Botulinum toxin type A therapy for blepharospasm

Adverse Events Associated With Botox as Reported in a Food and Drug Administration Database

BACKGROUND

Botulinum toxin treatment is the most frequently performed noninvasive cosmetic procedure performed in the USA. Because of its widespread use, an analysis of the adverse event (AE) profile of Botox injections is needed.

METHODS

The FDA Adverse Event Report System was queried using an online web-based tool to determine the top 15 adverse events reported for four Botox brand names: Botox/Botox Cosmetic, Dysport, and Xeomin. The proportional reporting ratios (PRR) and relative odds ratios (ROR) were determined. A literature review was performed for eight AEs of clinical significance: eyelid/eyebrow ptosis, asthenia, muscular weakness, facial paresis, dysphagia, botulism, and death.

RESULTS

Botox/Botox Cosmetic had 38367 AEs. Dysport had 3582 AEs. Xeomin had 1405 AEs. All drugs with reported cases of eyelid and eyebrow ptosis had significant PRR and ROR values. The PRR and ROR values for asthenia were not significant in any of the drugs and only reached significance for Dysport for muscular weakness and dysphagia. Both Botox/Botox Cosmetic and Dysport had elevated PRRs and RORs for facial paresis and botulism. While all drugs had at least one reported case of death related to Botox injection use, none of the PRR or ROR values were significant.

CONCLUSION

Known AEs for Botox injection use include eyelid/brow ptosis and muscular weakness. Feared but rare complications of Botox injection use include dysphagia, botulism, and possibly death, owing to systemic spread of the toxin. This is the first study to analyze the AE data reported to the FDA on Botox injection use.

EBM LEVEL

III.

Impact of Upper Eyelid Surgery on Symptom Severity and Frequency in Benign Essential Blepharospasm

Objective

To assess the impact of periocular surgery, other than orbicularis stripping, on the severity and frequency of blepharospasm symptoms.

Methods

Consecutive patients with benign essential blepharospasm (BEB) who underwent eyelid/eyebrow surgery with the aim of improving symptoms were retrospectively reviewed over a 5-year period. Patients who had completed the Jankovic Rating Scale (JRS) and Blepharospasm Disability Index (BDI) pre- and at least 3 months postoperatively were included.

Results

Twenty-four patients were included. JRS scores significantly improved from 7.0 preoperatively to 4.1 postoperatively (p < 0.001), and BDI scores significantly improved from 18.4 preoperatively to 12.7 postoperatively (p < 0.001); the mean percentage improvements were 41% and 30%, respectively. Patients were followed for a median of 24 months postoperatively.

Conclusion

Periocular surgery significantly reduced BEB symptoms in the majority (83%) of patients by an average of 33% and may therefore be offered for suitable patients. An important minority (17%) of patients experienced symptom worsening.

Botulinum Toxin in Movement Disorders: An Update

Since its initial approval in 1989 by the US Food and Drug Administration for the treatment of blepharospasm and other facial spasms, botulinum toxin (BoNT) has evolved into a therapeutic modality for a variety of neurological and non-neurological disorders. With respect to neurologic movement disorders, BoNT has been reported to be effective for the treatment of dystonia, bruxism, tremors, tics, myoclonus, restless legs syndrome, tardive dyskinesia, and a variety of symptoms associated with Parkinson’s disease. More recently, research with BoNT has expanded beyond its use as a powerful muscle relaxant and a peripherally active drug to its potential central nervous system applications in the treatment of neurodegenerative disorders. Although BoNT is the most potent biologic toxin, when it is administered by knowledgeable and experienced clinicians, it is one of the safest therapeutic agents in clinical use. The primary aim of this article is to provide an update on recent advances in BoNT research with a focus on novel applications in the treatment of movement disorders. This comprehensive review of the literature provides a critical review of evidence-based clinical trials and highlights recent innovative pilot studies.

Long-term adherence and response to botulinum toxin in different indications

Objective

The objective of the study was the analysis of adherence and self‐perceived treatment response to long‐term botulinum neurotoxin type A (BoNT‐A) treatment in different neurological indications.

