Safety and efficacy of NeuroBloc (botulinum toxin type B) in type A-responsive cervical dystonia.

OBJECTIVE: To determine the safety and efficacy of botulinum toxin type B (BoNT/B) in patients with cervical dystonia (CD). BACKGROUND: BoNT/B is a form of chemodenervation therapy for the treatment of patients with CD. METHODS: The authors performed a 16-week, randomized, multicenter, double-blind, placebo-controlled trial of BoNT/B in patients with CD who continue to respond to botulinum toxin type A. Placebo, or 5,000 U or 10,000 U of BoNT/B was administered in two to four muscles involved clinically in CD. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Total score at week 4 was the primary efficacy measure. Clinical assessments and adverse events were recorded for treatment day 1 and at weeks 2, 4, 8, 12, and 16. RESULTS: A total of 109 patients were enrolled randomly across all three treatment groups. The mean improvement in the TWSTRS-Total scores in each group at week 4 was 4.3 (placebo), 9.3 (5,000 U), and 11.7 (10,000 U). For the prospectively defined primary contrast (10,000 U versus placebo), highly significant differences were noted for the primary (TWSTRS-Total, baseline to week 4, p = 0.0004) and supportive secondary (Patient Global Assessment, baseline to week 4, p = 0.0001) outcome measures. Improvement in pain, disability, and severity of CD occurred for patients who were treated with BoNT/B when compared with placebo-treated patients. Overall, improvements associated with BoNT/B treatment were greatest for patients who received the 10,000-U dose. The duration of treatment effect for BoNT/B was 12 to 16 weeks for both doses. CONCLUSION: Botulinum toxin type B (NeuroBloc) is safe and efficacious at 5,000 U and 10,000 U for the management of patients with cervical dystonia.     

The barriers and facilitators to satisfaction with botulinum neurotoxin treatment in people with cervical dystonia: a systematic review

Neurological Sciences - Cervical dystonia (CD) is an isolated, focal, idiopathic dystonia affecting the neck and upper back. CD is usually treated by botulinum neurotoxin (BoNT) injections into the...     

Neutralizing botulinum toxin type a antibodies: clinical observations in patients with cervical dystonia

Neutralization of antibodies poses a problem for a substantial number of cervical dystonia (CD) patients treated with botulinum toxin type A (BoNT/A). Presence of these antibodies may lead to a secondary nonresponse to BoNT/A treatment. In this study, we compared 6 antibody-positive (Ab+) with 12 antibody- negative (Ab-) CD patients treated with BoNT/A (Dysport) and matched for du- ration of treatment, number of BoNT/A injections, and severity of clinical symptoms. The two groups differed in cumulative BoNT/A dose (Ab+, 5984 mouse units [MU ], SD = 3151 MU; Ab-, 3143 MU, SD =1294 MU; P <.05), in addition, ab+ patients were significantly younger (ab+ mean age = 41.3 y, sd =5.9 y; ab - mean age = 56.8 y, sd = 15.3 y; p <.05), in or- der to avoid formation of neutralizing antibodies, doses of bont/a should be kept as low as possible, the risk of antibody formation seems to be higher in younger patients.     

Clinical use of non-a botulinum toxins: Botulinum toxin type C and botulinum toxin type F

Botulinum neurotoxin (BoNT) serotype A is commonly used in the treatment of focal dystonia, but some patients are primarily or become secondarily resistant to it. Consequently, other serotypes have to be used when immuno-resistance is proven. In the literature, patients with focal dystonia have been treated with BoNT serotype F with clinical benefit but with short lasting effects. Recently, BoNT serotype C has been used with positive clinical outcome. An update on the clinical use of BoNT serotype F and BoNT serotype C is provided.     

Safety and efficacy of NeuroBloc (botulinum toxin type B) in type A-resistant cervical dystonia.

