Practical guidance for CD management involving treatment of botulinum toxin: a consensus statement

Comparison of different surgical strategies for cervical dystonia: Evidence from Bayesian network analysis

BACKGROUND AND PURPOSE

Several surgical techniques have been used to treat cervical dystonia (CD), however, to date, the optimal surgical technique for CD remains controversial. We therefore conducted the first network meta-analysis to compare different surgical strategies for CD to inform clinical practice.

METHODS

Electronic databases were searched for surgical strategies for treating CD. The primary outcome was improvement in total Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) score. Subgroup analysis was performed to compare short-term (< 1 year) and long-term (≥ 1 year) outcomes. Safety outcomes included surgery-related adverse events (AEs).

RESULTS

A total of 55 trials with 2032 patients employing five surgical strategies were identified, including globus pallidus internus (GPi)/subthalamic nucleus (STN)-deep brain stimulation (DBS), selective peripheral denervation (SPD), microvascular decompression (MVD) and pallidotomy. All strategies led to significant improvement in total TWSTRS score (mean improvement range 18.65-28.22). GPi-DBS showed significantly greater enhancement than SPD for the whole dataset (mean difference [MD] 7.03, 95% credible interval [Crl] 1.53-12.56), while both GPi-DBS (MD 8.05, 95% Crl 2.35-13.80) and STN-DBS (MD 10.71, 95% Crl 2.22-19.20) exhibited more long-term improvement than SPD. Regarding safety outcomes, GPi/STN-DBS and MVD were associated with fewer surgery-related AEs than SPD (ln odds ratio range -1.68 to -1.41).

CONCLUSION

We conclude that DBS should be the preferred surgical option for CD, and the STN is a promising alternative target choice due to its comparable efficacy with the GPi. However, more direct evidence is still required.

Treatment response to onabotulinumtoxinA in cervical dystonia patients with anterocollis and retrocollis

Anterocollis (AC) and retrocollis (RC) are less common cervical dystonia (CD) subtypes that are often under-represented in CD clinical trials. Herein we describe real-world demographics, disease characteristics, and treatment response to onabotulinumtoxinA (onabotA) in AC or RC patients from an observational, multicenter, prospective registry, CD PROBE. After three onabotA treatments, outcomes (CDIP-58, PGIC, CGIC, CD severity, TWSTRS) in patients with predominant AC or RC were compared to torticollis (TC) and all CD subtypes combined. The mean dosages at each treatment ranged from 153.5 to 195.4 U (AC) to 184.0-213.4 U (RC). After treatment, AC and RC patients reported improvements in the CDIP-58. "Much" or "very much improved" on PGIC and CGIC was reported by AC patients (n = 11/23, 48%) and clinicians (n = 14/23, 61%); and by RC patients (n = 14/24, 58%) and clinicians (n = 19/24, 83%). The mean total TWSTRS decreased from 45.7 (n = 59) to 36.1 (n = 23, 21.0% improvement) for AC patients and from 40.1 (n = 55) to 31.6 (n = 23, 21.2% improvement) for RC patients; the proportion of AC and RC patients with severe CD decreased. Outcomes for AC and RC were generally consistent with those for TC and all subtypes combined. Dysphagia was reported in 4/59 (6.8%) of AC patients (one serious), 7/55 (12.7%) of RC patients (none serious), 29/494 (5.9%) of TC patients (none serious), and 64/1012 (6.3%) of all CD patients (two serious). No new safety signals were identified. In conclusion, treatment with onabotA may relieve CD symptoms in some patients with AC and RC, consistent with results for other CD subtypes and the known safety profile of onabotA for the treatment of CD.

Duration of botulinum toxin efficacy in cervical dystonia clinical trials: A scoping review

INTRODUCTION

Botulinum toxin (BoNT) is first-line treatment for cervical dystonia (CD). Treatment of CD with BoNT usually requires injections every 3-4 months for as long as symptoms persist, which can be for the lifetime of the individual. Duration of BoNT effect can impact quality of life since it is important that efficacy is maintained throughout an injection cycle to avoid fluctuations of effect after each injection. There is currently no consensus on how to assess duration of BoNT effect in patients with CD.

METHODS

A scoping review was conducted to summarize the available evidence from phase 3 clinical trials of BoNT in CD and on the interpretation of the reported duration of effect. The available evidence was analyzed in the context of clinical experience and real-world treatment practices of CD.

RESULTS

Methods for estimating duration of effect varied across publications; most were based on artificial constructs developed for clinical trials (time until a pre-specified efficacy endpoint was reached) and are not appropriate to apply in clinical practice. Clinical trial outcomes in CD were not objectively evaluated, and did not prioritize patients' needs or focus on factors that impact patients' daily living activities and quality of life.

CONCLUSION

Better evidence and consistency of reporting for duration of effect for BoNT in CD is needed to help guide clinicians on when reinjection is likely to be required. The goal should be to keep patients as symptom-free as possible with flexible reinjection intervals tailored to individual needs.

Embracing the Versatility of Botulinum Neurotoxins in Conventional and New Therapeutic Applications

Botulinum neurotoxins (BoNTs) have been used for almost half a century in the treatment of excessive muscle contractility. BoNTs are routinely used to treat movement disorders such as cervical dystonia, spastic conditions, blepharospasm, and hyperhidrosis, as well as for cosmetic purposes. In addition to the conventional indications, the use of BoNTs to reduce pain has gained increased recognition, giving rise to an increasing number of indications in disorders associated with chronic pain. Furthermore, BoNT-derived formulations are benefiting a much wider range of patients suffering from overactive bladder, erectile dysfunction, arthropathy, neuropathic pain, and cancer. BoNTs are categorised into seven toxinotypes, two of which are in clinical use, and each toxinotype is divided into multiple subtypes. With the development of bioinformatic tools, new BoNT-like toxins have been identified in non-Clostridial organisms. In addition to the expanding indications of existing formulations, the rich variety of toxinotypes or subtypes in the wild-type BoNTs associated with new BoNT-like toxins expand the BoNT superfamily, forming the basis on which to develop new BoNT-based therapeutics as well as research tools. An overview of the diversity of the BoNT family along with their conventional therapeutic uses is presented in this review followed by the engineering and formulation opportunities opening avenues in therapy.

