Fifteen-year experience in treating blepharospasm with Botox or Dysport: same toxin, two drugs

Efficacy and safety of long-term botulinum toxin treatment for acquired cervical dystonia: a 25-year follow-up

Botulinum toxin A (BoNT/A) is the first-line treatment for idiopathic cervical dystonia (ICD) and is widely used in the clinical setting. To date, scanty data are available on the effectiveness of BoNT in treating acquired cervical dystonia (ACD). Here we present a long-term follow-up of ACD patients treated with BoNT/A that focused on safety and efficacy. The study included subjects who had received at least six treatments of three commercially available BoNT/A drugs [abobotulinumtoxinA (A/Abo), incobotulinumtoxinA (A/Inco) and onabotulinumtoxinA (A/Ona)]. Safety and efficacy were assessed based on patients' self-reports regarding adverse effects (AE), duration of improvement of dystonia and/or pain relief. Global clinical improvement was measured on a six-point scale. 23 patients with ACD were administered 739 treatments (A/Abo in 235, A/Inco in 72, A/Ona in 432) with a mean number of treatments of 31 ± 20 (range 6-76) and duration of 10 ± 6 weeks (range 2-25). The mean dose was 737 ± 292 U for A/Abo, 138 ± 108 U for A/Inco and 158 ± 80 U for A/Ona. The average benefit duration was 89 ± 26 (A/Abo), 88 ± 30 days (A/Inco), and 99 ± 55 days (A/Ona) (p = 0.011); global clinical improvement for all sessions was 4 ± 1. ANOVA one-way analysis indicated that A/Ona had the best profile in terms of duration (p < 0.05), whereas A/Abo had the best pain relief effect (p = 0.002). Side effects were reported in 9% of treatments (67/739), with ten treatments (1%) complicated by two side effects. Most side effects were rated mild to moderate; severe side effects occurred following three treatments with the three different BoNT; two required medical intervention. No allergic reactions were reported. Even after 25 years of repeated treatments, all serotypes of BoNT demonstrate positive effects in treating ACD with long-lasting efficacy and safety.

Frequency of Hemorrhagic Side Effects of Botulinum Neurotoxin Treatment in Patients with Blepharospasm and Hemifacial Spasm on Antithrombotic Medication

The aim of this study was to investigate the frequency of hemorrhagic side effects of botulinum neurotoxin A injections (BoNT/A) for the treatment of benign essential blepharospasm (BEB) and hemifacial spasm (HFS) in patients taking antithrombotic drugs (ATD). A total of 140 patients were included (female: 65%; BEB: 75%; mean age: 70 ± 12 years). According to their current antithrombotic medication, participants were either assigned to the ATD group (41%), or to the control group (59%). The ATD group was further divided into subgroups depending on the medication administered: acetylsalicylic acid, ADP receptor antagonists, direct oral anticoagulants, vitamin-K antagonists, or dual antiplatelet therapy. The frequency of hemorrhagic side effects was recorded by retrospective analysis of past treatments as documented in the patient's file set in relation to the number of past treatments (hematoma frequency of past treatments, HF_retro) as well as by a prospective survey capturing the side effects of one single treatment (hematoma frequency of actual treatment, HF_actual). There was no significant difference in hematoma frequency between the ATD group and the control group, neither for past (HF_retro: ATD: 2%; 45/2554; control: 4%; 109/2744) nor for the current BoNT/A treatments (HF_actual: ATD: 30%; 16/53; control: 31%; 22/72). Even between ATD subgroups, hematoma frequency did not differ significantly. Overall, hemorrhagic side effects of the BoNT/A treatment for BEB and HFS were mild and non-disabling.

Bibliometric analysis of studies on the treatment of hemifacial spasm

Objective

Hemifacial spasm (HFS) is a common neurological disorder of the brain, which is difficult to treat. Most patients are distracted by it and are unable to work or study normally, which seriously affects their physical and mental health. However, there are a few bibliometric studies on it. This paper searched the articles on HFS using a bibliometric approach.

Method

Articles about HFS were retrieved from the Web of Science (WoS) Core Collection database. We employed the Visualization of Similarities (VOS)viewer to analyze these publications.

Results

A total of 645 reviews or articles in English were retrieved from WoS. In this study, we found that the number of publications showed a rising trend and China is the most active in searching the treatment of HFS. About keywords, neurosciences and neurology was searched (422 times) keyword, followed by hemifacial spasm (420 times) and surgery (320 times). By assessing the organizations, Shanghai Jiao Tong University published the most papers (8.68%), followed by Sungkyunkwan University (3.26%) and Baylor College Medicine (2.64%). A total of 247 journals have delivered publications on the treatment of HFS, World Neurosurgery (44 papers) published the largest number of articles.

Conclusion

The annual publications have increased with a fluctuating tendency. More researchers were taking an interest in HFS. This study helped us find out the hotspot and trend in research about facial spasm treatment.

Clinical Features and Evolution of Blepharospasm: A Multicenter International Cohort and Systematic Literature Review

Objective:

Blepharospasm is a type of dystonia where the diagnosis is often delayed because its varied clinical manifestations are not well recognized. The purpose of this study was to provide a comprehensive picture of its clinical features including presenting features, motor features, and non-motor features.

