[Functional movement disorders in children and adolescents]

Functional movement disorders (FMDs), also known as psychogenic movement disorders (PMDs), should be considered a biological-psychological-social disease like other functional neurological diseases. It is not merely a psychological or mental disease. The etiology of FMDs includes neurobiological changes, such as abnormal patterns of cerebral activation and abnormal connectivity between the limbic system and the motor networks. Inheritance and epigenetic machinery, such as DNA methylation and changes in grey and white matter morphology, may influence the development of FMDs. FMDs are not rare in the outpatient service of pediatrics and are one of the most challenging movement disorders due to complex and diversified clinical manifestations. Due to a lack of clinical knowledge and unified diagnostic criteria, it is difficult for pediatricians to make a correct diagnosis of FMDs, which may be easily confused with other diseases. Pediatricians should pay more attention to children with FMDs and establish a multidisciplinary team with psychiatrists, specialists in developmental behavior, and physiotherapists, so as to provide active management and treatment for such children.

Gender Differences in Functional Movement Disorders

Background

Functional neurological disorders are generally more common in females than males, but the reason for this gender difference is not well understood.

Objectives

In this study, we aim to compare the clinical and demographic features of functional movement disorders (FMDs) between males and females.

Methods

We examined clinical data and video-recordings of patients with FMDs evaluated at the Baylor College of Medicine Movement Disorders Clinic.

Results

Of the 196 patients with FMDs, males represented only 30% (n = 59) of the entire cohort. Men had an older age at onset: 40.5 versus 34.1 years (P = 0.026) and an older age at evaluation: 43.8 versus 38.1 years (P = 0.041) compared to women. Functional dystonia was more frequently observed in women: 47.5 versus 20.3% (P < 0.001), but there was a trend for higher frequency of functional gait disorder in men: 44 versus 30% (P = 0.056). Females were particularly over-represented (73.7%) in children and adolescents; but the genders were equally represented in patients aged ≥50 years.

Conclusions

Female patients are over-represented in FMDs, except in individuals aged ≥50 years. Compared to female patients, males with FMDs present later in life and are less likely to have functional dystonia.

Prevalence of restless legs syndrome in functional movement disorders: a case-control study from the Czech Republic

OBJECTIVES

The prevalence of restless legs syndrome (RLS) in functional movement disorders (FMD) is not known. Patients with FMD often present with multiple motor and sensory symptoms. Some of these symptoms might be due to comorbid RLS. Therefore, our objective was to evaluate possible association between FMD and RLS.

DESIGN

Case-control study.

SETTING

Movement Disorders Center, 1st Faculty of Medicine and General University Hospital in Prague, Czech Republic.

PARTICIPANTS

96 consecutive patients with clinically established FMD (80 females, mean age (SD) 45.0 (13) years), and 76 matched controls.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was prevalence of RLS based on updated International RLS Study Group criteria. Secondary outcome measures included prevalence of periodic limb movements (PLM) using actigraphy; pain, motor and sensory symptoms in lower limbs; organic comorbidities and medication affecting RLS.

RESULTS

RLS criteria were fulfilled in 43.8% of patients (95% CI 34 to 54) and in 7.9% of controls (95% CI 3 to 17, p<0.00001). Both RLS and PLM indices (PLMi) ≥22.5/hour were found in 21.2% of patients with FMD and 2.6% of controls. Patients with FMD with RLS had a higher mean PLMi (p<0.001) and a higher proportion of PLMi ≥22.5/hour (p<0.01) than RLS-negative patients. Patients with RLS had higher prevalence of pain and sensory symptoms in lower limbs, no difference was found in medication and prevalence of organic comorbidities in patients with FMD with and without RLS.

CONCLUSIONS

We found an increased prevalence of RLS in patients with FMD. Clinical diagnosis of RLS was supported by actigraphic measurement of clinically relevant PLM in a significant proportion of patients with FMD. Although functional motor and sensory symptoms may mimic RLS, RLS may be unrecognised in patients with FMD. This finding may have clinical implications in management of FMD, and it raises the possibility of common pathophysiological mechanisms of FMD and RLS/PLM.

Functional Speech and Voice Disorders: Case Series and Literature Review

Background

Functional disorders of speech and voice, subtypes of functional movement disorders, represent abnormalities in speech and voice that are thought to have an underlying psychological cause. These disorders exhibit several positive and negative features that distinguish them from organic disorders.

Methods and Results

We describe the clinical manifestations of functional disorders of speech and voice, and illustrate these features using six clinical cases.

Conclusions

Functional disorders of speech and voice may manifest in a variety of ways, including dysphonia, stuttering, or prosodic abnormalities. Given that these disorders have been understudied and may resemble organic disorders, diagnosis may be challenging. Appropriate treatment may be quite effective, highlighting the importance of prompt and accurate diagnosis.

