Botulinum toxin type A (BOTOX) for treatment of migraine

Quality of information on Instagram about masseter botox injection for bruxism

STATEMENT OF PROBLEM

Nowadays, masseter botulinum toxin injections are frequently used to treat bruxism. People first search for social media resources for their health-related problems. However, the quality of the information on Instagram about masseter botox injection for bruxism is unknown.

PURPOSE

The aim of this study was to evaluate the quality ant content of the Instagram posts shared publicly about masseter botox. The hashtag #masseterbotox was searched on Instagram.

MATERIALS AND METHODS

A total of 1000 posts were scanned. Unrelated posts were excluded from the study. The video posts were evaluated by using Global Quality Scale (GQS) and reliability of information toolkits.

RESULTS

One-hundred seventy-nine photograph and 65 video posts that met the criteria were analyzed. Most of the posts were posted by doctors and healthcare professionals (151 posts), followed by clinics (87 posts) and patients (6 posts). The information reliability scores of Instagram video posts about #masseterbotox were found to be very low (1.34±1.28). Number of views, reliability of information and GQS scores were not statistically significant between groups according to the source of the video posts (p>.05). GQS scores were higher in experience videos than information and advertisement videos (p<.05).

CONCLUSIONS

Clinicians should warn their patients about the reliability of information on Instagram and should guide them to the right social media resources.

CLINICAL IMPLICATIONS

Dental professionals should direct their patients about masseter botox injections to the right resources on social media platforms.

Outpatient Approach to Resistant and Refractory Migraine in Children and Adolescents: a Narrative Review

PURPOSE OF REVIEW

Migraine is one of the top reasons for consulting a pediatric neurologist. Although the majority of children and adolescents who receive evidence-based first-line interventions for migraine will improve substantially, a subset of patients develop resistant or refractory migraine.

RECENT FINDINGS

In this review, we summarize the level of evidence for a variety of acute and preventive treatment options to consider in children and adolescents with resistant or refractory migraine. We describe the level of evidence for interventional procedures (onabotulinumtoxinA injections, greater occipital and other nerve blocks), neuromodulation (single-pulse transcranial magnetic stimulation, external trigeminal nerve stimulation, remote electrical neuromodulation, and non-invasive vagal nerve stimulation), calcitonin gene-related peptide (CGRP) pathway antagonists (anti-CGRP monoclonal antibodies and gepants), psychological therapies, and manual therapies (acupuncture, craniosacral therapy, massage and physical therapy, and spinal manipulation).

Using Botulinum Toxin A for Treatment of Interstitial Cystitis/Bladder Pain Syndrome-Possible Pathomechanisms and Practical Issues

Treatment for patients with interstitial cystitis/bladder pain syndrome (IC/BPS) is always challenging for urologists. The main mechanism of the botulinum toxin A (BoNT-A) is inhibition of muscle contraction, but the indirect sensory modulation and anti-inflammatory effect in the bladder also play important roles in treating patients with IC/BPS. Although current guidelines consider BoNT-A injection to be a standard treatment, some practical issues remain debatable. Most clinical evidence of this treatment comes from retrospective uncontrolled studies, and only two randomized placebo-control studies with limited patient numbers have been published. Although 100 U BoNT-A is effective for most patients with IC/BPS, the potential efficacy of 200 U BoNT-A has not been evaluated. Both trigone and diffuse body BoNT-A injections are effective and safe for IC/BPS, although comparison studies are lacking. For IC/BPS patients with Hunner’s lesion, the efficacy of BoNT-A injection remains controversial. Most patients with IC/BPS experience symptomatic relapse at six to nine months after a BoNT-A injection, although repeated injections exhibit a persistent therapeutic effect in long-term follow-up. Further randomized placebo-controlled studies with a larger number of patients are needed to support BoNT-A as standard treatment for patients with IC/BPS.

OnabotulinumtoxinA injections in chronic migraine, targeted to sites of pericranial myofascial pain: an observational, open label, real-life cohort study

Background

OnabotulinumtoxinA has proven its efficacy in reducing the number of headache days in chronic migraine (CM) patients. The usual paradigm includes 31 pericranial injection sites with low dose (5 U) per site. The aim of this study is to present the results obtained using a simpler injection protocol of onabotulinumtoxinA, with injection sites targeted to pericranial myofascial sites of pain.

Methods

Observational, open label, real-life, cohort study. We enrolled 63 consecutive patients fulfilling the diagnostic criteria of CM, and refractory to conventional treatments. The patients were injected using a “follow-the-pain” pattern into the corrugator and/or temporalis and/or trapezius muscles. The doses per muscle were fixed. According to the number of muscles injected, the total dose could vary from 70 to 150 U per session. Patients were considered responders if they had a ≥ 50% decrease in number of headache days in at least two consecutive injection cycles.