Cervical motion alterations and brain functional connectivity in cervical dystonia

INTRODUCTION

Evaluating the neural correlates of sensorimotor control deficits in cervical dystonia (CD) is fundamental to plan the best treatment. This study aims to assess kinematic and resting-state functional connectivity (RS-FC) characteristics in CD patients relative to healthy controls.

METHODS

Seventeen CD patients and 14 age-/sex-matched healthy controls were recruited. Electromagnetic sensors were used to evaluate dystonic pattern, mean/maximal cervical movement amplitude and joint position error with eyes open and closed, and movement quality during target reaching with the head. RS-fMRI was acquired to compare the FC of brain sensorimotor regions between patients and controls. In patients, correlations between motion analysis and FC data were assessed.

RESULTS

CD patients relative to controls showed reduced mean and maximal cervical range of motion (RoM) in rotation both towards and against dystonia pattern and reduced total RoM in rotation both with eyes open and closed. They had less severe dystonia pattern with eyes open vs eyes closed. CD patients showed an altered movement quality and sensorimotor control during target reaching and a higher joint position error. Compared to controls, CD patients showed reduced FC between supplementary motor area (SMA), occipital and cerebellar areas, which correlated with lower cervical RoM in rotation both with eyes open and closed and with worse movement quality during target reaching.

CONCLUSIONS

FC alterations between SMA and occipital and cerebellar areas may represent the neural basis of cervical sensorimotor control deficits in CD patients. Electromagnetic sensors and RS-fMRI might be promising tools to monitor CD and assess the efficacy of rehabilitative interventions.

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.

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.

Adult-Onset Idiopathic Cervical Dystonia

Adult-onset idiopathic focal dystonia is the most common type of primary dystonia, and adult-onset idiopathic cervical dystonia (AOICD) is its most prevalent phenotype. AOICD is an autosomal-dominant disorder with markedly reduced penetrance; clinical expression is dependent on age, sex, and environmental exposure. Motor symptoms at presentation are poorly recognised by non-specialists, leading to long delays in diagnosis. Certain features of history and examination can help diagnose cervical dystonia. There is a relatively high prevalence of anxiety and/or depression, which adversely affects health-related quality of life. Recent studies indicate that patients with AOICD also have disordered social cognition, particularly affecting emotional sensory processing. AOICD can be treated reasonably effectively with botulinum toxin injections, given at 3-month intervals. Oral antidystonic medications are often trialled initially, but are largely ineffective. Comprehensive modern management of patients with AOICD requires recognition of presence of mood disorders, and actively treating the endogenous mood disorder with antidepressant therapy. Botulinum toxin injections alone, no matter how expertly given, will not provide optimal therapy and improved health-related quality of life without an holistic approach to patient management. Increasing evidence indicates that AOICD is a neurophysiological network disorder of GABAergic inhibition, causing a syndrome of dystonia, mood disturbance, and social cognitive dysfunction, with the superior colliculus playing a central role.

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.

Pilot Feasibility Study of a Multi-View Vision Based Scoring Method for Cervical Dystonia

Abnormal movement of the head and neck is a typical symptom of Cervical Dystonia (CD). Accurate scoring on the severity scale is of great significance for treatment planning. The traditional scoring method is to use a protractor or contact sensors to calculate the angle of the movement, but this method is time-consuming, and it will interfere with the movement of the patient. In the recent outbreak of the coronavirus disease, the need for remote diagnosis and treatment of CD has become extremely urgent for clinical practice. To solve these problems, we propose a multi-view vision based CD severity scale scoring method, which detects the keypoint positions of the patient from the frontal and lateral images, and finally scores the severity scale by calculating head and neck motion angles. We compared the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) subscale scores calculated by our vision based method with the scores calculated by a neurologist trained in dyskinesia. An analysis of the correlation coefficient was then conducted. Intra-class correlation (ICC)(3,1) was used to measure absolute accuracy. Our multi-view vision based CD severity scale scoring method demonstrated sufficient validity and reliability. This low-cost and contactless method provides a new potential tool for remote diagnosis and treatment of CD.

KinesioTaping after botulinum toxin type A for cervical dystonia in adult patients

INTRODUCTION

Studies explored physiotherapeutic approaches in cervical dystonia (CD) patients with or without botulinum toxin (BoNT) injections, however the results are varying. There are no clinical trials investigating the effects of kinesiology taping in CD patients. The objective of this study is to investigate the efficacy of kinesiology taping as an adjunct to the BoNT injections in patients with CD.

METHODS

Twenty-five patients were enrolled to the study. Patients were randomly assigned to the experimental 1 (BoNT + KinesioTaping), experimental 2 (BoNT + ShamTaping) or control (BoNT) treatment. After 12 weeks they were moved to the next experimental group and finally every patient received all 3 proposed treatment options. The severity of CD was quantified with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) including Torticollis severity, Disability, and Pain scales. Quality of life was evaluated using Craniocervical dystonia questionnaire (CDQ4).

RESULTS

In all treatment groups, there was a significant improvement in dystonia symptoms measured with TWSTRS (total score) after BoNT injection regardless of the allocation to the experimental treatment (p < .05). ANOVA analysis revealed no differences in any of the TWSTRS variables after the intervention. Quality of life was significantly improved after application of taping (p < .05, p = .03).

CONCLUSIONS

Application of KinesioTaping after BoNT injection provided no additional effect on the severity of dystonia, although the quality of life was improved in patients with CD. Further research investigating the effect of KinesioTaping prior to BoNT injection is required.

