Benefits, Safety, and Adjunct Modality Prevalences of Long-Term Botulinum Toxin Injections for Cervical Dystonia and Myofascial Neck Pain: A Retrospective Cohort Study

Pain Reduction With AbobotulinumtoxinA for the Treatment of Hallux Valgus in Adult Participants: Results of a Randomized and Placebo-Controlled Phase 2 Trial

AbobotulinumtoxinA (aboBoNT-A, Dysport® [Ipsen, Paris, France]) inhibits acetylcholine release at the neuromuscular junction and may modulate pain signaling in hallux valgus (HV). This randomized study (NCT03569098) included a double-blind phase (aboBoNT-A 300U, 500U or placebo injections into forefoot muscles) and an open-label aboBoNT-A treatment period in participants with an HV diagnosis and no HV surgery. The primary endpoint was change from baseline in numeric pain rating scale (NPRS) score at week 8. Secondary endpoints included change in NPRS (other time points) and proportion of participants with ≥20% reduction from baseline NPRS (responders). Post-hoc analyses assessed number of days in a 7-day evaluation period that participants spent in a lower pain state than at baseline. Participants received aboBoNT-A 300U (n = 63), 500U (n = 60) or placebo (n = 63). Superiority to placebo was not observed with either aboBoNT-A dose at week 8, thus the primary endpoint was unmet. At week 12, a trend toward efficacy was observed with aboBoNT-A 500U versus placebo and the proportion of participants with ≥20% reduction from baseline NPRS was greater with aboBoNT-A 500U versus placebo (p = .006). Participants in the aboBoNT-A 500U group spent more days with lower NPRS than their lowest baseline score, and with NPRS ≥2 points lower than their mean baseline NPRS at weeks 8 and 12 versus placebo (all p < .05; post-hoc). AboBoNT-A was well tolerated. Although the primary endpoint was unmet, other endpoints showed a nominal advantage for aboBoNT versus placebo for treatment of HV-related pain, particularly at week 12. Further clinical evaluation is needed to establish whether botulinum toxins represent a viable non-operative treatment option for HV-associated pain. PLAIN LANGUAGE SUMMARY: Hallux valgus is the medical name for a bunion, a foot deformity that can worsen over time. Patients with bunions experience pain and walking can become difficult, which can affect their quality of life. Foot support aids (e.g., braces, splints and inserts) are available, but surgery is the standard treatment. This study looked at how injections of a specific type of botulinum toxin, called abobotulinumtoxinA or "aboBoNT-A", into the foot may help to reduce pain in patients with bunions. The study included 186 patients aged 18 to 75 years who had not had surgery on their bunion. The researchers looked at how well the injections worked using scales that measure the pain levels the patient experienced. The main outcome was whether patients who had aboBoNT-A injections had less pain after 8 weeks than they did before treatment. The study included patients who were injected with saltwater (no treatment) to check that any treatment effect was real. Researchers also looked at the results after 12 weeks, as well as how many patients had less pain after treatment than before and how many days in a given week patients experienced less pain after treatment than they did before. There was no reduction in pain levels with aboBoNT-A injections after 8 weeks compared with no treatment. However, the other study outcomes suggested that aboBoNT-A resulted in a small benefit compared with no treatment, especially after 12 weeks. Further medical research is needed to establish whether botulinum toxins represent an alternative treatment to surgery for the pain associated with bunions.

Expert consensus on the diagnosis and treatment of myofascial pain syndrome

Myofascial pain syndrome (MPS) is characterized by myofascial trigger points and fascial constrictions. At present, domestic and foreign scholars have not reached a consensus on the etiology and pathogenesis of MPS. Due to the lack of specific laboratory indicators and imaging evidence, there is no unified diagnostic criteria for MPS, making it easy to confuse with other diseases. The Chinese Association for the Study of Pain organized domestic experts to formulate this Chinese Pain Specialist Consensus on the diagnosis and treatment of MPS. This article reviews relevant domestic and foreign literature on the definition, epidemiology, pathogenesis, clinical manifestation, diagnostic criteria and treatments of MPS. The consensus is intended to normalize the diagnosis and treatment of MPS and be used by first-line doctors, including pain physicians to manage patients with MPS.

Long-term therapy with botulinum toxin in facial synkinesis: Retrospective data analysis of data from 1998 to 2018

OBJECTIVES

Treatment with botulinum toxin A (BoNT) is the therapy of choice for many patients with facial synkinesis. Repeated injections relieve hypertonicity and hyperkinesis of reinnervated mimic muscles. Aim of the study was to prove if the injection regime and dosage of BoNT change during long-time therapy.

DESIGN

Retrospective analysis of patients´ data, who were treated for synkinesis with BoNT from 1998 to 2018.

SETTING

Tertiary referral facial nerve centre.

PARTICIPANTS

Injection pattern of BoNT was based on clinical symptoms, observations of the specialist and on previous treatment pattern. Onabotulinumtoxin (OnaBoNT), Incobotulinumtoxin (IncoBoNT) and Abobotulinumtoxin (AboBoNT) were available for treatment. Patients consulted our department for following treatment as soon as the symptoms re-occurred.

MAIN OUTCOME MEASURES

Change in dosage and injection pattern, the time intervals between treatments over the entire therapy period.

RESULTS

Seventy-three patients were repeatedly injected. The median number of treatments was 18, the median treatment interval was 3.0 months. During the initial treatment, orbicularis oculi and the mentalis muscles were the most frequently injected muscles (94%). During repeated treatment, the number of injected muscles increased significantly (P < .0001), whereas the dose per muscle remained stable. The initial dose was 24 U (95%-CI 22-27 U) for OnaBoNT and IncoBoNT; 69 U for AboBoNT(95%-CI 44-94 U). We observed a significant increase in dosage for OnaBoNT and IncoBoNT (P < .0001) during the long-term therapy. The time intervals between treatments were stable for all three BoNT preparations (P > .05).

CONCLUSIONS

We observed significant change in treatment dose and injection pattern of BoNT in patients with facial synkinesis. These results provide an orientation in dose finding and injection regimen of BoNT in the long-term course of therapy.

Targeting pain in the long-term treatment of cervical dystonia with botulinum toxin A

AIMS

Cervical pain is one of the most common non-motor symptoms of cervical dystonia (CD) and affects from 54.6% to 88.9% of patients. To date, minority of studies investigated the relevance of pain in a long-term botulinum toxin (BoNT) therapy of CD. The aim of the study was to define an impact of cervical pain on the disease severity and disability, as well as to assess antinociceptive BoNT efficacy in a long-term treatment of CD.

MATERIALS AND METHODS

In this case-control study, CD patients who received stable doses of BoNT for at least 3 years were assessed with the use of validated scales. Participants were divided into two groups depending on the occurrence of CD-related pain.

RESULTS

We examined 50 participants who received a mean of 24 injection cycles (6-51) of BoNT during a mean treatment period of 10.3 years (3.0-23.5). Participants with cervical pain (68.0%) were characterized by higher scores in all scales used in this study: TWSTRS severity (p = 0.030), disability (p < 0.001), total (p < 0.001) and TSUI score (p = 0.046). Pain reduction following BoNT injection lasted longer than muscle relaxation in 85.3% of patients. Pain improvement between first and last BoNT injection cycle was reported by 76.5% of patients with CD-related pain.

CONCLUSIONS

The presence of cervical pain in CD may increase the severity of muscular symptoms and disease-related disability. BoNT has a noticeable antinociceptive effect in the long-term treatment of CD.