Botulinum toxin therapy for cervical dystonia

The Collicular-Pulvinar-Amygdala Axis and Adult-Onset Idiopathic Focal Dystonias

Adult-onset idiopathic focal dystonias (AOIFD) are the most common type of dystonia. It has varied expression including multiple motor (depending on body part affected) and non-motor symptoms (psychiatric, cognitive and sensory). The motor symptoms are usually the main reason for presentation and are most often treated with botulinum toxin. However, non-motor symptoms are the main predictors of quality of life and should be addressed appropriately, as well as treating the motor disorder. Rather than considering AOIFD as a movement disorder, a syndromic approach should be taken, one that accommodates all the symptoms. Dysfunction of the collicular-pulvinar-amygdala axis, with the superior colliculus as a central node, can explain the diverse expression of this syndrome.

An Update on Botulinum Toxin in Neurology

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

Reduced Global-Brain Functional Connectivity and Its Relationship With Symptomatic Severity in Cervical Dystonia

Background: Altered functional connectivity (FC) is related to pathophysiology of patients with cervical dystonia (CD). However, inconsistent results may be obtained due to different selected regions of interest. We explored voxel-wise brain-wide FC changes in patients with CD at rest in an unbiased manner and analyzed their correlations with symptomatic severity using the Tsui scale.

Method: A total of 19 patients with CD and 21 sex- and age-matched healthy controls underwent resting-state functional magnetic resonance imaging scans. Global-brain FC (GFC) was applied to analyze the images. Support vector machine was used to distinguish the patients from the controls.

Results: Patients with CD exhibited decreased GFC in the right precentral gyrus and right supplementary motor area (SMA) that belonged to the M1-SMA motor network. Significantly negative correlation was observed between GFC values in the right precentral gyrus and symptomatic severity in the patients (r = −0.476, p = 0.039, uncorrected). Decreased GFC values in these two brain regions could be utilized to differentiate the patients from the controls with good accuracies, sensitivities and specificities (83.33, 85.71, and 80.95% in the right precentral gyrus; and 87.59, 89.49, and 85.71% in the right SMA).

Conclusions: Our investigation suggests that patients with CD show reduced GFC in brain regions of the M1-SMA motor network and provides further insights into the pathophysiology of CD. GFC values in the right precentral gyrus and right SMA may be used as potential biomarkers to recognize the patients from the controls.

Use of botulinum toxin for movement disorders

The term movement disorders encompasses all disorders hypokinetic and hyperkinetic, which were previously known as extrapyramidal syndromes. With the definition of movement disorders and their diagnostic criteria and classifications, new studies for therapeutics could be performed. New drugs were launched, functional neurosurgery was developed, and the introduction of botulinum toxin (BoNT) for hyperkinesias was introduced. BoNT is an important therapy for dystonia, tics, myoclonus, and tremors. The aim of this review is to present the new and well-established uses of BoNT for movement disorders.

Long-term quality of life in cervical dystonia after treatment with abobotulinum toxin A: a 2-year prospective study

BACKGROUND

The short-term quality of life (QoL) in cervical dystonia (CD) after treating with abobotulinum toxin A (Abo-BTX A) and neubotulinum toxin A (Neu-BTX A) have been studied in Thai CD patients. However; the long-term study has not been published.

OBJECTIVE

The aim of the present study was to determine long-term improvement of the health-related quality of life (HRQoL) after eight injections of Abo-BTX A over 2 years in CD patients.

PATIENTS AND METHODS

A 2-year prospective study on the QoL of CD patients, as measured by HRQoL, before and after receiving eight injections of Abo-BTX A at 3-month intervals over a 2-year treatment period was performed. The disease-specific HRQoL was assessed before and after the treatment by using the Cervical Dystonia Impact Profile-58 (CDIP-58) questionnaire. The general HRQoL was assessed by using the Medical Outcomes 36-Item Short Form Health Survey (SF-36), while depressive disorder screening was assessed by using the Center of Epidemiologic Studies-Depression (CES-D) questionnaire. The SF-36 and CES-D questionnaire were administered before treatment and every 3 months before the next injection for a 2-year period.

RESULTS

A total of 20 CD patients were enrolled from January 2013 to December 2015. CDIP-58 showed a significant improvement after long-term injections of Abo-BTX A in all domains (P < 0.001). However, only vitality domain of SF-36, which assessed general HRQoL, showed a significant improvement after long-term injections (P = 0.037). There was no prevalence of depressive disorder in all patients (CES-D score <20) in this study.

