Safety Of Botulinum Toxin Type A Research Articles

Efficacy and Safety of Botulinum Toxin in the Management of Temporomandibular Symptoms Associated with Sleep Bruxism: A Systematic Review.

Sleep bruxism, characterized by involuntary grinding or clenching of teeth during sleep, poses significant challenges in management due to its potential to induce temporomandibular joint disorders (TMDs) and other related symptoms. The use of Botulinum toxin Type A (BoNT-A), also known as Botox®, has been proposed as a therapeutic intervention. This systematic review aims to evaluate the efficacy and safety of BoNT-A in the management of sleep bruxism, focusing on pain reduction, improvement in jaw function, reduction in bruxism episodes, and the incidence of adverse effects. An exhaustive search was conducted across PubMed, Scopus, and Embase databases up to January 2024, adhering to the PRISMA guidelines. Nine randomized clinical trials (RCTs) involving 137 participants were analyzed for efficacy and safety outcomes. The studies demonstrated a significant reduction in mean pain scores (from 7.1 to 0.2 at 6 months and 1 year post-treatment in one study) and a notable decrease in the number of bruxism events (from 4.97/h to 1.70/h in the BoNT-A group in another study). Additionally, improvements were observed in jaw stiffness and total sleep time. Adverse effects varied but were generally mild and transient, including injection site pain in 20% of participants in one study and cosmetic changes in smile in 15.4% of patients in another. These findings suggest that BoNT-A injections may provide some benefits for treating nocturnal bruxism, potentially reducing TMD symptoms like pain and improving jaw function. However, these findings are preliminary due to variability in study designs and the absence of detailed statistical analysis.

Efficacy and safety of botulinum toxin A in the treatment of female pattern hair loss.

Female pattern hair loss (FPHL) is the most prevalent type of alopecia among adult women. Presently, topical minoxidil stands as the sole treatment endorsed by the FDA. Addressing cases of FPHL in individuals who develop contact dermatitis in response to minoxidil can pose a challenge for dermatologists. To assess the efficacy and safety of subcutaneous injections of Botulinum Toxin Type A (BTA) in treating FPHL. Enrolled outpatients with FPHL who exhibited an allergic reaction to minoxidil solution. Diagnosis of FPHL was established through clinical examination and trichoscopy. Inclusion criteria involved patients with no prior treatment within the last year and without any comorbidities. BTA, specifically 100 units, was mixed with 2mL of 0.9% normal saline. Twenty injection target sites, spaced 2-3cm apart, were symmetrically marked on the hairless area of the scalp. A dosage of five units was intradermally injected at each target site. Representative photographs and dermoscopic images of the scalp were captured before and after 3months of treatment. A total of 10 FPHL, aged between 26 and 40years, were included. The average age was 30.3±4.64years, and all patients had a positive family history of Androgenetic Alopecia. The average duration of the disease was 3.70±1.42years. According to patients' self-assessment, after 1month of treatment, 10 FPHL patients reported experiencing moderate to marked improvement in symptoms related to scalp oil secretion. Three months later, dermatological assessments showed that three had mild improvement, six had no change, and one had a worsening condition. No adverse effects were observed. Our study suggests that the effectiveness of BTA for FPHL is limited to 3months. However, it can be considered for tentative use after effective communication with patients. The long-term efficacy and safety of BTA in treating FPHL require further observation and study.

Effect of botulinum toxin type A on muscular temporomandibular disorder: A systematic review and meta-analysis of randomized controlled trials.