Results

Forty one patients (65.1% in intention to treat analysis) responded to treatment. In 70.7% of responders, the effect size was even higher, with a reduction ≥70% in the number of headache days. The associated cervical pain and muscle tenderness, present in 33 patients, was reduced by ≥50% in 31 patients (94%). Triptan consumption dramatically decreased (81%) in responders. The trapezius was the most frequently injected muscle. We observed no serious adverse event. The mean patient satisfaction rate was 8.5/10.

Conclusions

This study provides additional robust evidence supporting the efficacy of onabotulinumtoxinA injections in CM. Furthermore, the paradigm we used, with reduced number of injection sites targeted to pericranial myofascial sites of pain, may provide evidence in favor of the implication of myofascial trigger points in migraine chronicization.

Trial Registration

ClinicalTrials.gov Protocol Record I17022 ClinicalTrials.gov Identifier: NCT03175263.

Date of registration: June 7, 2017. Retrospectively registered.

OnabotulinumtoxinA for trigeminal neuralgia: a review of the available data

Trigeminal neuralgia (TN) patients may develop side effects from centrally acting drugs, have contraindications for neurosurgical procedures, or experience relapse during conventional therapies. OnabotulinumtoxinA (BoNT/A) has been reported to be effective for TN, although this finding has been challenged. An overview of the available evidence based on a narrative/qualitative analysis of the literature is presented. About 90% of patients who receive BoNT/A show an improvement, a higher figure than that reported for the placebo effect of BoNT/A for other headaches. Tolerability of BoNT/A is good, and its few side-effects are transient. The articles reviewed were mainly case reports, case series and open-label trials; however, randomized controlled trials have endorsed the efficacy of BoNT/A for TN. This evidence, together with a better understanding of the analgesic mechanisms of BoNT/A and its proven efficacy in treating other pain syndromes, supports the use of this toxin as a therapeutic option for TN.

Two doses of botulinum toxin type A for the treatment of trigeminal neuralgia: observation of therapeutic effect from a randomized, double-blind, placebo-controlled trial

BACKGROUND

In the majority of cases, trigeminal neuralgia (TN) is a unilateral condition with ultra-short stabbing pain located along one or more branches of the trigeminal nerve. Although prophylactic pharmacological treatment is first choise, considering of insufficient effect or unacceptable side effects, neurosurgical treatment or lesion treatment should be considered. In addition to all these procedures mentioned above, one approach has been based on local intradermal and/or submucosal injections of Botulinum Toxin Type A (BTX-A).

METHODS

We conducted a randomized, double-blind, placebo-controlled since November 2012, and adopted local multi-point injection in 84 cases of classical TN with different doses of BTX-A. Eighty four patients were randomized into following groups: placebo (n = 28); BTX-A 25U (n = 27); BTX-A 75U (n = 29). Follow-up visits were conducted every week after the injection, and the overall duration of the study for each patient were 8 weeks to observe the pain severity, efficacy and adverse reactions at endpoint.

RESULTS

The visual analogue scale (VAS) scores of 25U and 75U groups reduced significantly compared to placebo as early as week 1, and sustained until week 8 throughout the study. There was no significant difference in VAS between 25U and 75U groups throughout the study. The response rates of 25U group (70.4%) and 75U group (86.2%) were significantly higher than placebo group (32.1%) at week 8, and there was no significant difference between 25U and 75U groups. Evaluation of the Patient Global Impression of Change (PGIC) demonstrated that 66.7% (25U group) and 75.9% (75U group) of the patients reported that their pain symptoms were 'much improved' or 'very much improved' versus 32.1% of the placebo group, and there was also no significant difference between 25U and 75U groups. All adverse reactions were graded as mild or moderate.

CONCLUSIONS

BTX-A injection in TN is safe and efficient. It is a useful treatment for refractory TN. Lower dose (25U) and high dose (75U) were similar in efficacy in short-term.

