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     

Single‐fiber electromyography of the laryngeal muscles

Single‐fiber electromyography (SFEMG) is useful in the evaluation of disorders of neuromuscular transmission and the assessment of motor unit morphology. Standard EMG techniques are used routinely in the evaluation of laryngeal dysfunction, but the feasibility of laryngeal SFEMG has not been established. We, therefore, performed laryngeal SFEMG in 10 normal individuals to demonstrate the feasibility of the technique and generate preliminary normative data. We also studied 2 patients with amyotrophic lateral sclerosis and 1 patient previously treated with botulinum toxin for comparative purposes. © 1999 John Wiley & Sons, Inc. Muscle Nerve 22: 111–114, 1999     

Botulinum toxin A versus B in sialorrhea: A prospective,randomized, double‐blind,crossover pilot study in patients with amyotrophic lateral sclerosis or Parkinson's disease

Background: Either botulinum toxins (BoNTs) A and B have been used for improving drooling in different neurological conditions. Methods: Consecutive patients affected by Amyotrophic Lateral Sclerosis (ALS) or Parkinson's Disease (PD) accompanied by severe drooling were randomized to receive botulinum neurotoxin type A (BoNT‐A) or B (BoNT‐B) injections into the salivary glands. Following the first treatment, when sialorrhea returned to baseline (at least three months after the first injection), subjects were re‐treated with the other serotype. Ultrasound‐guided injections into parotid and submandibular glands were bilaterally performed: total doses were 250 U BoNT‐A (Dysport) and 2500 U BoNT‐B (Neurobloc). Objective (cotton roll weight) and subjective (ad hoc clinical scales) evaluations were performed at baseline, after 1 and 4 weeks, and every 4 weeks until drooling returned to baseline. Results: Twenty‐seven patients (15 ALS and 12 PD) were enrolled, fourteen completed the study. BoNT‐A and BoNT‐B treatments gave both subjective and objective improvements in all patients. The latency was significantly shorter after BoNT‐B treatments (3.2 ± 3.7 days) compared to BoNT‐A (6.6 ± 4.1 days; P = 0.002). The mean benefit duration was similar at 75 and 90 days for BoNT‐A and BoNT‐B, respectively (P = NS). The only toxin‐related side effect was a change to saliva thickness. Conclusions: Either 250 U Dysport or 2500 U Neurobloc have similar effectiveness and safety in controlling sialorrhea. BoNT‐B has a shorter latency and comparable duration. Cost analysis, considering the doses used in this study protocol favored BoNT‐B treatment. © 2011 Movement Disorder Society     

Distant effects of locally injected botulinum toxin: a double-blind study of single fiber EMG changes

We used single fiber electromyography (SFEMG) to study 42 patients who had enrolled in a double-blind, placebo-controlled trial undertaken to assess the efficacy of botulinum toxin (BTX) injection of neck muscles to treat torticollis. SFEMG in a limb muscle was performed before treatment, 2, and 12 weeks after injection of placebo or BTX. Before treatment, the mean jitter was 26.8 microsec in patients who were to receive BTX, and 25.7 microsec in the placebo group. Two weeks after injection, mean jitter in the group receiving BTX was 43.6 microsec. In the placebo group, it was 26.5 microsec (P = less than .05). Twelve weeks after injection, mean jitter in the BTX group was 35.5; for the placebo group it was 24.5. Fiber density did not change in any patient during the study. There were no remote clinical effects of BTX. Injection of BTX into muscles affected with focal dystonia is a promising and safe treatment, but there are subclinical effects on uninjected muscles.     

Respective potencies of Botox® and Dysport® in a human skin model: A randomized,double‐blind study

Mouse units used to quantify the activity of botulinum A toxin preparations are not equivalent and issues concerning efficacy and safety remain with regard to their respective potencies and diffusion qualities in human tissue. We compared the effects of Botox® (BOT) and Dysport® (DYS) in different doses and dilutions in a human skin model. Eighteen (8 women, 10 men) healthy volunteers, aged 28.4 years ± 5.7 years were injected intradermally with pure saline, BOT and DYS at 16 points in the abdomen in random order and in a double‐blind condition, using two conversion ratios (1:3 and 1:4) and three different dilution schemes. For an objective outcome, the Ninhydrin sweat test was used to compare the anhidrotic areas. Both preparations showed a linear dose and dilution relationship with similar variances of responses for anhidrosis and hypohidrosis, indicating the same reliability of response. The dose equivalence conversion ratios (BOT: DYS) were 1:1.3 for anhidrosis and 1:1.6 for hypohidrosis (1:1.1‐1.5 and 1:1.4‐1.8 95% confidence intervals). The diffusion characteristics of both products were similar. A dose equivalence factor of more than 1:2 (BOT:DYS) is not supported by these objective and reproducible data. © 2008 Movement Disorder Society     

Botulinum toxin type B (Myobloc®) in subjects with hemifacial spasm: Results from an open‐label,dose‐escalation safety study

Ojbective

Evaluate the safety of botulinum toxin type B (BoNT‐B) in subjects with hemifacial spasm (HFS).

Methods

This open‐label, sequential dose‐escalation study evaluated BoNT‐B in subjects with HFS. Eligible subjects were enrolled and received a single injection of one of four sequential BoNT‐B doses (100, 200, 400, or 800 U). Following injection, subjects were evaluated in person at Weeks 2 and 8 and by phone at Weeks 1, 4, and 10 and every 2 weeks thereafter until benefit was lost. Safety was assessed by adverse events (AEs), vital signs and clinical laboratory evaluation. The severity of HFS was assessed using a patient social impairment visual analog scale (VAS), subject severity of contraction VAS, the HFS physician assessment, and subject HFS frequency and severity assessment.