Botulinum toxin type A (BTX-A) is increasingly used to manage painful temporomandibular disorders (TMD). However, the effect of BTX-A on muscular TMD remains unclear. To assess the efficacy, safety and optimal dose of BTX-A for treating TMD. We conducted systematic literature searches in MEDLINE, Embase, Web of Science, ClinicalTrials.gov and Cochrane Library until March 2023. We extracted data from randomized controlled trials (RCTs) that evaluated the efficacy and safety of BTX-A in treating muscular TMD. We performed a meta-analysis using a random-effects model. Fifteen RCTs involving 504 participants met the inclusion criteria. BTX-A was significantly more effective than placebo in reducing pain intensity, as measured on a 0-10 scale, at 1 month (MD [95% CI] = -1.92 [-2.87, -0.98], p < .0001) and 6 months (MD [95% CI] -2.08, [-3.19 to -0.98]; p = .0002). A higher dosage of BTX-A (60-100 U bilaterally) was associated with a greater reduction in pain at 6 months (MD [95% CI] = -2.98 [-3.52, -2.44]; p < .001). BTX-A also resulted in decreased masseter muscle intensity (μV) (MD [95% CI] = -44.43 [-71.33, -17.53]; p = .001) at 1 month and occlusal force (kg) at 3 months (MD [95% CI] = -30.29 [-48.22 to -12.37]; p = .0009). There was no significant difference in adverse events between BTX-A and placebo. BTX-A is a safe and effective treatment for reducing pain and improving temporomandibular muscle and joint function in muscular TMD patients. A bilateral dose of 60-100 U might be an optimal choice for treating muscular TMD pain.

The Efficacy and Safety of Botulinum Toxin Type A Injections in Improving Facial Scars: A Systematic Review and Meta-Analysis

Background: Botulinum toxin type A (BTA) has a wide range of clinical applications, and its use in improving aesthetics is one of them. The aim of this study was to better assess the efficacy and safety of BTA in patients with facial scars. Summary: We extracted the data of the visual analog scale (VAS) score, Vancouver scar scale (VSS) score, scar width, observer scar assessment scale (OSAS), patient scar assessment scale (PSAS), and/or drug-related adverse events. Five studies provided the data of VAS score, and the results showed that the VAS score in the BTA group was significantly higher than that in the control group. Three randomized controlled trials (RCTs) reported the VSS score. A statistically significant difference exists between the BTA group and the control group. Three RCTs reported the scar width after BTA treatment. A more favorable change was found in the BTA group with scar width even without statistical significance. Data about the OSAS and PSAS scores were available in two trials. There was no significant difference in OSAS and PSAS scores between the BTA group and the control group. Only three studies recorded three slight adverse events. There were no reports of severe complications. In conclusions, this study demonstrated that BTA has the potential to improve facial scars with an acceptable safety profile.

Botulinum toxin for chronic rhinitis: A systematic review and meta-analysis.

Botulinum toxin type A (BTX-A) is a potential treatment for chronic rhinitis. This study aimed to assess the effectiveness and safety of BTX-A in treating patients with chronic rhinitis. Systematic searches of MEDLINE, Scopus, and EMBASE databases were performed. Randomized controlled trials (RCTs) that assessed the efficacy of BTX-A in allergic rhinitis and/or nonallergic rhinitis patients, compared with either placebo or active treatment, were included. The outcomes were total nasal symptom (TNSS), disease-specific quality of life (QOL), and adverse events. Nine RCTs (340 patients) met the eligibility criteria. Compared with placebo, the ≤ 12-week effects favored BTX-A injection on TNSS (standardized mean difference [SMD] -2.22, 95% confidence interval [CI] -3.27 to -1.17, p<0.01, four RCTs). Beneficial effects>12 weeks over placebo (MD -9.69, 95% CI -11.29 to -8.09, p<0.01, one RCT) were demonstrated up to 24weeks. However, the benefits were not shown on nasal congestion and individual nasal symptoms. Compared with active comparators (triamcinolone injection, ipratropium bromide, and cetirizine), there was no difference in the<12-week effect between groups on TNSS. There was no difference between BTX-A and cetirizine on QOL (one RCT). The>12-week effects on TNSS and individual nasal symptoms favored BTX-A over triamcinolone injection (one RCT). The risk ratio of adverse events favored BTX-A over cetirizine (one RCT). BTX-A improved TNSS and QOL in patients with chronic rhinitis. These effects were demonstrated up to 24weeks post treatment. BTX-A was safe, well tolerated, and may be considered in patients who are refractory to current standard-of-care therapies.

