Multicenter observational study of abobotulinumtoxinA neurotoxin in cervical dystonia: The ANCHOR-CD registry

Can symptoms or signs of cervical dystonia occur without abnormal movements of the head or neck?

INTRODUCTION

Cervical dystonia is defined by excessive contraction of muscles that produce abnormal postures and movements of the head, neck, and sometimes the shoulders. Many affected individuals also have pain, local muscle hypertrophy, and/or abnormally increased EMG activity. However, abnormal movements are considered the defining feature.

CASES

Three cases are described suggesting that some features of cervical dystonia may occur without abnormal movements. In these cases, the only clinical features are pain, local muscle hypertrophy, or abnormal EMG activity. These features may occur years before abnormal movements emerge, or they may occur coincidentally with dystonia affecting regions other than the neck. In some cases, some features associated with cervical dystonia may occur without any obvious abnormal movements.

CONCLUSIONS

Some symptoms of cervical dystonia may occur without abnormal movements of the head or neck. The purpose of this report is not to question current diagnostic criteria for cervical dystonia, but to call attention to a phenomenon that deserves further attention. Such cases may be considered to have a pro-dromal form of cervical dystonia or a formes fruste of cervical dystonia. Whatever diagnostic label is applied, the phenomenon is important to recognize, because symptoms may be readily alleviated with botulinum toxin.

[Pain and cervical dystonia]

BACKGROUND

Dystonia is a hyperkinetic movement disorder that results in twisting, cramps and tremors due to sustained or intermittent muscle contractions. Cervical dystonia is the most common form of dystonia, in which the head, neck and/or shoulder areas are affected. In addition to these motor symptoms, pain and psychiatric symptoms are frequent in (cervical) dystonia.

OBJECTIVE

Description of the incidence and evaluation of pain in cervical dystonia, summary and discussion of treatment options and effects.

MATERIAL AND METHODS

In this review article the results in the scientific literature on pain in dystonia are summarized and discussed.

RESULTS

Compared to other forms of dystonia, pain occurs most frequently in patients with cervical dystonia. A large proportion of patients with cervical dystonia suffer from pain, which contributes most to impairment of the patient. The motor symptoms of dystonia are usually treated with botulinum toxin injections. These have a muscle relaxing effect and also relieve pain. The study situation on the occurrence and treatment of pain in other forms of dystonia is so far very limited. Pain can dominate the clinical picture in patients with cervical dystonia. Evaluation of pain in cervical dystonia can be performed using standardized questionnaires.

CONCLUSION

It is important to ask patients with cervical dystonia about pain and to consider it in treatment planning and evaluation. Vice versa, if pain is present the possibility of a causative dystonia should also be considered. For pain assessment there are some newly developed questionnaires to assess pain in a standardized way in patients with dystonia. Further research is needed to better understand the pathomechanisms of pain in dystonia.

Botulinum Neurotoxins: From Toxin to Medicine

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Improving the Efficacy of Botulinum Toxin for Cervical Dystonia: A Scoping Review

Cervical dstonia (CD) is a chronic disorder with a significant detrimental impact on quality of life, requiring long-term treatment. Intramuscular injections of botulinum neurotoxin (BoNT) every 12 to 16 weeks have become the first-line option for CD. Despite the remarkable efficacy of BoNT as a treatment for CD, a significantly high proportion of patients report poor outcomes and discontinue the treatment. The reasons that drive sub-optimal response or treatment failure in a proportion of patients include but are not limited to inappropriate muscle targets and/or BoNT dosing, improper method of injections, subjective feeling of inefficacy, and the formation of neutralizing antibodies against the neurotoxin. The current review aims to complement published research focusing on the identification of the factors that might explain the failure of BoNT treatment in CD, highlighting possible solutions to improve its outcomes. Thus, the use of the new phenomenological classification of cervical dystonia known as COL-CAP might improve the identification of the muscle targets, but more sensitive information might come from the use of kinematic or scintigraphic techniques and the use of electromyographic or ultrasound guidance might ensure the accuracy of the injections. Suggestions are made for the development of a patient-centered model for the management of cervical dystonia and to emphasize that unmet needs in the field are to increase awareness about the non-motor spectrum of CD, which might influence the perception of the efficacy from BoNT injections, and the development of dedicated rehabilitation programs for CD that might enhance its effectiveness.

