Treatment of Dystonia: Medications, Neurotoxins, Neuromodulation, and Rehabilitation

Health-Related Quality of Life in Romanian Patients with Dystonia: An Exploratory Study

Background/Objectives: Dystonia is a neurological movement disorder characterized by involuntary muscle contractions that lead to abnormal movements and postures; it has a major impact on patients' health-related quality of life (HRQoL). The aim of this study was to examine the HRQoL of Romanian patients with dystonia using the EQ-5D-5L instrument. Methods: Responses to the EQ-5D-5L and the visual analogue scale (VAS) were collected alongside demographic and clinical characteristics. Health profiles were analyzed via the metrics of the EQ-5D-5L, severity levels, and age groups. Using Shannon's indexes, we calculated informativity both for patients' health profile as a whole and each individual dimension. Level sum scores (LSS) of the EQ-5D-5L were calculated and compared with scores from the EQ-5D-5L index and VAS. The HRQoL measures were analyzed through demographic and clinical characteristics. Descriptive statistics, Spearman correlation, and non-parametric tests (Mann-Whitney U or Kruskall-Wallis H) were used. The level of agreement between HRQoL measures was assessed using their intraclass correlation coefficient (ICC) and Bland-Altman plots. Results: A sample of 90 patients was used, around 75.6% of whom were female patients, and the mean age at the beginning of the survey was 58.7 years. The proportion of patients reporting "no problems" in all five dimensions was 10%. The highest frequency reported was "no problems" in self-care (66%), followed by "no problems" in mobility (41%). Shannon index and Shannon evenness index values showed higher informativity for pain/discomfort (2.07 and 0.89, respectively) and minimal informativity for self-care (1.59 and 0.68, respectively). The mean EQ-5D-5L index, LSS, and VAS scores were 0.74 (SD = 0.26), 0.70 (SD = 0.24), and 0.61 (SD = 0.21), respectively. The Spearman correlations between HRQoL measures were higher than 0.60. The agreement between the EQ-5D-5L index and LSS values was excellent (ICC = 0.970, 95% CI = 0.934-0.984); the agreement was poor-to-good between the EQ-5D-5L index and VAS scores (ICC = 683, 95% CI = 0.388-0.820), and moderate-to-good between the LSS and VAS scores (ICC = 0.789, 95% CI = 0.593-0.862). Conclusions: Our results support the utilization of the EQ-5D-5L instrument in assessing the HRQoL of dystonia patients, and empirical results suggest that the EQ-5D-5L index and LSS measure may be used interchangeably. The findings from this study highlight that HRQoL is complex in patients with dystonia, particularly across different age groups.

Update in Pediatric Neurocritical Care: What a Neurologist Caring for Critically Ill Children Needs to Know

Currently nearly one-quarter of admissions to pediatric intensive care units (PICUs) worldwide are for neurocritical care diagnoses that are associated with significant morbidity and mortality. Pediatric neurocritical care is a rapidly evolving field with unique challenges due to not only age-related responses to primary neurologic insults and their treatments but also the rarity of pediatric neurocritical care conditions at any given institution. The structure of pediatric neurocritical care services therefore is most commonly a collaborative model where critical care medicine physicians coordinate care and are supported by a multidisciplinary team of pediatric subspecialists, including neurologists. While pediatric neurocritical care lies at the intersection between critical care and the neurosciences, this narrative review focuses on the most common clinical scenarios encountered by pediatric neurologists as consultants in the PICU and synthesizes the recent evidence, best practices, and ongoing research in these cases. We provide an in-depth review of (1) the evaluation and management of abnormal movements (seizures/status epilepticus and status dystonicus); (2) acute weakness and paralysis (focusing on pediatric stroke and select pediatric neuroimmune conditions); (3) neuromonitoring modalities using a pathophysiology-driven approach; (4) neuroprotective strategies for which there is evidence (e.g., pediatric severe traumatic brain injury, post-cardiac arrest care, and ischemic stroke and hemorrhagic stroke); and (5) best practices for neuroprognostication in pediatric traumatic brain injury, cardiac arrest, and disorders of consciousness, with highlights of the 2023 updates on Brain Death/Death by Neurological Criteria. Our review of the current state of pediatric neurocritical care from the viewpoint of what a pediatric neurologist in the PICU needs to know is intended to improve knowledge for providers at the bedside with the goal of better patient care and outcomes.

