Motor and non-motor subtypes of cervical dystonia

Evaluation of non-motor symptoms in cervical dystonia, hemifacial spasm, and blepharospasm patients and their correlation with motor symptoms

BACKGROUND

Awareness of non-motor symptoms has been increasing in recent years, but there are still few studies on this topic.

OBJECTIVE

Our aim was to evaluate various non-motor symptoms, especially psychiatric disorders, cognitive status, and sleep, in cervical dystonia (CD), hemifacial spasm (HFS), and blepharospasm (BPS) patients and to investigate whether these symptoms are related to the severity of motor symptoms.

METHODS

This was a single-center cross-sectional, observational, case-control study. Motor severity scales were used to determine disease severity. We evaluated non-motor symptoms with commonly used scales. A total of 73 patients and 73 control groups participated.

RESULTS

In CD patients, the MoCA total score, 'language', 'abstraction', and 'orientation' scores were statistically significantly lower; PSQI, ESS, and NMSQ scores were statistically significantly higher than controls. In the BPS group, the MoCA total score and the 'language' score were significantly lower, and the NMSQ score was statistically significantly higher than the controls. In the HFS group, MoCA total score, 'executive functions', 'language', and 'abstraction' scores were statistically significantly lower; PSQI scores are statistically significantly higher than controls. There was a positive correlation between the severity score and the PSQI score in the CD group and between the severity score and the NMSQ score in the BPS group. All three groups had significant cognitive impairments.

CONCLUSIONS

In CD, BPS, and HFS, non-motor symptoms are apparent with undeniable frequency in addition to common motor symptoms. Importantly, these NMS may cause significant deterioration in the quality of life of the patients.

Social cognition in cervical dystonia

Background

Whilst traditionally considered a movement disorder, it is now generally accepted that cervical dystonia (CD) presents with additional non-motor symptoms which significantly impact quality of life. Our study primarily aimed to explore social cognition and levels of psychological distress in individuals with CD, in comparison to age- and sex-matched healthy controls.

Methods

20 participants with CD attending a specialist movement disorders clinic were recruited. 20 age and sex matched neurologically healthy controls were recruited in parallel. Participants completed the Hospital Anxiety and Depression Scale, and two novel social cognition tasks: The Cambridge Mindreading Face-Voice Battery (CAFMB) and the Edinburgh Social Cognition Test (ESCoT).

Results

Participants with CD exhibited poorer complex emotion recognition abilities for visual and auditory stimuli, compared to controls on the CAFMB task. Participants with CD did not differ significantly from controls on performance on cognitive or affective Theory of Mind tasks, or interpersonal or intrapersonal understanding of social norms, as measured by the ESCoT. The proportion of depressive symptoms was significantly higher for participants with CD than controls. 40% of participants with CD reported clinically elevated depressive symptoms, and 60% reported clinically elevated anxiety. Poorer understanding of emotional facial expressions was associated with higher levels of depression in the CD group.

Conclusions

Significant between-group differences between participants with CD and controls suggests socio-cognitive dysfunction is an important aspect of the non-motor syndrome of CD. Findings highlight the need for assessment of and intervention for both social cognitive difficulties and psychological distress in individuals with CD.

The effect of botulinum toxin on anxiety in cervical dystonia: A prospective, observational study

INTRODUCTION

Anxiety is present in 30-40% of patients with cervical dystonia (CD). It has been ascribed to a direct effect of the state of motor symptoms on related pain, disability, and disfigurement. Accordingly, any reported benefit of botulinum toxin (BoNT) on anxiety is thought to be secondary to its effect on the same. We sought to evaluate the distinctive impact of botulinum toxin (BoNT) on anxiety in cervical dystonia (CD).

METHODS

In this prospective observational study, 60 participants with idiopathic isolated CD were recruited from clinic. We assessed motor and anxiety burden using Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) parts I-III and State-Trait Anxiety Inventory (STAI). Assessments were done at time of BoNT (baseline) and at 6 weeks post-injection.

