Recognizing uncommon presentations of psychogenic (functional) movement disorders

Periorbital injections of botulinum toxin a: a novel therapeutic option for convergence spasm in neuropsychiatric disorders

PURPOSE

Convergence spasm (CS, spasm of near reflex) is characterized by transient attacks of convergence, miosis and accommodation, often associated with functional neurological disorders. To date, no simple and efficient treatment option is available for CS. This study investigates whether periorbital botulinum toxin injections as used in essential blepharospasm are also a treatment option in these patients.

METHODS

All patients with convergence spasm having been treated with periorbital BoNTA injections in the department of neuro-ophthalmology were identified. Data were extracted from patient files concerning details and subjective effectiveness of botulinum toxin injections and relation to psychiatric or neurological disorders. Patients reporting with a history of closed-head trauma or organic neurologic pathologies possibly causing CS were excluded. A telephone assessment with a standardized questionnaire was performed to evaluate mental health issues as a trigger, as well as the long-term effect and satisfaction with periorbital injections.

RESULTS

Of 16 patients treated with periorbital botulinum toxin injections for convergence spasm, 9 patients reported depression and/or anxiety disorders ongoing or in the past. A median number of 3 injections (range 1-13) was administered with a variable effect (relief of symptoms) between no effect and effect of up to more than 12 weeks. A longitudinal follow-up revealed ongoing symptoms in five patients.

CONCLUSIONS

Periorbital botulinum toxin injections are less invasive than injections in the medial rectus muscle and can be a bridging therapeutic option in patients with CS. Mental health exploration is important due to psychiatric comorbidity.

Tics and TikTok: Functional Tics Spread Through Social Media

BACKGROUND

Functional movement disorder is a subtype of functional neurologic symptom disorder a syndrome of involuntary physical, neurologic-type symptoms that are incongruous with "organic" disease. Throughout history, there have been outbreaks of functional symptoms in communities; until recently, spread had been confined to groups of people who shared a physical location. However, in the era of social media, a new mode of dissemination may have arisen.

CASES

We describe six teenage girls, each with the explosive onset of tic-like movements. Mean age of onset was 14.2 years. The presence of features incongruous with Tourette syndrome on history and examination prompted the diagnosis of functional tics. All patients reported exposure to a specific social media personality before symptom onset.

CONCLUSIONS

Our series suggests that social media may contribute to the spread of functional neurologic symptom disorder, in a way previously requiring physical proximity.

A dimensional approach to functional movement disorders: Heresy or opportunity

Functional movement disorders (FMD) are a common and disabling neuropsychiatric condition, part of the spectrum of functional neurological/conversion disorder. FMD represent one of the most enigmatic disorders in the history of medicine. However, in the twenty years after the first report of distinctive abnormal brain activity associated with functional motor symptoms, there have been tremendous advances in the pathophysiologic understanding of these disorders. FMD can be characterized as a disorder of aberrant neurocircuitry interacting with environmental and genetic factors. These developments suggest that research on FMD could be better served by an integrative, neuroscience-based approach focused on functional domains and their neurobiological substrates. This approach has been developed in 'Research Domain Criteria' (RDoC) project, which promotes a dimensional approach to psychiatric disorders. Here, we use the RDoC conceptualization to review recent neuroscience research on FMD, focusing on the domains most relevant to these disorders. We discuss how the adoption of a similar integrative framework may facilitate the identification of the mechanisms underlying FMD and could also have potential clinical applicability.

Suggestibility as a valuable criterion for laboratory-supported definite functional movement disorders

OBJECTIVE

To evaluate the application of suggestibility in electrophysiologic studies as a tool to increase the diagnostic certainty of "laboratory-supported definite" FMD.

METHODS

We retrospectively reviewed the electrophysiologic studies performed in our center on patients with FMD. Recordings where suggestibility was included in the test battery were then selected.

RESULTS

We present three cases with equivocal clinical features, but with findings on electrophysiologic studies that were consistent with "laboratory-supported definite" FMD.

CONCLUSION

When combined with other tests, demonstration of suggestibility in electrophysiologic studies may increase the accuracy in differentiating functional from organic movement disorders.

