A Critical Appraisal of the Whack-a-Mole and Swivel Chair Signs in the Diagnosis of Functional Movement Disorders

BACKGROUND

The demonstration of positive signs during neurological examination is a cornerstone of the diagnosis of functional movement disorders, however, the available data supporting the diagnostic value of some of these signs is limited.

OBJECTIVES

To determine the diagnostic value (sensitivity and specificity) of the "whack-a-mole" (WAM) and "swivel chair" (SC) tests in patients with functional movement disorders (FMD).

METHODS

We enrolled patients with functional and organic movements in the WAM test if they exhibited tremor, dystonia, myoclonus, chorea, or tics. For the SC test, patients with a gait disorder as their primary impairment were recruited. Two blinded movement disorder specialists rated the presence of these signs in edited videos.

RESULTS

Inclusion criteria were met by 42 patients with FMD and 65 patients with organic movement disorders. Both tests demonstrated high specificity (means, 78% and 96%), but their sensitivity was low (means, 52% and 37%). Interobserver agreement for the WAM sign was 0.77 in the FMD group, against 0.28 in patients with organic movement disorders, whereas Movement Disorders Clinical Practice for Review Only for the SC sign was 0.69 in both groups.

CONCLUSIONS

The present study indicates that physicians must be cautious in the application and interpretation of these clinical signs in the diagnosis of functional movement disorders, and they should be carefully considered and used as necessary.

Hazard Perception Skill and Driver Behavior in Patients With Functional Neurologic Disorders

BACKGROUND AND OBJECTIVES

Driving in patients with functional neurologic disorders (FND) is a major concern, but current guidelines (where they exist) are based on expert consensus only due to a lack of relevant empirical evidence. This study aimed to provide such evidence by comparing drivers with FND with healthy controls on aspects of driving performance and behavior important to crash risk, including hazard perception skill.

METHODS

Participants completed validated self-report questionnaires of driving behaviors (assessing lapses, errors, violations, and attentional issues) and 2 computer-based measures of hazard perception skill (both known to be associated with crash risk).

RESULTS

We compared 43 patients who experience dissociative attacks or functional motor symptoms and 43 healthy controls. Patients with FND self-reported significantly more driving lapses and driving errors compared with healthy controls. However, there were no significant between-group differences in self-reports of ordinary violations, aggressive violations, or attention-related errors. Participants in the FND group and healthy controls exhibited a similar performance on a response time hazard perception test (6.27 vs 5.51 seconds, p = 0.245). However, participants with FND remarkably outperformed the controls in the number of plausible predictions they made in a verbal response hazard prediction test (1.55 vs 1.18 predictions per clip, p = 0.006).

DISCUSSION

Our findings suggest that the ability of drivers with FND to predict traffic hazards in between attacks or flares is not worse than that of healthy individuals, with the possibility that it might even be better under some circumstances. Further studies with various populations are needed to replicate our findings.

The antecedents and consequences of stereotype threat in Parkinson's disease

OBJECTIVE

The aim of this study was to examine what factors make people with Parkinson's disease more susceptible to stereotype threat (i.e., the concern of being evaluated in line with negative group-based stereotypes) and the clinical consequences of this.

METHOD

Forty-nine people with Parkinson's disease completed a measure of stereotype threat, as well as measures that indexed potential antecedents and clinical consequences of stereotype threat.

RESULTS

Younger age and greater communication difficulties emerged as significant predictors of stereotype threat. Higher stereotype threat was also associated with increased emotional distress.

CONCLUSIONS

These findings are an important first step in understanding stereotype threat in Parkinson's disease and may help to guide the development of intervention and educational efforts aimed at countering its effects.

Health Care Utilization in Functional Neurologic Disorders: Impact of Explaining the Diagnosis of Functional Seizures on Health Care Costs

Background and Objective

The objectives of this study were to investigate health care utilization costs of patients with video-electroencephalography (VEEG)-confirmed functional seizures (FS), determine whether patients who received a satisfactory functional neurologic disorder (FND) diagnosis explanation had reduced health care utilization compared with those with a poor explanation; and to quantify the overall health care costs 2 years prediagnosis and postdiagnosis for those receiving a different explanation.

Methods

Patients with VEEG-confirmed pure FS (pFS) or mixed (functional seizure plus epileptic seizures) diagnosis between July 1, 2017, and July 1, 2019, were evaluated. Explanation of the diagnosis was determined "unsatisfactory" or "satisfactory" using self-developed criteria, and health care utilization data were collected using an itemized list. The subsequent costs 2 years post-FND diagnosis were compared with those 2 years before, and cost outcomes were compared between both groups.

Results

In patients who received a satisfactory explanation (n = 18), total health care costs were reduced from $169,803 to $117,133 USD (-31%). An increase in costs was found ($73,430 to $186,553 USD = +154%) in patients with pPNES after an unsatisfactory explanation (n = 7). On an individual level, 78% with a satisfactory explanation saw a reduction in total health care costs per year (mean $5,111 USD to $1,728 USD), and in 57%, an unsatisfactory explanation led to an increase (mean $4,425 to $20,524 USD). A similar effect was seen from explanation on patients with a dual diagnosis.

Discussion

The method of communicating an FND diagnosis has a significant impact on subsequent health care utilization. Those receiving satisfactory explanations demonstrated reduced health care utilization, whereas an unsatisfactory explanation resulted in additional expenses.