RESULTS

STAI and motor severity TWSTRS scores poorly correlated at the baseline visit (rho = -0.30, p = 0.411). Both, motor TWSTRS (Mdifference = -1.46, p < 0.024) and STAI (Mdifference = -10.37, p = 0.007) improved from baseline to 6 weeks (peak effect). The change in motor TWSTRS poorly correlated with change in anxiety scores from baseline visit to 6 weeks (rho = -0.14, p > 0.999). Of these measures of anxiety, improvement in STAI-T had the largest effect size (rank biserial = 0.52).

CONCLUSION

BoNT improves both motor severity and anxiety in CD. Poor correlation between motor severity and anxiety at both the time of injection and during the time of peak effect, and improvement in trait anxiety suggests that BoNT has a direct beneficial effect on anxiety.

What can epidemiological studies teach on the pathophysiology of adult-onset isolated dystonia?

Several demographic and environmental factors may play an important role in determining the risk of developing adult-onset isolated dystonia (AOID) and/or modifying its course. However, epidemiologic studies have provided to date only partial insight on the disease mechanisms that are actively influenced by these factors. The age-related increase in female predominance in both patients diagnosed with AOID and subjects carrying its putative mediational phenotype suggests sexual dimorphism that has been demonstrated for mechanisms related to blepharospasm and cervical dystonia. The opposite relationship that spread and spontaneous remission of AOID have with age suggests age-related decline of compensatory mechanisms that protect from the progression of AOID. Epidemiological studies focusing on environmental risk factors yielded associations only with specific forms of AOID, even for those factors that are not likely to predispose exclusively to specific focal forms (for example, only writing dystonia was found associated with head trauma, and only blepharospasm with coffee intake). Other factors show biological plausibility of their mechanistic role for specific forms, e.g., dry eye syndrome or sunlight exposure for blepharospasm, scoliosis for cervical dystonia, repetitive writing for writing dystonia. Overall, the relationship between environment and AOID remains complex and incompletely defined. Both hypothesis-driven preclinical studies and well-designed cross-sectional or prospective clinical studies are still necessary to decipher this intricate relationship.

Fixel-Based Analysis Reveals Whole-Brain White Matter Abnormalities in Cervical Dystonia

BACKGROUND

Cervical dystonia (CD) is a form of isolated focal dystonia typically associated to abnormal head, neck, and shoulder movements and postures. The complexity of the clinical presentation limits the investigation of its pathophysiological mechanisms, and the neural networks associated to specific motor manifestations are still the object of debate.

OBJECTIVES

We investigated the morphometric properties of white matter fibers in CD and explored the networks associated with motor symptoms, while regressing out nonmotor scores.

METHODS

Nineteen patients affected by CD and 21 healthy controls underwent diffusion-weighted magnetic resonance imaging. We performed fixel-based analysis, a novel method evaluating fiber orientation within specific fiber bundles, and compared fiber morphometric properties between groups. Moreover, we correlated fiber morphometry with the severity of motor symptoms in patients.

RESULTS

Compared to controls, patients exhibited decreased white matter fibers in the right striatum. Motor symptom severity negatively correlated with white matter fibers passing through inferior parietal areas and the head representation area of the motor cortex.

CONCLUSIONS

Abnormal white matter integrity at the basal ganglia level may affect several functional networks involved, for instance, in motor preparation and execution, visuomotor coordination, and multimodal integration. This may result in progressive maladaptive plasticity, culminating in overt symptoms of dystonia. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Effect of botulinum toxin type A on non-motor symptoms and quality of life in Meige syndrome

Background

It has been shown in previous studies that botulinum toxin type A (BTX-A) can effectively relieve the motor symptoms of Meige syndrome. However, its effect on non-motor symptoms (NMS) and quality of life (QoL) has not been comprehensively studied. This study aimed to explore the effects of BTX-A on NMS and QoL and to clarify the relationship between changes in motor symptoms, NMS, and QoL after BTX-A.

