High-dose Botulinum Toxin Therapy: Safety, Benefit, and Endurance of Efficacy

Is Vibration Anesthesia Effective and Safe for Pain Reduction in Botulinum Toxin Injection? A Randomized Split-Face Controlled Trial and Cadaver Experiment

BACKGROUND

Pain is an important issue in botulinum toxin injection. Vibration anesthesia is a noninvasive method for pain alleviation, but few studies have reported its use during botulinum toxin injection.

OBJECTIVES

The aim of this study was to investigate whether vibration anesthesia was effective and safe for pain reduction during botulinum toxin injection for masseter reduction.

METHODS

A randomized split-face controlled trial was performed in patients who required masseter reduction. Vibration anesthesia was randomly administered on either side. Study outcomes were pain scores on a visual analog scale, duration of effect, satisfaction, and complications. Intergroup comparison and linear regression analyses were performed.

RESULTS

In a total of 216 patients, the pain score on the vibration side (2.97 ± 1.44) was significantly lower than that on the nonvibration side (4.72 ± 2.13) (P < .0001), with a higher proportion of mild pain. Linear regression showed that a history of injection and more injection points and doses increased the pain, whereas a 2-mL syringe reduced the pain compared to a 1-mL syringe. Side effects were found in 19 patients and 21 sides (7%), but were not associated with vibration. High satisfaction was reported. A cadaver experiment confirmed that vibration did not alter the diffusion radius and depth of injection.

CONCLUSIONS

Vibration anesthesia significantly relieved pain during botulinum toxin injection for masseter reduction, and it did not cause adverse effects and or affect duration of effect. Therefore, we recommend vibration anesthesia, a larger syringe size, and fewer injection points to improve patient experience and satisfaction.

LEVEL OF EVIDENCE: 3 (THERAPEUTIC)

Intramuscular Injection of BOTOX® Boosts Learning and Memory in Adult Mice in Association with Enriched Circulation of Platelets and Enhanced Density of Pyramidal Neurons in the Hippocampus

BOTOX® is a therapeutic form of botulinum neurotoxin. It acts by blocking the release of acetylcholine (ACh) from the synaptic vesicles at the neuromuscular junctions, thereby inhibiting the muscle contraction. Notably, many neurological diseases have been characterized by movement disorders in association with abnormal levels of ACh. Thus, blockade of aberrant release of ACh appears to be a potential therapeutic strategy to mitigate many neurological deficits. BOTOX® has widely been used to manage a number of clinical complications like neuromuscular disorders, migraine and neuropathic pain. While the beneficial effects of BOTOX® against movement disorders have extensively been studied, its possible role in the outcome of cognitive function remains to be determined. Therefore, we investigated the effect of BOTOX® on learning and memory in experimental adult mice using behavioural paradigms such as open field task, Morris water maze and novel object recognition test in correlation with haematological parameters and histological assessments of the brain. Results revealed that a mild dose of BOTOX® treatment via an intramuscular route in adult animals improves learning and memory in association with increased number of circulating platelets and enhanced structural plasticity in the hippocampus. In the future, this minimally invasive treatment could be implemented to ameliorate different forms of dementia resulting from abnormal ageing and various neurocognitive disorders including Alzheimer's disease (AD).

Perspectives for the use of therapeutic Botulinum toxin as a multifaceted candidate drug to attenuate COVID-19

The recent outbreak of coronavirus disease (COVID-19) resulting from a distinctive severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) continues to evolve in many countries and pose life-threatening clinical issues to global public health. While the lungs are the primary target for the SARS-CoV-2-mediated pathological consequence, the virus appears to invade the brain and cause unpredicted neurological deficits. In the later stage, COVID-19 can progress to pneumonia, acute respiratory failure, neurodegeneration and multi-organ dysfunctions leading to death. Though a significant portion of individuals with COVID-19 has been recovering from clinical symptoms, the pathological impact of the SARS-CoV-2 infection on the structural and functional properties of the lungs, heart, brain and other organs at the post-recovery state remains unknown. Presently, there is an urgent need for a remedial measure to combat this devastating COVID-19. Botulinum toxins (BoNTs) are potent neurotoxins that can induce paralysis of muscle and acute respiratory arrest in humans. However, a mild dose of the purified form of BoNT has been known to attenuate chronic cough, dyspnoea, pneumonia, acute respiratory failure, abnormal circulation, cardiac defects and various neurological deficits that have been recognised as the prominent clinical symptoms of COVID-19. Considering the fact, this review article provides 1) an overview of the SARS-CoV-2 mediated pathological impact on the lungs, heart and brain, 2) signifies the therapeutic uses of BoNTs against pulmonary failure, cardiac arrest and neurological deficits, and 3) emphasize the rationality for the possible use of BoNT to prevent SARS-CoV-2 infection and manage COVID-19.

High Dosage of Botulinum Toxin Type A in Adult Subjects with Spasticity Following Acquired Central Nervous System Damage: Where Are We at?

Spasticity is a common disabling disorder in adult subjects suffering from stroke, brain injury, multiple sclerosis (MS) and spinal cord injury (SCI). Spasticity may be a disabling symptom in people during rehabilitation and botulinum toxin type A (BTX-A) has become the first-line therapy for the local form. High BTX-A doses are often used in clinical practice. Advantages and limitations are debated and the evidence is unclear. Therefore, we analysed the efficacy, safety and evidence for BTX-A high doses. Studies published from January 1989 to February 2020 were retrieved from MEDLINE/PubMed, Embase, Cochrane Central Register. Only obabotulinumtoxinA (obaBTX-A), onabotulinumtoxinA (onaBTX-A), and incobotulinumtoxinA (incoBTX-A) were considered. The term “high dosage” indicated ≥ 600 U. Thirteen studies met the inclusion criteria. Studies had variable method designs, sample sizes and aims, with only two randomised controlled trials. IncoBTX-A and onaBTX-A were injected in three and eight studies, respectively. BTX-A high doses were used predominantly in treating post-stroke spasticity. No studies were retrieved regarding treating spasticity in MS and SCI. Dosage of BTX-A up to 840 U resulted efficacious and safety without no serious adverse events (AEs). Evidence is insufficient to recommend high BTX-A use in clinical practice, but in selected patients, the benefits of high dose BTX-A may be clinically acceptable.

A pragmatic approach to Botulinum Toxin safety

Botulinum Toxin (BoNT) is widely used to treat hypertonia in pediatric patients. Although serious adverse events (AEs) occur infrequently, they can lead to significant patient morbidity and mortality. This paper will discuss potential safety risks that may affect outcomes, medical comorbidities, medication dosing, targeting techniques, and muscle morphology. It is the responsibility of the physician to discuss risks and benefits regarding the use of BoNT and mitigate risks of AEs while maximizing the effectiveness of the medication.