions associated with brain activations, especially in the temporal-parietal cortex, anterior cingulate cortex, and insular cortex, there is evidence to assume an effect in specific mental disorders. Therefore, we go on to hypothesize that lateralized cold vestibular caloric stimulation will be effective in treating conversion disorder and we present provisional evidence from one patient that supports this conclusion. If our hypothesis is correct, this will be the first time in psychiatry and neurology that a clinically well-known mental disorder, long considered difficult to understand and to treat, is relieved by a simple or common, non-invasive medical procedure.

A retrospective study of the clinical and electrophysiological characteristics of 32 patients with orthostatic myoclonus

OBJECTIVES

To review the electrophysiological and clinical characteristics of 32 patients with orthostatic myoclonus (OM), a relatively newly identified movement disorder, and compare these characteristics to those of primary orthostatic tremor (OT) patients and patients with similar gait and balance complaints without either hyperkinesia diagnosed during the same 30-month period.

METHODS

The database of the Mayo Clinic Florida Movement Disorders Electrophysiology Laboratory (MDEL) was searched for all patients referred for possible OM or OT from 6/2010 to 12/2012. All available clinical records and archived surface electromyographical data for these patients were reviewed and analyzed.

RESULTS

32 patients with OM (mean age 74 years), 8 with primary OT (mean age 71), and 55 with neither orthostatic hyperkinesia (NOH) (mean age 68) were identified. All OT patients and 84% each of OM and NOH patients complained of involuntary leg movements while standing, e.g., "shaking," "trembling," or "jerking." All OM and OT patients experienced symptomatic and electrophysiological abatement or attenuation of their leg hyperkinesias by leaning forward onto an object while standing.

CONCLUSIONS

OM has some similarities to OT, including causing "shaky legs" subjectively in standing older patients. Novel data from this work include that, as in OT, OM essentially abates when patients remove their weight from their legs. This shared isometric phenomenon may reflect that OT and OM are on a pathophysiological continuum. Further, many patients who complain of their legs "shaking" while standing may have neither OT nor OM. Surface electromyography may be a useful adjunct in extrapolating patients complaining of "shaky legs."

Diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT: a clinical follow up study

The [¹²³I]ioflupane—a dopamine transporter radioligand—SPECT (DaT-SPECT) has proven to be useful in the differential diagnosis of tremor. Here, we investigate the diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT. Therefore, 30 patients with tremor and normal DaT-SPECT were followed up for 2 years. In 18 cases we were able to make a diagnosis. The residual 12 patients underwent a second DaT-SPECT, were then followed for additional 12 months and thereafter the diagnosis was reconsidered again. The final diagnoses included cases of essential tremor, dystonic tremor, multisystem atrophy, vascular parkinsonism, progressive supranuclear palsy, corticobasal degeneration, fragile X–associated tremor ataxia syndrome, psychogenic parkinsonism, iatrogenic parkinsonism and Parkinson's disease. However, for 6 patients the diagnosis remained uncertain. Larger series are needed to better establish the relative frequency of the different conditions behind these cases.

Sensory aspects of movement disorders

Movement disorders, which include disorders such as Parkinson's disease, dystonia, Tourette's syndrome, restless legs syndrome, and akathisia, have traditionally been considered to be disorders of impaired motor control resulting predominantly from dysfunction of the basal ganglia. This notion has been revised largely because of increasing recognition of associated behavioural, psychiatric, autonomic, and other non-motor symptoms. The sensory aspects of movement disorders include intrinsic sensory abnormalities and the effects of external sensory input on the underlying motor abnormality. The basal ganglia, cerebellum, thalamus, and their connections, coupled with altered sensory input, seem to play a key part in abnormal sensorimotor integration. However, more investigation into the phenomenology and physiological basis of sensory abnormalities, and about the role of the basal ganglia, cerebellum, and related structures in somatosensory processing, and its effect on motor control, is needed.

Pharmacotherapy of essential tremor

Essential tremor (ET) is a common movement disorder but its pathogenesis remains poorly understood. This has limited the development of effective pharmacotherapy. The current therapeutic armamentaria for ET represent the product of careful clinical observation rather than targeted molecular modeling. Here we review their pharmacokinetics, metabolism, dosing, and adverse effect profiles and propose a treatment algorithm. We also discuss the concept of medically refractory tremor, as therapeutic trials should be limited unless invasive therapy is contraindicated or not desired by patients.