Methods

Seventy-five patients were recruited for the study. All patients were assessed by a series of clinical assessments before, one, and 3 months after BTX-A treatment. Dystonic symptoms, psychiatric disturbances, sleep disorders, and QoL were evaluated.

Results

After 1 and 3 months of BTX-A treatment, the scores of motor symptoms, anxiety, and depression were significantly decreased (P < 0.05). Except for general health, the scores of the other 36-item short-form health survey QoL subitems were significantly improved after BTX-A (P < 0.05). After 1 month of treatment, the changes in anxiety and depression were not correlated with changes in motor symptoms (P > 0.05). Still, they were negatively correlated with changes in physical functioning, role-physical and mental component summary QoL (P < 0.05).

Conclusions

BTX-A effectively improved motor symptoms, anxiety, depression, and QoL. Anxiety and depression improvement did not correlate with motor symptom changes after BTX-A, and QoL improvements were strongly associated with psychiatric disturbances.

Mood symptoms in cervical dystonia: Relationship with motor symptoms and quality of life

Background

Cervical dystonia (CD) has a high prevalence of anxiety and depression. The relationship between motor severity, mood symptoms and QoL is unclear and how to adequately assess these is also unknown. Instruments like the BAI, BDI and HADS are often used but items within these relating to somatic symptoms might influence the results.

Methods

Patients with idiopathic cervical dystonia (CD) were included. The BAI, BDI, HADS, CIDP58 and TWSTRS2- severity score were used for assessment of motor, mood and QoL symptoms. Pearson's correlations between motor and non-motor symptom scores were assessed. The psychometric properties of the psychiatric tools were measured and principal component analysis performed after identifying items that could correspond to somatic symptoms.

Results

201 participants were included. 42% of participants had either significant depression or anxiety symptoms or both when measured by BAI and BDI and 51% of patients met criteria on HADS. HADS-A and HADS-D, BAI and BDI were poorly correlated with TWSTRS2-S. The HADS-A and HADS-D both showed strong correlation with the sleep subdomain of CDIP58. Psychometric and principal component analysis on 149/201 participants did not reveal factor loadings consistent with the a priori somatic groupings. However mean scores were higher for somatic items.

Conclusion

A good score on the CDIP58, a commonly used tool, does not indicate mild disease severity or minimal mood symptoms. Minimal motor symptoms, similarly, also does not imply a positive QoL. Clinicians should be mindful on ideal methods for performing a holistic assessment of CD patients. This likely warrants a combination of motor, QoL and mood assessment tools.

Use of remote monitoring and integrated platform for the evaluation of sleep quality in adult-onset idiopathic cervical dystonia

BACKGROUND

Up to 70% of individuals diagnosed with adult-onset idiopathic focal cervical dystonia (AOIFCD) report difficulties with sleep. Larger cohort studies using wrist-worn accelerometer devices have emerged as an alternative to smaller polysomnography studies, in order to evaluate sleep architecture.

METHODS

To measure activity during the sleep/wake cycle, individuals wore a consumer-grade wrist device (Garmin vivosmart 4) continuously over 7 days on their non-dominant wrist, while completing a daily sleep diary and standardised sleep and non-motor questionnaires via a dedicated app. Sleep measures were derived from the captured raw triaxial acceleration and heart rate values using previously published validated algorithms.

RESULTS

Data were collected from 50 individuals diagnosed with AOIFCD and 47 age- and sex-matched controls. Those with AOIFCD self-reported significantly higher levels of excessive daytime sleepiness (p = 0.04) and impaired sleep quality (p = 0.03), while accelerometer measurements found the AOIFCD cohort to have significantly longer total sleep times (p = 0.004) and time spent in NREM sleep (p = 0.009), compared to controls. Overall, there was limited agreement between wearable-derived sleep parameters, and self-reported sleep diary and visual analogue scale records.