Methods

In this retrospective, monocentric, observational study, cross‐sectional and longitudinal data of 1351 patients documenting 20705 injection appointments at the BoNT outpatient clinic of Heinrich Heine University Duesseldorf between 1989 and 2014 were retrospectively analyzed. Patients had been treated with BoNT for neurological conditions, including cervical dystonia (CD), blepharospasm (BSP), other dystonia (ODT), hemifacial spasm (HFS), and spasticity (SPAS). The parameters longitudinally analyzed for the entire cohort were therapy duration as well as the mean and cumulative BoNT‐A dose. Cross‐sectionally, for subgroups of at least 721, patients’ global self‐perceived quality of health and life, global self‐perceived reduction of symptoms by BoNT‐A treatment as well as the clinical global impression were evaluated. Furthermore, mouse hemidiaphragm assay antibodies (MHDA‐ABs) were analyzed in a subgroup.

Results

The mean treatment duration was 4.58 years (95% CI 4.32–4.84), and 678 (50.2%) therapy dropouts of 1351 patients occurred within the first 8 years. Therapy adherence and self‐perceived symptom reduction in long‐term BoNT‐A treatment over the years were significantly longer in BSP, HFS, and CD patients than in ODT and SPAS patients.

Interpretation

The treatment indication determines long‐term adherence and self‐perceived symptom reduction in BoNT‐A therapy, which are better in BSP, HFS, and CD patients than in ODT and SPAS patients. MHDA‐ABs had a significant impact on global self‐perceived symptom reduction, but with only a limited degree.

Botulinum toxin type A therapy for blepharospasm

BACKGROUND

This is an update of a Cochrane Review first published in 2005. Blepharospasm is the second most common form of focal dystonia. It is a disabling disorder, characterised by chronic, intermittent or persistent, involuntary eyelid closure, due to spasmodic contractions of the orbicularis oculi muscles. Currently, botulinum toxin type A (BtA) is considered the first line of therapy for this condition.

OBJECTIVES

To compare the efficacy, safety, and tolerability of BtA versus placebo in people with blepharospasm.

SEARCH METHODS

We searched Cochrane Movement Disorders' Trials Register, CENTRAL, MEDLINE, Embase, reference lists of included articles, and conference proceedings. We ran all elements of the search, with no language restrictions, in July 2020.

SELECTION CRITERIA

Double-blind, parallel, randomised, placebo-controlled trials (RCTs) of BtA versus placebo in adults with blepharospasm.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed records, selected included studies, extracted data using a paper pro forma, and evaluated the risk of bias. We resolved disagreements by consensus, or by consulting a third review author. We performed meta-analyses using a random-effects model, for the comparison of BtA versus placebo, to estimate pooled effects and corresponding 95% confidence intervals (95% CI). We did not carry out any prespecified subgroup analyses. The primary efficacy outcome was improvement on any validated symptomatic rating scale. The primary safety outcome was the proportion of participants with any adverse event.

MAIN RESULTS

We included three RCTs, assessed at low to moderate overall risk of bias, which randomised 313 participants with blepharospasm. Two studies excluded participants with poorer prior responses to BtA treatment, therefore, they included an enriched population with a higher probability of benefiting from this therapy. All trials were industry-funded. All RCTs evaluated the effect of a single BtA treatment session. BtA resulted in a moderate to large improvement in blepharospasm-specific severity, with a reduction of 0.93 points on the Jankovic Rating Scale (JRS) severity subscale at four to six weeks after injection (95% confidence interval (CI) 0.61 to 1.25; I² = 9%) compared to placebo. BtA was also resulted in a moderate to large improvement in blepharospasm-specific disability and blepharospasm-specific involuntary movements at four to six weeks after injection (disability: 0.69 JRS disability subscale points, 95% CI 0.18 to 1.19; I² = 74%; blepharospasm-specific involuntary movements: standardised mean difference (SMD) 0.79, 0.31 to 1.27; I² = 58%) compared to placebo. BtA did not show a risk of adverse events (risk ratio (RR) 1.18, 95% CI 0.87 to 1.60; I² = 0%). However, BtA increased the risk of vision complaints and eyelid ptosis (vision complaints: RR 5.73, 95% CI 1.79 to 18.36; I² = 51%; eyelid ptosis: RR 4.02, 95% CI 1.61 to 10.00; I² = 39%). There was no distinction between BtA and placebo in the number of participants who dropped out of the trial. A single trial estimated the duration of effects to be 10.6 weeks (range 6.1 to 19.1). We found no evidence supporting the existence of a clear dose-response relationship with BtA. We found no data reporting the impact of BtA on health-related quality of life, or the development of secondary non-responsiveness.