Randomized Trial of Botulinum Toxin Type A in Hereditary Spastic Paraplegia - The SPASTOX Trial.

Hereditary spastic paraplegia presents spasticity as the main clinical manifestation, reducing gait quality and producing incapacity. Management with botulinum toxin type A (BoNT-A) is not well elucidated. The objective of the current study was to evaluate the efficacy and safety of BoNT-A in patients with hereditary spastic paraplegias. This was a double-blind, randomized, placebo-controlled crossover trial. Each participant was randomly assigned to receive 1 injection session of either BoNT-A (100 IU/2 mL of Prosigne in each adductor magnus and each triceps surae) or saline 0.9% (2 mL). The primary outcome measure was change from baseline in maximal gait velocity, and secondary outcome measures included changes in gait at self-selected velocity, spasticity, muscle strength, Spastic Paraplegia Rating Scale, pain, fatigue, and subjective perception of improvement. We also looked at adverse events reported by the patients. We enrolled 55 patients, 36 of whom were men and 41 with the pure phenotype. Mean age was 43 ± 13.4 years (range, 19-72 years), mean age of onset waws 27 ± 13.1 years (range, <1 to 55 yars), and mean disease duration was 17 ± 12.7 years (range, 1-62 years). Compared with baseline, we did not find significant differences between groups in primary and secondary outcomes, except for reduction in adductor tone (P=0.01). The adverse events were transient and tolerable, and their incidence did not significantly differ between treatments (P=0.17). BoNT-A was safe in patients with hereditary spastic paraplegias and reduced the adductor tone, but it was not able to produce functional improvement considering the doses, injection protocol, measures, and instruments used. © 2021 International Parkinson and Movement Disorder Society.

Botulinum toxin type A for hand tremor: a meta-analysis of randomised controlled trials.

Tremor is one of the most common movement disorders. It does not usually respond to first-line drug treatments (e.g. propranolol, primidone, anticholinergics, gabapentin and clonazepam) due to side effects and frequent dose limitations. Botulinum toxin type A (BoNT-A) has been widely used to treat tremor, but its efficacy and safety are uncertain. To evaluate the efficacy and safety of BoNT-A in the treatment of hand tremor. We searched the MEDLINE, EMBASE, PsycINFO and Cochrane Library databases for relevant randomised controlled trials of the effects of BoNT-A injections on tremors, up to 20 February 2020. A meta-analysis of comparative effects was performed using R studio software, and publication bias was examined using Egger's test. Six studies examining a total of 245 participants with tremor were included in the meta-analysis. The primary outcome of meta-analysis showed no difference in clinical tremor scale scores between the BoNT-A group versus the placebo group (standardised mean difference (SMD): -0.42, 95% confidence interval (CI): -1.94 to 1.10; I2 = 96%). For clinical tremor scale scores, subgroup analyses suggested that the BoNT-A group may differ in terms of multiple sclerosis (MS) related tremor (SMD: -1.10; 95% CI: -2.17 to -0.04; I2 = 79%) compared to a placebo, but the difference did not exist in the outcome of essential tremor (ET) or hand tremor (MD: -1.31; 95% CI: -3.39; 1.31; I2 = 97%). Grip strength (MD: -1.25, 95% CI: -5.99 to 3.50, I2 = 97%) was slightly lower in the BoNT-A group, but the difference was not significant. The incidence of adverse events (AEs), including hand weakness (RR: 2.96, 95% CI: 1.40 to 6.24, I2 = 37%), was significantly greater in the BoNT-A group than in the placebo group. Two studies were assessed as having an overall low risk of bias. Our study confirms that BoNT-A injections are unlikely to have an impact on patients with hand tremors. However, subgroup analysis suggested that BoNT-A injections could have possible benefits in MS-related tremor. While moderate to severe hand weakness AEs often limits their use in clinical practice, additional well-designed double-blind, placebo-controlled trials are needed to provide more robust conclusions.