OBJECTIVE: To determine the safety and efficacy of botulinum toxin type B (BoNT/B) in patients with type A-resistant cervical dystonia (CD). Background: Local intramuscular injections of BoNT are an effective therapy for CD. After repeated use, some patients become resistant to therapy. BoNT/B, effective in type A toxin-responsive patients, is proposed as an alternative therapy for type A-resistant patients. METHODS: The authors performed a 16-week, double-blind, placebo-controlled trial of BoNT/B in type A-resistant patients with CD. After resistance to therapy was confirmed with the frontalis-type A test, placebo or 10,000 U BoNT/B was administered in a single session into two to four clinically involved muscles. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) was the primary efficacy measurement. TWSTRS-Total, three visual analog scales (Patient Global Assessment of Change, Principal Investigator Global Assessment of Change, Patient Analog Pain Assessment), and adverse events were assessed at baseline and weeks 2, 4, 8, 12, and 16. RESULTS: A total of 77 patients participated (38 placebo, 39 active). Improvements in severity, disability, and pain were documented in the BoNT/B-treated group. TWSTRS-Total scores were improved in the BoNT/B-treated group at weeks 4 (p = 0.0001), 8 (p = 0.0002), and 12 (p = 0.0129). All three visual analog scales demonstrated improvements at week 4 (p < 0.0001, 0.0001, and 0.001). A Kaplan-Meier analysis supported a duration of effect of 12 to 16 weeks in the active group. Dry mouth and dysphagia were self-limited adverse effects, reported more commonly in the BoNT/B group. CONCLUSIONS: Botulinum toxin type B (BoNT/B) (NeuroBloc) is safe and efficacious for the management of patients with type A-resistant cervical dystonia with an estimated duration of treatment effect of 12 to 16 weeks.     

Health related quality of life is improved by botulinum neurotoxin type A in long term treated patients with focal dystonia

OBJECTIVES: The advent of botulinum neurotoxin type A (BoNT/A) gave rise to substantial progress in the treatment of focal dystonias. In the light of the high costs of the toxin and the necessity to establish valid outcome indices for this treatment apart from sheer reduction of dystonic muscle tone and posture, the impact of focal dystonia and its treatment with BoNT/A on patients' health related quality of life (HRQL) was determined. METHODS: Fifty patients with cranial and cervical dystonia treated long term with BoNT/A were enrolled in a prospective, open labelled cohort study. The HRQL was assessed using the EuroQol (EQ-5D) and the short form 36 health survey questionnaire (SF-36) at baseline before BoNT/A injections and at two follow up visits after 6 and 12 weeks covering one BoNT/A treatment period with maximum effect size at the first follow up. RESULTS: Compared with a general population sample, a considerable negative impact of focal dystonia on HRQL was found in patients under investigation. In both disease types, BoNT/A treatment led to a significant improvement in several HRQL dimensions, in particular providing moderate to marked effect sizes in the fields of mental health and pain. The impairment of HRQL due to pain as well as the BoNT/A induced improvement within this SF-36 subscore were significantly higher in patients with cervical dystonia. Under BoNT/A therapy, no correlation was found between changes of clinical outcome scores and HRQL measures. CONCLUSIONS: The data confirm that BoNT/A is able to induce a significant, but temporary amelioration of several aspects of HRQL in both types of focal dystonia. This may substantially contribute to the patients' subjective benefit from the therapy. Moreover, the data provide further arguments to accept high costs of the BoNT/A treatment in these severely handicapped patients, as a consequence of its considerable benefit on quality of life.     

Cervical dystonia: clinical and therapeutic features in 85 patients

We studied patients with cervical dystonia (CD) to determine clinical features and response to botulinum toxin A (BoNT/A). Patients were submitted to clinical, laboratory and neuroimaging evaluation. BoNT/A was injected locally in 81 patients using electromyographic guidance. Four patients who had had previous treatment were considered to be in remission. The average ages at onset of focal dystonia and segmental dystonia were greater than for generalized dystonia (p<0.0003). The severity of the abnormal head-neck movements were more severe among the patients with generalized dystonia (p<0.001). Pain in the cervical area was noted in 59 patients. It was not possible to determine the etiology of the disease in 62.3% of patients. Tardive dystonia was the most common secondary etiology. A major improvement in the motor symptoms of CD and pain was observed in patients following treatment with BoNT/A. The tardive dystonia subgroup did not respond to the treatment. Dysphagia was observed in 2.35% of the patients.     