Methods:

This was a two-part study. The first part involved a systematic literature review that summarized clinical features for 10,324 cases taken from 41 prior reports. The second part involved a summary of clinical features for 884 cases enrolled in a large multicenter cohort collected by the Dystonia Coalition investigators, along with an analysis of the factors that contribute to the spread of dystonia beyond the periocular region.

Results:

For cases in the literature and the Dystonia Coalition, blepharospasm emerged in the 50s and was more frequent in women. Many presented with non-specific motor symptoms such as increased blinking (51.9%) or non-motor sensory features such as eye soreness or pain (38.7%), photophobia (35.5%), or dry eyes (10.7%). Non-motor psychiatric features were also common including anxiety disorders (34–40%) and depression (21–24%). Among cases presenting with blepharospasm in the Dystonia Coalition cohort, 61% experienced spread of dystonia to other regions, most commonly the oromandibular region and neck. Features associated with spread included severity of blepharospasm, family history of dystonia, depression, and anxiety.

Conclusions:

This study provides a comprehensive summary of motor and non-motor features of blepharospasm, along with novel insights into factors that may be responsible for its poor diagnostic recognition and natural history.

Ultra-Long-Term Therapy of Benign Essential Blepharospasm with Botulinumtoxin A-30 Years of Experience in a Tertiary Care Center

Aim of this study was to investigate the long-term results of botulinum toxin A (BoNT-A) injections for the treatment of benign essential blepharospasm (BEB) and to report our experience with (ultra-)long-term treatment with onabotulinumtoxin-A. We conducted a retrospective cross-sectional analysis at a university hospital. Patients with BEB and BoNT-A treatment were assigned to the Total Blepharospasm Group, patients with ≥21 onabotulinumtoxin-A injections to the Ona Long-Term Group. The Total Blepharospasm Group (n = 1940) included 33,933 BoNT-A injections. The age of patients at symptom onset was (mean ± SD) 58.0 ± 13.1 years, and 70.4% were female. The Ona long-term group (n = 234) included 10,632 onabotulinumtoxin-A injections. In this group, patients received 45.4 ± 22.9 injections with a mean dose of 22.2 IU ± 0.5. The duration of treatment was 12.6 ± 5.4 years, ranging from 2.9 to 30.0 years. The effect-duration-dose quotient did not change during long-term treatment. The observed side effects were comparable in type and frequency to other studies, even with the (ultra-)long treatment with onabotulinumtoxin-A. Our results, based on one of the largest patient populations and a treatment duration of up to 30 years, impressively demonstrate that onabotulinumtoxin-A is a safe and effective therapy for essential blepharospasm, even in the ultra-long term.

Nonlinear Changes in Botulinum Toxin Treatment of Task-Specific Dystonia during Long-Term Treatment

Botulinum toxin (BoTX) is the standard treatment for task-specific dystonias (TSDs) such as musician’s dystonia (MD). Our aim was to assess the long-term changes in BoTX treatment in a highly homogeneous and, to our knowledge, largest group of MD patients with respect to the following parameters: (1) absolute and (2) relative BoTX dosage, (3) number of treated muscles, and (4) inter-injection interval. We retrospectively assessed a treatment period of 20 years in 233 patients, who had received a cumulative dose of 68,540 MU of BoTX in 1819 treatment sessions, performed by two neurologists. Nonlinear correlation was used to analyze changes in the parameters over the course of repeated treatments. Post-hoc we applied a median-split to classify two subgroups (high-BoTX, low-BoTX) depending on the total amount of BoTX needed during treatment. Across all patients, we found a decrease of dosage for the first approximately 25 treatments with an increase afterwards. The number of muscles and inter-injection intervals increased with time with a discrete decrease of inter-injection intervals after about 35 treatments. Subgroup differences were observed in the amount of BoTX and inter-injection intervals, with continuously increasing inter-injection intervals and decreasing BoTX dosage in the low-BTX group. Both groups showed a continuously increasing number of injected muscles. In summary, we found nonlinear changes of BoTX dosage and inter-injection intervals and a continuously increasing number of injected muscles with treatment duration in TSD-patients. Furthermore, we, for the first time, identified two subgroups with distinct differences. Increasing inter-injection intervals and decreasing BoTX dosages in the low-BoTX group indicated improvement of symptoms with continued treatment. Continually increasing BoTX dosages with unchanged inter-injection intervals in the high-BoTX group indicated deterioration.

The good toxin: 10 years of experience with botulinum toxin A in the treatment of benign essential blepharospasm

PURPOSE

To describe the efficacy and safety of botulinum toxin A (Botox) in patients with benign essential blepharospasm.

METHODS

Retrospective review of operation, injection, and medical records.

RESULTS

Information of 29 patients (nine males) was reviewed, and the average age of benign essential blepharospasm onset was 59.1 years. The average number of injections per patient was 14.2 ± 8.2 (5-44) and the average follow-up was 75.8 ± 47.3 months (15-180). The average unit dose was 14.2 ± 8.2 (10-30) ipsilaterally in the patient's first year and was 21.4 ± 5.0 (12.5-30) ipsilaterally in their last year (p = 0.00458). The average onset time was 3.8 ± 1.9 (1-7) days in a patient's first year and was 3.6 ± 1.7 (2-7) days in their last year (p = 0.549). The average effective duration was 2.86 ± 1.1 months in a patient's first year and was 2.53 ± 0.9 in their final year (p = 0.187). The Subjective Spasm Alleviation Scale was 1.72 ± 0.4 at the first year and was 1.79 ± 0.5 in the last year (p = 0.187). Ten (34.5%) patients with eyelid disease had surgical correction. The Subjective Spasm Alleviation Scale was 1.50 ± 0.5 before and was 2.0 ± 0 six months after the operation (p = 0.0268). Post-injection complications were experienced in eight (27.6%) patients. The most common complication was ptosis (n = 7), followed by diplopia (n = 1), dry eye (n = 1), and tearing (n = 1). No life-threatening complication was reported.