Pain Reduction in Cervical Dystonia Following Treatment with IncobotulinumtoxinA: A Pooled Analysis

This analysis pooled pain severity data from four phase 3 and 4 studies of incobotulinumtoxinA (incoBoNT-A) for the treatment of cervical dystonia (CD) in adults. CD-related pain severity was assessed at baseline, each injection visit, and 4 weeks after each injection of incoBoNT-A using the Toronto Western Spasmodic Torticollis Rating Scale pain severity subscale or a pain visual analog scale. Both were analyzed using a score range of 0-10 and pain was categorized as mild, moderate, or severe. Data for 678 patients with pain at baseline were assessed and sensitivity analyses evaluated pain responses in the subgroup not taking concomitant pain medication (n = 384 at baseline). At Week 4 after the first injection, there was a mean change of -1.25 (standard deviation 2.04) points from baseline pain severity (p < 0.0001), with 48.1% showing ≥ 30% pain reduction from baseline, 34.4% showing ≥50% pain reduction from baseline, and 10.3% becoming pain free. Pain responses were sustained over five injection cycles with a trend to incremental improvements with each successive cycle. Pain responses in the subgroup not taking concomitant pain medication demonstrated the lack of confounding effects of pain medications. These results confirmed the pain relief benefits of long-term treatment with incoBoNT-A.

Pain in cervical dystonia: mechanisms, assessment and treatment

INTRODUCTION

In patients with cervical dystonia (CD), pain is a major contributor to disability and social isolation and is often the main reason patients seek treatment. Surveys evaluating patient perceptions of their CD symptoms consistently highlight pain as a troublesome and disabling feature of their condition with significant impact on daily life and work.

AREAS COVERED

In this article, the authors review the epidemiology, assessment, possible mechanisms and treatment of pain in CD, including a meta-analysis of randomized controlled trial data with abobotulinumtoxinA.

EXPERT OPINION

Mechanisms of pain in CD may be muscle-based and non-muscle based. Accumulating evidence suggests that non-muscle-based mechanisms (such as abnormal transmission and processing of nociceptive stimuli, dysfunction of descending pain inhibitory pathways as well as structural and network changes in the basal ganglia, cortex and other areas) may also contribute to pain in CD alongside prolonged muscle contraction. Chemodenervation with botulinum toxin is considered the first-line treatment for CD. Treatment with botulinum toxin is usually effective, but optimization of the injection parameters should include consideration of pain as a core symptom in addition to the motor problems.

An Update on Botulinum Toxin in Neurology

Botulinum neurotoxin (BoNT) is an effective treatment for many neurologic disorders. This article gives a comprehensive overview of the clinical applications of BoNT across the field of neurology.

Use of AbobotulinumtoxinA in Adults with Cervical Dystonia: A Systematic Literature Review

Cervical dystonia (CD) is a neurological movement disorder characterized by sustained involuntary muscle contractions. First-line therapy for CD is intramuscular injections of botulinum neurotoxin (e.g., abobotulinumtoxinA) into the affected muscles. The objective of this systematic literature review is to assess the clinical evidence regarding the effects of abobotulinumtoxinA for treatment of CD in studies of safety, efficacy, patient-reported outcomes, and economic outcomes. Using comprehensive electronic medical literature databases, a search strategy was developed using a combination of Medical Subject Heading terms and keywords. Results were reviewed by two independent reviewers who rated the level of evidence. The search yielded 263 publications, of which 232 were excluded for being duplicate publications, not meeting the selection criteria, or failing to meet predefined eligibility criteria, leaving a total of 31 articles. Clinical efficacy, patient-reported outcomes, and safety data were in 6 placebo-controlled trials (8 articles), 6 active-controlled trials, and 16 observational studies (17 articles). Data on health economic outcomes were provided in one of the clinical trials, in two of the observational studies, and in one specific cost-analysis publication. This review demonstrated that the routine use of abobotulinumtoxinA in CD is well-established, effective, and generally well-tolerated, with a relatively low cost of treatment.

