Western Spasmodic Torticollis Rating Scale Research Articles

Minimal clinically important change in patients with cervical dystonia: Results from the CD PROBE study

ObjectiveTo determine the minimal clinically important change (MCIC) on Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) scores using data from Cervical Dystonia Patient Registry for Observation of OnabotulinumtoxinA Efficacy (CD PROBE), which captured real-world practices and outcomes. MethodsChanges in the baseline TWSTRS scores (point and percentage changes) were compared to changes in the Patient and Clinician Global Impression of Change (PGIC and CGIC) ratings. Using logistic regression, the discrimination of the model was determined. ResultsAmong the 479 patients who completed all TWSTRS assessments, the mean TWSTRS Total score significantly decreased from baseline (39.2) to the final visit (27.1) (P < .0001). TWSTRS Total score point changes that compared with PGIC assessments “very much improved,” “much improved” or better, and “minimally improved” or better were −11, −9, and −8, respectively, and were similar to previously published changes (ie, a decrease of ≥10 points). TWSTRS Total score data met indicators of good cutoffs for discrimination of the model including ≥70% percentage of outcomes correctly classified when compared with PGIC ratings. The TWSTRS Total score mapped to PGIC and CGIC ratings better than any TWSTRS subscale score. ConclusionsThe MCIC for improvement was ≥8 points based on mean TWSTRS Total scores in patients with cervical dystonia when compared against the patient-based evaluation of benefit (PGIC).

Torticaput versus Torticollis: Clinical Effects with Modified Classification and Muscle Selection.

BackgroundSeveral different subtypes are distinguished in cervical dystonia, depending on their different levels of movement. In simple rotation, classified as torticollis spasmodicus, we now differentiate between torticollis and torticaput dependent on whether only the head or the neck is turned. The new classification system permits for different injection schemes.Case reportsIn a retrospective study of 22 patients, we examined whether modifying the injected muscles leads to improvement in the results as evaluated in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). The results showed that both injection schemes do in fact lead to improvements while differentiating between caput and collum has significantly better effects.DiscussionDue to our results we recommend the classification differentiating between torticollis and torticaput type.

Torticaput versus Torticollis: Clinical Effects with Modified Classification and Muscle Selection

<strong>Background:</strong> Several different subtypes are distinguished in cervical dystonia, depending on their different levels of movement. In simple rotation, classified as torticollis spasmodicus, we now differentiate between torticollis and torticaput dependent on whether only the head or the neck is turned. The new classification system permits for different injection schemes. <strong>Case reports:</strong> In a retrospective study of 22 patients, we examined whether modifying the injected muscles leads to improvement in the results as evaluated in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). The results showed that both injection schemes do in fact lead to improvements while differentiating between caput and collum has significantly better effects. <strong>Discussion:</strong> Due to our results we recommend the classification differentiating between torticollis and torticaput type.

Reliability, feasibility and satisfaction of telemedicine evaluations for cervical dystonia

Introduction Telemedicine is used successfully for evaluating patients with neurologic diseases, but has not been tested in cervical dystonia (CD). CD is uniquely suited for telemedicine as the scales validated to assess its severity rely only on visual inspection. The study sought to determine reliability, feasibility and satisfaction of telemedicine visits for evaluating CD. Methods Patients 18 years and older with a diagnosis of CD and scheduled for botulinum toxin (BoNT) injections were recruited, with a total of 46 enrolled. Dystonia severity was evaluated using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) motor severity subscale. Three total evaluations took place: an initial telemedicine evaluation on the day prior to a scheduled BoNT injection; an in-person evaluation in clinic immediately before injections; and a follow-up telemedicine visit 4–6 weeks after injection with subsequent completion, by both participants and the clinician, of satisfaction questionnaires. Agreement between telemedicine and in-person TWSTRS data was calculated using intra-class correlation coefficients (ICC) and kappa statistics where appropriate. Feasibility was determined by the percent of patients completing all three visits, and satisfaction with telemedicine visits was determined based on answers to satisfaction questionnaires. Results There was excellent agreement between visit types for the TWSTRS motor severity summary score (κ = 0.890; 95th CI 0.713; 0.949). Only two individual TWSTRS items failed to meet the threshold for moderate agreement. Feasibility and satisfaction were high. Discussion Telemedicine is reliable and feasible in the evaluation of CD. Some CD patients would prefer telemedicine visits. Participants and the clinician were satisfied with telemedicine visits.

