Dysport

Effects of Botulinum Toxin Injection on Reducing Myogenic Artifacts during Video-EEG Monitoring: A Longitudinal Study

Medically refractory seizures affect one-third of patients with epilepsy (PwE), for whom epilepsy surgery is considered. Video electroencephalography (vEEG) monitoring is a fundamental tool for pre-operative seizure localization. Facial and cranial myogenic artifacts can obscure vEEG findings, thus interfering with seizure localization. Studies have shown the beneficial effects of botulinum toxin type A (BTX-A) injection into cranial muscles for reducing myogenic artifacts. This longitudinal study aimed to assess the effects of BTX-A injection on these artifacts. Twenty-two patients with medically refractory hypermotor seizures with daily seizure frequency and undetermined epilepsy localization were included in this study and underwent Dysport® injection (200 units) into the frontotemporal region. vEEG recordings were performed at baseline (one week before the injection), and at three days and six days post-injection. Before and after the injection, the amplitudes of myogenic artifacts were compared during various states (ictal, blinking, chewing, bruxism, head lateralization, scowling, talking, and yawning). BTX-A injection significantly reduced the amplitudes of EEG myogenic artifacts, except during blinking (day three) and talking (days three and six). On day six, significant reduction in EEG myogenic artifacts were noted during blinking, chewing, and bruxism for the greatest number of patients (95.5%, 90.9%, 81.8%), while significant reductions in EEG myogenic artifacts during talking, head lateralization, and ictal phase were associated with the least number of patients (22.7%, 36.3%, and 40.9%). Therefore, BTX-A injection could be a convenient method for filtering myogenic contamination, improving EEG interpretation, and facilitating seizure localization in patients with medically refractory seizures.

Overview of Botulinum Toxins for Aesthetic Uses

Botulinum toxin type A (BTA) can be used for facial aesthetics. The 3 currently available BTA types include onabotulinumtoxinA (Botox; Botox Cosmetic, Allergan, Irvine, CA), abobotulinumtoxinA (Dysport; Ipsen, Ltd, Berkshire, UK), and incobotulinumtoxinA (Xeomin; Merz Pharmaceuticals, Frankfurt, Germany). The mechanism of action and clinical uses for treatment of dynamic lines of the forehead, brow, glabella, lateral orbit, nose, and lips are presented, as well as treatment of masseter hypertrophy, platysmal bands, and improvements of the perioral region. Specific BTA injection sites and suggested doses are presented.

Aesthetic Uses of Neuromodulators: Current Uses and Future Directions

BACKGROUND

The introduction of neuromodulators for aesthetic facial improvements greatly expanded the limits of nonsurgical facial rejuvenation. Although many current uses are considered "off-label," the widespread acceptance and favorable safety profile of properly used botulinum toxins have made them one of the most common aesthetic treatments available.

METHODS

A literature review of current facial aesthetic uses of various botulinum toxin preparations was done, and general concepts were identified.

RESULTS

Currently, Food and Drug Administration-approved botulinum toxin preparations onabotulinumtoxinA (Botox), abobotulinumtoxinA (Dysport), and incobotulinumtoxinA (Xeomin) have similar off-label indications and clinical uses.

CONCLUSIONS

Although not considered interchangeable, administration and clinical outcomes are not much different between the 3 commonly used botulinum products. The impact of botulinum products currently in development has yet to be determined.

The evolution of botulinum neurotoxin type A for cosmetic applications

Very few pharmaceutical preparations share an evolutionary history as remarkable as that of botulinum neurotoxin (BoNT). The exotoxin of the organism Clostridium botulinum, once feared as a terrible poison, has been reborn as a highly regarded and widely used therapeutic and aesthetic agent. In less than two decades since the report of the success of BoNT type A (BoNTA) in reducing glabellar lines, injection of this product has become the most common non-surgical cosmetic procedure performed in the USA and worldwide. In addition to temporarily eliminating rhytids by muscle weakening, other dermatologic applications of BoNTA include correcting facial asymmetries and treating hyperhidrosis. Although BOTOX is the most clinically substantiated and published of the BoNTA preparations, other BoNTA products, as well as a BoNT type B product, are available in some parts of the world, and others are in development.