Botulinum toxin type B vs. type A in toxin‐naïve patients with cervical dystonia: Randomized,double‐blind,noninferiority trial

The objective of this study was to compare efficacy, safety, and duration of botulinum toxin type A (BoNT‐A) and type B (BoNT‐B) in toxin‐naïve cervical dystonia (CD) subjects. BoNT‐naïve CD subjects were randomized to BoNT‐A or BoNT‐B and evaluated in a double‐blind trial at baseline and every 4‐weeks following one treatment. The primary measure was the change in Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) from baseline to week 4 post‐injection. Secondary measures included change in TWSTRS‐subscale scores, pain, global impressions, and duration of response and safety assessments. The study was designed as a noninferiority trial of BoNT‐B to BoNT‐A. 111 subjects were randomized (55 BoNT‐A; 56 BoNT‐B). Improvement in TWSTRS‐total scores 4 weeks after BoNT‐B was noninferior to BoNT‐A (adjusted means 11.0 (SE 1.2) and 8.8 (SE 1.2), respectively; per‐protocol‐population (PPP)). The median duration of effect of BoNT‐A and BoNT‐B was not different (13.1 vs. 13.7 weeks, respectively; P‐value = 0.833; PPP). There were no significant differences in the occurrence of injection site pain and dysphagia. Mild dry mouth was more frequent with BoNT‐B but there were no differences for moderate/severe dry mouth. In this study, both BoNT‐A and B were shown to be effective and safe for the treatment of toxin‐naive CD subjects. © 2007 Movement Disorder Society     

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 repeated doses of botulinum toxin type B in type A resistant and responsive cervical dystonia.

Efficacy of botulinum toxin type B (BoNT B) for the treatment of type A-resistant (AR) and non-A-resistant (NAR) cervical dystonia (CD) has been demonstrated in several single injection studies. There is little data available on long-term therapy with repeated injection sessions and it is unknown if AR and NAR patients respond in a similar manner over time. To evaluate the long-term efficacy and safety of BoNT B in AR and NAR CD patients, we carried out a prospective, open-label study examining 10 repeated dosing sessions of BoNT B in 34 patients with CD (15 AR and 19 NAR). Dosing was started at 10,000 units and could be increased to 25,000. Assessments included the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and a patient global assessment at each baseline (injection) and Week 4 (peak effect) visit. Change in TWSTRS total was the primary efficacy end point. Data was analyzed using repeated-measures analysis of variance. BoNT B therapy resulted in an overall significant improvement of CD (P<0.001) and improvement was seen in all 10 individual sessions (2.5 years). The magnitude of response decayed over time (P<0.001). There was no difference between AR and NAR patients with regard to dose, treatment effect, or decay in response. The AR group perceived (patient global) treatment as being less effective (P=0.047). Dry mouth frequency decreased with each session despite increasing doses whereas flu-like syndrome and weakness increased. BoNT B therapy provides long-term benefit for CD patients but the magnitude of response diminishes over time. The cause of this decay is probably multifactorial. AR and NAR CD patients respond in a similar fashion.     

The broadening application of chemodenervation in X-linked dystonia-parkinsonism (Part I): muscle afferent block versus botulinum toxin-A in cervical and limb dystonias

Botulinum toxin (BoNT) is an established mainstay treatment for dystonia. However, its use, especially in developing countries, is significantly limited by its cost. Chemodenervation with muscle afferent block (MAB) using lidocaine-ethanol may provide a more cost-effective alternative to traditional BoNT injections. A study comparing MAB with BoNT type-A in cases of X-linked dystonia-Parkinsonism (XDP) having cervical dystonia indicated a modest and short-lived efficacy with MAB, while a more robust efficacy in dystonia and pain parameters, lasting up to 11 weeks, was observed in the two BoNT type-A preparations (Dysport? and Botox?). In another study comparing BoNT type-A formulations for limb dystonia of XDP, a prior MAB was used to select target muscles for toxin injection. During toxin injections in the limb muscles, Dysport? and Botox? did not show significant differences with regard to global severity and disability scales, duration of effect, and adverse event (AE) profile. Dysphagia was the most common AE following BoNT type-A injections in cervical dystonia, while weakness was the most frequent AE noted with injections for limb dystonia. MAB injections carried a high incidence of dizziness and pain during injections. However, because MAB is a more cost-effective alternative that can be given repeatedly, it has been used in the XDP population while awaiting funds for BoNT type-A and/or for selecting muscles for injection as a test drug.     