AUTHORS' CONCLUSIONS

We are moderately certain that a single BtA treatment resulted in a clinically relevant reduction of blepharospasm-specific severity and disability, and have low certainty that it is well tolerated, when compared with placebo. There is low-certainty evidence that people treated with BtA are not at an increased risk of developing adverse events, though BtA treatment likely increases the risk of visual complaints and eyelid ptosis. There are no data from RCTs evaluating the effectiveness and safety of repeated BtA injection cycles. There is no evidence from RCTs to allow us to draw definitive conclusions on the optimal treatment intervals and doses, or the impact on quality of life.

IncobotulinumtoxinA for the Treatment of Blepharospasm in Toxin-Naïve Subjects: A Multi-Center, Double-Blind, Randomized, Placebo-Controlled Trial

This study aimed to assess the efficacy/safety of incobotulinumtoxinA (Xeomin^®, Merz Pharmaceuticals GmbH) in botulinum neurotoxin-naïve subjects with blepharospasm. Botulinum neurotoxin-naïve subjects (≥ 12 months without botulinum neurotoxin treatment for blepharospasm) received single-dose incobotulinumtoxinA 50 U, 25 U, or placebo. Subjects were followed for 6-20 weeks (main period). Qualified subjects entered an open-label extension period and received another incobotulinumtoxinA injection (≤ 70 U). The primary efficacy variable was change from baseline in the Jankovic Rating Scale (JRS) severity subscore at the main period of week 6. Other efficacy variables included changes in the Blepharospasm Disability Index score and JRS frequency subscore and sumscore. Adverse events were monitored. Sixty-one subjects were randomized (main period: incobotulinumtoxinA 50 U, n = 19; incobotulinumtoxinA 25 U, n = 22; placebo, n = 20); 39 entered the open-label extension period (9, 14, and 16 subjects from the incobotulinumtoxinA 50 U, incobotulinumtoxinA 25 U, and placebo groups [main period], respectively, changed to open-label extension period dosing). A statistically significantly greater reduction in JRS severity subscore was reported for subjects receiving incobotulinumtoxinA 50 U versus placebo (ANCOVA, least square mean difference: - 1.2, p = 0.0004). Subjects receiving incobotulinumtoxinA experienced improvements in other efficacy variables versus baseline and/or placebo. Sustained clinical improvements and low adverse event rates (22.2-42.1%) were observed. This is the second placebo-controlled, double-blind study that demonstrates favorable efficacy/safety of incobotulinumtoxinA in subjects with blepharospasm. IncobotulinumtoxinA is the first botulinum neurotoxin that could fulfill the American Academy of Neurology criteria for a Level A recommendation for blepharospasm.Trial registration ClinicalTrials.gov identifier, NCT01896895.

Four-Repeat Tauopathies: Current Management and Future Treatments

Four-repeat tauopathies are a neurodegenerative disease characterized by brain parenchymal accumulation of a specific isoform of the protein tau, which gives rise to a wide breadth of clinical syndromes encompassing diverse symptomatology, with the most common syndromes being progressive supranuclear palsy-Richardson's and corticobasal syndrome. Despite the lack of effective disease-modifying therapies, targeted treatment of symptoms can improve quality of life for patients with 4-repeat tauopathies. However, managing these symptoms can be a daunting task, even for those familiar with the diseases, as they span motor, sensory, cognitive, affective, autonomic, and behavioral domains. This review describes current approaches to symptomatic management of common clinical symptoms in 4-repeat tauopathies with a focus on practical patient management, including pharmacologic and nonpharmacologic strategies, and concludes with a discussion of the history and future of disease-modifying therapeutics and clinical trials in this population.

