Hyperkinetic psychogenic movement disorders

Diagnosis of psychogenic (functional) gait disorders

Psychogenic gait is common in patients with medically unexplained neurological symptoms and provides significant challenges to healthcare providers. Clinicians may arrive at a correct diagnosis earlier if distinctive positive signs are identified and acknowledged. Psychogenic disorders of posture and gait are common and are the major manifestation in 8–10 % of patients with psychogenic movement disorders. Psychogenic movement disorders can present with varied phenomenology that may resemble organic movement disorders. The diagnosis is based on clinical evaluation with a supporting history and classic features on neurologic examination. In functional gait disorders, walking is often bizarre and does not conform to any of the usual patterns observed with neurologic gait disorders. Astasia-abasia, an inability to stand (astasia) or walk (abasia) in the absence of other neurologic abnormalities, was the term applied by investigators in the mid to late 19thcentury to describe certain patients with a frankly functional gait. Other descriptive terms include gaits that resemble walking on ice, walking a sticky surface, walking through water (bringing to mind excessive slowness), tightrope walking, habitual limping, and bizarre, robotic, knock-kneed, trepidant, anxious, and cautious gaits. Ancillary testing, such as imaging and neurophysiologic studies, can provide supplementary information but is not necessary for diagnosis. 

Functional Neurological Disorders: Clinical Spectrum, Diagnosis, and Treatment

BACKGROUND

Functional neurological disorders (FNDs) are common but often misdiagnosed.

REVIEW SUMMARY

The incidence of FNDs is between 4 and 12 per 100,000, comparable to multiple sclerosis and amyotrophic lateral sclerosis, and it is the second most common diagnosis in neurology clinics. Some clues in the history are sudden onset, intermittent time course, variability of manifestation over time, childhood trauma, and history of other somatic symptoms. Anxiety and depression are common, but not necessarily more than in the general population. Although there are no tests currently capable of demonstrating whether symptoms are willfully produced, there may not be a clear categorical difference between voluntary and involuntary symptoms. The prognosis of an FND is linked to early diagnosis and symptom duration, but unfortunately, the majority of the patients are diagnosed after considerable delays.

CONCLUSIONS

A positive diagnosis of FNDs can be made on the basis of history and neurological signs without reliance on psychological stressors. Past sensitizing events and neurobiological abnormalities contribute to the pathogenesis of FNDs. Physical rehabilitation and psychological interventions alone or in combination are helpful in the treatment.

Clinical overlap of functional neurologic symptom disorder and complex regional pain syndrome in pediatrics: A case report

This case study documents a 13-year-old female who presented to our intensive inpatient chronic pain rehabilitation program with complex regional pain syndrome (CRPS) of her left leg, which was significantly interfering with her normal daily functioning. She participated in a full day of traditional interdisciplinary therapies, including physical and occupational therapy for 3 hours daily. As assistive equipment was altered or weaned her physical mobility, balance, and tremors worsened and/or increased. As she began advancing her legs more independently (versus requiring physical assist), she demonstrated more variable functional strength and stability, inconsistent balance reactions, and a more unsteady gait pattern. The team was treating her according to her incoming CRPS diagnosis; however, as treatment progressed, her physical and psychological presentation seemed more aligned with diagnostic criteria of functional neurologic symptom disorder (FND). Staff then treated according to the FND diagnosis resulting in successful long-term outcomes. The clinical impact from this case study includes highlighting the commonalities between CPRS and FND clinically, discussing treatment suggestions depending on the diagnosis, and emphasizing key components of family/patient education.

Chorea

PURPOSE OF REVIEW

This article reviews the clinical approach to the diagnosis of adult patients presenting with chorea, using Huntington disease (HD) as a point of reference, and presents the clinical elements that help in the diagnostic workup. Principles of management for chorea and some of the associated features of other choreic syndromes are also described.

RECENT FINDINGS

Mutations in the C9orf72 gene, previously identified in families with a history of frontotemporal dementia, amyotrophic lateral sclerosis, or both, have been recognized as one of the most prevalent causes of HD phenocopies in the white population.

SUMMARY

The diagnosis of chorea in adult patients is challenging. A varied number of associated causes require a physician to prioritize the investigations, and a detailed history of chorea and associated findings will help. For chorea presenting as part of a neurodegenerative syndrome, the consideration of a mutation in the C9orf72 gene is a new recommendation after excluding HD. There are no new treatment options for chorea, aside from dopamine blockers and tetrabenazine. There are no disease-modifying treatments for HD or other neurodegenerative choreic syndromes.

Psychogenic tremor: a video guide to its distinguishing features

BACKGROUND

Psychogenic tremor is the most common psychogenic movement disorder. It has characteristic clinical features that can help distinguish it from other tremor disorders. There is no diagnostic gold standard and the diagnosis is based primarily on clinical history and examination. Despite proposed diagnostic criteria, the diagnosis of psychogenic tremor can be challenging. While there are numerous studies evaluating psychogenic tremor in the literature, there are no publications that provide a video/visual guide that demonstrate the clinical characteristics of psychogenic tremor. Educating clinicians about psychogenic tremor will hopefully lead to earlier diagnosis and treatment.

METHODS

We selected videos from the database at the Parkinson's Disease Center and Movement Disorders Clinic at Baylor College of Medicine that illustrate classic findings supporting the diagnosis of psychogenic tremor.

RESULTS

We include 10 clinical vignettes with accompanying videos that highlight characteristic clinical signs of psychogenic tremor including distractibility, variability, entrainability, suggestibility, and coherence.