CONCLUSION

The Abo-BTX A injections at 3-month intervals over a 2-year period improved the CDIP-58 scores, which assess disease-specific HRQoL, as well as an increased vitality domain of general HRQoL. No patient suffered from depression in this study.

The Dilution Confusion: Easy Dosing for Botulinum Toxins

Aesthetic practitioners prefer various reconstitution volumes for botulinum toxins (BoNTAs). Some injectors prefer larger volumes of bacteriostatic normal saline (NaCl) to achieve a larger diffusion in certain areas and a smaller volume for more precise administration of the BoNTA. Some practitioners believe dilution volumes do not matter at all in relation to spread or diffusion, asserting the diffusion area is simply dose-related. It can get confusing when there is more than one injector in an office, different volumes of saline, and more than one type of syringe to administer the neurotoxin. This leaves possibilities for confusion and dosage errors. This article explores four steps to take the confusion out of reconstituting BoNTAs and delivering accurate and consistent doses within a medical office.

Quality of life in cervical dystonia after treatment with botulinum toxin A: a 24-week prospective study

OBJECTIVE

This study aimed to identify possible improvements in disease-specific health-related quality of life (HRQoL) after multiple injections of botulinum toxin A over 24 weeks in Thai cervical dystonia (CD) patients.

MATERIALS AND METHODS

A 24-week prospective study comparing HRQoL of Thai CD patients before and after multiple injections of botulinum toxin A at 3-month intervals was performed. Disease-specific HRQoL was assessed by using the Cervical Dystonia Impact Profile-58 questionnaire (CDIP-58) and the Craniocervical Dystonia Questionnaire-24 (CDQ-24). General HRQoL was assessed by using the Medical Outcomes' 36-Item Short Form Health Survey (SF-36) and the EuroQoL 5-dimension questionnaire (EQ-5D). All the assessments were performed before and after the 24-week treatment period.

RESULTS

A total of 20 CD patients were enrolled in this study from April to December 2011. CDIP-58 and CDQ-24 scores, which assess disease-specific HRQoL, showed a significant improvement after 24 weeks of treatment by botulinum toxin A (P<0.001). However, EQ-5D and SF-36 scores, which assess general HRQoL, showed no significant improvement after the treatment (P>0.05).

CONCLUSION

CD patients' disease-specific HRQoL improved after being treated with multiple botulinum toxin A injections. However, general HRQoL was not improved.

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.

Botulinum toxin type A products are not interchangeable: a review of the evidence

Botulinum toxin type A (BoNTA) products are injectable biologic medications derived from Clostridium botulinum bacteria. Several different BoNTA products are marketed in various countries, and they are not interchangeable. Differences between products include manufacturing processes, formulations, and the assay methods used to determine units of biological activity. These differences result in a specific set of interactions between each BoNTA product and the tissue injected. Consequently, the products show differences in their in vivo profiles, including preclinical dose response curves and clinical dosing, efficacy, duration, and safety/adverse events. Most, but not all, published studies document these differences, suggesting that individual BoNTA products act differently depending on experimental and clinical conditions, and these differences may not always be predictable. Differentiation through regulatory approvals provides a measure of confidence in safety and efficacy at the specified doses for each approved indication. Moreover, the products differ in the amount of study to which they have been subjected, as evidenced by the number of publications in the peer-reviewed literature and the quantity and quality of clinical studies. Given that BoNTAs are potent biological products that meet important clinical needs, it is critical to recognize that their dosing and product performance are not interchangeable and each product should be used according to manufacturer guidelines.

Usefulness of (18)f-fluorodeoxyglucose positron emission tomography/computed tomography in management of cervical dystonia

Objective

To evaluate the usefulness of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in the management of cervical dystonia (CD) with botulinum toxin type A (BoNT-A) injection.

Method

Thirty two subjects with CD were included. A BoNT-A injection was provided either by clinically targeting method (group 1) or by ¹⁸F-FDG PET/CT-assisted, clinically targeting method (group 2). In group 2, selection of target muscles and dosage of BoNT-A were determined according to the increased ¹⁸F-FDG uptake, in addition to physical examination and functional anatomy. The outcomes of BoNT-A injection was compared between the two groups, in terms of the number of subjects who had reinjection before and after 6 months, the number of reinjections, the interval of reinjections, the duration to the minimal Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), the number of adverse events, the reduction rate of TWSTRS at 1-3 months and 3-6 months after injection, and the probability of reinjection-free living.