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.

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.

Deep brain stimulation for dystonia

BACKGROUND

Dystonia is a painful and disabling disorder, characterised by painful, involuntary posturing of the affected body region(s). Deep brain stimulation is an intervention typically reserved for severe and drug-refractory cases, although uncertainty exists regarding its efficacy, safety, and tolerability.

OBJECTIVES

To compare the efficacy, safety, and tolerability of deep brain stimulation (DBS) versus placebo, sham intervention, or best medical care, including botulinum toxin and resective or lesional surgery, in adults with dystonia.

SEARCH METHODS

We identified studies by searching the CENTRAL, MEDLINE, Embase, three other databases, four clinical trial registries, four grey literature databases, and reference lists of included articles. We ran the last search of all elements of the search strategy, with no language restrictions, on 29 May 2018.

SELECTION CRITERIA

Double-blind, parallel, randomised, controlled trials (RCTs) comparing DBS with sham stimulation, best medical care, or placebo in adults with dystonia.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed records, selected included studies, extracted data onto a standardised (or prespecified) data extraction form, and evaluated the risk of bias. We resolved disagreements by consensus or by consulting a third review author. We conducted meta-analyses using a random-effects model, to estimate pooled effects and corresponding 95% confidence intervals (95% CI). We assessed the quality of the evidence with GRADE methods. The primary efficacy outcome was symptom improvement on any validated symptomatic rating scale, and the primary safety outcome was adverse events.

MAIN RESULTS

We included two RCTs, enrolling a total of 102 participants. Both trials evaluated the effect of DBS on the internal globus pallidus nucleus, and assessed outcomes after three and six months of stimulation. One of the studies included participants with generalised and segmental dystonia; the other included participants with focal (cervical) dystonia. We assessed both studies at high risk for performance and for-profit bias. One study was retrospectively registered with a clinical trial register, we judged the second at high risk of detection bias.Low-quality evidence suggests that DBS of the internal globus pallidus nucleus may improve overall cervical dystonia-related symptoms (mean difference (MD) 9.8 units, 95% CI 3.52 to 16.08 units; 1 RCT, 59 participants), cervical dystonia-related functional capacity (MD 3.8 units, 95% CI 1.41 to 6.19; 1 RCT, 61 participants), and mood at three months (MD 3.1 units, 95% CI 0.73 to 5.47; 1 RCT, 61 participants).Low-quality evidence suggests that In people with cervical dystonia, DBS may slightly improve the overall clinical status (MD 2.3 units, 95% CI 1.15 to 3.45; 1 RCT, 61 participants). We are uncertain whether DBS improves quality of life in cervical dystonia (MD 3 units, 95% CI -7.71 to 13.71; 1 RCT, 57 participants; very low-quality evidence), or emotional state (MD 2.4 units, 95% CI -6.2 to 11.00; 1 RCT, 56 participants; very low-quality evidence).Low-quality evidence suggests that DBS of the internal globus pallidus nucleus may improve generalised or segmental dystonia-related symptoms (MD 14.4 units, 95% CI 8.0 to 20.8; 1 RCT, 40 participants), overall clinical status (MD 3.5 units, 95% CI 2.33 to 4.67; 1 RCT, 37 participants), physical functioning-related quality of life (MD 6.3 units, 95% CI 1.06 to 11.54; 1 RCT, 33 participants), and overall dystonia-related functional capacity at three months (MD 3.1 units, 95% CI 1.71 to 4.48; 1 RCT, 39 participants). We are uncertain whether DBS improves physical functioning-related quality of life (MD 5.0 units, 95% CI -2.14 to 12.14, 1 RCT, 33 participants; very low-quality evidence), or mental health-related quality of life (MD -4.6 units, 95% CI -11.26 to 2.06; 1 RCT, 30 participants; very low-quality evidence) in generalised or segmental dystonia.We pooled outcomes related to safety and tolerability, since both trials used the same intervention and comparison. We found very low-quality evidence of inconclusive results for risk of adverse events (relative risk (RR) 1.58, 95% 0.98 to 2.54; 2 RCTs, 102 participants), and tolerability (RR 1.86, 95% CI 0.16 to 21.57; 2 RCTs,102 participants).