Sensory Tricks Are Associated with Higher Sleep-Related Quality of Life in Cervical Dystonia

<strong>Background:</strong> Sensory tricks are compensatory gestures that cervical dystonia (CD) patients use to reduce abnormal neck posture and movements. Although sensory tricks are common in CD, little is known about whether trick efficacy changes over time or has effect on quality of life. <strong>Methods:</strong> We analyzed clinical data and video recordings from 188 patients with isolated CD. We calculated the duration of CD and assessed the Toronto Western Spasmodic Torticollis Rating Scales and the Cervical Dystonia Impact Profile (CDIP-58). <strong>Results:</strong> A longer duration of CD corresponded to a less effective sensory trick (r(187) = 0.1901, p = 0.009). Patients who demonstrated more effective sensory tricks reported higher sleep-related quality of life than patients with less effective sensory tricks (r(187) = 0.1680, p = 0.0212). There were no significant relationships between the effectiveness of a sensory trick and the other aspects of quality of life as measured by the CDIP-58. <strong>Discussion:</strong> Patients who have had CD longer had less effective sensory tricks consistent with patients’ verbal reports of previously having a trick that no longer works. Patients should be apprised of a wide variety of sensory tricks because their previous tricks may lose efficacy over time and because more effective tricks are associated with higher sleep-related quality of life.

Sensory Tricks Are Associated with Higher Sleep-Related Quality of Life in Cervical Dystonia.

BackgroundSensory tricks are compensatory gestures that cervical dystonia (CD) patients use to reduce abnormal neck posture and movements. Although sensory tricks are common in CD, little is known about whether trick efficacy changes over time or has effect on quality of life.MethodsWe analyzed clinical data and video recordings from 188 patients with isolated CD. We calculated the duration of CD and assessed the Toronto Western Spasmodic Torticollis Rating Scales and the Cervical Dystonia Impact Profile (CDIP-58).ResultsA longer duration of CD corresponded to a less effective sensory trick (r(187) = 0.1901, p = 0.009). Patients who demonstrated more effective sensory tricks reported higher sleep-related quality of life than patients with less effective sensory tricks (r(187) = 0.1680, p = 0.0212). There were no significant relationships between the effectiveness of a sensory trick and the other aspects of quality of life as measured by the CDIP-58.DiscussionPatients who have had CD longer had less effective sensory tricks consistent with patients’ verbal reports of previously having a trick that no longer works. Patients should be apprised of a wide variety of sensory tricks because their previous tricks may lose efficacy over time and because more effective tricks are associated with higher sleep-related quality of life.

Head tremor at disease onset: an ataxic phenotype of cervical dystonia.

Cervical dystonia (CD) can present with head tremor. It is unclear whether ataxic features are differentially associated with this phenotype at onset of CD. We sought to evaluate: (1) the demographic features of CD patients with (Tr-CD) and without head tremor (nTr-CD) at onset, and (2) the differential ataxic features between these CD subtypes. For the first objective, we compared demographic data in Tr-CD versus nTr-CD subtypes in the entire cohort of CD subjects enrolled in the Dystonia Coalition Natural History and Biorepository studies (n = 1608). For the second objective, we rated the standardized videos from consecutively enrolled Tr-CD subjects (n = 50) and age-, gender-, and disease duration-matched nTr-CD subjects (n = 50) for ataxia severity scoring using the Scale for the Assessment and Rating of Ataxia (SARA) and the International Cooperative Ataxia Rating Scale (ICARS); and for dystonia severity using the Toronto Western Spasmodic Torticollis Rating Scale section-I (TWSTRS) and the Global Dystonia Rating Scale (GDRS). Of 1,608 subjects, 18.1% (n = 291) were classified as Tr-CD and 81.9% (n = 1317) as nTr-CD. The Tr-CD cohort was older, predominantly female, and had longer disease duration than the nTr-CD cohort (p = 0.01). Compared to nTr-CD, Tr-CD subjects had worse generalized ataxia, speech, and gait and posture scores. High ataxia severity with low dystonia severity distinguished Tr-CD from nTr-CD with high accuracy (area under the curve, 0.91 (95% CI 0.85-0.97). Head tremor at disease onset represents a clinically distinguishable subtype of cervical dystonia affecting predominantly older women, with worse ataxia and milder dystonia than the non-tremulous dystonic phenotype.