Reduction of established antibody responses against botulinum neurotoxin A by synthetic monomethoxypolyethylene glycol peptide conjugates

In cervical dystonia, injection of botulinum neurotoxin (BoNT) A or B into affected neck muscle reduces symptoms but may elicit anti-toxin antibodies (Abs) that block responsiveness to treatment. Previously, we localized the BoNT/A and BoNT/B sites that bind mouse or human blocking Abs. We also reported that site-specific auto-Abs can be suppressed by a monomethoxypolyethylene glycol (mPEG)-epitope conjugate. So we elicited here anti-toxin Abs in outbred mice by immunization with sublethal-suboptimal doses of active BoNT/A and determined the efficacy of selected mPEG-epitopes in reducing established anti-BoNT/A Abs. We tested in outbred mice four synthetic mPEG-N(α)-epitopes [N8 (residues 547-565), N25 (785-803), C15 (1051-1069), C31 (1275-1296)] of BoNT/A in tolerance against ongoing anti-toxin Abs. After short immunizations, tolerization with an mPEG-peptide reduced Abs to correlate peptide and caused varying Ab reductions to the other 3 peptides. Anti-N8 Abs were unaffected by mPEG-N25 tolerization, but mPEG-N8 and mPEG-N25 caused drop in anti-BoNT/A Abs. After long immunization with BoNT/A, tolerization with mPEG-N8 lessened anti-N8 Abs. Anti-C15 Abs decreased by tolerization with mPEG-C15 or any other mPEG-peptide. Anti-N25 Abs were not altered by mPEG-N25, but decreased after tolerization with mPEG-C15. Anti-C31 Abs disappeared on day 474 by tolerization with mPEG-C31 or mPEG-N8, mPEG-N25 or mPEG-C15. When an Ab response returns, a decrease can be re-established by re-administering the correlate mPEG-peptide. The method may be beneficial for extending BoNT treatment in immunoresistant patients.

The use of botulinum toxin for the treatment of overactive bladder syndrome

Over the last 50 years, botulinum toxin has been transformed from a cause of life-threatening disease to an effective medical therapy. It has been used in a variety of specialties for different indications, significantly improving patient quality of life. A recent growing body of evidence suggests that intra-detrusor injection of botulinum toxin may have beneficial effects in patients with medication refractory detrusor overactivity and may offer a new minimally invasive alternative to patients with severe overactive bladder symptoms. To review current data regarding the effects of botulinum toxin in patients with overactive bladder, a MEDLINE^®/PubMed^® literature search was carried out. The mechanism of action, clinical usage, adverse effects, and treatment efficacy were reviewed and the results are presented in this paper.

Improvement in pelvic pain with botulinum toxin type A - Single vs. repeat injections

The aim of this prospective study was to report the outcomes of pain and vaginal pressures of successive botulinum toxin type A injections for women with objective pelvic floor muscle overactivity and a two-year history of pelvic pain. Between 2005 and 2008, 37 women underwent injection of 100 IU of botulinum toxin type A into the puborectalis and pubococcygeous muscles with dysmenorrhoea, dyspareunia, dyschesia, and non-menstrual pelvic pain assessed using a visual analogue scale (VAS), and vaginal pressure measured by vaginal manometry, at 0, 4, 12 and 26 weeks from each injection. 26 women (70%) had one injection of botulinum toxin type A and 11 (30%) had 2 or more injections. The second injection was performed at the earliest at 26 weeks after the first, with subsequent injections having a median time to re-injection of 33.4 weeks (range 9.4-122.7 weeks). Single and repeated injections both demonstrated a statistically significant reduction in dyspareunia by VAS scores from 54 to 30 in the single injection group and from 51 to 23 in the multiple injection group (p = .001), non-menstrual pelvic pain VAS from 37 to 25 (p = .04), as well as vaginal pressures; 40 versus 34 cm H(2)O (p = .02). No statistically significant difference in dysmenorrhoea or dyschesia was observed for either group from their baseline scores. Multiple injections of botulinum toxin type A in women with pelvic floor muscle overactivity provide significant relief from dyspareunia and non-menstrual pelvic pain. The upper limit between re-injection is not yet determined, nor is the maximum number of treatments. Clinical outcomes for single and subsequent injection of botulinum toxin type A for recurrent pelvic pain are equivalent. Women who have had benefit from a single injection of botulinum toxin type A can be reassured that if symptoms reoccur, repeated injections can be expected to be equally efficacious.