DISCUSSION

This study shows the potential feasibility of using consumer-grade wearable devices in estimating sleep measures at scale in dystonia cohorts. Those diagnosed with AOIFCD were observed to have altered sleep architecture, notably longer total sleep time and NREM sleep, compared to controls. These findings suggest that previously reported disruptions to brainstem circuitry and serotonin neurotransmission may contribute to both motor and sleep pathophysiology.

Cognitive and Neuropsychiatric Impairment in Dystonia

PURPOSE OF REVIEW

To review recent literature evaluating psychiatric and cognitive symptoms in dystonia, the two non-motor symptom groups most frequently evaluated in dystonia research and recognised in clinical practice.

RECENT FINDINGS

Recent work has embedded clinical recognition of psychiatric symptoms in dystonia, with depressive and anxiety-related symptoms routinely observed to be the most common. Less explored symptoms, such as self-harm, suicidal ideation, and substance abuse, represent newer areas of investigation, with initial work suggesting higher rates than the background population. Investigation of cognitive function has provided less consistent results, both within individual dystonia subtypes and across the spectrum of dystonias, partly reflecting the heterogeneity in approaches to assessment. However, recent work indicates impairments of higher cognitive function, e.g. social cognition, and disrupted visual and auditory sensory processing. Dystonia demonstrates psychiatric and cognitive symptom heterogeneity, with further work needed to recognise endophenotypes and improve diagnostic accuracy, symptom recognition, and management.

Cognitive impairment in Chinese patients with cervical dystonia

Objective

Cognitive impairment (CI) in patients with cervical dystonia (CD) has been reported in many studies but with inconsistent findings. We investigated the prevalence, characteristics, and clinical factors related to CI in Chinese patients with CD.

Methods

Sixty-eight patients with CD and 68 healthy controls (HCs) were included in the study. Demographic and clinical data were investigated. A logistic regression analysis was conducted to discriminate the clinical factors associated with CI in patients with CD. A cluster analysis was performed to explore the different characteristics within the group of CD patients with CI.

Results

We found that 42 (61.76%) patients with CD had CI. The most frequent CI domain was visuospatial function (39.71%), followed by memory (38.24%), attention/working memory (29.41%), language (25.00%), and executive function (23.53%). CD patients with CI were older, less educated, had an older age of onset, more severe motor symptoms and disability, and experienced more pain than CD patients without CI. The presence of CI in patients with CD was associated with less education (OR = 0.802, p = 0.034) and a higher Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) severity subscore (OR = 1.305, p = 0.001). The cluster analysis identified two different subgroups of patients, one with relatively mild cognitive impairment and the other with relatively severe cognitive impairment.

Conclusion

CI is relatively common in Chinese patients with CD, with the most common CI domain of the visuospatial function. In the present study, CI in patients with CD was associated with less education and more severe motor symptoms, and patients with CI may be further divided into two subgroups based on different extent and domain of cognitive decline.

Effect of Botulinum Toxin on Non-Motor Symptoms in Cervical Dystonia

Patients with cervical dystonia (CD) may display non-motor symptoms, including psychiatric disturbances, pain, and sleep disorders. Intramuscular injection of botulinum toxin type A (BoNT-A) is the most efficacious treatment for motor symptoms in CD, but little is known about its effects on non-motor manifestations. The aim of the present study was to longitudinally assess BoNT-A’s effects on CD non-motor symptoms and to investigate the relationship between BoNT-A-induced motor and non-motor changes. Forty-five patients with CD participated in the study. Patients underwent a clinical assessment that included the administration of standardized clinical scales assessing dystonic symptoms, psychiatric disturbances, pain, sleep disturbances, and disability. Clinical assessment was performed before and one and three months after BoNT-A injection. BoNT-A induced a significant improvement in dystonic symptoms, as well as in psychiatric disturbances, pain, and disability. Conversely, sleep disorders were unaffected by BoNT-A treatment. Motor and non-motor BoNT-A-induced changes showed a similar time course, but motor improvement did not correlate with non-motor changes after BoNT-A. Non-motor symptom changes after BoNT-A treatment are a complex phenomenon and are at least partially independent from motor symptom improvement.