The Safety and efficacy of botulinum toxin type A injection for postoperative scar prevention: A systematic review and meta-analysis.

Active prevention and treatment of scars are particularly important. Several studies have used botulinum toxin type A(BTXA) to prevent postoperative scarring. The aim of this systematic review and meta-analysis was to systematically evaluate the efficacy and safety of BTXA in preventing and treating postoperative scars. A computer-based search was conducted for the five databases including PubMed, Cochrane Library, EMBASE, CNKI, and Wanfang up to May 22, 2019, to collect the relevant literatures on BTXA treatment of postoperative hypertrophic scars. A meta-analysis was made with the software of Revman 5.3 based on the study endpoint of scar width, Vancouver Scar Scale (VSS), Visual Analogue Scale (VAS) scores, and patient satisfaction as well. A total of 18 randomized controlled trials (RCTs) studies were included with 915 patients in all. The result showed that, compared with the control group, the scar width, VAS scores, and VSS scores of the BTXA group were significantly improved and higher patient satisfaction was achieved. BTXA has a certain curative effect on postoperative scar prevention and treatment without obvious side effects.

Efficacy and Safety of Botulinum Toxin Type A for Limb Spasticity after Stroke: A Meta-Analysis of Randomized Controlled Trials.

Background Inconsistent data have been reported for the effectiveness of intramuscular botulinum toxin type A (BTXA) in patients with limb spasticity after stroke. This meta-analysis of available randomized controlled trials (RCTs) aimed to determine the efficacy and safety of BTXA in adult patients with upper and lower limb spasticity after stroke. Methods An electronic search was performed to select eligible RCTs in PubMed, Embase, and the Cochrane library through December 2018. Summary standard mean differences (SMDs) and relative risk (RR) values with corresponding 95% confidence intervals (CIs) were employed to assess effectiveness and safety outcomes, respectively. Results Twenty-seven RCTs involving a total of 2,793 patients met the inclusion criteria, including 16 and 9 trials assessing upper and lower limb spasticity cases, respectively. For upper limb spasticity, BTXA therapy significantly improved the levels of muscle tone (SMD=-0.76; 95% CI -0.97 to -0.55; P<0.001), physician global assessment (SMD=0.51; 95% CI 0.35-0.67; P<0.001), and disability assessment scale (SMD=-0.30; 95% CI -0.40 to -0.20; P<0.001), with no significant effects on active upper limb function (SMD=0.49; 95% CI -0.08 to 1.07; P=0.093) and adverse events (RR=1.18; 95% CI 0.72-1.93; P=0.509). For lower limb spasticity, BTXA therapy was associated with higher Fugl-Meyer score (SMD=5.09; 95%CI 2.16-8.01; P=0.001), but had no significant effects on muscle tone (SMD=-0.12; 95% CI -0.83 to 0.59; P=0.736), gait speed (SMD=0.06; 95% CI -0.02 to 0.15; P=0.116), and adverse events (RR=1.01; 95% CI 0.71-1.45; P=0.949). Conclusions BTXA improves muscle tone, physician global assessment, and disability assessment scale in upper limb spasticity and increases the Fugl-Meyer score in lower limb spasticity.

Therapeutic efficacy and safety of Botulinum Toxin A Therapy in Trigeminal Neuralgia: a systematic review and meta-analysis of randomized controlled trials.