AUTHORS' CONCLUSIONS

DBS of the internal globus pallidus nucleus may reduce symptom severity and improve functional capacity in adults with cervical, segmental or generalised moderate to severe dystonia (low-quality evidence), and may improve quality of life in adults with generalised or segmental dystonia (low-quality evidence). We are uncertain whether the procedure improves quality of life in cervical dystonia (very low-quality evidence). We are also uncertain about the safety and tolerability of the procedure in adults with either cervical and generalised, or segmental dystonia (very-low quality evidence).We could draw no conclusions for other populations with dystonia (i.e. children and adolescents, and adults with other types of dystonia), or for other DBS protocols (i.e. other target nuclei or stimulation paradigms). Further research is needed to establish the long-term efficacy and safety of DBS of the internal globus pallidus nucleus.

[Modern non-cosmetic treatment with botulinum toxins]

Botulinum toxin has been known in medical history for a long time. The first scientific investigations and thoughts on possible indications in the treatment of muscular disorders were published by the German physician and poet Justinus Kerner in 1822. The physiological effect of botulinum toxin was identified in the middle of the twentieth century and the first clinical use was reported in 1977. It was first used in ophthalmology for the correction of strabismus and some years later the therapy of blepharospasm and cervical dystonia was established. Further indications, all supported by randomized controlled studies, are spastic tone increase of the limbs after lesions of the central nervous system, idiopathic axillar hyperhidrosis, chronic migraine and neurogenic or idiopathic bladder hyperactivity. In addition to these indications, a large number of further possible options have been published in the literature. Beside its effect on transmission at the neuromuscular synapses, botulinum toxin has also been shown to affect the sensory transmission of nociceptive fibers.

The therapeutic usage of botulinum toxin (Botox) in non-cosmetic head and neck conditions - An evidence based review

Botulinum toxin (Botox) is an exotoxin produced from Clostridium botulinum. It blocks the release of acetylcholine from the cholinergic nerve end plates resulting in inactivity of the muscles or glands innervated. The efficacy of Botox in facial aesthetics is well established; however, recent literature has highlighted its utilization in multiple non-cosmetic medical and surgical conditions. The present article reviews the current evidence pertaining to Botox use in the non-cosmetic head and neck conditions. A literature search was conducted using MEDLINE, EMBASE, ISI Web of Science and the Cochrane databases limited to English Language articles published from January 1980 to December 2014. The findings showed that there is level 1 evidence supporting the efficacy of Botox in the treatment of laryngeal dystonia, headache, cervical dystonia, masticatory myalgia, sialorrhoea, temporomandibular joint disorders, bruxism, blepharospasm, hemifacial spasm and rhinitis. For chronic neck pain there is level 1 evidence to show that Botox is ineffective. Level 2 evidence exists for vocal tics and trigeminal. For stuttering, facial nerve paresis, Frey's syndrome and oromandibular dystonia the evidence is level 4. Thus, there is compelling evidence in the published literature to demonstrate the beneficial role of Botox in a wide range of non-cosmetic conditions pertaining to the head and neck (mainly level 1 evidence). With more and more research, the range of clinical applications and number of individuals getting Botox will doubtlessly increase. Botox appears to justify its title as 'the poison that heals'.