AbobotulinumtoxinA provides flexibility for the treatment of cervical dystonia with 500 U/1 mL and 500 U/2 mL dilutions

INTRODUCTION

Cervical dystonia (CD) is a neurologic movement disorder with potentially disabling effects and significant impact on quality of life of those affected. AbobotulinumtoxinA (aboBoNT-A) was initially approved for a dilution of 500 U/1 mL and subsequently for a dilution of 500 U/2 mL, providing flexibility for clinicians to treat CD. Here, we explore the safety and efficacy of the 500 U/2 mL dilution versus 500 U/1 mL dilution of aboBoNT-A in a retrospective analysis based on published clinical trial data.

METHODS

The safety and efficacy of aboBoNT-A in patients with CD was evaluated in three multicenter, double-blind, randomized, placebo-controlled trials and open-label extensions. Trials 1 (NCT00257660) and 2 (NCT00288509) evaluated the 500 U/1 mL dilution in 80 and 116 patients, respectively; Trial 3 (NCT01753310) evaluated the 500 U/2 mL dilution in 125 patients.

RESULTS

Comparison of the adjusted mean difference in TWSTRS total scores at Week 4 from baseline for aboBoNT-A in Trial 1 (-6.0; 95% CI, -10.8, -1.3), Trial 2 (-8.8; 95% CI, -12.9, -4.7), and Trial 3 (-8.7; 95% CI, -13.2, -4.2) showed similar, significant improvements. Dysphagia and muscle weakness patterns were comparable across the three trials, indicating that an increased dilution of aboBoNT-A does not result in an increased risk of diffusion-related adverse events.

CONCLUSION

The results of these trials show that aboBoNT-A is similarly efficacious using either dilution, with similar safety and tolerability across trials. Having the 500 U/1 mL and 500 U/2 mL dilution volumes available provides further flexibility in administration, benefiting patient care.

AbobotulinumtoxinA Versus OnabotulinumtoxinA in Adults with Upper Limb Spasticity: A Randomized, Double-Blind, Crossover Study Protocol

INTRODUCTION

The safety and efficacy of both abobotulinumtoxinA and onabotulinumtoxinA for upper limb spasticity are well established, but head-to-head comparisons are lacking.

METHODS

DIRECTION is an international, randomized, double-blind, crossover study comparing the safety and efficacy of abobotulinumtoxinA with onabotulinumtoxinA in the management of upper limb spasticity at doses at or near maximum recommended in product labelling. Participants (18-75 years) will be randomized (1:1) to either one cycle of abobotulinumtoxinA (900U) followed by onabotulinumtoxinA (360U) or vice versa. To maintain blinding, a fixed volume (3.6 ml) will be injected into the target upper limb muscles (four wrist and finger flexors and biceps brachii). The second treatment cycle will begin at Week 12 if retreatment criteria are fulfilled, and if not, they will be reassessed every 4 weeks until they meet retreatment parameters.

PLANNED OUTCOMES

The primary hypothesis is that there is comparable safety between products; non-inferiority will be tested based on treatment-emergent adverse event (TEAE) rates from injection to Week 12. A secondary hypothesis is that abobotulinumtoxinA has longer duration of effect than onabotulinumtoxinA. This hypothesis will be tested with secondary efficacy endpoints, including injection cycle duration, Modified Ashworth Scale, Disability Assessment Scale and Physician Global Assessment.

TRIAL REGISTRATION

EudraCT ( http://eudract.ema.europa.eu ): 2021-000161-32 and Clinicaltrials.gov ( http://clinicaltrials.gov ): NCT04936542. Overview of the study protocol by the principal investigator (MP4 185265 KB).

Real-World Dosing of OnabotulinumtoxinA and IncobotulinumtoxinA for Cervical Dystonia and Blepharospasm: Results from TRUDOSE and TRUDOSE II

The real-world use of onabotulinumtoxinA and incobotulinumtoxinA for cervical dystonia and blepharospasm treatment was assessed in two separate retrospective studies using identical protocols (TRUDOSE and TRUDOSE II). The studies were conducted in Mexico, Norway, and United Kingdom and designed to evaluate dose utilization of the two botulinum toxins in clinical practice. Eighty-three patients treated with both onabotulinumtoxinA and incobotulinumtoxinA for ≥2 years for each botulinum toxin were included, (52, cervical dystonia; 31, blepharospasm). All patients switched from onabotulinumtoxinA to incobotulinumtoxinA for administrative/financial reasons. A range of dose ratios (incobotulinumtoxinA to onabotulinumtoxinA) was reported; with the majority of dose ratios being >1. The mean dose ratio was >1 regardless of the study site or underlying clinical condition. The inter-injection interval was significantly longer for onabotulinumtoxinA versus incobotulinumtoxinA when assessed for all patients (15.5 vs. 14.3 weeks; p = 0.006), resulting in fewer onabotulinumtoxinA treatments over the study time period. Consistent with product labeling, no single fixed-dose ratio exists between incobotulinumtoxinA and onabotulinumtoxinA. The dosage of each should be individualized based on patient needs and used as per product labeling. These real-world utilization data may have pharmacoeconomic implications.

Management of Secondary Poor Response to Botulinum Toxin in Cervical Dystonia: A Multicenter Audit

Background

Botulinum toxin A (BoNT‐A) is an effective treatment for cervical dystonia. Nevertheless, up to 30% to 40% patients discontinue treatment, often because of poor response. The British Neurotoxin Network (BNN) recently published guidelines on the management of poor response to BoNT‐A in cervical dystonia, but adherence to these guidelines has not yet been assessed.

Objectives

To assess adherence to and usefulness of BNN guidelines in clinical practice.

Methods

We undertook a retrospective medical notes audit of adherence to the BNN guidelines in 3 United Kingdom tertiary neurosciences centers.