Recommendations for the Management of Initial and Refractory Pediatric Status Dystonicus

Status dystonicus is the most severe form of dystonia with life-threatening complications if not treated promptly. We present consensus recommendations for the initial management of acutely worsening dystonia (including pre-status dystonicus and status dystonicus), as well as refractory status dystonicus in children. This guideline provides a stepwise approach to assessment, triage, interdisciplinary treatment, and monitoring of status dystonicus. The clinical pathways aim to: (1) facilitate timely recognition/triage of worsening dystonia, (2) standardize supportive and dystonia-directed therapies, (3) provide structure for interdisciplinary cooperation, (4) integrate advances in genomics and neuromodulation, (5) enable multicenter quality improvement and research, and (6) improve outcomes. © 2024 International Parkinson and Movement Disorder Society.

GNB1 Encephalopathy: Clinical Case Report and Literature Review

GNB1 encephalopathy is a rare genetic disease caused by pathogenic variants in the G Protein Subunit Beta 1 (GNB1) gene, with only around 68 cases documented worldwide. Although most cases had been caused by de novo germline mutations, in this case, the pathogenic variant was inherited from patient's mother, indicating an autosomal dominant inheritance pattern. The patient presented at 25 years of age with mild developmental delay and cognitive impairment, prominent generalized dystonia, and horizontal nystagmus which are all characterizing symptoms of GNB1 encephalopathy. Electroencephalography (EEG) showed no epileptiform patterns, and magnetic resonance imaging (MRI) revealed hypointensities in globus pallidus and dentate nucleus areas. The main theory for GNB1 encephalopathy pathogenesis is neuronal hyperexcitability caused by impaired ion channel regulation. Due to low specificity of symptoms, diagnosis relies on genetic testing. As there are no standardized GNB1 encephalopathy treatment guidelines, evaluation of different treatment options is based on anecdotal cases. Reviewing different treatment options, deep brain stimulation and intrathecal baclofen pump, as well as some other medications still in preclinical trials, seem to be the most promising.

Spatiotemporal Gait Differences before and after Botulinum Toxin in People with Focal Dystonia: A Pilot Study

BACKGROUND

The impact of focal dystonia on gait has attracted little attention and remains elusive. Considering the importance of both visual and head control in gait, blepharospasm and cervical dystonia should affect gait. Improvement of cervical/eyelid control following botulinum toxin (BTX) injections would translate into gait changes.

OBJECTIVES

To assess gait differences in people with focal dystonia before and after BTX treatment.

METHODS

Ten patients with blepharospasm, 10 patients with cervical dystonia, and 20 healthy age- and gender-matched controls were included. Gait was assessed before and 1-month after BTX injections using Biodex Gait Trainer™ 3. Gait velocity, cadence, step length, step asymmetry, and variability of step length were compared between patients and controls, and between the two time-points using non-parametric statistics.

RESULTS

At baseline, compared to controls, cervical dystonia patients showed reduced gait velocity, step length, and cadence. After BTX injections, while gait velocity and step length were significantly increased and step length variability reduced, gait parameters still differed between patients and controls. In blepharospasm patients, baseline gait velocity and step length were significantly smaller than in controls. After BTX injections, these gait parameters were significantly increased and variability decreased, so that patients no longer differed from controls.

CONCLUSION

Gait differences exist between patients with focal dystonia not directly affecting the lower limbs and healthy controls. These gait abnormalities were improved differently by BTX treatment according to the type of dystonia. These disparities suggest different pathophysiological mechanisms and support the need for changes in rehabilitation routines in cervical dystonia.

Basis of movement control in dystonia and why botulinum toxin should influence it?

Dystonia is a network disorder involving multiple brain regions, such as the motor cortex, sensory cortex, basal ganglia, and cerebellum. Botulinum toxin (BoNT) is the first-line therapy for treating focal dystonia and is a potent molecule that blocks the release of acetylcholine at the peripheral neuromuscular junction. However, the clinical benefits of BoNT are not solely related to peripheral muscle relaxation or modulation of afferent input from the muscle spindle. An increasing body of evidence, albeit in smaller cohorts, has shown that BoNT leads to distant modulation of the pathological brain substrates implicated in dystonia. A single treatment session of BoNT has been observed to reduce excessive motor excitability and improve sensory processing. Furthermore, owing to plasticity effects that are induced by botulinum, neural reorganization of pathological networks occurs, presumably leading to defective motor programs of dystonia replaced with normal movement patterns. However, longitudinal studies investigating the effects of multiple treatment sessions in large, well-characterized homogenous cohorts of dystonia will provide further compelling evidence supporting central botulinum mechanisms.