An evidence-based review of botulinum toxin (Botox) applications in non-cosmetic head and neck conditions

Botulinum toxin (Botox) is an exotoxin produced from Clostridium botulinum. It works by blocking the release of acetylcholine from the cholinergic nerve end plates leading to inactivity of the muscles or glands innervated. Botox is best known for its beneficial role in facial aesthetics but recent literature has highlighted its usage in multiple non-cosmetic medical and surgical conditions. This article reviews the current evidence pertaining to Botox use in the head and neck. A literature review was conducted using The Cochrane Controlled Trials Register, Medline and EMBASE databases limited to English Language articles published from 1980 to 2012. The findings suggest that there is level 1 evidence supporting the efficacy of Botox in the treatment of spasmodic dysphonia, essential voice tremor, headache, cervical dystonia, masticatory myalgia, sialorrhoea, temporomandibular joint disorders, bruxism, blepharospasm, hemifacial spasm and rhinitis. For chronic neck pain there is level 1 evidence to show that Botox is ineffective. Level 2 evidence exists for vocal tics, trigeminal neuralgia, dysphagia and post-laryngectomy oesophageal speech. For stuttering, 'first bite syndrome', facial nerve paresis, Frey's syndrome, oromandibular dystonia and palatal/stapedial myoclonus the evidence is level 4. Thus, the literature highlights a therapeutic role for Botox in a wide range of non-cosmetic conditions pertaining to the head and neck (mainly level 1 evidence). With ongoing research, the spectrum of clinical applications and number of people receiving Botox will no doubt increase. Botox appears to justify its title as 'the poison that heals'.

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 toxin physiology in focal hand and cranial dystonia

The safety and efficacy of botulinum toxin for the treatment of focal hand and cranial dystonias are well-established. Studies of these adult-onset focal dystonias reveal both shared features, such as the dystonic phenotype of muscle hyperactivity and overflow muscle contraction and divergent features, such as task specificity in focal hand dystonia which is not a common feature of cranial dystonia. The physiologic effects of botulinum toxin in these 2 disorders also show both similarities and differences. This paper compares and contrasts the physiology of focal hand and cranial dystonias and of botulinum toxin in the management of these disorders.

Transcranial magnetic brain stimulation modulates blepharospasm: a randomized controlled study

BACKGROUND

Benign essential blepharospasm (BEB) is a common form of focal dystonia. Besides pathology in the basal ganglia, accumulating evidence suggests pathologic changes in the anterior cingulate cortex (ACC).

METHODS

This is a randomized, sham-controlled, observer-blinded prospective study. In 12 patients with BEB, we evaluated the effects of a 15-minute session of low-frequency (0.2 Hz) repetitive transcranial magnetic stimulation (rTMS) over the ACC with stimulation intensities at 100% active motor threshold with 3 stimulation coils: a conventional circular coil (C-coil), a sham coil (S-coil), and a Hesed coil (H-coil, which allows stimulation of deeper brain regions. Primary outcome was the clinical effects on BEB (blink rate, number of spasms rated by a blinded physician and patient rating before, immediately after, and 1 hour after stimulation); secondary outcome was the blink reflex recovery curve.

RESULTS

Subjective stimulation comfort was similar for each coil with no stimulation-associated adverse events. Stimulation with the H- and C-coils resulted in a significant improvement in all 3 outcome measures and was still detectable in physician rating and patient rating 1 hour after stimulation. S-coil stimulation had no effects. The active motor threshold was significantly lower for the H-coil compared to the other 2 coils.

CONCLUSIONS

rTMS could be used as a therapeutic tool in BEB. Further studies will be necessary to show whether repeated stimulation applications result in lasting clinical effects.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with BEB, H- and C-coil rTMS is safe and improves clinical symptoms of BEB immediately and 1 hour after stimulation.

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

OBJECTIVES

To compare the clinical characteristics and the long-term outcome of a large series of patients with blepharospasm (BS) treated with the two most used brands of BoNT-A over the last 15 years.

METHODS

We have reviewed the clinical charts of 128 patients with BS who received botulinum neurotoxin (BoNT) in 1341 treatments (Botox in 1009, Dysport in 332) over the last 15 years.