Long-Term Specialized Physical Therapy in Cervical Dystonia: Outcomes of a Randomized Controlled Trial

ObjectiveTo evaluate the effectiveness of a specialized physical therapy (SPT) program on disability in cervical dystonia (CD) compared to regular physical therapy (RPT). DesignA single-blinded randomized controlled trial. SettingThis study was performed by a physical therapist in a primary health care setting. Measurements were performed at baseline, 6 and 12 months in the botulinum toxin (BoNT) outpatient clinic of the neurology department. ParticipantsPatients with primary CD and stable on BoNT treatment for 1 year (N=96). Main Outcome MeasuresThe primary outcome was disability assessed with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). Secondary outcomes were pain, anxiety, depression, quality of life (QOL), and health related costs over 12 months. ResultsA total of 72 participants (30 men, 42 women) finished the study: 40 received SPT, 32 RPT. No significant between group differences were found after 12 months of treatment (P=.326). Over these 12 months both groups improved significantly (P<.001) on the TWSTRS disability scale compared to baseline (SPT 1.7 points, RPT 1.0 points). Short Form 36 (SF-36) General Health Perceptions (P=.046) and self-perceived improvement (P=.007) showed significantly larger improvements after 12 months in favor of SPT. Total health related costs after 12 months were $1373±556 for SPT compared to $1614±917 for RPT. ConclusionSPT revealed no significant differences compared to RPT after 12 months of treatment on the TWSTRS disability scale. Both groups showed similar improvements compared to baseline. Positive results in the SPT group were higher patient perceived effects and general health perception. Treatment costs were lower in the SPT group. With lower costs and similar effects, the SPT program seems to be the preferred program to treat CD.

Effects of A 3-Month Physiotherapy Intervention in Stable Cervical Dystonia As Add-On to Botulinum Toxin Therapy

Abstract Background Treatment of choice for cervical dystonia comprises botulinum neurotoxin therapy. Whether additional physiotherapy can achieve better results is unclear. Objectives To show effects of physiotherapy as an add-on treatment to botulinum neurotoxin therapy. Methods 18 patients participated in this prospective interventional study (DRKS00006562) consisting of 2, 3-month periods. In the first period, usual botulinum toxin was applied. The second period comprised an additional multimodal physiotherapy program. Outcome measures were: range of motion, SF-36, Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), surface electromyography. Results In the comparison first phase vs. second phase patients showed significant improvements in range of motion (flexion/extension: 16.3 ± 25.4; rotation: 19.1 ± 24.6), TWSTRS (severity: 3.8 ± 3.0; disability: 1.7 ± 2.0; pain: 4.4 ± 4,1) and in mental health (SF-36: 5.9 ± 7.5); p &lt;0.05, respectively. No significant changes were seen in the lateral flexion ROM, physical health (SF-36) and the surface electromyography. Conclusion Multimodal physiotherapy is a feasible and save additional treatment option for patients with cervical dystonia. An add-on physiotherapy program can achieve better treatment outcomes. Patients benefited especially with improved range of motion, and reduced pain and severity of symptoms.

Deep Brain Stimulation Versus Peripheral Denervation for Cervical Dystonia: A Systematic Review and Meta-Analysis