CONCLUSION

Botox was a safe and effective treatment in benign essential blepharospasm which required an increased dosage over time. Ptosis was the most common complication and no life-threatening condition was reported. Surgical correction of those with eyelid diseases showed subjective improvement of subsequent Botox treatment.

FDA Approvals and Consensus Guidelines for Botulinum Toxins in the Treatment of Dystonia

In 2016, the American Academy of Neurology (AAN) published practice guidelines for botulinum toxin (BoNT) in the treatment of blepharospasm, cervical dystonia, adult spasticity, and headache. This article, focusing on dystonia, provides context for these guidelines through literature review. Studies that led to Food and Drug Administration (FDA) approval of each toxin for dystonia indications are reviewed, in addition to several studies highlighted by the AAN guidelines. The AAN guidelines for the use of BoNT in dystonia are compared with those of the European Federation of the Neurological Societies (EFNS), and common off-label uses for BoNT in dystonia are discussed. Toxins not currently FDA-approved for the treatment of dystonia are additionally reviewed. In the future, additional toxins may become FDA-approved for the treatment of dystonia given expanding research in this area.

Treatment of blepharospasm and Meige's syndrome with abo- and onabotulinumtoxinA: long-term safety and efficacy in daily clinical practice

INTRODUCTION

Thirty years after their approval, botulinum toxin injections still are the first-line therapy for blepharospasm. The aim of our study was to analyze long-term data concerning safety and efficacy in a large cohort over decades.

METHODS

Treatment data of all patients with blepharospasm and Meige´s syndrome in our outpatient clinic having undergone at least three subsequent treatment sessions with current onabotulinumtoxinA or abobotulinumtoxin A were analyzed with respect to the course of dose, effect duration, side effects, patients´ satisfaction and occurrence/reasons for treatment discontinuation.

RESULTS

The observation period was up to 18 years for onabotulinumtoxinA and 29 years for abobotulinumtoxinA with a total of 1778 and 9319 treatment sessions in 69 patients with onabotulinumtoxinA, 281 with abobotulinumtoxin A and 2 of these having used both products. The dose increased in the first years followed by a stable dose in the following years. The mean dose was 39.1/198.7 mouse units (onabotulinumtoxinA/abobotulinumtoxinA). In over 25% of all sessions, inhibition of the eyelid opening was effectively treated with pretarsal injections. The most common adverse events included ptosis (4%/5%), epiphora/sicca (4%/5%), double vision (1%/1%) and facial asymmetry (1%/1%). Reasons for therapy discontinuation were change to a nearby doctor, age, other diseases, spontaneous improvement, side effects or possible treatment failure. Only one patient was tested positive for neutralizing antibodies against botulinum toxin A.

CONCLUSION

The treatment of blepharospasm and Meige's syndrome with onabotulinumtoxinA and abobotulinumtoxinA is safe and effective, also over a long observation period of up to 29 years.

The Use of Botulinum Toxin for Treatment of the Dystonias

Dystonias are characterized by involuntary muscle contractions, twisting movements, abnormal postures, and often tremor in various body regions. However, in the last decade several studies have demonstrated that dystonias are also characterized by sensory abnormalities. While botulinum toxin is the gold standard therapy for focal dystonia, exactly how it improves this disorder is not entirely understood. Neurophysiological studies in animals and humans have clearly demonstrated that botulinum toxin improves dystonic motor manifestations by inducing chemodenervation, therefore weakening the injected muscles. In addition, neurophysiological and neuroimaging evidence also suggests that botulinum toxin modulates the activity of various neural structures in the CNS distant from the injected site, particularly cortical motor and sensory areas. Concordantly, recent studies have shown that in patients with focal dystonias botulinum toxin ameliorates sensory disturbances, including reduced spatial discrimination acuity and pain. Overall, these observations suggest that in these patients botulinum toxin-induced effects encompass complex mechanisms beyond chemodenervation of the injected muscles.

Botulinum neurotoxin formulations: overcoming the confusion

Botulinum toxin A is produced by anaerobic spore-forming bacteria and is used for various therapeutic and cosmetic purposes. Botulinum toxin A injections are the most popular nonsurgical procedure worldwide. Despite an increased demand for botulinum toxin A injections, the clinical pharmacology and differences in formulation of commonly available products are poorly understood. The various products available in the market are unique and vary in terms of units, chemical properties, biological activities, and weight, and are therefore not interchangeable. For safe clinical practice and to achieve optimal results, the practitioners need to understand the clinical issues of potency, conversion ratio, and safety issues (toxin spread and immunogenicity). In this paper, the basic clinical pharmacology of botulinum toxin A and differences between onabotulinum toxin A, abobotulinum toxin A, and incobotulinum toxin A are discussed.