RESULTS

Mean dose per session was 34U +/- 15 for Botox and 152U +/- 54 for Dysport. Mean latency of clinical effect was 4.5 +/- 4.6 days for Botox and 5.0 +/- 5.7 days for Dysport (P > 0.05). Mean duration of clinical improvement was higher for Dysport than Botox: 80.1 +/- 36.3 and 66.2 +/- 39.8 days, respectively (P < 0.01). In a six-point scale (0: no efficacy, 6: remission of BS), the mean efficacy of both treatments was 3.60 +/- 1.3; 3.51 +/- 1.4 (Botox) and 3.85 +/- 1.2 (Dysport), P < 0.01. The doses of Botox (beta = 0.40) and Dysport (beta = 0.16) were significantly increased over time. Side effects occurred in 325 out of 1341 treatments (24.2%): 21.8% of the patients who had received Botox, and in 31.6% of those who had received Dysport (P < 0.01).

CONCLUSIONS

Both brands are effective and safe in treating blepharospasm; efficacy is long lasting. The differences in outcome and side effects suggest that, albeit the active drug is the same, Botox and Dysport should be considered as two different drugs.

Proteomic changes in rat thyroarytenoid muscle induced by botulinum neurotoxin injection

Botulinum neurotoxin (BoNT) injection into the thyroarytenoid (TA) muscle is a commonly performed medical intervention for adductor spasmodic dysphonia. The mechanism of action of BoNT at the neuromuscular junction is well understood, however, aside from reports focused on myosin heavy chain isoform abundance, there is a paucity of data addressing the effects of therapeutic BoNT injection on the TA muscle proteome. In this study, 12 adult Sprague Dawley rats underwent unilateral TA muscle BoNT serotype A injection followed by tissue harvest at 72 h, 7 days, 14 days, and 56 days postinjection. Three additional rats were reserved as controls. Proteomic analysis was performed using 2-D SDS-PAGE followed by MALDI-MS. Vocal fold movement was significantly reduced by 72 h, with complete return of function by 56 days. Twenty-five protein spots demonstrated significant protein abundance changes following BoNT injection, and were associated with alterations in energy metabolism, muscle contractile function, cellular stress response, transcription, translation, and cell proliferation. A number of protein abundance changes persisted beyond the return of gross physiologic TA function. These findings represent the first report of BoNT-induced changes in any skeletal muscle proteome, and reinforce the utility of applying proteomic tools to the study of system-wide biological processes in normal and perturbed TA muscle function.

Neurologic uses of botulinum neurotoxin type A

This article reviews the current and most neurologic uses of botulinum neurotoxin type A (BoNT-A), beginning with relevant historical data, neurochemical mechanism at the neuromuscular junction. Current commercial preparations of BoNT-A are reviewed, as are immunologic issues relating to secondary failure of BoNT-A therapy. Clinical uses are summarized with an emphasis on controlled clinical trials (as appropriate), including facial movement disorders, focal neck and limb dystonias, spasticity, hypersecretory syndromes, and pain.

Efficacy and safety of a new Botulinum Toxin Type A free of complexing proteins in the treatment of blepharospasm

NT 201 is a new development of Botulinum Toxin Type A free of complexing proteins. In this double-blind Phase III trial, we compared the efficacy and safety of NT 201 and BOTOX in patients suffering from blepharospasm. Of 304 enrolled patients, 300 patients received study medication (intent-to-treat population), and 256 patients completed the study as planned (per-protocol population). At baseline, patients received a single injection of NT 201 or BOTOX (<or=35 units per eye). No significant differences were found between NT 201 and BOTOX for all efficacy and safety variables three weeks after injection. Both the NT 201 and the BOTOX group showed a decrease in the Jankovic Rating Scale (JRS) sum score signifying an improvement in the symptoms of blepharospasm during this time period. These data show that NT 201* is an effective and safe treatment for patients suffering from blepharospasm.