Location of the synaptosome-binding regions on botulinum neurotoxin B

The regions of botulinum neurotoxin B (BoNT/B) involved in binding to mouse brain synaptosomes (snps) were localized. Sixty 19-residue overlapping peptides (peptide C31 consisted of 24 residues) encompassing BoNT/B H chain (residues 442-1291) were synthesized and used to inhibit binding of (125)I-labeled BoNT/B to snps. Synaptosome-binding regions were noncompeting and existed on both H(N) and H(C) domains of neurotoxin. At 37 °C, inhibitory activities on H(N) resided, in decreasing order, in peptides 638-656 (26.7%), 596-614 (18.2%), 512-530 (13.9%), 778-796 (13.8%), and 526-544 (11.6%). On H(C), activity resided in decreasing order in peptides 1170-1188 (44.6%), 1128-1146 (21.6%), 1184-1202 (18.6%), 1156-1174 (13.0%), 946-964 (11.8%), 1114-1132 (11.2%), 1100-1118 (6.2%), 876-894 (6.1%), 1268-1291 (4.6%), and 1226-1244 (4.3%). The 45 remaining H(N) and H(C) peptides had no activity. At 4 °C, peptide C24 (1170-1188) remained quite active (inhibiting, 31.2%), while activities of peptides N15, C21, and C25 were little under 10%. The snp-binding regions contained sites that bind synaptotagmin II and gangliosides. Despite the low degree of sequence homology, BoNT/B and BoNT/A display significant structural homology and appeared to bind in part to the same snp-binding regions. Binding of each labeled toxin to snps was inhibited ~50% by the other toxin, 70-72% by its correlate H(C), and by the H(C) of the other toxin [29% (BoNT/A by H(C) of B) or 32% (BoNT/B by H(C) of A)]. In the three-dimensional structure of BoNT/B, the greater part of H(C), one H(N) face, and part of the belt on the same side interact with snps. Thus, BoNT/B binds to snps through the H(C) head and employs regions on one H(N) face and the belt, reserving flexibility for the belt's unbound part to release the light chain. Most snp-binding regions coincide or overlap with blocking antibody (Ab)-binding regions explaining how such Abs prevent BoNT/B toxicity.

Molecular immune recognition of botulinum neurotoxin B. The light chain regions that bind human blocking antibodies from toxin-treated cervical dystonia patients. Antigenic structure of the entire BoNT/B molecule

We recently mapped the regions on the heavy (H) chain of botulinum neurotoxin, type B (BoNT/B) recognized by blocking antibodies (Abs) from cervical dystonia (CD) patients who develop immunoresistance during toxin treatment. Since blocking could also be effected by Abs directed against regions on the light (L) chain, we have mapped here the L chain, using the same 30 CD antisera. We synthesized, purified and characterized 32 19-residue L chain peptides that overlapped successively by 5 residues (peptide L32 overlapped with peptide N1 of the H chain by 12 residues). In a given patient, Abs against the L chain seemed less intense than those against H chain. Most sera recognized a limited set of L chain peptides. The levels of Abs against a given region varied with the patient, consistent with immune responses to each epitope being under separate MHC control. The peptides most frequently recognized were: L13, by 30 of 30 antisera (100%); L22, by 23 of 30 (76.67%); L19, by 15 of 30 (50.00%); L26, by 11 of 30 (36.70%); and L14, by 12 of 30 (40.00%). The activity of L14 probably derives from its overlap with L13. The levels of Ab binding decreased in the following order: L13 (residues 169-187), L22 (295-313), L19 (253-271), and L26 (351-369). Peptides L12 (155-173), L18 (239-257), L15 (197-215), L1 (1-19) and L23 (309-327) exhibited very low Ab binding. The remaining peptides had little or no Ab-binding activity. The antigenic regions are analyzed in terms of their three-dimensional locations and the enzyme active site. With the previous localization of the antigenic regions on the BoNT/B H chain, the human Ab recognition of the entire BoNT/B molecule is presented and compared to the recognition of BoNT/A by human blocking Abs.

Regions of botulinum neurotoxin A light chain recognized by human anti-toxin antibodies from cervical dystonia patients immunoresistant to toxin treatment. The antigenic structure of the active toxin recognized by human antibodies

This work was aimed at determining the BoNT/A L-chain antigenic regions recognized by blocking antibodies in human antisera from cervical dystonia patients who had become immunoresistant to BoNT/A treatment. Antisera from 28 immunoresistant patients were analyzed for binding to each of 32 overlapping synthetic peptides that spanned the entire L-chain. A mixture of the antisera showed that antibodies bound to three peptides, L11 (residues 141-159), L14 (183-201) and L18 (239-257). When mapped separately, the antibodies were bound only by a limited set of peptides. No peptide bound antibodies from all the patients and amounts of antibodies bound to a given peptide varied with the patient. Peptides L11, L14 and L18 were recognized predominantly. A small but significant number of patients had antibodies to peptides L27 (365-383) and L29 (379-397). Other peptides were recognized at very low and perhaps insignificant antibody levels by a minority (15% or less) of patients or had no detectable antibody with any of the sera. In the 3-dimensional structure, antibody-binding regions L11, L14 and L18 of the L-chain occupy surface areas and did not correlate with electrostatic potential, hydrophilicity/hydrophobicity, or temperature factor. These three antigenic regions reside in close proximity to the belt of the heavy chain. The regions L11 and L18 are accessible in both the free light chain and the holotoxin forms, while L14 appears to be less accessible in the holotoxin. Antibodies against these regions could prevent delivery of the L-chain into the neurons by inhibition of the translocation.