Results

Nineteen predominately Caucasian (92%) and female (67%) subjects (aged 36–80 years) with HFS participated in this study. Subjects remained in the study an average of 88 days (range of 41–332 days) after receiving a single dose of BoNT‐B. No deaths, serious AEs or AEs leading to trial discontinuation occurred during the study period. Two subjects in the 400 U dose group requested early withdrawal, whereas all other subjects completed the study. A reduction in HFS severity was observed in subjects treated with doses of 200 U or more. Improvements in subject HFS assessments tended to return to baseline values by 8 weeks following injection.

Conclusion

BoNT‐B was well‐tolerated and reduced HFS severity in subjects who received injections of 200 to 800 U. Additional investigation is necessary to confirm the findings from this open‐label study. © 2007 Movement Disorder Society     

Corticosteroid iontophoresis to treat carpal tunnel syndrome: A double‐blind randomized controlled trial

Even though injection of corticosteroids into the carpal tunnel alleviates the symptoms of mild to moderately severe carpal tunnel syndrome (CTS), it has not gained universal popularity due to its invasiveness. This study was designed to investigate the effectiveness of dexamethasone iontophoresis as a noninvasive method of treating CTS. We carried out a double‐blind randomized controlled trial comparing six sessions of iontophoresis with 0.4% dexamethasone sodium phosphate with distilled water in 17 patients. Outcome measures including nerve conduction studies, the Levine Self‐Assessment Questionnaire, and the Semmes–Weinstein Monofilaments were done monthly for 6 months after intervention. Most of the outcome measures did not show any significant change following treatment. Although there was subjective improvement of symptom severity scores in the treatment group as quantified by the Levine Self‐Assessment Questionnaire, similar improvement was also observed in the control group (P < 0.05). Although corticosteroid iontophoresis is feasible in clinical settings and is well‐tolerated by patients, iontophoresis of 0.4% dexamethasone was not effective in the treatment of mild to moderate CTS. Muscle Nerve 39: 627–633, 2009     

Comparison of orally dissolving carbidopa/levodopa (Parcopa) to conventional oral carbidopa/levodopa: A single‐dose,double‐blind,double‐dummy,placebo‐controlled,crossover trial

Levodopa use in fluctuating Parkinson's disease (PD) is complicated by an inconsistent and prolonged onset to clinical improvement. An orally dissolved carbidopa/levodopa (OD C/L) preparation (Parcopa UCB Pharma) is available in the United States. This offers potential advantages to shorten the duration from ingestion to clinical improvement. Surprisingly, this has never been clinically assessed. We tested 20 patients with fluctuating PD and a Unified Parkinson's Disease Rating Scale (UPDRS) “off” motor score of ≥25 in a 2‐day, single‐dose, double‐blind, double‐dummy, crossover study. Patients arrived in the morning in the practically defined “off” state and were randomly assigned to receive identical doses of either oral C/L and OD placebo or OD C/L and oral C/L placebo on 1st day and the reverse combination on a 2nd day. After training, patients underwent bilateral hand tapping at baseline and every 5 minutes for 60 minutes after dose ingestion. Stride length (SL) was recorded at 5‐minute intervals with an ambulatory gait monitor. Patients identified their subjective latency to “on” and noted drug preferences and adverse events. They also underwent a UPDRS motor examination at baseline and 60 minutes after dose. Twenty subjects [15 male, age 68.7 (9.7), PD duration 13.4 (6.8)] completed. There were no significant group differences in tapping speed, subjective time to “on,” latency of increased SL, or overall preference. However, all trends did favor OD C/L. Adverse events were similar. This small pilot study did not show significant group differences favoring OD C/L; however, larger studies may be justified, and individual patients may benefit. © 2010 Movement Disorder Society     

Orodispersible sublingual piribedil to abort OFF episodes: A single dose placebo‐controlled,randomized, double‐blind,cross‐over study

S90049, a novel sublingual formulation of the non‐ergoline D₂‐D₃ agonist piribedil, has a pharmacokinetic profile promising to provide rapid relief on motor signs in Parkinson's disease (PD). We assessed the efficacy and safety of S90049 in aborting OFF episodes responding to subcutaneous apomorphine in PD patients with motor fluctuations. This was a single‐dose double‐blind double‐placebo 3 × 3 cross‐over study. Optimal tested doses were determined during a previous open‐label titration phase (S90049 median dose: 60 mg, apomorphine: 5 mg). Primary endpoint was the maximal change versus baseline in UPDRS motor score (ΔUPDRS III) assessed after drug administration following an overnight withdrawal of antiparkinsonian medications. Thirty patients (age: 60 ± 8 years, PD duration: 12 ± 6 years, UPDRS III OFF: 37 ± 15) participated. S90049 wassuperior to placebo on ΔUPDRS III (?13 ± 12 versus ?7 ± 9 respectively; estimated difference ?5.2, 95% Confidence Interval (CI)[?10.4;0.05], P = 0.05). This was also true for secondary outcomes: number of patients switching from OFF to ON (17 on S90049 vs. 8 on placebo, P = 0.03), time to turn ON (P = 0.013) and duration of the ON phase (P = 0.03). In the 17 patients who switched ON on S90049, ΔUPDRS III was similar on S90049 (?21.2 ± 10.1) and apomorphine (?23.6 ± 14.1) (estimated difference: 4.0 95% CI [?2.9;10.9]). S90049 was well tolerated: no serious or unexpected adverse event occurred. A single dose of up to 60 mg of S90049 given sublingually was superior to placebo in improving UPDRS III and aborting a practical OFF in patients with advanced PD. Testing greater doses might improve response rate. © 2009 Movement Disorder Society