BackgroundSeveral different interventions have been examined to alleviate pain and reduce frequency of trigeminal neuralgia (TN) paroxysms. However, some patients continue to have persistent or recurrent painful attacks. Using a systematic review and meta-analysis approach, we aimed to synthesize evidence from published randomized controlled trials (RCTs) regarding safety and efficacy of botulinum toxin type A (BTX-A) as a possible emerging choice of treatment for TN.MethodsWe conducted an electronic search in 10 databases/electronic search engines to access relevant publications. All articles in all languages reporting RCTs on the efficacy and safety of BTX-A in the treatment of TN were included for systematic review and meta-analysis.ResultsA total of four RCTs (n = 178) were identified for final meta-analysis. The overall effect favored BTX-A versus placebo in terms of proportion of responders (risk ratio RR = 2.87, 95 % confidence interval CI [1.76, 4.69], p <0.0001) with no significant detected heterogeneity (p = 0.31; I2 = 4 %). Paroxysms frequency per day was significantly lower for BTX-A group (mean difference MD = -29.79, 95 % CI [-38.50,–21.08], p <0.00001) with no significant heterogeneity (p = 0.21; I2 = 36 %).ConclusionDespite limited data, our results suggest that BTX-A may be an effective and safe treatment option for patients with TN. Further larger and well-designed RCTs are encouraged to translate these findings into better clinical outcome and better quality of life for TN patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s10194-016-0651-8) contains supplementary material, which is available to authorized users.

Patient Satisfaction and Efficacy of Full-Facial Rejuvenation Using a Combination of Botulinum Toxin Type A and Hyaluronic Acid Filler.

Combination treatments using hyaluronic acid (HA) fillers and botulinum toxin Type A (BoNT-A) are common in aesthetic medicine; however, this has been evaluated in only a few clinical studies. To evaluate subject satisfaction, efficacy, and safety of BoNT-A (Speywood Unit; s.U) and a range of HA fillers for full-facial aesthetic rejuvenation. A 6-month, multicenter, open-label clinical study, using BoNT-A (s.U) and 5 HA fillers to treat up to 13 facial zones. Subject satisfaction questionnaires were administered 3 weeks and 6 months after the last injection. Global aesthetic improvement and improvement on each treated zone as well as safety were evaluated. A high level of satisfaction was achieved throughout the study, with 96.5% of subjects at least satisfied with the full-facial aesthetic outcome at 3 weeks, and 92.9% at 6 months. More than 91% considered the treatment outcome to meet or surpass their expectations, and more than 94% would recommend the treatment to others. At Week 3, subject and investigator assessment showed aesthetic improvement for all subjects. The treatment was well tolerated. The combination of BoNT-A (s.U) and HA fillers results in high patient satisfaction and in an overall improvement of aesthetic outcomes and quality of life.

Efficacy and safety of botulinum toxin type A for treatment of Frey's syndrome: evidence from 22 published articles.

Frey’s syndrome (FS) is an unavoidable sequela following the surgery of the parotid gland. Although several treatment methods are available, their efficacy is short term or accompanied by unacceptable complications. In the past two decades, botulinum toxin type A (BTXA) has been widely used to treat FS. Although several systematic reviews have been reported recently, they were conflicting and with obvious deficiencies. Thus, we performed an objectively systematic review to determine whether BTXA is an effective and safe treatment for FS. A literature retrieval covering PubMed, Web of Science, Ovid, Embase and Cochrane library was performed on 16 January, 2015. Proportion meta-analysis and corresponding 95% confidence interval (CI) were performed to evaluate the efficacy and safety of BXTA in treatment of FS. A total of 499 records were retrieved and 22 articles with 23 studies were included after scrutiny by two independent authors. Statistical analyses regarding the effective rate, incidence of complications were used to estimate the efficacy and safety of BTXA. Our results suggested that the effective rate of BTXA for treatment of FS is 98.5% (95% CI = 0.971–0.994) and the incidence of complication is 3.6% (95% CI = 0.017–0.061). In conclusion, our study supports that BTXA produces meaningful benefits on the treatment of patients with FS. However, owing to lack of strong evidence, future studies with well-designed inclusion criteria and multicenter randomized controlled trials are needed to give more credible evidence, if possible.