Anatomical consideration of the anterior and lateral cutaneous nerves in the scalp

To better understand the anatomic location of scalp nerves involved in various neurosurgical procedures, including awake surgery and neuropathic pain control, a total of 30 anterolateral scalp cutaneous nerves were examined in Korean adult cadavers. The dissection was performed from the distal to the proximal aspects of the nerve. Considering the external bony landmarks, each reference point was defined for all measurements. The supraorbital nerve arose from the supraorbital notch or supraorbital foramen 29 mm lateral to the midline (range, 25-33 mm) and 5 mm below the supraorbital upper margin (range, 4-6 mm). The supratrochlear nerve exited from the orbital rim 16 mm lateral to the midline (range, 12-21 mm) and 7 mm below the supraorbital upper margin (range, 6-9 mm). The zygomaticotemporal nerve pierced the deep temporalis fascia 10 mm posterior to the frontozygomatic suture (range, 7-13 mm) and 22 mm above the upper margin of the zygomatic arch (range, 15-27 mm). In addition, three types of zygomaticotemporal nerve branches were found. Considering the superficial temporal artery, the auriculotemporal nerve was mostly located superficial or posterior to the artery (80%). There were no significant differences between the right and left sides or based on gender (P>0.05). These data can be applied to many neurosurgical diagnostic or therapeutic procedures related to anterolateral scalp cutaneous nerve.

Molecular recognition of botulinum neurotoxin B heavy chain by human antibodies from cervical dystonia patients that develop immunoresistance to toxin treatment

We determined the entire profile of the continuous antigenic regions recognized by blocking antibodies (Abs) in sera from 30BoNT/B-treated cervical dystonia (CD) patients who developed unresponsiveness to treatment. The sera protected mice against a lethal dose of BoNT/B. We analyzed Ab binding to a panel of 60 synthetic 19-residue peptides (peptide C31 was 24 residues) that overlapped consecutively by 5 residues and encompassed the entire BoNT/B heavy (H) chain (residues 442-1291). Most Abs recognized a limited set of peptides but the pattern and Ab levels bound varied with the patient, consistent with genetic control of immune responses and with responses to each epitope being separately controlled. Abs were bound by peptides (in decreasing order): C1 (residues 848-866), C10 (974-992), C16 (1058-1076), C14 (1030-1048), N15 (638-656), N21/N22 (722-740/736-754), N24/N25 (764-782/778-796) and N29 (834-852). Peptides N3/N4 (470-488/484-502), N27 (806-824), C2 (862-880), C4 (890-908), C6/C7 (918-936/932-950), C17 (1072-1090), C24 (1170-1188), C29 (1240-1258) and C31 (1268-1291) exhibited low Ab binding. The remaining peptides bound little or no Abs. Of the 30 antisera, 28 (93.3%) had Abs that bound to peptides C1, C10, C14 or C16, and 27 (90.0%) bound to peptide N22. No peptide was recognized by all the antisera, but peptide combinations N24+C1, N22+N24+C1, N24+C1+C10, C10+C14+C16, N22+N24+C1+C10, C1+C10+C14+C16 or N22+N24+C1+C10+C14 bound blocking Abs in 30 (100%) antisera. BoNT/B-treated CD patients had higher Ab levels and bound to more epitopes (at least 11) than did BoNT/A-treated patients (5 regions). The regions recognized by anti-BoNT/B Abs occupied surface areas that displayed no correlation to surface electrostatic potential, hydrophilicity, hydrophobicity, or temperature factor. These regions afford candidates for epitope-specific manipulation of anti-toxin immune responses.

Immune recognition of botulinum neurotoxin B: antibody-binding regions on the heavy chain of the toxin

The purpose of this work was to map the continuous regions recognized by human, horse and mouse anti-botulinum neurotoxin B (BoNT/B) antibodies (Abs). We synthesized a panel of sixty 19-residue peptides (peptide C31 was 24 residues) that overlapped consecutively by 5 residues and together encompassed the entire heavy chain of BoNT/B (H/B, residues 442-1291). Abs from the three host species recognized similar, but not identical, peptides. There were also peptides recognized by two or only by one host species. Where a peptide was recognized by Abs of more than one host species, these Abs were at different levels among the species. Human, horse and mouse Abs bound, although in different amounts, to regions within peptides 736-754, 778-796, 848-866, 932-950, 974-992, 1058-1076 and 1128-1146. Human and horse Abs bound to peptides 890-908 and 1170-1188. Human and mouse Abs recognized peptides 470-488/484-502 overlap, 638-656, 722-740, 862-880, 1030-1048, 1072-1090, 1240-1258 and 1268-1291. We concluded that the antigenic regions localized with the three antisera are quite similar, exhibiting in some cases a small shift to the left or to the right. This is consistent with what is known about protein immune recognition. In the three-dimensional structure, the regions recognized on H/B by anti-BoNT/B Abs occupied surface locations and analysis revealed no correlation between these surface locations and surface electrostatic potential, hydrophilicity, hydrophobicity, or temperature factor. A region that bound mouse Abs overlapped with a recently defined site on BoNT/B that binds to mouse and rat synaptotagmin II, thus providing a molecular explanation for the blocking (protecting) activity of these Abs. The regions thus localized afford candidates for incorporation into a synthetic vaccine design.