Case report: Migraine resolution post bilateral subthalamic deep brain stimulation

Background:

Chronic migraine can be challenging to treat and despite recent advances in treatment, there are cases that do not respond to current available pharmacological therapies.

Case:

We report a case of a 64-year-old male with a long history of chronic migraine who developed severe tremor-dominant Parkinson’s disease.

Conclusion:

After implantation of subthalamic deep brain stimulation (DBS), he reported not only benefit for his parkinsonian symptoms, but also a complete remission of his migraine attacks.

‘Tricked’ sensory trick: a geste antagoniste in functional dystonia

A sensory trick, or geste antagoniste, is a manoeuvre used by patients with dystonia to ameliorate their dystonic movements or posturing. Typically, a sensory trick is a confirmatory clue indicating an organic nature of the dystonia. In this report, we present an extremely rare case of a sensory trick in a patient with functional dystonia.

Moving beyond emotions in Parkinson's disease

OBJECTIVE

Emotion recognition is a fundamental neurocognitive capacity that is a critical predictor of interpersonal function and, in turn, mental health. Although people with Parkinson's disease (PD) often exhibit difficulties recognizing emotions, almost all studies to date have focused on basic emotions (happiness, sadness, anger, surprise, fear, and disgust), with little consideration of how more cognitively complex self-conscious emotions such as contempt, embarrassment, and pride might also be affected. Further, the few studies that have considered self-conscious emotions have relied on high intensity, static stimuli. The aim of the present study was to therefore provide the first examination of how self-conscious emotion recognition is affected by PD using a dynamic, dual-intensity measure that more closely captures how emotion recognition judgements are made in daily life.

METHOD

People with PD (n = 42) and neurotypical controls (n = 42) completed a validated measure of self-conscious facial emotion recognition. For comparative purposes, in addition to a broader clinical test battery, both groups also completed a traditional static emotion recognition measure and a measure of self-conscious emotional experience.

RESULTS

Relative to controls, the PD group did not differ in their capacity to recognize basic emotions but were impaired in their recognition of self-conscious emotions. These difficulties were associated with elevated negative affect and poorer subjective well-being.

CONCLUSIONS

Difficulties recognizing self-conscious emotions may be more problematic for people with PD than difficulties recognizing basic ones, with implications for interventions focused on helping people with this disorder develop and maintain strong social networks.

PRACTITIONER POINTS

This is the first direct investigation into how the recognition of self-conscious emotion is affected in Parkinson's disease using dynamic, dual-intensity stimuli, thus providing an important extension to prior literature that has focused solely on basic emotion recognition and/or relied on static, high-intensity stimuli. Results revealed preserved basic facial emotional recognition coexisting with impairment in all three self-conscious emotions assessed, therefore suggesting that the latter stimuli type may function as a more sensitive indicator of Parkinson's disease-related social cognitive impairment. Problems with self-conscious emotion recognition in people with Parkinson's disease were associated with poorer broader subjective well-being and increased negative affect. This aligns with the broader literature linking interpersonal difficulties with poorer clinical outcomes in this cohort.

Thalamic Ventral Intermediate Nucleus Deep Brain Stimulation for Orthostatic Tremor

Background

Orthostatic tremor (OT) was first described in 1977. It is characterized by rapid tremor of 13–18 Hz and can be recorded in the lower limbs and trunk muscles. OT remains difficult to treat, although some success has been reported with deep brain stimulation (DBS).

Case Report

We report a 68‐year‐old male with OT who did not improve significantly after bilateral thalamic stimulation.

Discussion

Although some patients were described who improved after DBS surgery, more information is needed about the effect of these treatment modalities on OT, ideally in the form of randomized trial data.

Tracking Parkinson's: Study Design and Baseline Patient Data

Background:

There is wide variation in the phenotypic expression of Parkinson’s disease (PD), which is driven by both genetic and epidemiological influences.

Objectives:

To define and explain variation in the clinical phenotype of PD, in relation to genotypic variation.

Methods:

Tracking Parkinson’s is a multicentre prospective longitudinal epidemiologic and biomarker study of PD. Patients attending specialist clinics in the United Kingdom with recent onset (<3.5 years) and young onset (diagnosed <50 years of age) PD were enrolled. Motor, non-motor and quality of life assessments were performed using validated scales. Cases are followed up 6 monthly up to 4.5 years for recent onset PD, and up to 1 year for young onset PD. We present here baseline clinical data from this large and demographically representative cohort.

Results:

2247 PD cases were recruited (1987 recent onset, 260 young onset). Recent onset cases had a mean (standard deviation, SD) age of 67.6 years (9.3) at study entry, 65.7% males, with disease duration 1.3 years (0.9), MDS-UPDRS 3 scores 22.9 (12.3), LEDD 295 mg/day (211) and PDQ-8 score 5.9 (4.8). Young onset cases were 53.5 years old (7.8) at study entry, 66.9% male, with disease duration 10.2 years (6.7), MDS-UPDRS 3 scores 27.4 (15.3), LEDD 926 mg/day (567) and PDQ-8 score 11.6 (6.1).

Conclusions:

We have established a large clinical PD cohort, consisting of young onset and recent onset cases, which is designed to evaluate variation in clinical expression, in relation to genetic influences, and which offers a platform for future imaging and biomarker research.