Results

Of 76 patients identified with poor response, 42 (55%) had a suboptimal response and, following BNN recommendations, 25 of them (60%) responded to adjustments in BoNT dose, muscle selection or injection technique. Of the remaining 34 (45%) patients with no BoNT response, 20 (59%) were tested for immune resistance, 8 (40%) of whom showed resistance. Fourteen (18%) of all patients were switched to BoNT‐B, and 27 (36%) were referred for deep brain stimulation surgery. In those not immune to BoNT‐A, clinical improvement was seen in 5 (41%) after adjusting their dose and injection technique.

Conclusion

Our audit shows that optimizing BoNT dose or injection strategy largely led to improvements in those with suboptimal response and in those reporting no response without resistance. It would be helpful to standardize investigations of potential resistance in those with no therapeutic response.

Consensus guidelines for botulinum toxin therapy: general algorithms and dosing tables for dystonia and spasticity

Botulinum toxin (BT) therapy is a complex and highly individualised therapy defined by treatment algorithms and injection schemes describing its target muscles and their dosing. Various consensus guidelines have tried to standardise and to improve BT therapy. We wanted to update and improve consensus guidelines by: (1) Acknowledging recent advances of treatment algorithms. (2) Basing dosing tables on statistical analyses of real-life treatment data of 1831 BT injections in 36 different target muscles in 420 dystonia patients and 1593 BT injections in 31 different target muscles in 240 spasticity patients. (3) Providing more detailed dosing data including typical doses, dose variabilities, and dosing limits. (4) Including total doses and target muscle selections for typical clinical entities thus adapting dosing to different aetiologies and pathophysiologies. (5) In addition, providing a brief and concise review of the clinical entity treated together with general principles of its BT therapy. For this, we collaborated with IAB—Interdisciplinary Working Group for Movement Disorders which invited an international panel of experts for the support.

Improvement in Quality of Life with OnabotulinumtoxinA for Cervical Dystonia: POSTURe

Introduction:

Symptoms of cervical dystonia (CD) can vary in severity and cause significant pain. OnabotulinumtoxinA is an approved treatment for CD. This study assessed health-related quality of life (HRQoL) in patients with CD who received multiple onabotulinumtoxinA treatments.

Methods:

This prospective, observational standard-of-care study was conducted at multiple neurology centers in Québec, Canada. Patients reported the health impact of CD using the Cervical Dystonia Impact Profile (CDIP)-58, before and after up to eight onabotulinumtoxinA treatments. Other measures included the Cervical Dystonia Severity Rating Scale by physician, employment status using the Work Productivity Questionnaire and pain using the Pain Numeric Rating Scale (PNRS). Adverse events (AEs) were recorded.

Results:

Sixty-two patients were enrolled (safety population, n = 61; modified efficacy population, n = 58). Participants were mostly females who were employed; most (79.3%) had torticollis. In all, 21/62 patients (33.9%) discontinued the study. At the final visit, there was a statistically significant (p < 0.001) improvement in all eight CDIP-58 subscales, particularly head and neck symptoms (−31.0) and psychosocial functioning (−28.2). Employment increased from baseline (55%) to the end of the study (64%), and there was improvement in work productivity. There was a significant (p < 0.0001) reduction in pain measured by the PNRS, from −0.5 post-treatment 1 to −2.4 at end of study. AEs (neck pain, muscular weakness, dysphagia, nausea) were consistent with onabotulinumtoxinA use.

Conclusion:

These real-world data indicate that after repeated, long-term use, onabotulinumtoxinA continues to be a safe and effective treatment for CD, improving HRQoL and work productivity.

Ultrasound Imaging of Injections in Masseter Muscle without Contrast Agent Using Strain Elastography and a Novel B-Mode Spatiotemporal Filter

Botulinum toxin type A (BTX-A) injections in masseter muscle can alleviate muscle tightness and aching pain caused by idiopathic masticatory myalgia, a subform of the myofascial pain syndrome. Yet the injection procedure (number, amount) is currently empirical. In this ex vivo study, we determined the feasibility of using contrast-free ultrasound imaging to visualize the short-term injectate propagation. Ultrasound annotations of BTX-A injectate spread in N = 12 porcine masseter muscles were compared with the histopathology of the excised masseter. BTX-A presence was automatically detected in the ultrasound cine by: compensating tissue motion and deformation during injection with a novel spatiotemporal filtering (SF) algorithm, and by imaging tissue swelling strains with strain elastography (SE). BTX-A injectate introduced 6.5% (standard deviation = 5.0%) echogenicity contrast and 13.9% (standard deviation = 3.7%) tissue swelling strain. Muscle fasciae were a border for BTX-A distribution. The SF algorithm achieved significantly higher noise rejection (contrast-to-noise ratio = 4.63) than SE (2.56, p = 0.01), and state-of-the-art 2-D digital image correlation (1.81, p < 0.001) and direct image subtraction (1.29, p < 0.001) methods. Histopathology agreed well with ultrasound (Dice coefficient = 0.48), with deviations mainly explained by the three-dimensional inhomogeneous distribution of BTX-A. Preliminary in vivo patient results indicated that SF and SE discard artifactual BTX-A detection outside the injection region. The proposed methods contribute to objectivize ultrasound-guided injections, with additional applications, for instance, to monitor injectate spread of local anesthetics.

Social cognition in cervical dystonia: phenotype and relationship to anxiety and depression

BACKGROUND AND PURPOSE

Anxiety and depression are common disabling comorbidities in cervical dystonia (CD) and may predispose to social withdrawal and social cognitive impairments. The relationship between social cognition and depressive/anxiety symptoms in CD is under-investigated.