DISCUSSION

Psychogenic tremor should be considered in the differential diagnosis of patients presenting with tremor, particularly if it is of abrupt onset, intermittent, variable and not congruous with organic tremor. The diagnosis of psychogenic tremor, however, should not be simply based on exclusion of organic tremor, such as essential, parkinsonian, or cerebellar tremor, but on positive criteria demonstrating characteristic features. Early recognition and management are critical for good long-term outcome.

Diagnosis and treatment of essential tremor

SUMMARY Essential tremor (ET) is one of the most prevalent movement disorders in the world, affecting millions of people. Medications that are commonly used to treat ET include antiepileptic or antihypertensive medications. Primidone and propranolol are considered effective, first-line agents for treating ET, while atenolol, alprazolam and topiramate are considered second-line agents. Gabapentin appears to improve ET when used as a monotherapy, although not as an adjunct therapy. Alternatives to pharmacologic treatment for refractory ET include botulinum toxin A injections, deep-brain stimulation of the ventral intermediate nucleus of the thalamus and thalamotomy. Future developments in the treatment of ET will depend on valid animal models and a greater understanding of its pathophysiology.

How to tackle tremor - systematic review of the literature and diagnostic work-up

Background: Tremor is the most prevalent movement disorder in clinical practice. It is defined as involuntary, rhythmic, oscillatory movements. The diagnostic process of patients with tremor can be laborious and challenging, and a clear, systematic overview of available diagnostic techniques is lacking. Tremor can be a symptom of many diseases, but can also represent a distinct disease entity. Objective: The objective of this review is to give a clear, systematic and step-wise overview of the diagnostic work-up of a patient with tremor. The clinical relevance and value of available laboratory tests in patients with tremor will be explored. Methods: We systematically searched through EMBASE. The retrieved articles were supplemented by articles containing relevant data or provided important background information. Studies that were included investigated the value and/or usability of diagnostic tests for tremor. Results: In most patients, history and clinical examination by an experienced movement disorders neurologist are sufficient to establish a correct diagnosis, and further ancillary examinations will not be needed. Ancillary investigation should always be guided by tremor type(s) present and other associated signs and symptoms. The main ancillary examination techniques currently are electromyography and SPECT imaging. Unfortunately, many techniques have not been studied in large prospective, diagnostic studies to be able to determine important variables like sensitivity and specificity. Conclusion: When encountering a patient with tremor, history, and careful clinical examination should guide the diagnostic process. Adherence to the diagnostic work-up provided in this review will help the diagnostic process of these patients.

Believing is perceiving: mismatch between self-report and actigraphy in psychogenic tremor

We assessed the duration and severity of tremor in a real-life ambulatory setting in patients with psychogenic and organic tremor by actigraphy, and compared this with self-reports of tremor over the same period. Ten participants with psychogenic tremor and eight with organic tremor, diagnosed using standardized clinical criteria, were studied. In an explicit design, participants were asked to wear a small actigraph capable of continuously monitoring tremor duration and intensity for 5 days while keeping a diary of their estimates of tremor duration during the same period. Eight patients with psychogenic tremor and all patients with organic tremor completed the study. Psychogenic patients reported significantly more of the waking day with tremor compared with patients with organic tremor (83.5 ± 14.0% of the waking day versus 58.0 ± 19.0% of the waking day; P < 0.01), despite having almost no tremor recorded by actigraphy (3.9 ± 3.7% of the waking day versus 24.8 ± 7.7% of the waking day; P = 0.001). Patients with organic tremor reported 28% more tremor than actigraphy recordings, whereas patients with psychogenic tremor reported 65% more tremor than actigraphy. These data demonstrate that patients with psychogenic tremor fail to accurately perceive that they do not have tremor most of the day. The explicit study design we employed does not support the hypothesis that these patients are malingering. We discuss how these data can be understood within models of active inference in the brain to provide a neurobiological framework for understanding the mechanism of psychogenic tremor.

Moving toward "laboratory-supported" criteria for psychogenic tremor

A confident clinical diagnosis of psychogenic tremor is often possible, but, in some cases, a “laboratory-supported” level of certainty would aid in early positive diagnosis. Various electrophysiological tests have been suggested to identify patients with psychogenic tremor, but their diagnostic reliability has never been assessed “head to head” nor compared to forms of organic tremor other than essential tremor or PD. We compared baseline tremor characteristics (e.g., frequency and amplitude) as well as electrophysiological tests previously reported to distinguish psychogenic and organic tremor in a cohort of 13 patients with psychogenic tremor and 25 patients with organic tremor, the latter including PD, essential-, dystonic-, and neuropathic tremors. We assessed between-group differences and calculated sensitivity and specificity for each test. A number of tests, including entrainment or frequency changes with tapping, pause of tremor during contralateral ballistic movements, increase in tremor amplitude with loading, presence of coherence, and tonic coactivation at tremor onset, revealed significant differences on a group level, but there was no single test with adequate sensitivity and specificity for separating the groups (33%–77% and 84%–100%, respectively). However, a combination of electrophysiological tests was able to distinguish psychogenic and organic tremor with excellent sensitivity and specificity. A laboratory-supported level of diagnostic certainty in psychogenic tremor is likely to require a battery of electrophysiological tests to provide sufficient specificity and sensitivity. Our data suggest such a battery that, if supported in a prospective study, may form the basis of laboratory-supported criteria for the diagnosis of psychogenic tremor. © 2011 Movement Disorder Society