The Expanding Therapeutic Utility of Botulinum Neurotoxins

Botulinum neurotoxin (BoNT) is a major therapeutic agent that is licensed in neurological indications, such as dystonia and spasticity. The BoNT family, which is produced in nature by clostridial bacteria, comprises several pharmacologically distinct proteins with distinct properties. In this review, we present an overview of the current therapeutic landscape and explore the diversity of BoNT proteins as future therapeutics. In recent years, novel indications have emerged in the fields of pain, migraine, overactive bladder, osteoarthritis, and wound healing. The study of biological effects distal to the injection site could provide future opportunities for disease-tailored BoNT therapies. However, there are some challenges in the pharmaceutical development of BoNTs, such as liquid and slow-release BoNT formulations; and, transdermal, transurothelial, and transepithelial delivery. Innovative approaches in the areas of formulation and delivery, together with highly sensitive analytical tools, will be key for the success of next generation BoNT clinical products.

Use of Botulinum Neurotoxin in Ophthalmology

Botulinum neurotoxin (BoNT) is the first biological toxin used in the treatment of ophthalmic diseases and to decrease skin wrinkles as an aesthetic agent. When used appropriately, it weakens the force of muscular contraction and/or inhibits glandular secretion. The most common areas for botulinum toxin treatment are the upper face, including the glabella, forehead, brows, and lateral canthal lines, or crow's feet. By relaxing the muscles causing wrinkles, non-permanent results may be achieved with its use. BoNT has gained widespread use in a variety of ophthalmic diseases. The effect of BoNT is temporary, but the therapeutic benefit is usually maintained even after repeated injections. Treatment is usually well tolerated. Complications and side effects associated with the treatment are rare and temporary. Complications occur due to weakness (chemodenervation) of adjacent muscle groups, immunological mechanisms and injection technique. Current therapeutic indications, doses, complications and contraindications of BoNT use in the following disorders related to ophthalmology were investigated: aesthetic use, strabismus, blepharospasm, hemifacial spasm, eyelid retraction, entropion, lacrimal hypersecretion syndrome, and facial paralysis.

Practice guideline update summary: Botulinum neurotoxin for the treatment of blepharospasm, cervical dystonia, adult spasticity, and headache: Report of the Guideline Development Subcommittee of the American Academy of Neurology

OBJECTIVE

To update the 2008 American Academy of Neurology (AAN) guidelines regarding botulinum neurotoxin for blepharospasm, cervical dystonia (CD), headache, and adult spasticity.

METHODS

We searched the literature for relevant articles and classified them using 2004 AAN criteria.

RESULTS AND RECOMMENDATIONS

Blepharospasm: OnabotulinumtoxinA (onaBoNT-A) and incobotulinumtoxinA (incoBoNT-A) are probably effective and should be considered (Level B). AbobotulinumtoxinA (aboBoNT-A) is possibly effective and may be considered (Level C). CD: AboBoNT-A and rimabotulinumtoxinB (rimaBoNT-B) are established as effective and should be offered (Level A), and onaBoNT-A and incoBoNT-A are probably effective and should be considered (Level B). Adult spasticity: AboBoNT-A, incoBoNT-A, and onaBoNT-A are established as effective and should be offered (Level A), and rimaBoNT-B is probably effective and should be considered (Level B), for upper limb spasticity. AboBoNT-A and onaBoNT-A are established as effective and should be offered (Level A) for lower-limb spasticity. Headache: OnaBoNT-A is established as effective and should be offered to increase headache-free days (Level A) and is probably effective and should be considered to improve health-related quality of life (Level B) in chronic migraine. OnaBoNT-A is established as ineffective and should not be offered for episodic migraine (Level A) and is probably ineffective for chronic tension-type headaches (Level B).

Considerations on patient-related outcomes with the use of botulinum toxins: is switching products safe?

Introduction

Botulinum toxin (BoNT) is the treatment of choice for many neurologic movement disorders, including blepharospasm, hemifacial spasm, and cervical dystonia. There are two serotypes approved for use by the US Food and Drug Administration: three brands of serotype A and one of serotype B. Many attempts have been made at establishing dose conversion ratios between brands and serotypes. This review focuses on the existing data comparing different formulations of the same BoNT serotypes as well as that comparing different serotypes with one another. We focus on existing data regarding switching from one formulation or serotype to another and will also discuss the issue of immunogenicity of BoNT. With this information as a foundation, recommendations on safety of switching agents are addressed.

Method

Literature review searching PubMed and Google Scholar using the search terms “switching botox”, “dosing equivalency in botox”, and “comparing botox”.

Results/conclusion

Overall, there are many studies that demonstrate the efficacy and safety of each of the brands of BoNTs used in clinical practice. However, determination of dosing equivalencies among these brands and serotypes is complex with inconsistencies among the studies. When switching from one brand to another, the clinician should be aware of these issues, and not make the assumption that such ratios exist. Tailoring the dosage of each brand of BoNT to the clinical situation is the most prudent treatment strategy rather than focusing closely on conversion factors and concerns for immunogenicity.

Systematic Literature Review of AbobotulinumtoxinA in Clinical Trials for Blepharospasm and Hemifacial Spasm

Background

The aim was to elucidate clinical trial efficacy, safety, and dosing practices of abobotulinumtoxinA (ABO) treatment in adult patients with blepharospasm and hemifacial spasm. To date, most literature reviews for blepharospasm and hemifacial spasm have examined the effectiveness of all botulinum neurotoxin type A products as a class. However, differences in dosing units and recommended schemes provide a clear rationale for reviewing each product separately.