Cervical Dystonia Caused by Chronic Nonunion C2 Fracture: A Case Report

Chronic nonunion cervical fracture leading to cervical dystonia (CD) is very rare. This study reports a 72-year-old man who presented with 9-month history of progressively worsening neck tilting, neck tightness, neck pain, headache, and difficulty with swallowing. The patient was referred to speech therapy and confirmed to have dysphagia on modified barium swallow study. A cervical spine radiograph showed a chronic C2 nonunion fracture. Subsequent cervical spine magnetic resonance imaging confirmed chronic C2 nonunion fracture with kyphotic deformity of the cervical canal with associated cord compression at C1-C2 and severe central canal stenosis. Needle electromyography revealed dystonic or spasmodic neck muscles, consistent with diagnosis of CD. Botulinum toxin injection resulted in marked clinical improvement. The patient finally underwent occipital to C4 posterior segmental fusion. No recurrence of CD had occurred 12 months after botulinum toxin injection and surgery, which supports the conclusion that chronic C2 nonunion fracture is most likely responsible for CD in this case. The authors suggest that all patients with CD receive dysphagia evaluation and more importantly cervical spine imaging to rule out chronic C2 nonunion fracture.

Impact of abobotulinumtoxinA on the clinical features of cervical dystonia in routine practice

INTRODUCTION

The efficacy and safety of abobotulinumtoxinA in the management of cervical dystonia has been established in randomized, controlled trials that use a selected trial population. In this meta-analysis of observational data, we evaluated the real-life effectiveness of abobotulinumtoxinA as delivered in routine clinical practice.

METHODS

Meta-analysis of patient-level data for adult patients with cervical dystonia treated with abobotulinumtoxinA from three prospective, multicenter, observational studies (NCT01314365, NCT00833196 and NCT01753349).

RESULTS

We report data for patients treated with abobotulinumtoxinA over one injection cycle at 181 neurology centers in 35 countries. CD clinical features as assessed by Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) Total scores (N = 920) significantly reduced by a mean [95%CI] of -12.9 [-13.9, -11.8] points at Week 4 (N = 449) and -3.2 [-3.8, -2.7] points at the end of the injection cycle (N = 890). All three TWSTRS domains (symptom severity, disability and pain) contributed to the overall improvement. Patients were generally content with symptom control at peak effect of the treatment cycle, with 86% reporting overall satisfaction.

CONCLUSION

Findings from this meta-analysis of observational studies confirm the effectiveness of abobotulinumtoxinA in routine practice. Despite inclusion of a broader population sample, the magnitude of improvements observed is consistent with that seen in the pivotal, randomized controlled trials.

Benefits, Safety, and Adjunct Modality Prevalences of Long-Term Botulinum Toxin Injections for Cervical Dystonia and Myofascial Neck Pain: A Retrospective Cohort Study

Introduction

There is a paucity of long-term treatment benefit and safety data of botulinum toxin A (BTX-A) for cervical dystonia (CD) and myofascial neck pain syndrome (MPS). Additionally, the prevalence of adjunct modality uses during this period is unknown despite evolving practices.

Objective

To assess and compare treatment benefit, safety, and adjunct modality prevalences of long-term BTX-A injections between CD and MPS patients.

Design

Retrospective cohort study.

Setting

Private practice tertiary care clinics in Toronto.

Patients

Convenience sample of 37 (52.9%) CD and 33 (47.1%) MPS patients treated for a mean±SD duration of 7.2±4.3 and 8.3±4.7 years, respectively.