Evolution of dose and response to botulinum toxin A in cervical dystonia: a multicenter study

Botulinum neurotoxin (BoNT) is an effective treatment for cervical dystonia (CD). Long-term changes of several variables, including the dose of BoNT, in these patients is largely unknown. We reviewed the clinical charts of 275 patients with CD treated with BoNT type A (BoNT-A) for at least 5 years since 1989 at ten tertiary centers. The mean dose of BoNT-A per session during the first 5 years of treatment was calculated and the appearance of resistance was noted. The dose of BoNT-A for the whole group showed a significant trend to increase over time (year 1: 180 ± 65 U; year 5: 203 ± 63 U; ANOVA: p < 0.0001). However, when we studied the evolution of the dose of BoNT-A for those patients (n = 49) first injected after 2000 (introduction of current BOTOX preparation in our country), there was no significant increase in dose (year 1: 181.8 ± 75 U; year 5: 181.7 ± 75 U; ANOVA p: ns). A total of 19 patients became secondary nonresponders; all but one of these patients began BoNT-A treatment before 2000. In summary, there is a statistically significant increase of mean dose of BoNT-A per session over time, and this could be explained by the appearance of secondary nonresponders. On the other hand, those patients initially treated after 2000 did not show any statistically significant increase in dose for 5 years. This could be explained by better experience and techniques, fewer immunogenic problems with the current BoNT-A, and also less variability of the dose per vial.     

Botulinum toxin type A and cervical dystonia: a seven-year follow-up

Most cases of cervical dystonia (CD) are idiopathic, and focal injections of botulinum toxin A (BoNT/A) are the treatment of choice. The objective of our study was to document the effects of long-term BoNT/A treatment in idiopathic CD patients. Fifty-eight patients with idiopathic CD were recruited from March 2001 to May 2002. Twenty-eight of the subjects were available for reassessment after seven years. During this period, all had received regular treatment with BoNT/A injections. Clinical information about patients and the severity of CD (TWSTRS and VAPS) at baseline assessment (2001-2002) and follow-up (2008-2009) was compared. Significant motor improvement was detected based on TWSTRS scale scores, which were used to analyze clinical severity (19.6 ± 6.6 and 17.7 ± 4.8; p<0.05). There was no improvement in the severity of cervical pain (p=0.43). In conclusion, BoNT/A was a safe and effective long-term therapy for CD.     

Treatment of complex cervical dystonia with botulinum toxin: involvement of deep-cervical muscles may contribute to suboptimal responses

Complex cervical dystonia is a subgroup of cervical dystonia (CD) characterised by a combination of head deviations in more than one plane. In addition to superficial neck muscles, deep-cervical muscles contribute to a broad range of neck movements. These deep muscles include prevertebral muscles for primary neck flexion, lateral vertebral muscles for shoulder elevation and head tilt and a posterior group of muscles for neck extension. The authors describe three cases of complex deviations of the neck including anterocollis, retrocollis and lateral or sagittal shifts with involvement of deep-cervical muscles, which are not easily accessible by routine botulinum toxin (BoNT) therapy. Incomplete muscle selection may be one of the causes of treatment failures with BoNT in patients with complex CD, and targeting of deep-cervical muscles should be considered when patients exhibit complex deviations involving anterocollis, retrocollis, lateral or sagittal shifts.     

An Update on the Use of Botulinum Toxin Therapy in Parkinson’s Disease

Botulinum toxin (BoNT) has gained widespread use in a variety of neurological conditions. Parkinson’s disease is a complex neurodegenerative disorder manifested by motor and non-motor symptoms that can cause significant disability. BoNT has been used to effectively treat a variety of symptoms related to Parkinson’s disease. This review will examine the current therapeutic indications of BoNT use in the following disorders related to Parkinson’s disease: cervical dystonia, blepharospasm and lid apraxia, focal hand dystonia, foot dystonia, laryngeal dystonia, oromandibular dystonia, camptocormia, hand and jaw tremor, sialorrhea, hyperhidrosis, dysphagia, constipation, and overactive bladder.     

Human T-cell responses to botulinum neurotoxin: proliferative responses in vitro of lymphocytes from botulinum neurotoxin A-treated movement disorder patients

We determined the T-cell responses against botulinum neurotoxin type A (BoNT/A) and tetanus toxin (TeNT) of peripheral blood lymphocytes from 95 BoNT-treated patients and 63 non-treated control subjects. The patient group included 80 cervical dystonia and 15 other movement disorder cases. Positive T-cell responses to BoNT/A were detected in 70% of the treated patients, and in only 3% of controls. T-cell responses of BoNT-treated patients against BoNT/A did not differ between patients who were clinically responsive and those who had become non-responsive to the treatment. BoNT-treated patients gave significantly higher in vitro T-cell responses to TeNT than did the controls.     