Methods

A systematic literature review was performed to identify randomized controlled trials and other comparative clinical studies of ABO in the treatment of blepharospasm and hemifacial spasm published in English between January 1991 and March 2015. Medical literature databases (PubMed, Cochrane library, EMBASE) were searched. A total of five primary publications that evaluated ABO for the management of blepharospasm and hemifacial spasm were identified and summarized.

Results

Data included 374 subjects with blepharospasm and 172 subjects with hemifacial spasm treated with ABO. Total ABO doses ranged between 80 and 340 U for blepharospasm and 25 and 85 U for hemifacial spasm, depending on the severity of the clinical condition. All studies showed statistically significant benefits for the treatment of blepharospasm and hemifacial spasm. ABO was generally well tolerated across the individual studies. Adverse events considered to be associated with ABO treatment included: ptosis, tearing, blurred vision, double vision, dry eyes, and facial weakness.

Discussion

These data from 5 randomized clinical studies represents the available evidence base of ABO in blepharospasm and hemifacial spasm. Future studies in this area will add to this evidence base.

Clinical differences between botulinum neurotoxin type A and B

In humans, the therapeutic use of botulinum neurotoxin A (BoNT/A) is well recognized and continuously expanding. Four BoNTs are widely available for clinical practice: three are serotype A and one is serotype B: onabotulinumtoxinA (A/Ona), abobotulinumtoxinA (A/Abo) and incobotulinumtoxinA (A/Inco), rimabotulinumtoxinB (B/Rima). A/Abo, A/Inco, A/Ona and B/Rima are all licensed worldwide for cervical dystonia. In addition, the three BoNT/A products are approved for blepharospasm and focal dystonias, spasticity, hemifacial spasm, hyperhidrosis and facial lines, with remarkable regional differences. These toxin brands differ for specific activity, packaging, constituents, excipient, and storage. Comparative literature assessing the relative safety and efficacy of different BoNT products is limited, most data come from reports on small samples, and only a few studies meet criteria of evidence-based medicine. One study compared the effects of BoNT/A and BoNT/B on muscle activity of healthy volunteers, showing similar neurophysiological effects with a dose ratio of 1:100. In cervical dystonia, when comparing the effects of BoNT/A and BoNT/B, results are more variable, some studies reporting roughly similar peak effect and overall duration (at a ratio of 1:66, others reporting substantially shorter duration of BoNT/B than BoNT/A (at a ratio 1/24). Although the results of clinical studies are difficult to compare for methodological differences (dose ratio, study design, outcome measures), it is widely accepted that: BoNT/B is clinically effective using appropriate doses as BoNT/A (1:40-50), injections are generally more painful, in most of the studies on muscular conditions, efficacy is shorter, and immunogenicity higher. Since the earliest clinical trials, it has been reported that autonomic side effects are more frequent after BoNT/B injections, and this observation encouraged the use of BoNT/B for sialorrhea, hyperhidrosis and other non-motor symptoms. In these indications the efficacy of toxins A and B are comparable and dose ratio is 1:25-30.

Botulinum toxin in the management of blepharospasm: current evidence and recent developments

Blepharospasm is a focal (although usually bilateral) dystonia of the orbicularis oculi muscles, producing excessive eye closure. This produces significant disability through functional blindness. Botulinum neurotoxins (BoNT) have become the treatment of choice for blepharospasm; the impressive response rate and the tolerable safety profile have been proven through multiple clinical studies. There are currently four BoNT approved in the United States for different indications - we review the data on blepharospasm for each of these drugs. Currently, incobotulinumtoxinA and onabotulinumtoxinA have the most evidence of benefit for patients with blepharospasm. Current evidence, recent development and future directions are discussed.

Influence of injection of Chinese botulinum toxin type A on the histomorphology and myosin heavy chain composition of rat gastrocnemius muscles

BACKGROUND AND OBJECTIVE

Botulinum toxin type A (BoNT/A) is a metalloprotease that blocks synaptic transmission via the cleavage of a synaptosomal-associated protein of 25 kDa (SNAP-25). It has gained widespread use as a treatment for cerebral palsy and skeletal muscle hypertrophy. In China, Chinese botulinum toxin type A (CBTX-A), a type of BoNT/A, is in widespread clinical use. However, the changes in the morphological and biochemical properties of treated muscles and in remote muscles from the CBTX-A injection site are relatively unknown. Therefore, we investigated the changes in histomorphology and myosin heavy chain (MyHC) isoform composition and distribution in rat gastrocnemius muscles after intramuscular injection of CBTX-A.

METHODS

The weakness of the injected muscles was assessed periodically to identify their functional deficiency. Muscle slices were stained with hematoxylin-eosin (HE) and adenosine triphosphatase (ATPase). MyHC isoform composition was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to uncover changes in morphological and biochemical properties.

RESULTS

Our findings demonstrate that following injection of CBTX-A 5 U into rat gastrocnemius muscles, shifts in MyHC isoform composition emerged on the third day after injection and peaked in the fourth week. The composition remained distinctly different from that of the control group after the twelfth week. More specifically, there was a decrease in the proportion of the type IIb isoform and an increase in the proportions of type IIx, type IIa, and type I isoforms.