METHODS

Forty-six CD patients (40 women; mean age ± SD, 55.57 ± 10.84 years) were administered the following social cognition battery: Affect Naming, Prosody Face and Pair Matching subtests from the Wechsler Adult Intelligence Scale IV and Wechsler Memory Scale IV (social perception), reality-known and reality-unknown false belief reasoning tasks (theory of mind), Empathy Quotient and Social Norms Questionnaire 22 (social behaviour), alongside the Benton Facial Recognition Task (non-emotional facial discrimination). Alongside CD severity, the Hospital Anxiety and Depression Scale measured depressive/anxiety comorbid diagnostic status and severity, and the Liebowitz Social Anxiety Scale assessed social phobia. Social cognition tasks were standardized using published normative data and a cut-off of z < -1.5 for impairment.

RESULTS

More than 90% of our CD patients performed normally on social perception and social behaviour tests. Performance on impaired belief reasoning (theory of mind) was impaired in 10 of 46 (21.74%); five of 46 (10.87%) were impaired on the Empathy Quotient. Better performance on the Affect Naming task was associated with comorbid anxiety (η²  = 0.09, medium-to-large effect size) and greater anxiety, depression and social phobia severity. Worse performance on the Empathy Quotient was associated with comorbid depression (η²  = 0.11, medium-to-large effect size) and greater depression severity. CD patients had significantly more difficulties with fearful face identification (P < 0.001).

CONCLUSIONS

Greater social perception abilities in CD patients with more severe anxiety and depression suggest efficient modulation and self-adaptation of social cognitive skills.

Botulinum Neurotoxin-A Injection in Adult Cervical Dystonia and Spastic Paresis: Results From the INPUT (INjection Practice, Usage and Training) Survey

Botulinum toxin-A (BoNT-A) is an effective treatment for cervical dystonia (CD) and spastic paresis (SP), but it requires in-depth knowledge of anatomy and injection techniques. The Ixcellence Network® is an educational programme to provide neurology, neuropaediatrics, and physical medicine and rehabilitation (PMR) specialists with access to best clinical practices and innovations regarding SP and CD management with BoNT-A. To assess the benefits of such educational programmes and identify unmet needs, a multidisciplinary scientific committee designed INPUT (INjection Practice, Usage & Training), an international multicentric survey describing training and practices among this trained and experienced population. A self-completed questionnaire was sent online to 553 trainees and 14 trainers from the Ixcellence Network®. Among the 131 respondents, 92% specialized in PMR (48%) or neurology (44%), with a mean experience of 15.5 years in their clinical fields and 10.9 years of BoNT-A injection. Most of them (98%) reported having received training before performing their first BoNT-A injection and attending specific courses on how to perform it without any instrumental guidance (76%), and with ultrasound (73%), electrical stimulation (44%) or electromyography (41%). In terms of practices, 92% of respondents reported using at least one guidance technique while injecting, with ultrasound being the most used technique (48%). Attending specific courses was significantly associated with greater self-confidence and use, e.g. for injection with ultrasound, mean self-confidence, on a scale from 1 (not confident) to 10 (fully confident), was 7.9 for trained respondents (vs 4.0 for untrained respondents, p < 0.001) of whom 70% stated that they used this technique regularly or systematically (vs. 11% of untrained healthcare professionals (HCPs), p < 0.0001). Moreover, 84% of respondents reported having trained colleagues, residents or fellows through theoretical (70%) or practical teaching in individuals (80%) or in small groups (65%). Overall, 86% of respondents reported a notable increase over the past 5 years of the number of patients treated with BoNT-A. INPUT is the first international survey describing training and practices in SP and CD management of physicians who attended a dedicated educational programme. The results highlighted the importance of training for self-confidence, and the use of specific techniques and new approaches.

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: ways to improve the effectiveness of botulinum therapy]

Cervical dystonia is one of the most complex movement disorders, in which type A botulinum toxin (BTA) preparations are used. A significant number of types of dystonic installation of the head and neck determines a large number of different muscle patterns, sometimes with outwardly similar manifestations. Objective difficulties in choosing the actual pathological muscle pattern for subsequent injection in some cases determine the low effectiveness of botulinum therapy. Given this situation, it is necessary to adapt the anatomical approach to the correct choice of dystonic muscles in order to improve the results of botulinum therapy of cervical dystonia.

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.

Clinical duration of action of different botulinum toxin types in humans

The Botulinum NeuroToxin (BoNT) comprises several serotypes with distinct properties, mechanisms of action, sensitivity and duration of effect in different species. The serotype A (BoNT/A) is the prevalent neurotoxin applied in human's disease. In this paper we present an overview of the current knowledge regarding the duration of effect and the neuromuscular sprouting of different BoNT serotypes in humans. Then, we report the original results of a study in healthy subjects treated with BoNT/A, B, C and F using different neurophysiological techniques. Twelve healthy volunteers (7 men, 5 women) are treated with BoNT/A, B, C and F or placebo in Abductor digiti minimi (ADM) muscle of the hand. Before and after injections, an extensive neurophysiological study is performed with the CMAP amplitude variation, Multi-Motor Unit Action Potentials (MUAPs) analysis, the Turns/Amplitude ratio of interference pattern (IP) and determination of jitter and Fiber Density (FD) at single-fiber electromyography (SFEMG), at week 2 (w2), 4 (w4), 6 (w6) and 8 (w8). A maximal neuromuscular block is obtained at w2 for all the serotypes. Afterwards, the CMAP trend appear similar for BoNT/A, B, and C while, BoNT/F shows a faster recover. Multi-MUAPs analysis and IP detect mild changes at w2 for all serotypes, except for BoNT/F that shows a greater change since w4. SFEMG have minimal changes in FD while, Jitter increase at w2 with a slower decrease over the time for all BoNTs. In conclusion, BoNT/F has earlier sprouting and complete recovery at w8. Other serotypes present a slower and similar profile. The EMG appear useful to study the functional recovery in humans, and these results should provide new evidence for assessing different serotypes. These findings improve our knowledge regarding the methods to evaluate duration of effects and dose equivalents in different serotypes, that in the future could change the clinicians strategy for disease-tailored BoNT therapies.