Neurologic uses of botulinum neurotoxin type A

This article reviews the current and most neurologic uses of botulinum neurotoxin type A (BoNT-A), beginning with relevant historical data, neurochemical mechanism at the neuromuscular junction. Current commercial preparations of BoNT-A are reviewed, as are immunologic issues relating to secondary failure of BoNT-A therapy. Clinical uses are summarized with an emphasis on controlled clinical trials (as appropriate), including facial movement disorders, focal neck and limb dystonias, spasticity, hypersecretory syndromes, and pain.

Comparison of botulinum neurotoxin preparations for the treatment of cervical dystonia

BACKGROUND

Comparative studies of botulinum neurotoxin preparations to date have generally examined 2 preparations at prespecified dose ratios in relatively homogeneous groups of patients under controlled study conditions. It is unclear whether the differences in adverse-event rates that have been noted under these controlled conditions can be generalized to the broader population of cervical dystonia patients, who are treated with a wider range of doses in a variety of settings.

OBJECTIVE

We conducted a systematic review and analysis of the published literature to compare rates of dysphagia and dry mouth in studies of botulinum neurotoxin products.

METHODS

We searched the MEDLINE, EMBASE, Biosis, SciSearch, JICST (Japan Science and Technology Center), and Pascal databases from 1985 through 2006 using the terms cervical dystonia, spasmodic torticollis, and botulinum toxin for original English-language studies of Botox, Dysport, or Myobloc in the treatment of cervical dystonia (or spasmodic torticollis) that documented adverse events by treatment or patient. Studies that involved patients with various types of dystonias or movement disorders were included as long as adverse events were reported separately for those with cervical dystonia. Rates of dysphagia with the original preparation of Botox were considered separately from those with the current preparation of Botox.

RESULTS

Seventy published articles were included in the analysis (30 Botox, 24 Dysport, 3 Botox + Dysport, 11 Myobloc, 2 Botox + Myobloc). Mean total doses per treatment ranged from 60 to 374 U for Botox, 125 to 1200 U for Dysport, and 579 to 19,853 U for Myobloc. Botox was associated with a significantly lower rate of dysphagia than Dysport, with mean dysphagia rates of 10.5% for original Botox, 8.9% for current Botox, and 26.8% for Dysport (both, P < 0.05). Myobloc was associated with dry mouth (3.2%-90.0%) in 9 of 13 studies, but this adverse event was not reported in a sufficient number of studies of botulinum toxin type A preparations (Botox, n = 2; Dysport, n = 6) to permit statistical comparison. In the weighted analysis, the duration of effect differed between botulinum neurotoxin products (current Botox > Myobloc > original Botox > Dysport; all, P < 0.001), but only 43 (61.4%) of the 70 studies reported duration, and the definitions varied.

CONCLUSION

The results of this analysis indicate differences in adverse-event rates between botulinum neurotoxin preparations, suggesting that use of these products should be based on their individual dosing, efficacy, and safety profiles.

Botulinum neurotoxins: fundamentals for the facial plastic surgeon

The most commonly performed nonsurgical cosmetic procedure in the facial plastic surgery armamentarium involves the various commercial preparations of botulinum neurotoxins. These drugs have undergone a transformation from public health scourge to near ubiquitous therapeutic modality across the entire medical spectrum. Herein, the history of botulinum neurotoxins is reviewed, including an exploration of their pharmacology, neuromuscular junction physiology, a description of the commercially available preparations, and the recent research concerning the practicalities of their clinical use.

Botulinum neurotoxin type A in facial aesthetics

Injection of botulinum neurotoxin type A has rapidly become the most common non-surgical cosmetic procedure performed, due to its exceptional safety profile, as well as its ability to rejuvenate and enhance a number of facial areas. There are several marketed botulinum neurotoxin preparations, but products are not interchangeable as each possesses distinctive characteristics that are attributed to the unique toxin purification and manufacturing processes. These differences can emerge in the form of potency, duration of effect and the potential for migration outside targeted tissue, causing unwanted effects. However, although there are established preclinical pharmacologic and therapeutic differences between products, there are few well-controlled clinical comparisons in facial aesthetics. It is important for clinicians using these products to understand these differences as they relate to achieving desired outcomes for patients who seek improved facial aesthetics.