CONCLUSIONS

Data revealed that CBTX-A led to a shift in MyHC composition towards slower isoforms and that the MyHC composition remained far from normal six months after a single injection. However, no noticeable remote muscle weakness was induced.

Long-term efficacy, safety, and side effect profile of botulinum toxin in dystonia: a 20-year follow-up

Most long-term studies of the efficacy and safety profile of botulinum toxin (BoNT) in the treatment of dystonia are limited by lack of objective assessments, relatively small sample size, or short follow-up periods. We present one of the longest follow-up studies of BoNT treatment. This is a retrospective, longitudinal study that analyzes data on 89 patients treated with BoNT for dystonia at our Movement Disorders Clinic for up to 26 years (mean follow-up period of 18.5 years). The mean ages at the time of the first and last injections were 49 and 68 years old, respectively. The most common diagnoses were cervical dystonia (N = 51), blepharospasm (N = 34), and oromandibular dystonia (N = 26). The total number of onabotulinumtoxinA units received during the first injection was 140.3 as compared to 224.5 at the last injection (p < 0.0001). The global response effect was 3.18 after the first injection session and 3.57 after the last injection (p < 0.0001). The duration of response after the initial injection session and at the last injection was 16.33 weeks versus 19.42 weeks (p 0.0037), respectively. Adverse events, typically related to injection site, were reported in 19% of the visits. This series of dystonia patients with the longest reported treatment with BoNT provide evidence that in selected patients repeated chemodenervation is associated with sustained symptomatic benefit, decreased latency effect, and prolonged duration of therapeutic response. Despite the higher requirement of mean units per visit over time, only 19% of all treatment cycles are associated with adverse, but tolerable, side effects.

Blepharospasm: long-term treatment with either Botox®, Xeomin® or Dysport®

Botulinum toxin (BT) therapy is the treatment of choice for blepharospasm (BPS). Currently available BT type A drugs include Botox(®), Dysport(®) and Xeomin(®). Until now, there are few long-term studies on BT therapy for BPS. This is the first long-term study comparing all three major BT drugs. We collected treatment, efficacy and adverse effect data on BPS patients treated with either Botox(®), Dysport(®) or Xeomin(®) for at least eight consecutive treatments. Two hundred and eighty-eight patients (208 females, 80 males, age 62 ± 12 years) were included in this study. The treatment time was 11.2 ± 4.1 years covering 10,701 injection series. Doses were 47 ± 10 MU for Botox(®), 120 ± 35 MU for Dysport(®) and 62 ± 11 MU for Xeomin(®) (Botox(®) dose vs Xeomin(®) dose: p < 0.001, unpaired t test). 85 % of all patients had stable doses. The onset of the therapeutic effect was after 6.1 ± 3.3 days and its duration lasted 10.2 ± 3.5 weeks. The Global Clinical Improvement (GCI, 0 = no, 1 = slight, 2 = moderate, 3 = marked improvement in severity and function) as estimated by the patient was 2.5 ± 0.6. It was stable in 90% of the patients. Adverse effect frequency was 3.0% (ptosis 2.3%, dry eye 0.5%, diplopia 0.2%). None of these findings was significantly different between Botox(®), Dysport(®) and Xeomin(®). Our study, one of the largest studies on BT therapy of BPS and the study with the longest follow-up, confirms that BT therapy produces robust clinical improvement which is stable throughout the treatment time. Therapeutic effects start after 6.1 days and last for about 10 weeks before they start to vanish. With this, they are approximately 2 weeks shorter than the recommended inter-injection interval. Adverse effects were rare, mild and always transient. BT therapy is a safe and effective treatment for BSP. Shorter inter-injection intervals may improve therapeutic results.

Dystonia

PURPOSE OF REVIEW

The purpose of this review is to provide an update on the classification, phenomenology, pathophysiology, and treatment of dystonia.

RECENT FINDINGS

A revised definition based on the main phenomenologic features of dystonia has recently been developed in an expert consensus approach. Classification is based on two main axes: clinical features and etiology. Currently, genes have been reported for 14 types of monogenic isolated and combined dystonia. Isolated dystonia (with dystonic tremor) can be caused by mutations in TOR1A (DYT1), TUBB4 (DYT4), THAP1 (DYT6), PRKRA (DYT16), CIZ1 (DYT23), ANO3 (DYT24), and GNAL (DYT25). Combined dystonias (with parkinsonism or myoclonus) are further subdivided into persistent (GCHI [DYT5], SGCE [DYT11], and ATP1A3 [DYT12], with TAF1 most likely but not yet proven to be linked to DYT3) and paroxysmal (PNKD [DYT8], PRRT2 [DYT10], and SLC2A1 [DYT18]). Recent insights from neurophysiologic studies identified functional abnormalities in two networks in dystonia: the basal ganglia-sensorimotor network and, more recently, the cerebellothalamocortical pathway. Besides the well-known lack of inhibition at different CNS levels, dystonia is specifically characterized by maladaptive plasticity in the sensorimotor cortex and loss of cortical surround inhibition. The exact role (modulatory or compensatory) of the cerebellar-cortical pathways still has to be further elucidated. In addition to botulinum toxin for focal forms, deep brain stimulation of the globus pallidus internus is increasingly recognized as an effective treatment for generalized and segmental dystonia.