Repeated botulinum toxin type A (Dysport®) injections for women with intractable detrusor overactivity: a prospective outcome study

We present the cohort of 33 women who underwent botulinum toxin type A (BTX-A) injections examining the efficacy and safety of BTX-A in idiopathic detrusor overactivity (IDO). The aim of this report is to describe the outcomes of those who underwent repeated injections of BTX-A. All 33 women had 3 or more injections with an initial dose of 500 units of Dysport with subsequent injections between 500 and 750 U, administered by the classic trigone-sparing flexible/rigid cystoscopic technique. An informed consent was obtained in all cases. Efficacy was measured using voiding diaries and quality of life (QOL) assessed with the International Consultation on Incontinence Questionnaire-Short Form (ICIQ -SF). This project was approved by the Clinical Effectiveness Department and the Drugs and Therapeutics Committee (DTC). Therefore, ethical approval was not required. This study included 33 women who have been successfully treated with repeated intradetrusor injections of BTX-A (Dysport). Mean duration between the first and second injections was 15.2 ± 7.2 months, whereas between the second and third was 19.2 ± 10 months (P = 0.025). Two women developed urinary tract infection and required clean intermittent self-catheterization. Three women required dose escalation to 750 units. Longer duration of subjective QOL improvement was noted between the second and third botulinum toxin injections compared to duration between the first and second injections. BTX-A appears to be effective and safe after repeated administration in women with IDO. The duration of the injection tends to get prolonged after the second injection.

Therapeutic efficacy and safety of botulinum toxin type A in trigeminal neuralgia: a systematic review

Trigeminal neuralgia is a common disorder caused mainly by compression of the trigeminal nerve root by an overlying blood vessel. Pharmacotherapy and surgery are ineffective or unsuitable in many patients. Therefore, other therapeutic modalities have been tried, including injection of botulinum toxin type A (BTX-A). This study aims to systematically review the therapeutic efficacy and safety of BTX-A in trigeminal neuralgia. PubMed, EMBASE, Cochrane Library Clinical Trials and Web of Science from January 1966 to March 2013 were searched with the terms of “botulinum toxin” AND “trigeminal neuralgia”, and references of related articles were traced. Data on the efficacy and safety of BTX-A in this disorder were extracted and analyzed by at least 2 reviewers. Data for individual studies were reported, and pooled data were analyzed if appropriate. Five prospective studies and one double-blind, randomized, placebo-controlled study were identified. Response was achieved in approximately 70-100% of patients, and the mean pain intensity and frequency were reduced by approximately 60-100% at 4 weeks after treatment in most studies. Major adverse events were not reported. Available studies show BTX-A may be effective in treatment of trigeminal neuralgia. However, well-designed randomized, controlled, double-blinded trial is still lacking. Future BTX-A treatment studies on optimal dose, duration of the therapeutic efficacy, common AEs, and the time and indications for repeat injection would be promising.

Evidence-based systematic review on the efficacy and safety of botulinum toxin-A therapy in post-stroke spasticity

Botulinum toxin type A (BoNTA) has been suggested as an effective anti-spastic drug. In this article, we summarized the data of randomized, placebo-controlled, double- blind trials and conducted a meta-analysis to assess if BoNTA is an adequate treatment for spasticity following stroke. To evaluate the relevant literature and assess the effectiveness and safety of BoNTA in (1) reducing spasticity based on mean change in the Modified Ashworth Scale (MAS) for upper and lower limb spasticity from baseline; (2) reducing spasticity based on the percent of patients having > or = 1point(s) change in the MAS; (3) improving the patient's or caregivers' Global Assessment Scale (GAS); and (4) total adverse events. We selected all randomized, placebo controlled, double-blind clinical trials or previous meta-analyses evaluating the efficacy and safety of BoNTA (Botox or Dysport) for the treatment of spasticity in both upper and lower limbs after stroke. Validity assessment of studies was performed, and Revman 4.2.7 from Cochrane Collaboration and SPSS (statistical package for the social sciences), v 9.0, were applied for analysis. Overall analysis showed clinical improvement between baseline and 4-6 weeks after application of BoNTA of the patient's spasticity score using the MAS (weighted mean difference [WMD] = 0.87, 95% CI = 0.52-1.22). The odds ratio of the MAS spasticity score showing one or more points improvement at 4-6 weeks after giving BoNTA showed clinically significant improvement (OR = 4.5, 95% CI = 2.79-7.25). The odds ratio of having an improved GAS at 4-6 weeks after injecting BoNTA showed clinically significant improvement (Odds ratio = 5.85, 95% CI = 3.12-10.95). The odds ratio of having an adverse event during the entire study did not show any significant difference between placebo and BoNTA (odds ratio = 0.84, 95% CI = 0.55-1.28). BoNTA improves muscle tone in upper and lower limb spasticity following stroke. A global assessment of improvement was noted by the patients or the caregivers following BoNTA injection. BoNTA is considered a safe therapeutic agent.