Botulinum toxin: from life-threatening disease to novel medical therapy

Botulinum toxin A is the newest therapy for the treatment of a variety of medical disorders caused by abnormalities of muscle activity. After successful use in other medical subspecialties, the newest applications of this potent neurotoxin are within the lower urinary tract. The toxin has evolved from a cause of fatal disease into the newest neuropharmacologic medical therapy.

A peptide-based immunoassay for antibodies against botulinum neurotoxin A

Cervical dystonia (CD) is due to neck-muscle spasms that cause pain and involuntary contractions resulting in abnormal neck movements and posture. Symptoms can be relieved by injecting the affected muscle with a botulinum neurotoxin (BoNT, usually type A or type B). The therapeutic benefits are impermanent and toxin injections need to be repeated every 3-6 months. In a very small percentage of patients (less with BoNT/A than with BoNT/B) the treatment elicits blocking anti-toxin antibodies (Abs), which reduce or terminate the patient's responsiveness to further treatment. We have recently mapped (Dolimbek et al., 2006) the CD sera Ab-binding profile using a panel of 60, 19-residue peptides that encompassed the entire H chain sequence 449-1296 and overlapped consecutively by 5 residues. Abs in CD sera bound to one or more of the peptides N25, C10, C15, C20, and C31. This suggested the possibility that binding to these peptides could be used for assay of Abs in CD sera. Data analysis reported here found that Ab binding to these regions showed very significant deviations from the control responses. Of these four peptides, C10 showed the most significant level of separation between patient and control groups (p = 5 x 10(-7)) and the theoretical resolution (i.e., ability to distinguish CD patients from control, see full definition under 'Statistical analysis' in Methods), 84%, was about 4% higher than the least resolved response, C31 (p = 6 x 10(-6), resolution 80%). Since the amounts of Abs bound to a given peptide varied with the patient and not all the patients necessarily recognized all four peptides, there was the possibility that binding to combinations of two or more peptides might give a better discriminatory capability. Using two peptides, C10 plus C31, the resolution improved to 87% (p = 4 x 10(-8)). These two peptides appeared to compliment each other and negate the lower resolution of C31. Combination of three peptides gave resolutions that ranged from 85 (N25 + C15 + C31; p = 2 x 10(-7)) to 88% (C10 + C15 + C31; p = 1 x 10(-8)). Finally, using the data of all four peptides, N25 + C10 + C15 + C31, gave a resolution of 86% (p = 1 x 10(-7)). Although these levels of resolution are somewhat lower than that obtained with whole BoNT/A (resolution 97%; p = 6 x 10(-12)), it may be concluded that the two-peptide combination C10 + C31, or the three-peptide combination C10 + C15 + C31 (affording resolutions of 87 and 88%, respectively) provide a good diagnostic, toxin-free procedure for assay of total specific anti-toxin Abs in BoNT/A-treated CD patients.

Clinically significant placebo analgesic response in a pilot trial of botulinum B in patients with hand pain and carpal tunnel syndrome

OBJECTIVE

We conducted a pilot trial to assess the effect of botulinum toxin B on palmar pain and discomfort in carpal tunnel syndrome (CTS) patients. Design. Randomized, double-blind, placebo-controlled.

PATIENTS

Twenty ambulatory CTS patients. Intervention. Botulinum toxin B or placebo injections into three hypothenar muscles anatomically linked or attached to the carpal tunnel and its tentorium, that is, the Opponens Digiti Minimi and Flexor Digiti Minimi, located with electromyography (EMG), and the Palmaris Brevis Muscle, anatomically located without EMG.

SETTING

New York City hospital.