Results

The number of subjects who had reinjection within 6 months was significantly lower in group 2 than in group 1 (10 in group 1 vs. 3 in group 2). The reduction rate of TWSTRS after 3-6 months (37.8±15.7% of group 1 vs. 63.3±28.0% of group 2) and the probability of reinjection-free living were significantly higher in group 2 than in group 1.

Conclusion

These findings suggest that ¹⁸F-FDG PET/CT study could be useful in management of CD in terms of the identification of dystonic muscles if there is an increase in the ¹⁸F-FDG uptake in the cervical muscle of the images.

A botulinum toxin A treatment algorithm for de novo management of torticollis and laterocollis

OBJECTIVES

Few studies have investigated the injection patterns for botulinum toxin type A for the treatment of heterogeneous forms of cervical dystonia (CD). This large, prospective, open-label, multicentre study aimed to evaluate the effectiveness and safety of 500 U botulinum toxin A for the initial treatment according to a standardised algorithm of the two most frequent forms of CD, predominantly torticollis and laterocollis.

DESIGN

Patients (aged ≥ 18 years) with CD not previously treated with botulinum neurotoxin therapy were given one treatment with 500 U Dysport, according to a defined intramuscular injection algorithm based on clinical assessment of direction of head deviation, occurrence of shoulder elevation, occurrence of tremor (all evaluated using the Tsui rating scale) and hypertrophy of the sternocleidomastoid muscle.

RESULTS

In this study, 516 patients were enrolled, the majority of whom (95.0%) completed treatment. Most patients had torticollis (78.1%). At week 4, mean Tsui scores had significantly decreased by -4.01, -3.76 and -4.09 points in the total, torticollis and laterocollis populations, respectively. Symptom improvement was equally effective between groups. Tsui scores remained significantly below baseline at week 12 in both groups. Treatment was well tolerated; the most frequent adverse events were muscular weakness (13.8%), dysphagia (9.9%) and neck pain (6.6%).

CONCLUSIONS

Dysport 500 U is effective and well tolerated for the de novo management of a range of heterogeneous forms of CD, when using a standardised regimen that allows tailored dosing based on individual symptom assessment. Clinical trials information (NCT00447772; clinicaltrials.gov).

Comparison between (18)F-FDG PET/CT and EMG Mapping for Identifying Dystonic Superficial Muscles in Primary Cervical Dystonia: Preliminary Results

PURPOSE

This study was conducted to compare (18)F-FDG PET/CT and electromyography (EMG) mapping in patients with primary cervical dystonia (PCD) to find dystonic superficial cervical muscles.

METHODS

Ten consecutive patients with PCD (M:F = 5:5, age 44 ± 13 years) whose dystonic posture was not relieved with conventional muscle relaxant therapy were included. Target cervical muscles for the comparison between (18)F-FDG PET/CT and EMG mapping were four representative superficial bilateral cervical muscles: splenius capitis muscle, sternocleidomstoid muscle, upper trapezius muscle, and leavator scapulae muscle. The diagnostic efficacy was compared between (18)F-FDG PET/CT and EMG mapping using physical exam and measurement of rotation angle as the gold standard.

RESULTS

Among 80 muscles evaluated, there were 21 (26%) dystonic superficial cervical muscles assessed with physical exam and motion analysis. The sensitivity, specificity, and accuracy for localizing dystonic muscles were 76, 92, and 88% for (18)F-FDG PET/CT, and 95, 66, and 74% for EMG mapping, respectively. The sensitivity of EMG mapping was significantly higher than that of (18)F-FDG PET/CT. In contrast, (18)F-FDG PET/CT was significantly superior to EMG mapping for specificity and accuracy.

CONCLUSIONS

(18)F-FDG PET/CT is more specific and accurate than EMG mapping for finding superficial dystonic cervical muscles. The high sensitivity of EMG mapping suggests that (18)F-FDG PET/CT and EMG mapping are complementary for finding dystonic superficial cervical muscles.