SIGNIFICANCE

This case series is an essential first step in evaluating the applicability of suggestibility as an electrophysiologic criterion to aid in the diagnosis of FMD. Application in a larger cohort, incorporation in a test battery, and validation studies, including quantitative evaluation of suggestibility, are required to assess the reliability and the added value of this test.

What is the functional/organic distinction actually doing in psychiatry and neurology?

The functional-organic distinction aims to distinguish symptoms, signs, and syndromes that can be explained by diagnosable biological changes, from those that cannot. The distinction is central to clinical practice and is a key organising principle in diagnostic systems. Following a pragmatist approach that examines meaning through use, we examine how the functional-organic distinction is deployed and conceptualised in psychiatry and neurology. We note that the conceptual scope of the terms 'functional' and 'organic' varies considerably by context. Techniques for differentially diagnosing 'functional' and 'organic' diverge in the strength of evidence they produce as a necessary function of the syndrome in question. Clinicians do not agree on the meaning of the terms and report using them strategically. The distinction often relies on an implied model of 'zero sum' causality and encourages classification of syndromes into discrete 'functional' and 'organic' versions. Although this clearly applies in some instances, this is often in contrast to our best scientific understanding of neuropsychiatric disorders as arising from a dynamic interaction between personal, social and neuropathological factors. We also note 'functional' and 'organic' have loaded social meanings, creating the potential for social disempowerment. Given this, we argue for a better understanding of how strategic simplification and complex scientific reality limit each other in neuropsychiatric thinking. We also note that the contribution of people who experience the interaction between 'functional' and 'organic' factors has rarely informed the validity of this distinction and the dilemmas arising from it, and we highlight this as a research priority.

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.

Myoclonus: Pathophysiology and Treatment Options

OPINION STATEMENT

Treatment of myoclonus requires an understanding of the physiopathology of the condition. The first step in treatment is to determine if there is an epileptic component to the myoclonus and treat accordingly. Secondly, a review of medications (e.g., opiates) and comorbidities (e.g., hepatic or renal failure) is required to establish the possibility of iatrogenic and reversible conditions. Once those are eliminated, delineation between cortical, cortico-subcortical, subcortical, brainstem, and spinal generators can determine the first-line treatment. Cortical myoclonus can be treated with levetiracetam, valproic acid, and clonazepam as first-line agents. Phenytoin and carbamazepine may paradoxically worsen myoclonus. Subcortical and brainstem myoclonus can be treated with clonazepam as a first-line agent, but levetiracetam and valproic acid can be tried as well. L-5-Hydroxytryptophan and sodium oxybate are agents used for refractory cases. Spinal myoclonus does not respond to anti-epileptic drugs, and clonazepam is a first-line agent. Botulinum toxin treatment can be useful for focal cases of spinal myoclonus. The etiology of propriospinal myoclonus is controversial, and a functional etiology is suspected in most cases. Treatment can include clonazepam, levetiracetam, baclofen, valproate, carbamazepine, and zonisamide. Functional myoclonus requires multimodal and multidisciplinary treatment that may include psychotropic drugs and physical and occupational therapy. Close collaboration between neurologists and psychiatrists is required for effective treatment. Finally, deep brain stimulation targeting the globus pallidus pars-interna bilaterally has been used in myoclonus-dystonia when pharmacological treatments have been exhausted.

Functional (psychogenic) movement disorders - Clinical presentations

Functional or psychogenic movement disorders are common and disabling, and sometime difficult to diagnose. The history and physical exam can give positive features that will support the diagnosis, which should not be based solely on exclusion. Some clues in the history are sudden onset, intermittent time course, variability of manifestation over time, childhood trauma, history of other somatic symptom and secondary gain. Anxiety and depression are common, but not necessarily more than the general population. On examination, distraction and suggestibility may be present. There are specific signs that should be looked for with different types of movements. For example, with tremor, change in frequency over time and entrainment are common features. With myoclonus, the movements might be complex in type with long latencies to stimulus induced jerks. Gait disorders show good balance despite claims to the contrary. Functional dystonia still remains a challenging diagnosis in many circumstances, although fixed dystonia is one sign more likely to be functional.