Movement disorders in autoimmune encephalitis: an update

Autoimmune encephalitis (AE) is a form of encephalitis resulting from an immune response targeting central nervous system antigens, which is characterized by cognitive impairment, neuropsychiatric symptoms, seizures, movement disorders (MDs), and other encephalopathy symptoms. MDs frequently manifest throughout the progression of the disease, with recurrent involuntary movements leading to discomfort and, in some cases, necessitating admission to the intensive care unit. Prompt identification and management of MDs can aid in the diagnosis and prognosis of AE. This review synthesizes current knowledge on the characteristics, underlying mechanisms, and treatment options for MDs in the context of AE.

High Levels of Physical Activity Reduce the Esthetic Durability of Botulinum Toxin Type A: A Controlled Single-Blind Clinical Trial

The present study aimed to evaluate the influence of physical activity on the durability of the esthetic effect of botulinum toxin type A (BoNT-A). Sixty female patients were allocated to three groups (n = 20) according to their physical activity level (PA): Low PA, Moderate PA, and High PA. All groups received a single injection of onabotulinumtoxinA, considering standardized doses in the frontalis (12U), corrugator supercilia (7U, each), and procerus muscles (4U). Outcomes were measured using electromyography (EMG), Merz 5-point scales, and Face-Q scales (perceived age and lines between eyebrows). A follow-up occurred after 30, 60, and 90 days. EMG results showed a significant decrease in muscle activity in the Low-PA group at all follow-ups compared with the other groups (p < 0.001). The Merz scale scores showed that the severity of forehead and glabellar lines significantly improved in the Low-PA group throughout this study compared with the other groups (p < 0.001). No significant differences between groups were found in the Face-Q scale for perceived age, while the Face-Q scale for lines between eyebrows showed better results for Low-PA (p < 0.01) and Moderate-PA (p < 0.01) groups compared to the High-PA group at the 30- and 90-day follow-ups. The durability of the esthetic effect of BoNT-A seems to be negatively influenced by the level of physical activity.

Dystonias: Clinical Recognition and the Role of Additional Diagnostic Testing

Dystonia is the third most common movement disorder, characterized by abnormal, frequently twisting postures related to co-contraction of agonist and antagonist muscles. Diagnosis is challenging. We provide a comprehensive appraisal of the epidemiology and an approach to the phenomenology and classification of dystonia, based on the clinical characteristics and underlying etiology of dystonia syndromes. We discuss the features of common idiopathic and genetic forms of dystonia, diagnostic challenges, and dystonia mimics. Appropriate workup is based on the age of symptom onset, rate of progression, whether dystonia is isolated or combined with another movement disorder or complex neurological and other organ system eatures. Based on these features, we discuss when imaging and genetic should be considered. We discuss the multidisciplinary treatment of dystonia, including rehabilitation and treatment principles according to the etiology, including when pathogenesis-direct treatment is available, oral pharmacological therapy, chemodenervation with botulinum toxin injections, deep brain stimulation and other surgical therapies, and future directions.

GPi DBS treatment outcome in children with monogenic dystonia: a case series and review of the literature

Introduction

Dystonia is the third most common pediatric movement disorder and is often difficult to treat. Deep brain stimulation (DBS) of the internal pallidum (GPi) has been demonstrated as a safe and effective treatment for genetic dystonia in adolescents and adults. The results of DBS in children are limited to individual cases or case series, although it has been proven to be an effective procedure in carefully selected pediatric cohorts. The aim of our study was to present the treatment outcome for 7- to 9-year-old pediatric patients with disabling monogenic isolated generalized DYT-THAP1 and DYT-KMT2B dystonia after bilateral GPi-DBS.