Psychodynamic Psychotherapy for Functional (Psychogenic) Movement Disorders

OBJECTIVE

As the literature for the treatment of functional (psychogenic) movement disorders (FMD) is sparse, we assessed clinical outcomes in patients with FMD who underwent treatment with psychodynamic psychotherapy (PDP).

METHODS

A retrospective analysis of the data of patients with FMD who were referred for PDP from 2008-2014 at Emory University Medical Center was performed.

RESULTS

Thirty patients were included, mean age at presentation was 50 years (SD 13.9) and majority were female (27/30). Most common movement disorder was involuntary shaking/jerky movements (50%) and tremor (43%). Mean duration of symptoms was 3.2 years and mean number of PDP visits was 4.9. PDP lead to good outcomes in 10, modest in 8, and poor in 9. Three patients lost to follow up. Mean duration of symptoms between two groups (good vs. poor) was not statistically significant (p = 0.11), mean number of PDP visits showed a trend towards significance (p = 0.053). In all cases of good outcomes precipitants of the movement disorder were identified and a majority (60%) was receptive of the diagnosis and had good insight.

CONCLUSION

PDP lead to improvement in 60% of the patients which is encouraging as the treatment is challenging. This study supports heterogeneous causes of FMD including varied roles of past/recent events and demonstrates importance of psychological approaches such as PDP. Treatment with PDP should be considered in some patients with FMD but predicting who will respond remains a challenge. Further long term prospective studies with large sample size and placebo control are needed.

Non-Invasive Brain Stimulation in Conversion (Functional) Weakness and Paralysis: A Systematic Review and Future Perspectives

Conversion (functional) limb weakness or paralysis (FW) can be a debilitating condition, and often causes significant distress or impairment in social, occupational, or other important areas of functioning. Most treatment concepts are multi-disciplinary, containing a behavioral approach combined with a motor learning program. Non-invasive brain stimulation (NIBS) methods, such as electroconvulsive therapy (ECT), and transcranial magnetic stimulation (TMS) have been used in the past few decades to treat FW. In order to identify all published studies that used NIBS methods such as ECT, TMS and transcranial direct current stimulation (tDCS) for treating FW patients a systematic review of the literature was conducted in PubMed and Web of Science. In a second step, narratives were used to retrospectively determine nominal CGI-I (Clinical Global Impression scale–Improvement) scores to describe approximate changes of FW symptoms. We identified two articles (case reports) with ECT used for treatment of FW, five with TMS with a total of 86 patients, and none with tDCS. In 75 out of 86 patients treated with repetitive (r)TMS a nominal CGI-I score could be estimated, showing a satisfactory short-term improvement. Fifty-four out of seventy-five identified patients (72%) had a CGI-I score of 1 (very much improved), 13 (17%) a score of 2 (much improved), 5 (7%) a score of 3 (minimally improved), and 3 (5%) remained unchanged (CGI-I = 4). In no case did patients worsen after rTMS treatment, and no severe adverse effects were reported. At follow-up, symptom improvement was not quantifiable in terms of CGI-I for the majority of the cases. Patients treated with ECT showed a satisfactory short-term response (CGI-I = 2), but deterioration of FW symptoms at follow-up. Despite the predominantly positive results presented in the identified studies and satisfactory levels of efficacy measured with retrospectively calculated nominal CGI-I scores, any assumption of a beneficial effect of NIBS in FW has to be seen with caution, as only few articles could be retrieved and their quality was mostly poor. This article elucidates how NIBS might help in FW and gives recommendations for future study designs using NIBS in this condition.

Diagnostic performance of the "Huffing and Puffing" sign in psychogenic (functional) movement disorders

OBJECTIVE

To determine the diagnostic value of effort-associated behaviors ("huffing and puffing" spectrum) in patients with psychogenic movement disorders.

METHODS

Three blinded clinicians rated presence, severity, and duration of effort-associated features during standing and walking tasks on edited videos of 131 patients with psychogenic gait disorders and 37 patients with organic gait disorders.

RESULTS

Huffing, grunting, grimacing, and breath holding were the most common effort-associated behaviors in patients with psychogenic gait disorders, with a combined prevalence of 44% and disproportionate to the severity of gait impairment compared to organic gait disorders. The presence of "huffing and puffing"-type behaviors yielded a relatively low sensitivity but high specificity for the diagnosis of psychogenic movement disorders, increasing the odds of diagnosis 13-fold (95%, CI: 4.2-43.8) compared to organic gait disorders.

CONCLUSIONS

Demonstration of effort-associated behaviors during standing and walking strongly supports the psychogenic nature of disorders when gait is involved.