Cloning, Expression, Purification, and Characterization of Biologically Active Recombinant Hemagglutinin-33, Type A Botulinum Neurotoxin Associated Protein

Botulinum neurotoxin type A, the most toxic substance known to mankind, is produced by Clostridiurn botulinum type A as a complex with a group of neurotoxin-associated proteins (NAPs) through polycistronic expression of a clustered group of genes. Hemagglutinin-33 (Hn-33) is a 33 kDa subcomponent of NAPs, which is resistant to protease digestion, a feature likely to be involved in the protection of the botulinum neurotoxin from proteolysis. In order to fully understand the function of Hn-33, large amounts of Hn-33 will be needed without dealing with biosafety risks to grow large cultures of C. botulinum. There are difficulties to clone the genes with the high A + T contents produced by C. botulinum. We report here for the first time using the Gateway technology to clone functional Hn-33 that has been expressed in E. coli. The yield of the recombinant Hn-33 was about 12 mg per liter of E. coli culture. The recombinant Hn-33 folds well in aqueous solution as shown with circular dichroism spectra, resists temperature-denaturation, is totally resistant to trypsin proteolysis despite the presence of cleavage sites on the molecular surface, and maintains its biological activities comparable to the native Hn-33 hemagglutination.

Repeated Botulinum Toxin A Injections for the Treatment of Lines in the Upper Face: A Retrospective Study of 4,103 Treatments in 945 Patients

BACKGROUND

Although botulinum toxin type A (BoNT-A) is a common aesthetic intervention, there are few published data on treatment over more than two cycles.

OBJECTIVE

To evaluate the effectiveness/safety of repeated doses of BoNT-A (Dysport, Ipsen Ltd., Slough, UK) in the upper face for reduction of wrinkles.

METHODS

Retrospective, cross-sectional patient chart review from 945 patients who had received a minimum of three consecutive, documented treatment cycles.

RESULTS

The glabella was treated most frequently (93.9%), with the majority (81.5%) of patients receiving treatment in more than one area of the face. BoNT-A treatments were combined with other aesthetic procedures in 57.5% of cases, mostly with fillers (37.1%). There was no evidence of tachyphylaxia: the dose applied, the interval between treatments, and satisfaction with the results remained stable over the course of treatment. Adverse events were those expected with BoNT-A treatment (most common: local bruising and ptosis) and were all mild or moderate in intensity. There was no sign of any cumulative adverse effects: indeed, the adverse-event rate decreased in later treatment cycles.

CONCLUSIONS

Long-term, repeated injections of BoNT-A for corrections of wrinkles in the upper face yield a continuously high level of safety and effectiveness in actual practice.

Treatment of headaches with botulinum toxin

Primary headache disorders, such as migraine, chronic daily headache (CDH), and chronic tension-type headache (CTTH), are some of the most frequent disorders encountered by physicians in the outpatient setting. Chronic headache disorders cause significant morbidity and functional impairment. Despite important advances in both pharmacological and behavioral management of headache disorders, a number of patients remain treatment resistant. Botulinum toxin (BT) is emerging as a new therapeutic alternative in the preventative treatment of headaches. BT has several advantages over current prophylactic strategies, such as reduced side-effect profile and improved patient compliance. Furthermore, there have been several studies supporting the safety and tolerability of BT in the treatment of headache disorders. Although additional large-scale studies are needed to clarify clinical predictors of response as well as optimal dosing, injection sites and mechanism of action, BT has demonstrated efficacy in the treatment of migraines and CDH. The evidence for the treatment for CTTH is less compelling.

Hemagglutinin-33 of type A botulinum neurotoxin complex binds with synaptotagmin II

Botulinum neurotoxin type A (BoNT/A), the most toxic substance known to mankind, is produced by Clostridium botulinum type A as a complex with a group of neurotoxin-associated proteins (NAPs) through polycistronic expression of a clustered group of genes. NAPs are known to protect BoNT against adverse environmental conditions and proteolytic digestion. Hemagglutinin-33 (Hn-33) is a 33 kDa subcomponent of NAPs that is resistant to protease digestion, a feature likely to be involved in the protection of the botulinum neurotoxin from proteolysis. However, it is not known whether Hn-33 plays any role other than the protection of BoNT. Using immunoaffinity column chromatography and pull-down assays, we have now discovered that Hn-33 binds to synaptotagmin II, the putative receptor of botulinum neurotoxin. This finding provides important information relevant to the design of novel anti-botulism therapeutic agents targeted to block the entry of botulinum neurotoxin into nerve cells.