Objective Analysis of Neck Muscle Boundaries for Cervical Dystonia Using Ultrasound Imaging and Deep Learning

OBJECTIVE

To provide objective visualization and pattern analysis of neck muscle boundaries to inform and monitor treatment of cervical dystonia.

METHODS

We recorded transverse cervical ultrasound (US) images and whole-body motion analysis of sixty-one standing participants (35 cervical dystonia, 26 age matched controls). We manually annotated 3,272 US images sampling posture and the functional range of pitch, yaw, and roll head movements. Using previously validated methods, we used 60-fold cross validation to train, validate and test a deep neural network (U-net) to classify pixels to 13 categories (five paired neck muscles, skin, ligamentum nuchae, vertebra). For all participants for their normal standing posture, we segmented US images and classified condition (Dystonia/Control), sex and age (higher/lower) from segment boundaries. We performed an explanatory, visualization analysis of dystonia muscle-boundaries.

RESULTS

For all segments, agreement with manual labels was Dice Coefficient (64 ± 21%) and Hausdorff Distance (5.7 ± 4 mm). For deep muscle layers, boundaries predicted central injection sites with average precision 94 ± 3%. Using leave-one-out cross-validation, a support-vector-machine classified condition, sex, and age from predicted muscle boundaries at accuracy 70.5%, 67.2%, 52.4% respectively, exceeding classification by manual labels. From muscle boundaries, Dystonia clustered optimally into three sub-groups. These sub-groups are visualized and explained by three eigen-patterns which correlate significantly with truncal and head posture.

CONCLUSION

Using US, neck muscle shape alone discriminates dystonia from healthy controls.

SIGNIFICANCE

Using deep learning, US imaging allows online, automated visualization, and diagnostic analysis of cervical dystonia and segmentation of individual muscles for targeted injection.

Management of cervical dystonia with botulinum neurotoxins and EMG/ultrasound guidance

Purpose of review

We provide a practical guide on the use of electromyography (EMG) and ultrasound (US) to assist botulinum neurotoxin (BoNT) treatment in patients with cervical dystonia (CD).

Recent findings

US and EMG guidance improve BoNT treatment in CD. Their use is particularly valuable for targeting deep neck muscles and managing complex cases. There is also evidence that adverse events are reduced when superficial or intermediate layer muscles are injected with assisted guidance.

Summary

A structured clinical approach, based on functional neck anatomy, guides CD assessment and BoNT treatment. Muscles are selected according to clinical, EMG and US findings. US provides anatomical visualization, while EMG complements by detecting muscle activity. We review here the current practice for assisted treatment of CD through BoNT cycles. We also describe how to recognize and manage the main adverse events.

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.

AbobotulinumtoxinA Efficacy and Safety in Children With Equinus Foot Previously Treated With Botulinum Toxin

BACKGROUND

The effects of botulinum toxin are transient, and repeat injections are required in children with lower-limb spasticity. However, the efficacy of botulinum toxin in patients who have received previous injections has remained largely unexplored.

METHODS

We present subgroup analyses of a phase III study conducted in ambulatory children (aged two to 17) with spastic equinus foot. Patients were randomized to single doses of abobotulinumtoxinA 10 U/kg/leg, 15 U/kg/leg, or placebo injected into the gastrocnemius-soleus complex (one or both legs). The first analysis was prespecified to review the effect of abobotulinumtoxinA in children previously treated with botulinum toxin versus those children new to the treatment; a second post hoc analysis evaluated the effect of abobotulinumtoxinA in children who changed botulinum toxin formulation.

RESULTS

Of the 241 randomized patients, 113 had previously received botulinum toxin, including 86 who had been treated with another formulation. In both analyses, muscle tone (Modified Ashworth Scale) and the Physicians Global Assessment, at week 4, improved with abobotulinumtoxinA treatment versus placebo, regardless of baseline botulinum toxin status. Placebo responses in patients new to treatment were consistently higher than in the previously treated group.

CONCLUSIONS

These results demonstrate similar abobotulinumtoxinA efficacy and safety profiles in children with spasticity who are new to botulinum toxin treatment and those children who were previously treated. The efficacy and safety of abobotulinumtoxinA treatment in these previously treated patients were comparable with the overall trial population, indicating that doses of 10 and 15 U/kg/leg are suitable starting doses for children with spasticity regardless of the previous botulinum toxin preparation used.

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.

A 500 U/2 mL dilution of abobotulinumtoxinA vs. placebo: randomized study in cervical dystonia

Purpose/aim: AbobotulinumtoxinA (Dysport®, Ipsen Biopharmaceuticals, Inc., Basking Ridge, NJ, USA) is an acetylcholine release inhibitor and a neuromuscular blocking agent. The United States prescribing information for abobotulinumtoxinA previously indicated only one dilution for cervical dystonia: 500 U/1 mL. Clinical trial data supporting a larger volume with a 500 U/2 mL dilution would offer clinicians flexibility with injection volume to better meet patient needs.

MATERIALS AND METHODS

We conducted a 12-week, phase 3b, multicenter, randomized, double-blind, placebo-controlled trial (NCT01753310). Adult subjects with a primary diagnosis of cervical dystonia were randomized (2:1) to receive a single injection of either abobotulinumtoxinA, 500 U/2 mL dilution, or placebo. The primary efficacy endpoint was changed from baseline in Toronto Western Spasmodic Torticollis Rating Scale total score at Week 4.