SUMMARY

The revised classification and identification of new genes for different forms of dystonia, including adult-onset segmental dystonia, enable an improved diagnostic approach. Recent pathophysiologic insights have fundamentally contributed to a better understanding of the disease mechanisms and impact on treatment, such as functional neurosurgery and nonpharmacologic treatment options.

Conservative treatment of neuromuscular scoliosis in adult tetraplegia: a case report

We report successful correction of new onset neuromuscular scoliosis without spinal surgery in a man who is 30-years post-American Spinal Injury Association Impairment Scale grade A C6 injury with new onset of left neuromuscular scoliosis (Cobb angle 45°) after a motor vehicle collision. Interventions included nightly low-load prolonged stretching (LLPS) (4h left side lying over bolster), a series of 6 botulinum toxin injections (BTIs) at 3-month intervals, and progressive seating adjustments to counteract the spinal curvature. Monthly seating adjustments included rear quadrant wedging, lateral supports, and hip blocking to promote erect and symmetrical posture. A normative Cobb angle (5°) was achieved after 8 months of treatment. Improvements in alignment were demonstrated in physical examination outcome measures at the final session and follow-up. LLPS, seating adjustments, and paraspinal BTI are nonsurgical options for treating neuromuscular scoliosis in adults with tetraplegia. Further studies are necessary to determine optimum protocols and examine generalizability of these treatment methods.

Long-term efficacy and safety of botulinum toxin A injections to treat blepharospasm and hemifacial spasm

BACKGROUND

To evaluate efficacy and safety of botulinum toxin A injections after more than 10 consecutive years of treatment for benign essential blepharospasm and hemifacial spasm.

DESIGN

Retrospective chart review at university-affiliated hospital.

PARTICIPANTS

Study consisted of 64 patients treated with botulinum toxin A injections between October 2005 and May 2006.

METHODS

Inclusion criteria included patients treated with at least one annual botulinum toxin-A injection for more than 10 consecutive years. Data collected included diagnoses and patient characteristics, injection dates, doses administered at each visit, response scores, duration of effect, and adverse events.

MAIN OUTCOME MEASURES

Included changes in doses, response scores, duration of effects, and adverse events between the first and last botulinum toxin A injections.

RESULTS

Thirty-two of 64 patients (mean age at first injection, 57.2 ± 12.4 years; 25 women) met the inclusion criteria. The mean duration of follow up was 14.1 ± 3.1 years (range 10-20 years; mean total visits 44.4 ± 19). A higher mean injection dose per visit was administered during the last year compared with the first year (26.8 ± 10.3 vs. 22.5 ± 7.5 units, respectively) (P = 0.003). The mean durations of effect during the first and last years were 12.4 ± 7.1 and 14.6 ± 7.0 weeks, respectively (P = 0.076). There were no significant differences between genders or between benign essential blepharospasm and hemifacial spasm subgroups. The most common adverse events were ptosis, lagophthalmos and dry eye.

CONCLUSIONS

Botulinum toxin A is an effective, safe, long-term treatment for patients with benign essential blepharospasm and hemifacial spasm. Sustained treatment efficacy required higher doses; however, fewer adverse reactions developed.

Diffusion, spread, and migration of botulinum toxin

Botulinum toxin (BoNT) is an acetylcholine release inhibitor and a neuromuscular blocking agent used for the treatment of a variety of neurologic and medical conditions. The efficacy and safety of BoNT depends on accurate selection and identification of intended targets but also may be determined by other factors, including physical spread of the molecule from the injection site, passive diffusion, and migration to distal sites via axonal or hematogenous transport. The passive kinetic dispersion of the toxin away from the injection site in a gradient-dependent manner may also play a role in toxin spread. In addition to unique properties of the various BoNT products, volume and dilution may also influence local and systemic distribution of BoNT. Most of the local and remote complications of BoNT injections are thought to be due to unwanted spread or diffusion of the toxin's biologic activity into adjacent and distal muscles. Despite widespread therapeutic and cosmetic use of BoNT over more than three decades, there is a remarkable paucity of published data on the mechanisms of distribution and its effects on clinical outcomes. The primary aim of this article is to critically review the available experimental and clinical literature and place it in the practical context.

Long-term efficacy and safety of botulinum toxin injections in dystonia

Local chemodenervation with botulinum toxin (BoNT) injections to relax abnormally contracting muscles has been shown to be an effective and well-tolerated treatment in a variety of movement disorders and other neurological and non-neurological disorders. Despite almost 30 years of therapeutic use, there are only few studies of patients treated with BoNT injections over long period of time. These published data clearly support the conclusion that BoNT not only provides safe and effective symptomatic relief of dystonia but also long-term benefit and possibly even favorably modifying the natural history of this disease. The adverse events associated with chronic, periodic exposure to BoNT injections are generally minor and self-limiting. With the chronic use of BoNT and an expanding list of therapeutic indications, there is a need to carefully examine the existing data on the long-term efficacy and safety of BoNT. In this review we will highlight some of the aspects of long-term effects of BoNT, including efficacy, safety, and immunogenicity.