Psychogenic Movement Disorders: Gait Is a Give-Away!

The aim of this article is to point out that an incongruity of gait disorder (either in relation to the presenting movement disorder or incongruity with any type of organic gait disorder) is a useful clue in diagnosing psychogenic movement disorders. To illustrate this, we present a case series of patients with various types of psychogenic movement disorders (rest tremor, myoclonus, dystonia, and chorea). Incongruity of the walking pattern with the presenting movement disorder was a revealing diagnostic clue in all cases. "Incongruity" is currently a main plank in the diagnosis of psychogenic conditions. Our series emphasizes that incongruity of the gait pattern may be the most important sign in a patient where it is otherwise difficult to establish whether the movement disorder is congruous or incongruous with an organic disorder.

Clinical diagnosis of propriospinal myoclonus is unreliable: an electrophysiologic study

Propriospinal myoclonus is a rare movement disorder that is hypothesized to arise from a spinal generator that transmits activity up and down the spinal cord via long propriospinal pathways. Polymyography is mandatory for the diagnosis, but the typical electrophysiological pattern described for propriospinal myoclonus has been also found in patients with psychogenic axial jerks, supported by the presence of a Bereitschaftspotential (BP; from German, "readiness potential," also called the premotor potential). We evaluated polymyographic findings in 65 patients referred to us with a clinical diagnosis of propriospinal myoclonus and also looked for the presence of the BP, as detected by jerk-locked back-averaging. At clinical reassessment by a movement disorder specialist, nearly one-half of the patients had clinical clues suggestive of a psychogenic cause of the jerks. Electrophysiological studies were carried out on all 65 patients. Polymyography findings revealed an incongruent electromyographic pattern for propriospinal myoclonus in 84.6% of patients and the presence of the BP in 86.1% of the entire cohort. When taking into account either the presence of BP and/or incongruence of polymyographic features, all patients, including the approximately 50% clinically diagnosed as organic propriospinal myoclonus by a movement disorder expert, had strong neurophysiological evidence for a psychogenic origin of their jerks. The clinical distinction of propriospinal myoclonus from psychogenic axial jerks is unreliable. This is the largest cohort of patients with axial jerks reported so far and we suggest that most of the patients with a clinical picture that clinically resembles propriospinal myoclonus are likely to be psychogenic.

Familial psychogenic movement disorders

BACKGROUND

Psychogenic (or functional) movement disorders (PMDs) are considered sporadic. Despite the growing literature describing the clinical features and the natural history of sporadic cases with PMDs, their occurrence in familial clusters is not reported.

METHODS

We identified 10 patients from 5 families affected by PMDs. In this report, we describe the clinical characteristics along with videos and long-term follow-up of these patients.

RESULTS

Clinical clues from the history and signs suggesting a functional origin of the symptoms in these patients with familial PMD were similar to those identified in sporadic cases. The phenomenology of the PMD was similar in the affected members of the same family.

CONCLUSIONS

We wish to highlight that a positive family history does not necessarily imply an organic disorder. When a positive family history for a condition is reported by a patient with PMD, examination of these further affected members may be needed and may identify further family members suffering from PMDs. A positive family history of PMDs may be an additional risk factor for developing PMDs. © 2013 Movement Disorder Society.

Functional (psychogenic) movement disorders

PURPOSE OF REVIEW

This review provides an overview of recent developments in diagnosis, pathophysiology, neuroimaging and management of functional (psychogenic) movement disorders (FMD).

RECENT FINDINGS

There has been increasing interest to study the underlying pathophysiology of FMD, which has resulted in a broadened disease model, taking neurobiologic and psychosocial factors equally into account. In this context, the term 'psychogenic' has been replaced by 'functional' movement disorders by many authors in the field to express the changing focus toward a multifactorial disease model. The need for establishing a positive diagnosis of FMD as opposed to providing a diagnosis of exclusion is increasingly recognized and reflected by the introduction of 'laboratory-supported' diagnostic criteria of FMD. Important advances have been made through behavioral, electrophysiological and neuroimaging studies, although the fundamental cause of FMD remains poorly understood. Of particular interest have been several reports on abnormal sensorimotor features and cortical inhibition in both organic and functional dystonia, highlighting possible shared traits of both conditions. In terms of treatment, recent studies have reported benefit from both psychiatric and physical therapy-based interventions.

SUMMARY

Increasing efforts have been made toward better understanding of FMD, and the disease model has been broadened to include neurobiologic and psychosocial factors. Laboratory-based diagnostic criteria have been established for many FMD to support the clinical diagnosis. To determine the most effective management strategies for FMD, a closer collaboration between neurologists and psychiatrists and intensified research efforts with prospective treatment trials are needed.