Interventions

BTX-A injections administered at least once yearly, for a duration longer than 1 year.

Main Outcome Measures

Toronto Western Spasmodic Torticollis Rating Scales (TWSTRS) for disability and pain, Patient Global Impression of Change (PGIC) score, time to peak effect, duration of total response, adverse effects, and prevalence of adjunct modalities.

Results

CD patients experienced improvements in TWSTRS disability (17.57±6.79 to 9.81±4.35, p<0.001) and pain (14.61±3.08 to 9.05±3.49, p<0.001) scores as well as PGIC score (52.00%±23.60% to 64.80%±23.60%, p=0.007). MPS patients experienced improvements in TWSTRS disability (15.86±7.70 to 10.07±7.01, p=0.01) and pain (15.25±4.09 to 10.85±4.49, p=0.01) scores. In both cohorts, there were no changes in time to peak effect and duration of total response. Adverse effects were minimal and self-limiting. Prevalences of adjunct modalities used by CD versus MPS patients were 28.13% versus 50.00% for anesthetic procedures, 23.08% versus 15.38% for image-guidance, 65.71% versus 56.25% for pectoralis minor injections, and 47.06% versus 53.13% for cannabis-use.

Conclusion

There were demonstrated and comparable treatment benefit, safety, and adjunct modality prevalences. Our study is the first to demonstrate that long-term BTX-A injections for MPS, although commonly used off-label, can be effective and safe.

[99mTc]MIBI SPECT/CT for Identifying Dystonic Muscles in Patients with Primary Cervical Dystonia

PURPOSE

This study aimed to evaluate the usefulness of [^99mTc]sestamibi ([^99mTc]MIBI) single photon emission computed tomography (SPECT)/X-ray computed tomography (CT) imaging for the identification of dystonic muscles in primary cervical dystonia (PCD) patients who underwent botulinum neurotoxin type A (BoNT-A) therapy.

PROCEDURES

Thirty-six patients with PCD and 10 healthy subjects (control group) who underwent [^99mTc]MIBI SPECT/CT were enrolled. The image characteristics of dystonic muscles and normal muscles were evaluated. Muscle/background ratio (MBR) of six representative muscles was calculated for dystonic muscles in PCD group and normal muscles in control group. In PCD patients, target muscles injected with BoNT-A were selected by clinical evaluations and the results of needle electromyography (EMG) were considered as the gold standard. The sensitivity, specificity, and diagnostic efficacy of SPECT/CT were obtained from the receiver operator characteristic (ROC) curve.

RESULTS

Twenty-four PCD patients were included in our study eventually, because three PCD patients whose follow-up were lost and 9 PCD patients whose maximum reduction of Tsui scale scores was < 80 % were ruled out. Normal muscles of healthy subjects showed mild symmetrical radioactivity distribution, while in PCD patients, [^99mTc]MIBI uptake in dystonic muscles abnormally increased. The mean MBRs of dystonic muscles were significantly higher than those of normal muscles. The sensitivity, specificity, and area under the curve (AUC) of SPECT/CT were 93.2 %, 88.5 %, and 0.908, respectively.

CONCLUSIONS

Our study indicated that [^99mTc]MIBI SPECT/CT may be a useful method for identifying dystonic muscles and a guide to BoNT-A therapy in PCD patients.

Update on current and emerging therapies for dystonia

Treatment strategies for dystonia depend on the focal, segmental or generalized distribution of symptoms. Chemodenervation with botulinum toxin remains the treatment of choice for focal- or select-body regions in generalized and segmental dystonia. A potentially longer acting formulation of botulinum toxin is being investigated besides the currently available formulations. Electromyography increases toxin injection accuracy and may reduce injection number, frequency, side effects and costs by identifying dystonic muscle activity. Oral anticholinergics, baclofen and clonazepam are used off-label, but novel drugs in development include sodium oxybate, zonisamide and perampanel. Characterizing dystonia as a sensorimotor circuit disorder has prompted the use of noninvasive neuromodulation procedures. These techniques need further study but simultaneous rehabilitation techniques appear to also improve outcomes. Pallidal deep-brain stimulation is beneficial for medication-refractory primary generalized and possibly focal dystonia such as cervical dystonia. Certain genetic conditions are amenable to specific therapies and future gene-targeted therapies could benefit selected dystonia patients.

