comparing lower-concentration dysport treatment targeted to the neuromuscular junction with current clinical practice

Conditions: Arm Spasticity

Summary: the aim of the study was to compare dysport treatment results (as assessed by modified ashworth scale (mas) in the elbow joint 4 weeks post treatment) following two treatment techniques: the current clinical practice injection technique using high-concentration dilution (300 u/ml dysport) versus the neuromuscular junction (nmj)-targeted injection technique using low-concentration dilution (100 u/ml dysport). the hypothesis was that one high-volume, low-concentration injection located centrally in the area/band of the nmj zones would be as effective as the technique used in current medical practice.

this was a randomised, evaluator-blinded, comparative, parallel group, multicentre study, conducted in four countries (denmark, finland, norway and sweden). for each subject, the primary efficacy assessments using mas were performed by the same blinded evaluator, and every effort was made at each site to ensure that the mas evaluator was the same person throughout the study. dysport doses were to follow clinical practice for subjects suffering from upper limb spasticity position pattern type 1, 3 or 4 post stroke or traumatic brain injury. the hypothesis for this study was that one low-concentration botulinum neurotoxin type a (bont-a) injection per muscle, centrally located in the area/band of the nmj zones, would spread to and block the surrounding nmj zones and be as effective as the technique used today in clinical practice. the possibility to reduce the number of injection points would decrease the risk of injection discomfort, pain and injection site bleeding for the patient. a simplified injection technique with one injection per muscle and in a defined location would also benefit physicians. at baseline (visit 1), subjects were randomised to one of two treatment groups: * group 1: current clinical practice technique and high-concentration dilution: dysport 300 u/ml. * group 2: nmj targeted technique and low-concentration dilution: dysport 100 u/ml. each subject visited the clinic on at least three occasions: * baseline (visit 1): screening, randomisation and dysport treatment. * week 4 (visit 2): treatment follow-up, 4 weeks after dysport treatment. * week 12 (visit 3): treatment and study follow-up, 12 weeks after dysport treatment. for subjects not receiving any post study bont-a injection at week 12 due to remaining treatment effect, an extra visit (visit 4) for study follow-up was to take place at the next routine visit planned for a new bont-a injection, at the latest 24 weeks post study injection. the duration of each subject's study period was at a minimum 12 weeks and maximum 24 weeks. the overall duration of the study was planned to be approximately 36 months.

Eligibility criteria:
inclusion criteria: * provision of written informed consent prior to any study related procedures. * subjects male or female, aged 18 years or older. * upper limb spasticity post stroke or traumatic brain injury. * spasticity position pattern type 1, 3 or 4. * elbow flexor muscles spasticity mas 2 to 3. * at least 2 consecutive previous treatment cycles of bont-a for current diagnosis. * the latest treatment cycle demonstrating good treatment efficacy where the dysport dose administered was considered to be adequate according to investigator judgement. * need of the same treatment modality in muscle (m.) brachialis, m. biceps brachii, m. brachioradialis, m. flexor carpi ulnaris, m. flexor carpi radialis as the previous treatment cycle. * last bont-a treatment 12-24 weeks ago. exclusion criteria: * poor response to bont-a treatment, according to investigator. * need of dysport doses \>800 u in the upper limb. * concomitant treatment with bont-a for other indications than spasticity. * any elbow flexor contracture prohibiting mas evaluation and/or elbow flexion improvement of at least 1 step on the mas. * cutaneous or joint inflammation in the affected upper limb. * was likely to start other spasticity treatment during the study. * was likely to start physiotherapy treatment during the study. * other ongoing neurological disorder (e.g., myasthenia gravis). * history of dysphagia or aspiration. * use of agents interfering with neuromuscular transmission (e.g., aminoglycosides). * treated with an investigational medicinal product within 30 days before start of the study. * known sensitivity to bont-a or any components of dysport. * was at risk of pregnancy or was lactating. females of childbearing potential must have provided a negative pregnancy test (urinary human chorionic gonadotropin (u-hcg)) at visit 1 and must have been using adequate contraception. non-childbearing potential was defined as post-menopause for at least one year, surgical sterilisation or hysterectomy at least three months before the start of the study. * had a history of, or known current, problems with alcohol or drug abuse. * had a mental condition rendering the subject unable to understand the nature, scope and possible consequences of the study, and/or evidence of an uncooperative attitude. * had abnormal baseline findings, any other medical condition(s) or laboratory findings that, in the opinion of the investigator, might have jeopardised the subject's safety or decreased the chance of obtaining satisfactory data needed to achieve the objective(s) of the study.

Keywords: dysport arm spasticity modified ashworth scale neuromuscular junction botulinum toxin upper limb spasticity