Cervical dystonia is a disabling medical condition that drastically decreases quality of life. Surgical treatment consists of peripheral nerve denervation procedures with or without myectomies or deep brain stimulation (DBS). The current objective was to compare the efficacy of peripheral denervation versus DBS in improving the severity of cervical dystonia through a systematic review and meta-analysis. A search of PubMed, MEDLINE, EMBASE, and Web of Science electronic databases was conducted in accordance with PRISMA guidelines. Preoperative and postoperative Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total scores were used to generate standardized mean differences and 95% confidence intervals (CIs), which were combined in a random-effects model. Both mean percentage and absolute reduction in TWSTRS scores were calculated. Absolute reduction was used for forest plots. Eighteen studies met the inclusion criteria, comprising 870 patients with 180 (21%) undergoing DBS and 690 (79%) undergoing peripheral denervation procedures. The mean follow-up time was 31.5 months (range, 12-38 months). In assessing the efficacy of each intervention, forest plots revealed significant absolute reduction in total postoperative TWSTRS scores for both peripheral denervation (standardized mean difference 1.54; 95% CI 1.42-1.66) and DBS (standardized mean difference 2.07; 95% CI 1.43-2.71). On subgroup analysis, DBS therapy was significantly associated with improvement in postoperative TWSTRS severity (standardized mean difference 2.08; 95% CI 1.66-2.50) and disability (standardized mean difference 2.12; 95% CI 1.57-2.68) but not pain (standardized mean difference 1.18; 95% CI 0.80-1.55). Both peripheral denervation and DBS are associated with a significant reduction in absolute TWSTRS total score, with no significant difference in the magnitude of reduction observed between the 2 treatments. Further comparative data are needed to better evaluate the long-term results of both interventions.

Quality of life improvements in patients with cervical dystonia following treatment with a liquid formulation of abobotulinumtoxinA (Dysport® ).

In patients with cervical dystonia, abobotulinumtoxinA solution for injection (ASI) has been shown to be similarly effective to freeze-dried abobotulinumtoxinA in reducing Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total scores. In this secondary analysis, quality of life data as evaluated with the Cervical Dystonia Impact Profile (CDIP-58) are presented. This was a double-blind, randomized, active and placebo-controlled study followed by an open-label extension (NCT01261611). In the double-blind phase, patients were randomized (3:3:1) to one cycle of ASI 500U (n=156), abobotulinumtoxinA 500U (n=159) or placebo (n=54). Following the double-blind phase, all patients received open-label ASI for up to four cycles. The CDIP-58 total scores were significantly improved at week 4 of the double-blind phase in both the ASI 500U and abobotulinumtoxinA 500U groups versus placebo [least squares mean change from baseline of -9.5 (-11.51, -7.45) and -11.2 (-13.2, -9.26) vs. -0.9 (-4.04, 2.14), respectively; both P<0.0001 vs. placebo]. All CDIP-58 domains contributed to this improvement and benefits were maintained across open-label treatment. Positive correlations were observed between CDIP-58 total score and all three TWSTRS domains (R=0.42-0.62) and for all CDIP-58 subscales with the TWSTRS total score and domains (R=0.23-0.60). Repeat ASI injections are similarly effective to abobotulinumtoxinA in improving patient-reported outcomes of health-related quality of life. Positive correlations were found between TWSTRS total and domain scores and CDIP-58 total and domain scores.

Acupuncture as Adjuvant Therapy for the Management of Cervical Dystonia.

Objectives: There are no curative treatments for cervical dystonia (CD), therefore conventional management is aimed at pain relief and muscle relaxation. Many patients with CD use complementary and integrative medicine interventions to manage symptoms, yet there are limited data on the use of acupuncture for CD. The aim of the current study was to determine the feasibility, safety, and efficacy of adjuvant acupuncture. Materials and Methods: A pilot open-label study was conducted on acupuncture treatments as add-on therapy to botulinum-toxin injection sessions (3 months apart) in 5 subjects with chronic idiopathic CD. Six 1-hour acupuncture sessions were administered every other week over the 3-month period between consecutive botulinum-toxin sessions. Data from exploratory efficacy endpoints-including a visual analogue scale for pain, the Clinician Global Impression of Change, the Patient Global Impression of Change, the Toronto Western Spasmodic Torticollis Rating Scale, and the Short Form-36) Health Survey-were collected. Results: Five subjects completed the study with only 1 acupuncture session missed by 1 subject, thereby meeting the study's predetermined adherence goal. All participants reported improvement from acupuncture. Only minor adverse events were reported, with self-resolved discomfort in 1 subject and self-resolved minor bruising in 2 subjects. Conclusions: Acupuncture is feasible and safe as an adjunct treatment for chronic CD, and might be associated with subjective symptomatic benefits.