Botulinum Toxin Type A in Prophylactic Treatment of Migraine

Current migraine preventive therapies are often unsatisfactory because of their limited efficacy, adverse effects, and drug interactions. An open-label, non-controlled study of botulinum toxin type A (BTX-A) suggested some benefits for patients with migraine. To assess the efficacy and safety of BTX-A, a randomized, double-blind, vehicle-controlled, parallel group study was conducted in 32 patients with a history of 2 to 8 migraine attacks per month, with or without aura. The patients were randomized to receive single administrations of 50-U BTX-A or vehicle injected into multiple sites of pericranial muscles at the same visit. Patients kept daily diaries in which they recorded outcome measures like migraine frequency, migraine severity, and the occurrence of migraine-associated symptoms. Patients graded symptoms on a 4-point scale ranging from grades 0 to 3 before and up to 3-months after treatment. The assessments were made at 0, 1, and 3 months. The primary efficacy parameters included number of headaches resolved (grade 3/2 to grade 0) and alleviation of other accompanying symptoms of migraine. The supplementary end point included improvement in quality of life (QOL). About 75% of patients reported complete relief to mild headache (grade 0-1) by BTX-A and none by placebo group. Patient' QOL parameters like energy/vitality and feelings and concerns about the treatment had shown considerable improvement. However, normal day-to-day work functioning and social interactions deteriorated. No adverse effects were reported in any of the patients in either of the groups during the study. It is evident from the study that pericranial injection of 50-U BTX-A showed good efficacy and tolerability as a prophylactic agent. However, this therapy will be expensive to the patients, but it is far superior in providing relief to the patients compared with existing therapies.

A randomized, double-masked, crossover comparison of the efficacy and safety of botulinum toxin type A produced from the original bulk toxin source and current bulk toxin source for the treatment of cervical dystonia

In 1997, the US FDA approved a new bulk toxin source (now referred to as current) for the manufacture of botulinum toxin type A (BTX-A). The current BTX-A preparation has a lower neurotoxin complex protein load than the original BTX-A preparation, which may reduce antigenic potential. The present double-masked, multicenter study compared the efficacy and safety of BTX-A (BOTOX) produced from both original and current bulk toxin sources for the treatment of cervical dystonia. Patients (N = 133) were injected with BTX-A produced from original and current bulk toxin sources using a crossover design. Adverse events were assessed at each visit. Efficacy was assessed at 2 and 6 weeks post-injection using the severity and pain-disability subscales of the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). Mean BTX-A doses were comparable (original: 155 U, current: 156 U). Both BTX-A preparations produced similar, statistically significant reductions in TWSTRS severity and pain-disability scores at weeks 2 and 6 post-injection. The original and current BTX-A preparations showed no significant differences in adverse events, including both treatment-related (34%, 31%) and treatment-unrelated (27%, 32%), respectively. BTX-A produced from the original and current bulk toxin sources showed comparable efficacy and safety in the treatment of cervical dystonia; both significantly reduced dystonia severity and pain.