Patients and results

We present three boys aged <10 years; two siblings with disabling generalized DYT-THAP1 dystonia and a boy with monogenic-complex DYT-KMT2B. Dystonia onset occurred between the ages of 3 and 6. Significantly disabled children were mostly dependent on their parents. Pharmacotherapy was inefficient and patients underwent bilateral GPi-DBS. Clinical signs of dystonia improved significantly in the first month after the implantation and continued to maintain improved motor functions, which were found to have improved further at follow-up. These patients were ambulant without support and included in everyday activities. All patients had significantly lower Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) values, indicating >25% improvement over the first 15 months. However, there was a decline in speech and upper limb function, manifesting with bradylalia, bradykinesia, and dysphonia, which decreased after treatment with trihexyphenidyl.

Conclusion

Although reports of patients with monogenic dystonia, particularly DYT-THAP1, treated with DBS are still scarce, DBS should be considered as an efficient treatment approach in children with pharmacoresistent dystonia, especially with generalized monogenic dystonia and to prevent severe and disabling symptoms that reduce the quality of life, including emotional and social aspects. Patients require an individual approach and parents should be properly informed about expectations and possible outcomes, including relapses and impairments, in addition to DBS responsiveness and related improvements. Furthermore, early genetic diagnosis and the provision of appropriate treatments, including DBS, are mandatory for preventing severe neurologic impairments.

Evaluation of outcome of different neurosurgical modalities in management of cervical dystonia

Background

Cervical dystonia is the most common form of focal dystonia and is managed by multiple modalities including repeated botulinum toxin injections, in addition to medical treatment with anticholinergics, muscle relaxants, and physiotherapy. However, surgical interventions could be beneficial in otherwise refractory patients. This study aims to report our experience in the neurosurgical management of cervical dystonia and evaluate patient outcomes using reliable outcome scores for the assessment of patients with cervical dystonia and possible complications. This case series study was conducted on 19 patients with cervical dystonia of different etiologies who underwent surgical management [ten patients underwent selective peripheral denervation, five patients underwent pallidotomy, and four patients underwent bilateral globus pallidus internus (GPi) deep brain stimulation (DBS)] in the period between July 2018 and June 2021 at Ain Shams University Hospitals, Cairo, Egypt. With the assessment of surgical outcomes using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Tsui scale 6 months postoperatively.

Results

Surgical management of patients with cervical dystonia of either primary or secondary etiology was associated with significant improvement in head and neck postures after 6 months without major complications associated with the different surgical procedures. The mean improvement in total TWSTRS and Tsui scores were 51.2% and 64.8%, respectively, compared with preoperative scores, while the mean improvement in the TWSTRS subscales (severity, disability, and pain) were 40.2%, 66.9%, and 58.3%, respectively.

Conclusion

Cervical dystonia patients in whom non-surgical options have failed to alleviate their symptoms can be managed surgically leading to significant improvements with minimal adverse effects. However, surgical treatment should be tailored according to several factors including but not limited to the etiology, pattern of dystonic activity, and comorbidities. Therefore, management should be tailored to achieve long-term improvement with minimal risk of complications.

The Dystonias

PURPOSE OF REVIEW

This article discusses the most recent findings regarding the diagnosis, classification, and management of genetic and idiopathic dystonia.

RECENT FINDINGS

A new approach to classifying dystonia has been created with the aim to increase the recognition and diagnosis of dystonia. Molecular biology and genetic studies have identified several genes and biological pathways involved in dystonia.

SUMMARY

Dystonia is a common movement disorder involving abnormal, often twisting, postures and is a challenging condition to diagnose. The pathophysiology of dystonia involves abnormalities in brain motor networks in the context of genetic factors. Dystonia has genetic, idiopathic, and acquired forms, with a wide phenotypic spectrum, and is a common feature in complex neurologic disorders. Dystonia can be isolated or combined with another movement disorder and may be focal, segmental, multifocal, or generalized in distribution, with some forms only occurring during the performance of specific tasks (task-specific dystonia). Dystonia is classified by clinical characteristics and presumed etiology. The management of dystonia involves accurate diagnosis, followed by treatment with botulinum toxin injections, oral medications, and surgical therapies (mainly deep brain stimulation), as well as pathogenesis-directed treatments, including the prospect of disease-modifying or gene therapies.

Developing Novel Therapies for Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 7]: Opportunities From Restorative Neurobiology

STUDY DESIGN

Narrative review.