Botulinum toxins in the treatment of primary focal dystonias

Focal dystonia, such as cervical dystonia, blepharospasm, oromandibular dystonia, laryngeal dystonia, and limb dystonia, is often observed in adult-onset primary dystonia syndromes that affect a specific area of the body and tend to have little or no spread. This review will examine the past, present, and future approaches to the treatment of focal dystonia. Botulinum toxin (BoNT) has emerged as the treatment of choice for the majority of focal dystonias. Currently four products are widely available commercially, three of BoNT/A type and one of BoNT/B type. Each has important pharmacological differences that give rise to markedly different dosing recommendations. The four approved BoNTs are safe and effective for treating focal dystonias, including long-term treatment. Adverse events are limited and transient and, for the most part, mild in severity. Potential problems with the use of BoNT agents are diffusion and neutralizing antibody formation; the latter can lead to treatment resistance. Because each BoNT product is developed from distinct purification and manufacturing procedures and has varying toxin complex size and structures, physicians need to be aware of these differences when choosing an agent.

EFNS guidelines on diagnosis and treatment of primary dystonias

OBJECTIVES

to provide a revised version of earlier guidelines published in 2006.

BACKGROUND

primary dystonias are chronic and often disabling conditions with a widespread spectrum mainly in young people.

DIAGNOSIS

primary dystonias are classified as pure dystonia, dystonia plus or paroxysmal dystonia syndromes. Assessment should be performed using a validated rating scale for dystonia. Genetic testing may be performed after establishing the clinical diagnosis. DYT1 testing is recommended for patients with primary dystonia with limb onset before age 30, and in those with an affected relative with early-onset dystonia. DYT6 testing is recommended in early-onset or familial cases with cranio-cervical dystonia or after exclusion of DYT1. Individuals with early-onset myoclonus should be tested for mutations in the DYT11 gene. If direct sequencing of the DYT11 gene is negative, additional gene dosage is required to improve the proportion of mutations detected. A levodopa trial is warranted in every patient with early-onset primary dystonia without an alternative diagnosis. In patients with idiopathic dystonia, neurophysiological tests can help with describing the pathophysiological mechanisms underlying the disorder.

TREATMENT

botulinum toxin (BoNT) type A is the first-line treatment for primary cranial (excluding oromandibular) or cervical dystonia; it is also effective on writing dystonia. BoNT/B is not inferior to BoNT/A in cervical dystonia. Pallidal deep brain stimulation (DBS) is considered a good option, particularly for primary generalized or cervical dystonia, after medication or BoNT have failed. DBS is less effective in secondary dystonia. This treatment requires a specialized expertise and a multidisciplinary team.

Efficacy and safety of incobotulinumtoxinA (NT 201, Xeomin) in the treatment of blepharospasm-a randomized trial

IncobotulinumtoxinA (NT 201, Xeomin) is a highly purified botulinum neurotoxin type A formulation, free from complexing proteins. A randomized, placebo-controlled, double-blind trial of efficacy and safety compared incobotulinumtoxinA (up to 50 U per eye) to placebo administered in a single treatment session to patients with blepharospasm. All patients had documented satisfactory response to 2 previous treatments with botulinum neurotoxin type A other than incobotulinumtoxinA and had Jankovic Rating Scale severity subscores ≥ 2. Patients (n = 109) were randomized in a 2:1 ratio to incobotulinumtoxinA or placebo and followed up to 20 weeks; 94% completed the study. A significant difference was observed in the primary efficacy variable (change in Jankovic Rating Scale severity subscore rated by an independent rater 6 weeks following treatment), favoring incobotulinumtoxinA by 1.0 point (95% CI [0.5-1.4]; P < .001). Functional impairment, as measured by the Blepharospasm Disability Index, improved by 0.5 points (95% CI [0.2-0.7]; P = .002) compared with placebo. There was a strong correlation between the 2 scale scores. In addition, all secondary outcome measures favored incobotulinumtoxinA. Patients rated the mean therapeutic effect of incobotulinumtoxinA significantly better than placebo (P < .001). Adverse events were reported in 70.3% of incobotulinumtoxinA patients and 58.8% of placebo patients. Eyelid ptosis (18.9% vs 5.9%), dry eye (18.9% vs 11.8%), and dry mouth (14.9% vs 2.9%) occurred most frequently. Tolerability was rated good/very good by 91.9% of incobotulinumtoxinA versus in 85.2% of placebo patients. In conclusion, incobotulinumtoxinA was well tolerated and was associated with statistically significant and clinically relevant reductions in blepharospasm severity and functional impairment.

Randomized trial of botulinum toxin to prevent pes cavus progression in pediatric Charcot-Marie-Tooth disease type 1A

Pes cavus in Charcot-Marie-Tooth disease type 1A (CMT1A) is thought to be due to muscle imbalance of the lower leg. Botulinum toxin type A (BoNT-A) can modify foot deformity in other conditions of muscle imbalance. We tested the safety and effectiveness of BoNT-A on pes cavus progression in pediatric CMT1A. A 24-month, randomized, single-blind trial of BoNT-A was undertaken in 10 affected children (20 legs), aged 3-14 years. The treated leg received intramuscular BoNT-A injections at 6-month intervals in the tibialis posterior and peroneus longus. The control leg received no injections. Primary outcome was radiographic alignment at 24 months. Secondary outcomes were foot posture, ankle flexibility, and strength, assessed every 6 months. Radiographically, BoNT-A produced a small non-significant reduction in cavus progression. There was no effect of BoNT-A on secondary outcomes. There were no serious adverse events. At 24 months, the intramuscular BoNT-A injections proved safe and well-tolerated but did not affect the progression of pes cavus in CMT1A.