OUTCOME MEASURES

Outcomes were measured with numeric ratings, with higher scores indicating worse outcomes. Daily, subjects recorded their 0-10 numeric ratings of overall pain levels and pain-related sleep disturbances. During weekly telephone calls, they reported their 0-10 ratings for overall pain, pain-related sleep disturbance, and CTS-related tingling during the night and day as experienced over the preceding 24 hours. For each of four clinic visits, we averaged each subject's ratings of nine quality of life indicators from the West Haven-Yale Multidimensional Pain Inventory (WHYMPI), each measured on a 0-6 numeric scale.

RESULTS

Over the 13-week trial, compared to baseline scores, the following outcomes predominantly showed decreases of statistical significance (P < or = 0.050) or borderline significance (0.050 < P < or = 0.10) for weeks 2 through 8: overall pain per daily diary entries and per weekly telephone reports, and pain-related sleep disturbance in the placebo group per phone report and in the botulinum toxin B group per diary report. CTS painful night tingling and day tingling, as well as the average scores of the WHYMPI quality of life indicators, showed improvements with statistical or borderline significance for almost each follow-up week. Between-group analyses, however, demonstrated that at each follow-up week, there was no statistically significant difference between the two study groups regarding changes from baseline in any study outcome.

CONCLUSION

Botulinum toxin B is not dramatically superior to placebo for the relief of CTS symptoms. Possible explanations of the improvements in each study group are explored.

Inhibition by human sera of botulinum neurotoxin-A binding to synaptosomes: A new assay for blocking and non-blocking antibodies

The mouse protection assay (MPA), which is an in vivo assay, is currently the most widely used method for monitoring blocking antibodies (Abs) in botulinum neurotoxin (BoNT)-treated patients. In recent studies we found that a number of the regions on the heavy (H) subunit of BoNT/A that bind blocking mouse Abs coincided, or overlapped, with the regions that bind to mouse synaptosomes (snps). This suggested that blocking anti-BoNT/A Abs would be expected to inhibit BoNT/A binding to snps. In the present work, we analyzed sera from 58 cervical dystonia (CD) patients who had been treated with BOTOX (a preparation of BoNT/A serotype) for blocking Abs by MPA and by their abilities to inhibit in vitro the binding of 125I-labeled active BoNT/A or inactive toxin (toxoid) to mouse brain snps. With active 125I-labeled BoNT/A-snps binding, the MPA-positive sera (n = 30) displayed inhibition levels that were distinctly higher (mean = 21.1 +/- 5.8) than those obtained with MPA-negative sera (n = 28) (mean = -1.3 +/- 3.9; p < 0.0001) or control sera (n = 19) (mean = -3.4 +/- 2.8; p < 0.0001). Similarly, inhibition levels by MPA-positive sera of 125I-labeled toxoid snp-binding (mean = 48.6 +/- 8.7) were distinctly higher than inhibition by MPA-negative sera (mean=10.0+/-7.6; p < 0.0001) or control sera (mean = 1.8 +/- 6.9; p < 0.0001). Thus, using labeled active toxin or toxoid, the inhibition assay correlated very well with the MPA. The inhibitory activity of the non-protective sera generally correlated with the duration of survival after toxin challenge (correlation coefficients of inhibition: active toxin = 0.445; p = 0.0167; inactive toxoid = 0.774; p < 0.0001). It is concluded that the snp-inhibition assay reported here is reliable, reproducible and correlates very well with the MPA. It requires much less serum (0.75% of the amount needed for the MPA) and is considerably less costly than the MPA. With either 125I-labeled active toxin or toxoid, it is possible to distinguish CD sera that have blocking Abs from those that lack such Abs. Since the results with the toxoid were as discriminating as those of the active toxin, it would not even be necessary to use active toxin in these assays.

Botulinum toxin and the management of chronic headaches

PURPOSE OF REVIEW

There is an increasing number of reports on botulinum toxin in pain therapy, in particular in headache treatment. Therefore, the studies available from reference systems and published congress contributions on the prophylactic treatment of idiopathic and cervicogenic headache with botulinum toxin were analyzed with respect to study design, headache diagnosis, and the significance of results.

RECENT FINDINGS

For the prophylactic treatment of tension-type headache, migraine, and cervicogenic headache, no sufficient positive evidence for treatment with botulinum toxin is obtained from randomized, double-blind, placebo-controlled trials to date. For the treatment of miscellaneous headache, there is some but no consistent positive evidence.

SUMMARY

Most open studies and case reports suggest an efficacy of botulinum toxin in headache prophylaxis but double-blind, placebo-controlled studies do not confirm this assumption. Larger controlled studies are needed for a definite evaluation of subgroups that might possibly benefit from such a treatment. Migraine, tension-type headache, and cervicogenic headache cannot be regarded as a general indication for a treatment with botulinum toxin.