PII: S1877-0657(18)30795-4

The main purpose of this study is 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 is 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. Patients were assessed using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Numerical Rating Scale (NRS). Seventeen patients were initially enrolled, but one patient was excluded after the final evaluation because of a violation of the study protocol. At 4 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 but this difference was not statistically significant ( P = 0.0783 for ANCOVA). Dysphagia occurred in 3 out of 16 patients; 2 after BoNT-A and 1 after saline. The dysphagia was transient and improved naturally within 2 weeks without any special treatment. Botulinum toxin injection for cervical dystonia in adults with dyskinetic cerebral palsy is relatively safe and improves pain and disability.

Oropharyngeal Dysphagia in Adults With Dyskinetic Cerebral Palsy and Cervical Dystonia: A Preliminary Study

ObjectivesTo investigate the characteristics of oropharyngeal dysphagia in adults with dyskinetic cerebral palsy (DCP) and cervical dystonia (CD). DesignExploratory observational cross-sectional study. SettingUniversity hospital. ParticipantsSeventeen patients with DCP (8 men, 9 women; age, 45.7±6.3y) enrolled in a randomized controlled trial on the effects of botulinum toxin injection on CD. InterventionsNot applicable. Main Outcome MeasuresBaseline clinical assessments and videofluoroscopic swallowing studies (VFSSs) were conducted. VFSS findings were evaluated using the videofluoroscopic dysphagia scale (VDS) and the penetration-aspiration scale (PAS). The Gross Motor Function Classification System (GMFCS) and Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) scores were also assessed. Relationships between outcomes were evaluated using Spearman’s rank correlation. ResultsThe clinical assessment revealed abnormalities in chewing (n=10, 58.8%), tongue movement (n=10, 58.8%), and laryngeal elevation (n=8, 47.1%). The most common abnormality on the VDS was inadequate mastication (n=13, 76.5%), followed by premature bolus loss, vallecular residue, and penetration/aspiration (all: n=10, 58.8%). A maximum PAS score of 8 was observed in 8 of 17 patients (47.1%). Total and pharyngeal VDS scores were significantly correlated with TWSTRS scores (ρ=0.543, P=.024 and ρ=0.539, P=.026, respectively); the VDS oral score did not correlate with the TWSTRS score (ρ=0.446, P=.073). There was no significant correlation between VDS score and GMFCS level (ρ=0.212, P=.414). ConclusionsThis preliminary observational study presents the characteristics of oropharyngeal dysphagia in adults with DCP and CD. Pharyngeal stage difficulties were negatively correlated with severity of CD, but not with GMFCS level. Screening for dysphagia may be recommended in adults with DCP and severe CD.

Neuropsychological consequences of pallidal deep brain stimulation altering brain networks

The purpose of this study was to evaluate postoperative changes in the neuropsychological function of cervical dystonia patients who had undergone deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) and to investigate how DBS affects neuropsychological function by altering the neural networks of the brain. In 12 cervical dystonia patients, the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) was used to measure the preoperative and postoperative status of cervical dystonia, and the Seoul Neuropsychological Screening Battery was used to gather neuropsychological data. The data were analyzed using a Wilcoxon signed-rank test. The average improvement in the TWSTRS score at the time of the postoperative neuropsychological battery was 56.1 ± 26.8%. In the neuropsychological battery, inhibitory control, as evaluated by the Stroop test, was significantly decreased after GPi DBS. The average pre-/postoperative Stroop test word and color reading correct response score were 107.9/99.2 (P = 0.043) and 85.3/75.8 (P = 0.032), respectively. The observed neuropsychological consequence of GPi DBS in this study, i.e., decreased inhibitory control, implies that electrical stimulation of the GPi may alter brain networks via the centromedian-parafascicular nuclear complex, suppressing the inhibitory control function of the prefrontal cortex.

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.