Imaging psychogenic movement disorders

The neurobiological basis of psychogenic movement disorders (PMDs) has been elusive, and they remain difficult to treat. In the last few years, functional neuroimaging studies have provided insight into their pathophysiology and neural correlates. Here, we review the various methodological approaches that have been used in both clinical and research practice to address neural correlates of functional disorders. We then review the dominant hypotheses generated from the literature on psychogenic paralysis. Overall, these studies emphasize abnormalities in the prefrontal and anterior cingulate cortices. Recently, functional neuroimaging has been used to specifically examine PMDs. These studies have addressed a major point of controversy: whether higher frontal brain areas are directly responsible for inhibiting motor areas or whether they reflect modulation by attentional and/or emotional processes. In addition to elucidating the mechanism and cause, recent work has also explored the lack of agency that characterizes PMDs. We describe the results and implications of the results of these imaging studies and discuss possible interpretations.

Response inhibition in motor conversion disorder

Conversion disorders (CDs) are unexplained neurological symptoms presumed to be related to a psychological issue. Studies focusing on conversion paralysis have suggested potential impairments in motor initiation or execution. Here we studied CD patients with aberrant or excessive motor movements and focused on motor response inhibition. We also assessed cognitive measures in multiple domains. We compared 30 CD patients and 30 age-, sex-, and education-matched healthy volunteers on a motor response inhibition task (go/no go), along with verbal motor response inhibition (color-word interference) and measures of attention, sustained attention, processing speed, language, memory, visuospatial processing, and executive function including planning and verbal fluency. CD patients had greater impairments in commission errors on the go/no go task (P < .001) compared with healthy volunteers, which remained significant after Bonferroni correction for multiple comparisons and after controlling for attention, sustained attention, depression, and anxiety. There were no significant differences in other cognitive measures. We highlight a specific deficit in motor response inhibition that may play a role in impaired inhibition of unwanted movement such as the excessive and aberrant movements seen in motor conversion. Patients with nonepileptic seizures, a different form of conversion disorder, are commonly reported to have lower IQ and multiple cognitive deficits. Our results point toward potential differences between conversion disorder subgroups. © 2013 Movement Disorder Society.

The functional neuroimaging correlates of psychogenic versus organic dystonia

The neurobiological basis of psychogenic movement disorders remains poorly understood and the management of these conditions difficult. Functional neuroimaging studies have provided some insight into the pathophysiology of disorders implicating particularly the prefrontal cortex, but there are no studies on psychogenic dystonia, and comparisons with findings in organic counterparts are rare. To understand the pathophysiology of these disorders better, we compared the similarities and differences in functional neuroimaging of patients with psychogenic dystonia and genetically determined dystonia, and tested hypotheses on the role of the prefrontal cortex in functional neurological disorders. Patients with psychogenic (n = 6) or organic (n = 5, DYT1 gene mutation positive) dystonia of the right leg, and matched healthy control subjects (n = 6) underwent positron emission tomography of regional cerebral blood flow. Participants were studied during rest, during fixed posturing of the right leg and during paced ankle movements. Continuous surface electromyography and footplate manometry monitored task performance. Averaging regional cerebral blood flow across all tasks, the organic dystonia group showed abnormal increases in the primary motor cortex and thalamus compared with controls, with decreases in the cerebellum. In contrast, the psychogenic dystonia group showed the opposite pattern, with abnormally increased blood flow in the cerebellum and basal ganglia, with decreases in the primary motor cortex. Comparing organic dystonia with psychogenic dystonia revealed significantly greater regional blood flow in the primary motor cortex, whereas psychogenic dystonia was associated with significantly greater blood flow in the cerebellum and basal ganglia (all P < 0.05, family-wise whole-brain corrected). Group × task interactions were also examined. During movement, compared with rest, there was abnormal activation in the right dorsolateral prefrontal cortex that was common to both organic and psychogenic dystonia groups (compared with control subjects, P < 0.05, family-wise small-volume correction). These data show a cortical–subcortical differentiation between organic and psychogenic dystonia in terms of regional blood flow, both at rest and during active motor tasks. The pathological prefrontal cortical activation was confirmed in, but was not specific to, psychogenic dystonia. This suggests that psychogenic and organic dystonia have different cortical and subcortical pathophysiology, while a derangement in mechanisms of motor attention may be a feature of both conditions.