Very early reduction in efficacy of botulinum toxin therapy for cervical dystonia in patients with subsequent secondary treatment failure: a retrospective analysis

The objective of this study was to estimate the probability of development of partial secondary treatment failure (PSTF) in patients with cervical dystonia (CD) who had been treated over up to 9 years with repetitive intramuscular injections of botulinum neurotoxin type A (BoNT/A). The temporal course of treatment response in patients in whom PSTF was detected retrospectively was compared to patients with a normal clinical response. For this purpose, charts of all CD patients treated in our outpatient clinic between 1988 and 2001 were retrospectively analyzed. Extracted data included time of all injections, dose per visit, disease severity measured by TSUI scores, and time of determination of neutralizing antibodies. Final data analysis using a special formal definition of PSTF was based on charts of 568 patients having exclusively been treated with abobotulinumtoxinA. PSTF onset was observed in our CD cohort during the entire treatment period analyzed, with no clustering at any time point. Probability to develop PSTF was 14.5 % in 9 years. Thus, mean PSTF incidence was 1.6 % per year. The mean TSUI score of patients with retrospectively defined PSTF (n = 33) became already significantly worse after the second injection when compared with the group without PSTF (n = 535). Our data indicate that clinical response in patients developing PSTF later on differs from that of patients without PSTF already very early in the course of botulinum neurotoxin type A treatment, and that PSTF remains undetected at this early stage. Reduced response may therefore be present in a number of CD patients who think they still respond normally to continuous BoNT/A treatment.     

The effectiveness of physiotherapy for cervical dystonia: a systematic literature review

Cervical dystonia is a form of adult-onset, focal dystonia characterized by involuntary contractions of the neck muscles, leading to a disabling, abnormal head posture. CD has a great impact on the activities of daily living (ADL) and quality of life. Currently, the most widely used and recommended first line treatment is botulinum toxin type A (BoNT/A) injections. Physiotherapy is a potentially useful adjuvant, but little is known about its effectiveness. Consequently, our objective was to investigate the effectiveness of physiotherapy alone or as an adjuvant treatment to BoNT/A injections in cervical dystonia (CD) by means of a systematic literature review. Two online databases, PubMed and Web of Science, were searched for articles describing the effectiveness of physiotherapy treatment for CD. After screening, based on predefined in- and exclusion criteria, 16 studies were retained. Their methodological quality was assessed according to Cochrane guidelines. The methodological quality of most studies was low. Examples of shortcomings are small sample sizes, lack of randomization or blinding, and diversity in therapeutic techniques and outcome measures. Only seven studies were clinical trials; the remaining were either case reports or case series. The reported physiotherapy treatments included EMG biofeedback training, muscular elongation, postural exercises and electrotherapy. Improvements in head position, pain, cervical range of motion, quality of life and ADL have been reported, which is promising. Cautious interpretation on the effectiveness of physiotherapy as an adjuvant therapy is required. Before firm conclusions can be drawn, additional high quality trials are needed.     

Botulinum neurotoxin serotypes A and C do not affect motor units survival in humans: an electrophysiological study by motor units counting.

OBJECTIVES: Botulinum neurotoxin serotype A (BoNT/A) is a valid therapy for dystonia but repeated BoNT/A injections may induce a clinical immuno-resistance that could be overcome by using other BoNT serotypes. In vitro experiments and our preliminary investigations in vivo, indicate that botulinum neurotoxin serotype C (BoNT/C) could be an effective alternative to BoNT/A. Moreover, in cultured neurons 'in vitro' BoNT/C has been reported to be more toxic than BoNT/A. METHODS: To verify this possibility, we compare the effect of BoNT/C and BoNT/A on the motor units count in humans by using the electrophysiological motor unit number estimation (MUNE) technique ('multiple point nerve stimulation'). Preliminarily, BoNT/C and BoNT/A dosage was calibrated in a mouse hemidiaphragm neuromuscular junction preparation. Subsequently, 8 volunteers were treated with 3IU of BoNT/C in the extensor digitorum brevis muscle of one foot and 3IU of BoNT/A in the contralateral one. Other 4 subjects were similarly injected at higher doses (10IU of BoNT/C or BoNT/A) to detect a possible dose-toxic effect. RESULTS: In both groups, no statistically significant variations in MUNE counting or single motor unit potential size were detected after 4 months from injections, when it was evident a recovery from the BoNTs blockade. CONCLUSIONS: We conclude that BoNT/C, similarly to BoNT/A, is safe and effective in humans and it could be proposed for a clinical use.