Alterations in vestibular function in individuals with cervical dystonia and the effects of botulinum toxin treatment

IntroductionIndividuals with cervical dystonia (CD) often report difficulty with balance and an altered perception of vertical. Previous studies have suggested a decreased proprioceptive response to stretch of neck muscle spindles in these patients, and impaired dynamic balance changes in individuals with tremor. MethodsParticipants with CD were divided into three groups based on severity of tremor and dystonic position on the Toronto Western Spasmodic Torticollis Rating Scale 2 (TWSTRS2). Unaffected controls completed assessments including Fukuda, modified Romberg, and subjective visual vertical tests. Participants with CD completed the same assessments at baseline and 4 to 6 weeks following botulinum toxin treatment. ResultsCD participants with marked tremor and deviation had more difficulty perceiving what was vertical as demonstrated by a greater degree off midline on the subjective visual vertical test, compared to individuals with marked tremor with minimal deviation and controls, though this was not significant after adjustment for multiple comparisons. Individuals with CD also had more difficulty maintaining balance on a compliant surface with eyes closed compared to controls on the modified Romberg test. TWSTRS2 motor severity score was significantly associated with degrees off midline on the subjective visual vertical test at baseline for CD participants, but not after botulinum toxin treatment. ConclusionsIndividuals with more severe tremor and dystonic posture appear to have an altered perception of vertical associated with CD severity and that may improve following botulinum toxin treatment. Modified Romberg testing suggests that visual cues may also be important to compensate for tremor and dystonic positions found in CD.

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

BackgroundInjectable daxibotulinumtoxinA (an investigational botulinum toxin, RT002) may offer a more prolonged duration of response—and therefore less frequent dosing—than onabotulinumtoxinA.ObjectivesTo perform a phase 2, open‐label, dose‐escalation study to assess the efficacy and safety of daxibotulinumtoxinA in cervical dystonia.MethodsSubjects 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).ResultsOverall, 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%).ConclusionsPreliminary 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.

Objective Evaluation of Cervical Dystonia Using an Inertial Sensor-Based System

Cervical dystonia (CD) is a chronic neurological movement disorder that causes involuntary neck muscle contractions, leading to abnormal movements or posture of the head. However, objective evaluation of severity of CD is lacking in the clinical practice. This study aimed to provide an objective evaluation of the severity of CD based on three-dimensional (3D) kinematics of the neck using wearable inertial sensors. Each inertial sensor was attached to the anterior chest and head of eight patients with idiopathic CD. The involuntary movements of neck were quantified by the rotation angle (RA) and magnitude of angular velocity (MAV) through axis-angle representation expressing 3D rotation. The characteristic posture of each patient was visualized. Four kinematic parameters, the mean and peak values of RA and MAV (Meanangle, Peakangle, Meanvel, and Peakvel) were calculated and correlation between each parameter values and the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) scores from all patients was analyzed to assess clinical validity. The test–retest reliability of the parameters was examined as well. Correlation coefficients of the Meanangle and Peakangle with TWSTRS were 0.28 and 0.69, respectively, whereas those of the Meanvel and Peakvel were 0.84 and 0.84, respectively. The MAV parameters showed a higher correlation with clinical severity than RA parameters. The intraclass correlation coefficients of the four parameters between the test–retest were more than 0.9. We conclude that objective evaluation of severity of CD based on kinematic parameters is clinically valid and has test–retest reliability.

GABAA Receptor Availability Changes Underlie Symptoms in Isolated Cervical Dystonia.

GABAA receptor availability changes within sensorimotor regions have been reported in some isolated forms of dystonia. Whether similar abnormalities underlie symptoms in cervical dystonia is not known. In the present study, a total of 15 cervical dystonia patients and 15 age- and sex-matched controls underwent 11C-flumazenil PET/CT scanning. The density of available GABAA receptors was estimated using a Simplified Reference Tissue Model 2. Group differences were evaluated using a two-sample T-test, and correlations with dystonia severity, as measured by the Toronto Western Spasmodic Torticollis Rating Scale, and disease duration were evaluated using a regression analysis. Voxel-based analyses revealed increased GABAA availability within the right precentral gyrus in brain motor regions previously associated with head turning and the left parahippocampal gyrus. GABAA availability within the bilateral cerebellum was negatively correlated with dystonia severity, and GABAA availability within the right thalamus and a variety of cerebellar and cortical regions were negatively correlated with disease duration. While GABAA availability changes within primary motor areas could represent a partial compensatory response to loss of inhibition within sensorimotor network, GABAergic signaling impairment within the cerebellum may be a key contributor to dystonia severity.