Response to "Modifications to the PREEMPT Protocol for OnabotulinumtoxinA Injections for Chronic Migraine in Clinical Practice"

Injection technique of the upper face with onabotulinumtoxinA in chronic migraine

BACKGROUND

The objective is to review the technique of onabotulinumtoxinA injection treatment in the glabellar and frontal regions using the PREEMPT (Phase III REsearch Evaluating Migraine Prophylaxis Therapy) paradigm, with review of the aesthetic issues related to the procedure. OnabotulinumtoxinA is an effective medication for the prevention of chronic migraine. The PREEMPT injection paradigm has been validated in randomized clinical trials and real-world settings. This treatment includes injections in the forehead and glabella area. In addition, for aesthetic uses, glabella onabotulinumtoxinA injections are done in similar muscles specifically the procerus, corrugator supercilii, and frontalis muscles. Often patients who have been injected with onabotulinumtoxinA for chronic migraine have concerns about their appearance and will ask if they can see an aesthetic injector to improve this. This is a difficult issue as onabotulinumtoxinA should be injected with an interval of 10-12 weeks to avoid development of antibodies against onabotulinumtoxinA, so all injections (migraine and aesthetic) should ideally be done close together; however, if an aesthetic injection is done on the same day as a PREEMPT injection, the effect of the PREEMPT injection will not yet be visible as it takes time for onabotulinumtoxinA effects to be seen. Thus, there is a risk of a potential overdose in a particular area if aesthetic injections are done without input from the PREEMPT injector.

METHODS

This is a narrative review supported by photographic documentation showing the technique of onabotulinumtoxinA injection of the upper face, considering anatomical differences between patients, and combining the needs in neurology and aesthetic medicine fields.

RESULTS

Practitioners treating chronic migraine often modify some of the principles of the PREEMPT paradigm. Many practitioners are unsure about injections in the glabellar and frontal areas. The authors present a technique for using the PREEMPT protocol and adapting this to the individual patient's anatomy to prevent an unsightly appearance or ptosis. In addition, sites are provided where an aesthetic injector could inject to improve the patient's appearance without overlapping with the PREEMPT injection sites.

CONCLUSION

Adherence to the PREEMPT injection protocol provides an evidence-based approach to achieving clinical benefit for patients with chronic migraine. Aesthetic elements of the treatment of the glabella and forehead require additional attention. The authors provide practical considerations and recommendations regarding this.

[Botulinum toxin type A (Relatox) in the treatment of chronic migraine in adults: results of phase IIIb, randomized, one-blind, multicenter, active-controlled, parallel-group trial]

OBJECTIVE

To access the efficacy and safety of the first Russian botulinum toxin type A (Relatox) as a headache prophylaxis in adult with chronic migraine (CM).

MATERIAL AND METHODS

The randomized, one-blind, multicenter, active-controlled, parallel-group trial study involved 209 patients with CM aged from 19 to 65 years. The patients were randomized to injections of the Russian botulinum toxin type A - Relatox (n=101) or onabotulinumtoxinA injections - Botox (n=108). The duration of the study was 16 weeks, which included five visits of patients every 4 weeks. Relatox and Botox were injected once into seven muscle groups of the head and neck at a dose of 155-195 units. Primary efficacy variable was mean change from baseline in frequency of headache days after 12 weeks. Secondary efficacy variables were mean changes from the baseline to week 12 in frequency of migraine days, acute headache pain medication intakes days; headache intensity; proportion of patients achieving ≥50% reduction from baseline in headache days, the proportion of the patients with medication overuse, the proportion of the patients with severe (≥60) Headache Impact Test-6 score and with a severe (≥21) MIDAS score.

RESULTS

Analyses demonstrated a large mean decrease from baseline in frequency of headache days, without statistically significant between-group differences Relatox vs Botox at week 12 (-10.89 vs -10.06; p=0.365) and at other time points. Significant differences from baseline were also observed for all secondary efficacy variables at all time points without differences between the groups. The proportion of patients achieving ≥50% reduction from baseline in headache days was 75.0% and 70% in the Relatox and Botox groups, respectively (OR, CI 95% 1.58 [0.84; 3.02], p=0.155). Adverse events (AE) occurred in 15.8% of Relatox patients and 15.7% of Botox patients (p=1.000). No unexpected AE were identified.

CONCLUSION

The results demonstrate that the first Russian botulinum toxin type A (Relatox) is an effective prophylactic treatment for CM in adult patients. Relatox led to significant improvements from baseline in multiple measures of headache symptoms, headache-related disability and quality of life. For the first time, a comparative analysis of two botulinum toxin type A products in parallel groups showed no less (not inferior) efficacy and safety of Relatox relative to Botox in the treatment of CM in adults.

Botulinum Toxin in the Treatment of Headache

Botulinum toxin type A has been used in the treatment of chronic migraine for over a decade and has become established as a well-tolerated option for the preventive therapy of chronic migraine. Ongoing research is gradually shedding light on its mechanism of action in migraine prevention. Given that its mechanism of action is quite different from that of the new monoclonal antibodies directed against calcitonin gene-related peptide (CGRP) or its receptor, it is unlikely to be displaced to any major extent by them. Both will likely remain as important tools for patients with chronic migraine and the clinicians assisting them. New types of botulinum toxin selective for sensory pain neurons may well be discovered or produced by recombinant DNA techniques in the coming decade, and this may greatly enhance its therapeutic usefulness. This review summarizes the evolution of botulinum toxin use in headache management over the past several decades and its role in the preventive treatment of chronic migraine and other headache disorders.