Spectrum of practice in the routine management of cervical dystonia with abobotulinumtoxinA: findings from three prospective open-label observational studies

Background

Cervical dystonia is a heterogeneous disorder with several possible presentations, for which first-line therapy is often botulinum toxin (BoNT). In routine clinical practice the success of each BoNT injection is dependent on several variables, including individual presentation and injection technique. Large multicenter, observational studies provide important information on individualized administration strategies that cannot be otherwise ascertained from controlled clinical trials. In this meta-analysis of patient level data, we aimed to evaluate the clinical characteristics of patients with cervical dystonia undergoing routine treatment with botulinum toxin, specifically abobotulinumtoxinA. We also aimed to characterize current abobotulinumtoxinA injection techniques and parameters and to explore international differences in patient presentation and treatment.

Methods

This was a meta-analysis of baseline data from three prospective, international, multicenter, observational studies (NCT01314365, NCT00833196 and NCT01753349) of botulinum toxin treatment for the routine management of adult cervical dystonia.

Results

Data presented illustrate the significant heterogeneity of CD presentation in routine practice. Most subjects presented with a complex pattern of dystonic movements and the majority had additional components of shoulder elevation, tremor and/or jerk. Dosing was generally in accordance with that recommended in the abobotulinumtoxinA prescribing information, although the range of dosing also indicates that injections are tailored to individual presentation. Sub-group analyses at the country level revealed distinct differences in injection practice.

Conclusions

This meta-analysis is based on the largest dataset of subjects with cervical dystonia studied to date. The heterogeneity revealed in our baseline findings support the need to develop consistent, practical and comprehensive best practice guidelines.

Longitudinal studies of botulinum toxin in cervical dystonia: Why do patients discontinue therapy?

BACKGROUND

Numerous studies have established botulinum toxin (BoNT) to be safe and effective for the treatment of cervical dystonia (CD). Despite its well-documented efficacy, there has been growing awareness that a significant proportion of CD patients discontinue therapy. The reasons for discontinuation are only partly understood.

METHODS

This summary describes longitudinal studies that provided information regarding the proportions of patients discontinuing BoNT therapy, and the reasons for discontinuing therapy. The data come predominantly from un-blinded long-term follow-up studies, registry studies, and patient-based surveys.

RESULTS

All types of longitudinal studies provide strong evidence that BoNT is both safe and effective in the treatment of CD for many years. Overall, approximately one third of CD patients discontinue BoNT. The most common reason for discontinuing therapy is lack of benefit, often described as primary or secondary non-response. The apparent lack of response is only rarely related to true immune-mediated resistance to BoNT. Other reasons for discontinuing include side effects, inconvenience, cost, or other reasons.

DISCUSSION

Although BoNT is safe and effective in the treatment of the majority of patients with CD, approximately one third discontinue. The increasing awareness of a significant proportion of patients who discontinue should encourage further efforts to optimize administration of BoNT, to improve BoNT preparations to extend duration or reduce side effects, to develop add-on therapies that may mitigate swings in symptom severity, or develop entirely novel treatment approaches.