Clinically significant placebo analgesic response in a pilot trial of botulinum B in patients with hand pain and carpal tunnel syndrome

OBJECTIVE

We conducted a pilot trial to assess the effect of botulinum toxin B on palmar pain and discomfort in carpal tunnel syndrome (CTS) patients. Design. Randomized, double-blind, placebo-controlled.

PATIENTS

Twenty ambulatory CTS patients. Intervention. Botulinum toxin B or placebo injections into three hypothenar muscles anatomically linked or attached to the carpal tunnel and its tentorium, that is, the Opponens Digiti Minimi and Flexor Digiti Minimi, located with electromyography (EMG), and the Palmaris Brevis Muscle, anatomically located without EMG.

SETTING

New York City hospital.

OUTCOME MEASURES

Outcomes were measured with numeric ratings, with higher scores indicating worse outcomes. Daily, subjects recorded their 0-10 numeric ratings of overall pain levels and pain-related sleep disturbances. During weekly telephone calls, they reported their 0-10 ratings for overall pain, pain-related sleep disturbance, and CTS-related tingling during the night and day as experienced over the preceding 24 hours. For each of four clinic visits, we averaged each subject's ratings of nine quality of life indicators from the West Haven-Yale Multidimensional Pain Inventory (WHYMPI), each measured on a 0-6 numeric scale.

RESULTS

Over the 13-week trial, compared to baseline scores, the following outcomes predominantly showed decreases of statistical significance (P < or = 0.050) or borderline significance (0.050 < P < or = 0.10) for weeks 2 through 8: overall pain per daily diary entries and per weekly telephone reports, and pain-related sleep disturbance in the placebo group per phone report and in the botulinum toxin B group per diary report. CTS painful night tingling and day tingling, as well as the average scores of the WHYMPI quality of life indicators, showed improvements with statistical or borderline significance for almost each follow-up week. Between-group analyses, however, demonstrated that at each follow-up week, there was no statistically significant difference between the two study groups regarding changes from baseline in any study outcome.

CONCLUSION

Botulinum toxin B is not dramatically superior to placebo for the relief of CTS symptoms. Possible explanations of the improvements in each study group are explored.

From frown lines to fissures: Therapeutic uses for botulinum toxin

INTRODUCTION

Since the pharmacological mode of action of botulinum toxin (BTX) has been elucidated, its therapeutic potential has been increasingly recognised. The aims of this review were to summarize our current understanding of the pharmacological action of this agent and to review its therapeutic uses.

METHODS

An electronic literature search with Medline (January 1965 to December 2004) was carried out to identify articles related to the pharmacological mode of action and clinical uses for botulinum toxin using the keyword "botulinum toxin".

RESULTS AND CONCLUSION

Botulinum toxin A is emerging as a valuable clinical tool, both for diagnostic and therapeutic purposes in a wide variety of disorders, and is already the treatment of choice for selected conditions. Better understanding of its modes of action may identify alternative targets for pharmacological intervention, and may allow development of longer acting drugs with lower immunogenicity. Therapeutic uses of BTX-A must be assessed systematically in prospective studies, and the clinical role of other subtypes requires evaluation.

Update on botulinum toxin use in facial plastic and head and neck surgery

PURPOSE OF REVIEW

The purpose of this review is to discuss current trends in the medicinal use of botulinum toxin in head and neck and facial plastic surgery. The basic science of botulinum toxin is presented along with a comparison of the subtypes currently available on the market. Site-specific applications of botulinum toxin in the head and neck region are presented.

RECENT FINDINGS

The use of botulinum toxin continues to expand, both in volume and in number of applications. The main application of botulinum toxin in facial plastic surgery is in the effacement of dynamic or hyperkinetic facial lines. The granting of US Food and Drug Administration approval for the use of Botulinum Toxin type A in the treatment of glabella lines marks a major milestone for the more widespread usage of this product in cosmetic settings. Additional cosmetic applications include crow's feet, marionette lines, and platysma banding. Noncosmetic applications in the head and neck include dystonias (including torticollis), facial and generalized muscle spasms, migraine headaches, hyperhidrosis, spasmodic dysphonia, sialorrhea, gustatory sweating, and involuntary movement disorders.

SUMMARY

The use of botulinum toxin in the treatment of hyperkinetic conditions and disorders of excessive salivation is well established and enjoys an excellent safety profile. The cosmetic use of botulinum toxin continues to expand. The chronic use of botulinum toxin specifically for cosmetic purposes is worthy of additional study.