RESULTS

A total of 134 subjects (abobotulinumtoxinA, n = 89; placebo, n = 45) were randomized (intent-to-treat population) and 129 (abobotulinumtoxinA, n = 84; placebo, n = 45) completed the Week 4 primary endpoint evaluation (modified intent-to-treat population). In the modified intent-to-treat population, subjects receiving abobotulinumtoxinA experienced significantly greater changes from baseline versus placebo on the primary endpoint (weighted overall treatment difference -8.3, P < 0.001). The most common treatment-emergent adverse events (TEAEs) were dysphagia, muscle weakness, neck pain and headache. Overall, TEAEs were consistent with those reported in the abobotulinumtoxinA prescribing information (1 mL dilution) for cervical dystonia patients.

CONCLUSIONS

This trial provides evidence that a 500 U/2 mL dilution is an effective treatment for cervical dystonia and exhibits a safety profile consistent with the known safety profile of abobotulinumtoxinA.

Ultrasound Guidance for Botulinum Neurotoxin Chemodenervation Procedures

Injections of botulinum neurotoxins (BoNTs) are prescribed by clinicians for a variety of disorders that cause over-activity of muscles; glands; pain and other structures. Accurately targeting the structure for injection is one of the principle goals when performing BoNTs procedures. Traditionally; injections have been guided by anatomic landmarks; palpation; range of motion; electromyography or electrical stimulation. Ultrasound (US) based imaging based guidance overcomes some of the limitations of traditional techniques. US and/or US combined with traditional guidance techniques is utilized and or recommended by many expert clinicians; authors and in practice guidelines by professional academies. This article reviews the advantages and disadvantages of available guidance techniques including US as well as technical aspects of US guidance and a focused literature review related to US guidance for chemodenervation procedures including BoNTs injection.

[Botulinum toxin for treatment of the focal dystonia]

Dystonia is defined as a movement disorder characterized by sustained or intermittent muscles contraction causing abnormal, often repetitive, movements, postures, or both. Dystonic movements are typically patterned and twisting, and may be tremulous. The precis diagnosis of dystonia is difficult for physicians because neurological brain imaging does not provide enough practical information. The diagnosis is depend on clinical experience of physicians. Botulinum toxin treatment is the accepted standard of care for patients with focal dystonia. Botulinum toxin treatment results in significant improvement of decreasing the symptom of dystonia. The success of treatment is dependent on muscle selection for treating involved muscles. Usually performance of botulinum toxin treatment is injected according to clinical experience of surface anatomy or clinical location method. However, the benefit of guidance of botulinum toxin treatment is improve outcome in dystonia. Injection techniques with ultra sound echogram or EMG guidance to identify dystonic muscles can be more benefit for patients.

Treatment satisfaction with botulinum toxin: a comparison between blepharospasm and cervical dystonia

BACKGROUND

Differential effects of botulinum toxin (BoNT) treatment in cervical dystonia (CD) and blepharospasm (BSP) treatment satisfaction and emotional responses to a life with a disabling condition were investigated. Special interest was drawn to the course within a BoNT treatment cycle and the effects of subjective well-being vs perceived intensity of motor symptoms and quality of life.

METHODS

A questionnaire was distributed among 372 CD patients and 125 BSP patients, recruited from 13 BoNT centers throughout Germany. Items were related to dystonic symptoms, BoNT treatment responses and treatment satisfaction, quality of life, working situation, and emotional reactions to a life with dystonia.

RESULTS

CD patients and BSP patients were widely satisfied with BoNT treatment, but treatment satisfaction worsened significantly within the treatment cycle. Especially CD patients reported that both the dystonic symptoms and the effects of BoNT treatment were influenced by emotional factors. Despite good overall treatment effects, patients from both groups perceived marked persistence of motor symptoms, restrictions of everyday life functions, and reduced quality of life. Functional amelioration of motor symptoms and emotional well-being were only moderately correlated. About 22% of patients from both groups reported mental disorders or emotional disturbances prior to the onset of dystonia.

CONCLUSION

As numerous psychological factors determine perceived outcome, BoNT treatment should be further improved by patient's education strategies enhancing behavioral self-control. From the patient's perspective, individual intervals, which may avoid exacerbation between injection points, should be considered. Moreover, patients at risk, with reduced adherence and poor BoNT outcome, should be identified and addressed within psychoeducation.

Impact of Neu-botulinumtoxinA on the Severity and Quality of Life of Cervical Dystonia Patients

Background

Cervical dystonia (CD) is a debilitating neurological disorder that may gravely affect a patient’s quality of life (QoL). Botulinum toxin treatment has been approved as a first-line treatment for this condition. This study aims to look at the efficacy and impact on the QoL of neu-botulinumtoxinA, a newer and cheaper botulinum toxin type A, in patients with CD.

Methods

This is a prospective, open-label, single-arm study. CD patients were recruited and evaluated for severity of CD using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), and for QoL using the Craniocervical Dystonia Questionnaire (CDQ-24), and the 36-item Short Form Health Survey questionnaire (SF-36) at baseline and 6 weeks after injection.

Results

Twenty patients were recruited. Significant improvement was shown in part 1 and total TWSTRS score and total CDQ-24 scores. Analysis of individual items of the TWSTRS scale showed significant improvement in rotation, duration of CD, and work ability. Significant improvements in the QoL were also seen in some items of the stigma, emotional wellbeing, and energy/fatigue domains of the CDQ-24 and SF-36 questionnaires.

Discussion

Neu-botulinumtoxinA is efficacious in treating CD symptoms and improving QoL of patients with CD. A larger, double-blinded study is needed to study the extent of improvements.