Variability, regularity and coupling measures distinguish PD tremor from voluntary 5Hz tremor

A characteristic of Parkinson's disease (PD) is the development of tremor within the 4-6Hz range. One method used to better understand pathological tremor is to compare the responses to tremor-type actions generated intentionally in healthy adults. This study was designed to investigate the similarities and differences between voluntarily generated 4-6Hz tremor and PD tremor in regards to their amplitude, frequency and coupling characteristics. Tremor responses for 8 PD individuals (on- and off-medication) and 12 healthy adults were assessed under postural and resting conditions. Results showed that the voluntary and PD tremor were essentially identical with regards to the amplitude and peak frequency. However, differences between the groups were found for the variability (SD of peak frequency, proportional power) and regularity (Approximate Entropy, ApEn) of the tremor signal. Additionally, coherence analysis revealed strong inter-limb coupling during voluntary conditions while no bilateral coupling was seen for the PD persons. Overall, healthy participants were able to produce a 5Hz tremulous motion indistinguishable to that of PD patients in terms of peak frequency and amplitude. However, differences in the structure of variability and level of inter-limb coupling were found for the tremor responses of the PD and healthy adults. These differences were preserved irrespective of the medication state of the PD persons. The results illustrate the importance of assessing the pattern of signal structure/variability to discriminate between different tremor forms, especially where no differences emerge in standard measures of mean amplitude as traditionally defined.

Psychogenic facial movement disorders: clinical features and associated conditions

The facial phenotype of psychogenic movement disorders has not been fully characterized. Seven tertiary-referral movement disorders centers using a standardized data collection on a computerized database performed a retrospective chart review of psychogenic movement disorders involving the face. Patients with organic forms of facial dystonia or any medical or neurological disorder known to affect facial muscles were excluded. Sixty-one patients fulfilled the inclusion criteria for psychogenic facial movement disorders (91.8% females; age: 37.0 ± 11.3 years). Phasic or tonic muscular spasms resembling dystonia were documented in all patients most commonly involving the lips (60.7%), followed by eyelids (50.8%), perinasal region (16.4%), and forehead (9.8%). The most common pattern consisted of tonic, sustained, lateral, and/or downward protrusion of one side of the lower lip with ipsilateral jaw deviation (84.3%). Ipsi- or contralateral blepharospasm and excessive platysma contraction occurred in isolation or combined with fixed lip dystonia (60.7%). Spasms were reported as painful in 24.6% of cases. Symptom onset was abrupt in most cases (80.3%), with at least 1 precipitating psychological stress or trauma identified in 57.4%. Associated body regions involved included upper limbs (29.5%), neck (16.4%), lower limbs (16.4%), and trunk (4.9%). There were fluctuations in severity and spontaneous exacerbations and remissions (60%). Prevalent comorbidities included depression (38.0%) and tension headache (26.4%). Fixed jaw and/or lip deviation is a characteristic pattern of psychogenic facial movement disorders, occurring in isolation or in combination with other psychogenic movement disorders or other psychogenic features. © 2012 Movement Disorder Society

Metabolic hyperactivity of the medial posterior parietal lobes in psychogenic tremor

Background

The pathophysiology of psychogenic movement disorders, including psychogenic tremor (PT), is only emerging.

Case Report

This is a single case report of a patient who met diagnostic criteria for PT. He underwent positron emission tomography (PET) of brain with 18F-deoxyglucose at resting state. His PET study showed symmetrically increased 18F-deoxyglucose uptake in both posterior medial parietal lobes. There was no corresponding abnormality on structural imaging.

Discussion

Hypermetabolism of the medial aspects of posterior parietal lobes bilaterally may reflect abnormal activity of sensory integration that is important in the pathogenesis of PT. This further supports the idea that non-organic movement disorders may be associated with detectable functional brain abnormalities.