Botulinum Toxin Type A Injection for Cervical Dystonia in Adults with Dyskinetic Cerebral Palsy

We aimed to evaluate the efficacy and safety of injecting botulinum toxin A (BoNT-A) into the neck muscles to treat cervical dystonia (CD) in patients with dyskinetic cerebral palsy (CP). This was a randomized, double-blinded, placebo-controlled trial with cross-over design. We prospectively enrolled adults with dyskinetic CP who were over 20 years old and had been clinically diagnosed with CD for more than one year. The primary outcome measure was the change in Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) at four weeks from the baseline TWSTRS. Seventeen patients were initially enrolled, but one patient was excluded after the final evaluation because of a violation of the study protocol. At four weeks, the BoNT-A injections showed significant improvement in TWSTRS total scores compared to the saline injections (p = 0.0286 for ANCOVA). At 12 weeks, the BoNT-A injections resulted in greater improvements in TWSTRS total scores than the saline injections without statistical significance (p = 0.0783 for ANCOVA). Dysphagia occurred in three out of 16 patients: two after BoNT-A and one after saline. The dysphagia was transient and improved naturally within two weeks without any special treatment. BoNT-A injection for CD in adults with dyskinetic CP is relatively safe and improves pain and disability.

Injectable DaxibotulinumtoxinA in Cervical Dystonia: A Phase 2 Dose-Escalation Multicenter Study

Background

Injectable daxibotulinumtoxinA (an investigational botulinum toxin, RT002) may offer a more prolonged duration of response—and therefore less frequent dosing—than onabotulinumtoxinA.

Objectives

To perform a phase 2, open‐label, dose‐escalation study to assess the efficacy and safety of daxibotulinumtoxinA in cervical dystonia.

Methods

Subjects with moderate‐to‐severe isolated cervical dystonia were enrolled in sequential cohorts to receive a single open‐label, intramuscular dose of injectable daxibotulinumtoxinA of up to 200 U (n = 12), 200–300 U (n = 12), or 300–450 U (n = 13; https://clinicaltrials.gov identifier NCT02706795).

Results

Overall, 33/37 enrollees completed the trial. DaxibotulinumtoxinA was associated with mean reductions in Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)‐Total score of 16.8 (38%) at week 4, 21.3 (50%) at week 6, and 12.8 (30%) at week 24. The proportion of subjects who were responders (achieved ≥ 20% reduction in TWSTRS‐Total score) was 94% at week 6 and 68% at week 24. The median duration of response (time until > 20% of the improvement in TWSTRS‐Total score achieved at week 4 was no longer retained or re‐treatment was needed) was 25.3 weeks (95% CI, 20.14–26.14 weeks). There were no serious adverse events and there was no apparent dose‐related increase in the incidence of adverse events. The most common treatment‐related adverse events were dysphagia (14%) and injection site erythema (8%).

Conclusions

Preliminary assessments suggest that injectable daxibotulinumtoxinA at doses up to 450 U is well tolerated and may offer prolonged efficacy in the treatment of cervical dystonia. Further studies involving larger numbers of patients are now warranted.

Personalized botulinum toxin type A therapy for cervical dystonia based on kinematic guidance

BACKGROUND

Botulinum toxin type A (BoNT-A) injections is the accepted first-line therapy for cervical dystonia (CD), however, numerous patients discontinue treatment early due to perceived sub-optimal relief. To improve BoNT-A therapy for CD, proper assessment of neck motion and selection of relevant muscles and dosing must be met. Kinematic technology may improve treatment outcomes by guiding physicians to better tailor muscle selection and BoNT-A dosing for CD therapy.

METHODS

28 CD participants were placed into either group: expert injector determined injection patterns by visual assessment ("vb") versus injection patterns based on kinematics interpreted by an expert injector ("kb"). Injections occurred at weeks 0, 16 and 32 with follow-ups at weeks 6, 22 and 38. Kinematics utilized four sensors to capture the severity of multiaxial, static neck posturing (e.g., torticollis) and dynamic, spasmodic/tremor movements while participants were seated. Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) score changes were evaluated over 38 weeks.

RESULTS

For the "kb" participants, there was a significant 28.8% (- 11.25 points) reduction in TWSTRS total score at week 6, as well as significant reduction in severity and disability TWSTRS sub-scores (parts I and II) with maintained improvement at subsequent visits. As for the "vb" participants had a significant reduction in total TWSTRS score by 28.5% (- 9.84 points) after week 22. Disability score for the "vb" group trended towards improvement over 38 weeks.