Botulinum toxin treatment failures in cervical dystonia: causes, management, and outcomes

Botulinum toxin (BoNT) is highly effective in the treatment of cervical dystonia (CD), yet a significant proportion of patients report low levels of satisfaction following treatment and fail to follow up for repeated treatments. The goal of this study was to determine the reasons that some patients have unsatisfactory responses. A total of 35 subjects who came to our center requesting alternative treatments due to unsatisfactory responses following BoNT treatment for CD were evaluated. Included were 26 women and 9 men with an average age of 57.1 years (range 25-82 years), and an average duration of illness of 12.5 years (range 1-55 years). Details of unsatisfactory BoNT treatments were methodically collected by a movement specialist using a standardized intake form, including provider subspecialty, product used, the number of satisfactory or unsatisfactory trials, doses given, specific muscles treated, the use of electromyographic guidance, side effects, and tests of resistance. The specialist then provided repeat treatments if indicated, and followed each case until the reasons for unsatisfactory outcomes could be determined. Multiple reasons for unsatisfactory outcomes were found. They included suboptimal BoNT doses, suboptimal muscle targeting, intolerable side effects, complex movement patterns, discordant perceptions, and incorrect diagnoses. Only one patient was functionally resistant to BoNT. Of 32 subjects who received repeat BoNT treatments, 25 (78 %) achieved satisfactory responses after revision of the original treatment plan. These results indicate that the majority of unsatisfactory responses to BoNT treatment of CD were caused by correctible factors and imply a need for improved education regarding optimal treatment methods.

Ranking of Dystonia Severity by Pairwise Video Comparison

Background

Reviewers of dystonia rating scales agree on the need to assess symptoms more comprehensively. During the development of a quantitative dystonia assessment by video-perceptive computing, we devised a video-based severity ranking as a procedure to create a validation standard without the use of clinical scales.

Methods

Thirty-four patients with dystonia (17 with dystonic tremor) and 2 controls were assessed with clinical scales and video-recordings of 24 short movement tasks. Two to 4 raters compared multiple permutations of videos from 22 subjects, including 2 healthy controls, until a complete rank order was achieved. Inter-rater agreement was expressed as normalized Kendall tau distance. Spearman correlations of video rank order with clinical scales and self-rating were repeated for tremor/nontremor subgroups.

Results

Normalized Kendall tau distances were <0.3 for 15 items. The video rank order for sitting and head movements correlated with clinical scales for the whole group (rho 0.52-0.87) and in the subgroup without tremor. In the tremor subgroup such correlation was perceived in the 2 items involving sitting. Video rank order correlated with quality of life self-rating only in 1 item (arms held in front, palm down).

Conclusions

The agreement of video rankings between raters is remarkable. The lack of correlation in the tremor subgroup in several items may be interpreted as tremor being considered in video comparisons but not in clinical scales. This supports video-based ranking as a more comprehensive rating of dystonia and as a possible validation instrument applicable in situations in which no reference standard is available.

Striving for more good days: patient perspectives on botulinum toxin for the treatment of cervical dystonia

BACKGROUND

The recommended reinjection interval for botulinum neurotoxin (BoNT) formulations in the treatment of cervical dystonia (CD) is generally ≥12 weeks, though intervals ≥10 weeks are approved for incobotulinumtoxinA in Europe. However, recurring symptoms can occur before the end of this period. Using qualitative research, we sought a greater understanding of disease burden, unmet patient needs, and barriers to treatment.

METHODS

We conducted online semistructured, focus-group discussions, and online forum follow-up discussions among patients with CD, focusing on disease burden, patient needs, injection cycle preferences, and relationships with health care professionals. A subset of patients was also questioned in telephone interviews about individual experiences of CD and BoNT treatment. All participants were UK residents who had received onabotulinumtoxinA or abobotulinumtoxinA for CD for ≥1 year.

RESULTS

Thirty-one patients (81% female; mean duration of CD 16.4 [range 4-31] years; mean BoNT injection cycle length 12.8 weeks) participated in the online focus-group and forum follow-up discussions. Of these, seven patients participated in telephone interviews. All had recurring symptoms between treatments, which substantially impacted on their work, family, and social life. Symptom severity fluctuated throughout an injection cycle and differed between patients and across injection cycles. Participants' relationships with health care professionals and treatment satisfaction varied greatly. Many participants wanted longer-lasting and/or more stable symptom relief with shorter and/or more flexible injection intervals, according to individual needs. Lack of health care resources, long journeys to treatment centers, and immunogenicity/side-effect concerns were perceived as the main barriers to more flexible treatment.

CONCLUSION

The high burden of recurring primary and secondary symptoms of CD considerably affects patients' quality of life. Patient-led assessments of disease burden revealed that personalized, more flexible, and/or shorter BoNT injection intervals may reduce the day-to-day impact of CD. Collaboration between patients, clinicians, and health care systems may effect change and improve treatment for patients with CD.

AbobotulinumtoxinA in the management of cervical dystonia in the United Kingdom: a budget impact analysis

BACKGROUND

Cervical dystonia (CD) can be effectively managed by a combination of botulinum neurotoxin A (BoNT-A) and conventional therapy (skeletal muscle relaxants and rehabilitative therapy), but the costs of different interventions in the UK vary.

METHODS

A budget impact model was developed from the UK payer perspective with a 5-year time horizon to evaluate the effects of changing market shares of abobotulinumtoxinA, onabotulinumtoxinA, and incobotulinumtoxinA, and best supportive care from the UK payer perspective. Epidemiological and resource use data were retrieved from the published literature and clinical expert opinion. Deterministic sensitivity analyses were performed to determine the parameters most influential on the budgetary findings under base case assumptions.

RESULTS

Under base case assumptions, an increased uptake of abobotulinumtoxinA showed an accumulated savings of £2,250,992 by year 5. Treatment per patient per year with onabotulinumtoxinA and incobotulinumtoxinA costs more when compared to treatment with abobotulinumtoxinA. One-way sensitivity analyses showed that the prevalence of CD, dose per injection of each of the BoNT-As, and time to reinjection of incobotulinumtoxinA and abobotulinumtoxinA influenced the base case findings most.

CONCLUSION

There is potential for cost savings associated with the greater use of abobotulinumtoxinA rather than other BoNT-A treatments, permitting more patients to benefit more from effective BoNT-A treatment with a fixed budget.