OBJECTIVES

To provide an overview of contemporary therapies for the James Lind Alliance priority setting partnership for degenerative cervical myelopathy (DCM) question: 'Can novel therapies, including stem-cell, gene, pharmacological and neuroprotective therapies, be identified to improve the health and wellbeing of people living with DCM and slow down disease progression?'

METHODS

A review of the literature was conducted to outline the pathophysiology of DCM and present contemporary therapies that may hold therapeutic value in 3 broad categories of neuroprotection, neuroregeneration, and neuromodulation.

RESULTS

Chronic spinal cord compression leads to ischaemia, neuroinflammation, demyelination, and neuronal loss. Surgical intervention may halt progression and improve symptoms, though the majority do not make a full recovery leading to lifelong disability. Neuroprotective agents disrupt deleterious secondary injury pathways, and one agent, Riluzole, has undergone Phase-III investigation in DCM. Although it did not show efficacy on the primary outcome modified Japanese Orthopaedic Association scale, it showed promising results in pain reduction. Regenerative approaches are in the early stage, with one agent, Ibudilast, currently in a phase-III investigation. Neuromodulation approaches aim to therapeutically alter the state of spinal cord excitation by electrical stimulation with a variety of approaches. Case studies using electrical neuromuscular and spinal cord stimulation have shown positive therapeutic utility.

CONCLUSION

There is limited research into interventions in the 3 broad areas of neuroprotection, neuroregeneration, and neuromodulation for DCM. Contemporary and novel therapies for DCM are now a top 10 priority, and whilst research in these areas is limited in DCM, it is hoped that this review will encourage research into this priority.

Mechanisms of pallidal deep brain stimulation: Alteration of cortico-striatal synaptic communication in a dystonia animal model

Pallidal deep brain stimulation (DBS) is an important option for patients with severe dystonias, which are thought to arise from a disturbance in striatal control of the globus pallidus internus (GPi). The mechanisms of GPi-DBS are far from understood. Although a disturbance of striatal function is thought to play a key role in dystonia, the effects of DBS on cortico-striatal function are unknown. We hypothesised that DBS, via axonal backfiring, or indirectly via thalamic and cortical coupling, alters striatal function. We tested this hypothesis in the dtsz hamster, an animal model of inherited generalised, paroxysmal dystonia. Hamsters (dystonic and non-dystonic controls) were bilaterally implanted with stimulation electrodes in the GPi. DBS (130 Hz), and sham DBS, were performed in unanaesthetised animals for 3 h. Synaptic cortico-striatal field potentials, as well as miniature excitatory postsynaptic currents (mEPSC) and firing properties of medium spiny striatal neurones were recorded in brain slice preparations obtained immediately after EPN-DBS. The main findings were as follows: a. DBS increased cortico-striatal evoked responses in healthy, but not in dystonic tissue. b. Commensurate with this, DBS increased inhibitory control of these evoked responses in dystonic, and decreased inhibitory control in healthy tissue. c. Further, DBS reduced mEPSC frequency strongly in dystonic, and less prominently in healthy tissue, showing that also a modulation of presynaptic mechanisms is likely involved. d. Cellular properties of medium-spiny neurones remained unchanged. We conclude that DBS leads to dampening of cortico-striatal communication, and restores intrastriatal inhibitory tone.

Treatment of Disorders of Tone and Other Considerations in Pediatric Movement Disorders

Pediatric movement disorders (PMDs) consist of a heterogeneous group of signs and symptoms caused by numerous neurological diseases. Different neurological disorders in children also share overlapping movement disorders making a diagnosis of the underlying cause of the movement disorder challenging. The similarity of the symptoms across multiple disease types suggests that there may be a final common motor pathway causing the overlapping movement disorders. There are numerous disorders in children associated with disturbances in tone and involuntary movements. This chapter will focus primarily on those disorders that involve abnormalities of tone and other important considerations of pediatric movement disorders. This chapter will address rating scales and goals for treatment and will include a review of symptomatic treatment and, where possible, the treatment of the underlying disease processes. The chapter will review representative disorders, including an inborn error of metabolism, an autoimmune disorder, and a group of neurodegenerative disorders. These examples demonstrate how the disorder's underlying pathophysiology results in a specific approach to the underlying disease and the associated conditions of tone and involuntary movements. Finally, the multiple treatment options for cerebral palsy and considerations of cerebral palsy mimics will be discussed.