CONCLUSION

Clinical judgement guided by kinematic analysis of CD biomechanics can result in faster optimal muscle selections and minimize use of higher BoNT-A doses as compared to visual determination, thereby achieving comparable and potentially better treatment outcomes.

Minimal clinically important change in the Toronto Western Spasmodic Torticollis Rating Scale

OBJECTIVES

To characterize the minimal clinically important change (MCIC) after treatment in cervical dystonia patients using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS).

METHODS

Changes in the TWSTRS from an observational study of abobotulinumtoxinA in the routine management of cervical dystonia (NCT01314365) were analyzed using the Patient Global Impression of Change (PGIC) as anchor.

RESULTS

For the overall population (N = 304, baseline TWSTRS-Total score 43.4 ± 19.4), the MCIC for the TWSTRS Total score was -11.9 (95%CI: -13.9, -10.0; p < 0.0001). However, thresholds ranged from -3.2 to -18.0 dependent on baseline severity. TWSTRS-Total scores improved linearly by 3 points for every one-point PGIC increase. There was similar linearity between the graded PGIC categories and TWSTRS subscale scores (severity, disability, and pain).

CONCLUSIONS

A 3-point change is the minimal clinically important change after treatment using TWSTRS as endpoint with higher cutoffs for greater baseline disease severity. For an average trial population (TWSTRS-total: 40-45), a 12-point decrease is clinically meaningful.

INTEREST IN CD2, a global patient-centred study of long-term cervical dystonia treatment with botulinum toxin

BACKGROUND

Longitudinal cohort studies provide important information about the clinical effectiveness of an intervention in the routine clinical setting, and are an opportunity to understand how a population presents for treatment and is managed.

METHODS

INTEREST IN CD2 (NCT01753349) is a prospective, international, 3-year, longitudinal, observational study following the course of adult idiopathic cervical dystonia (CD) treated with botulinum neurotoxin type A (BoNT-A). The primary objective is to document long-term patient satisfaction with BoNT-A treatment. Here we report baseline data.

RESULTS

This analysis includes 1036 subjects (67.4% of subjects were female; mean age was 54.7 years old; mean TWSTRS Total score was 31.7). BoNT-A injections were usually given in line with BoNT-A prescribing information. The most commonly injected muscles were splenius capitis (87.3%), sternocleidomastoid (82.6%), trapezius (64.3%), levator scapulae (40.9%) and semispinalis capitis (26.9%); 35.5% of subjects were injected using a guidance technique. Most subjects (87.8%) had been previously treated with BoNT-A (median interval between last pre-study injection and study baseline was 4 months); of these 84.8% reported satisfaction with BoNT-A treatment at peak effect during their previous treatment cycle and 51.5% remained satisfied at the end of the treatment. Analyses by geographical region revealed heterogeneity in the clinical characteristics and BoNT-A injection practice of CD subjects presenting for routine treatment.

CONCLUSIONS

These baseline analyses provide sizeable data regarding the epidemiology and clinical presentation of CD, and demonstrate an international heterogeneity of clinical practice. Future longitudinal analyses of the full 3-year study will explore how these factors impact treatment satisfaction.

Botulinumtoxin Improves both Generic and Disease-Specific Quality of Life in Cervical Dystonia

Botulinumtoxin injection (BoNT) into affected muscles is effective to improve motor symptoms of cervical dystonia (CD) by reducing muscle contraction and involuntary dystonic movement and posturing. However, the understanding of the effect on health-related quality of life (HR-QoL) and patient referral under HR-QoL aspects is incomplete. In this open-label clinical prospective observational study, we characterized the outcomes in CD (n = 159) from botulinumtoxin on both generic HR-QoL (EuroQol; EQ-5D-5L) and disease-specific HR-QoL [craniocervical dystonia questionnaire (CDQ-24)]. Additionally, we characterized motor and non-motor signs of dystonia including motor symptom improvement, depressive symptoms, pain, and sleep quality. We assessed patients at the end of a regular 3-month period from last injection (Timepoint1) and 4 weeks after the re-injection of BoNT (Timepoint2). We aimed to define outcomes on both generic and disease-specific HR-QoL and to evaluate predictors of therapeutic outcome in terms of stepwise multiple regression models. Patients with CD showed a robust improvement of both generic and disease-specific HR-QoL. Furthermore, motor and non-motor signs improved. Multiple regression analyses revealed that EQ-5D-5L and “satisfaction with health” (Fragen zur Lebenszufriedenheit-G) at Timepoint1 predicted treatment response on generic HR-QoL outcome (R² = 0.284; P = 0.019). Similarly, CDQ-24 and Beck’s Depression inventory at Timepoint1 predicted the treatment response on disease-specific HR-QoL (R² = 0.253; P = 0.026). Our study underscores both generic and disease-specific HR-QoL improvements in CD, and provides useful predictors on HR-QoL outcomes.

An update on new and unique uses of botulinum toxin in movement disorders

The therapeutic applications of botulinum toxin (BoNT) have grown manifold since its initial approval in 1989 by the US Food and Drug Administration (FDA) for the treatment of strabismus, blepharospasm, and other facial spasms. Although it is the most potent biologic toxin known to man, long-term studies have established its safety in the treatment of a variety of neurologic and non-neurologic disorders. This review focuses on some novel and uncommon uses of BoNT in the treatment of movement disorders, such as oromandibular dystonia, including bruxism, anterocollis, camptocormia, tremor, tics, tardive and levodopa-induced dyskinesia, and restless legs syndrome. Despite a paucity of randomized controlled trials and lack of FDA approval for these movement disorders, there is growing body of evidence that BoNT provides benefit to patients with these hyperkinetic movement disorders and that BoNT is a safe treatment when used by clinicians skilled in the administration of the drug for these conditions.

Dystonia: Then and now

INTRODUCTION

Dystonia is a rare disorder that has undergone extensive scientific investigation leading to a transformation of understanding over the past century.

METHODS

This manuscript was prepared through a review of relevant literature for each topic.

RESULTS

Historically dystonia was considered the manifestation of psychiatric disorders. Subsequently, investigations have firmly established this as a neurological disorder. Though electrophysiological and imaging, dystonia is thought to arise from a loss inhibition of motor programs, defective sensorimotor integration and abnormal plasticity. The genetic studies in dystonia have revealed the hereditary nature of many forms of familial dystonia. Treatment of dystonia has focused primarily on botulinum toxin for focal and segmental dystonia and deep brain stimulation of the globus pallidus interna for generalized and medically refractory focal dystonia.

CONCLUSION

The progress in dystonia in the past century has revised the concepts of this disorder, increased knowledge of genetics and underlying pathophysiology, and provides new therapeutic targets. To promote future research the development of diagnostic criteria, biomarkers and validated rating scales for each form of dystonia is essential.

Botulinum toxin: State of the art

Botulinun neurotoxin (BoNT) has emerged as one of the most multipurpose therapeutic agents in modern medicine with more clinical applications than any other drug currently on the market. Initially developed in the treatment of strabismus and neurologic movement disorders, the use of botulinun neurotoxin has been expanding during the past 3 decades to include the treatment of a variety of ophthalmologic, gastrointestinal, urologic, orthopedic, dermatologic, dental, secretory, painful, cosmetic, and other conditions. In addition to onabotulinumtoxinA (Botox), abobotulinumtoxinA (Dysport), incobotulinumtoxinA (Xeomin), and RimabotulinumtoxinB (Myobloc or NeuroBloc) there are other novel botulinun neurotoxin products currently in development. With a better understanding of the cellular mechanisms of botulinun neurotoxin and advances in biotechnology, future botulinun neurotoxin products will likely be even more effective and customized to the specific indication and tailored to the needs of the patients. © 2017 International Parkinson and Movement Disorder Society.