The Therapeutic Potential of Botulinum Toxin

BACKGROUND

Botulinum toxin type A (BTX-A; commercial preparation BOTOX) is most well known for its effect on muscle contraction because of the BTX binding to the presynaptic nerve terminal, inhibiting the release of acetylcholine (ACH). The therapeutic benefit of BTX-A, however, can also be isolated to pain relief alone, suggesting that BTX-A also works through additional modes of action.

OBJECTIVE

This article provides insight by an experienced physician into four different case reports. Each case demonstrates the therapeutic potential of BTX-A and the possibility of a different mechanism of action for BTX other than the inhibition of ACH release.

RESULTS

Four patients, each with different symptoms such as relapsing-remitting multiple sclerosis, postherpetic neuralgia, peripheral neuropathy, and severe tingling caused by herniation of cervical vertebrae at the level of C8, were treated with BOTOX, and their symptoms were alleviated.

CONCLUSIONS

The BTX-A mechanism providing pain relief is hypothesized to be something other than muscle relaxation by inhibiting the release of ACH at the neuromuscular juncture, such as inhibition of the release of substance P or the blocking of autonomic pathways, etc. This article is intended to continue to keep physicians using this substance for dermatologic indications aware of the potential unsuspected effects.

Botox: beyond wrinkles

First used and approved over a decade ago for the treatment of strabismus (or misaligned eyes), botulinum toxin (BTX) has demonstrated efficacy in blepharospasm, hemifacial spasm, spastic lower eyelid entropion, and a number of other disorders seen in the traditional medical environment that are characterized by abnormal muscle contraction. Moreover, other conditions-notably some pain and gastrointestinal disorders-have responded to BTX injections.

Complete DNA sequences of the botulinum neurotoxin complex of Clostridium botulinum type A-Hall (Allergan) strain

BOTOX is manufactured with the purified native 900-kDa type A neurotoxin complex from Clostridium botulinum type A-Hall (Allergan) strain. This complex is composed of the botulinum neurotoxin (BoNT) and several toxin associated proteins known as the hemagglutinins (HAs) and the non-toxic non-hemagglutinin protein (NTNH). We describe here the complete gene sequences of the BoNT complex of type A-Hall (Allergan) strain. Using a polymerase chain reaction-based approach, we sequenced six open reading frames (ORFs) encoding BoNT (1296 amino acids), the toxin-associated proteins: HA70, 625 aa; HA17, 147 aa; HA34, 291 aa; NTNH, 1193 aa; and the regulatory component botR/OrfX, 178 aa. Comparative alignments of the amino acid sequence of BoNT/A shows a 98-100% sequence identity among different strains of the type A, except for the Kyoto-F strain (90%), whereas the sequence identity between BoNT/A and other toxin serotypes is only 30.4-39.1%. Similar to the neurotoxin, the toxin-associated proteins and botR from type A-Hall strain also share more than 95% identity to the homologous proteins found in type A-NCTC2916 strain. Among all the toxin associated proteins, NTNHs and HA70s are the most conserved with 65-87% identity across different serotypes. On the other hand, HA34s, present only in serotypes A-D, show greater diversity than all other toxin-associated proteins; HA34/A has 90% identity to HA34/B and only approximately 35% identity to HA34/C and HA34/D. Relatively higher sequence identity ( approximately 60%) is seen in HA17 and botR of Hall A when compared to their counterparts in serotypes C or D. Of all proteins within the toxin complex, NTNH and HA70 have the highest degree of conservation across serotypes and this may underscore a critical role for these proteins in the formation of the complexes. Physiologically, different duration of action in different serotypes may be due to different modifications of toxins by neuronal enzymes, which lead to different compartmentalization of different toxins. Computer-assisted motif analysis reveals that toxins contain several potential sites for phosphorylation by casein kinase II, protein kinase C, tyrosine kinases, glycogen synthase kinase 3, cGMP dependent protein kinase (PKG) that are well conserved. The reported sequence information for type A-Hall strain will potentially facilitate elucidation of the toxin interactions with the nontoxin proteins in the complex.

Is there a role for botulinum toxin in the treatment of migraine?

In this review, the studies and case reports that are available from reference systems and published congress contributions on the treatment of migraine with botulinum toxin are evaluated. The studies and reports were analyzed with respect to the study design, the efficacy parameters, and the significance of results. One double-blind, placebo-controlled, randomized study with negative (for a 75 U dose of botulinum toxin) and positive (for a 25 U dose of botulinum toxin) evidence of efficacy, one that was a partly positive controlled study (pain intensity, but not attack-frequency improved), and four positive open studies were available. For the acute treatment of migraine with botulinum toxin, only positive case reports were published. As a result of this analysis, there is no sufficient scientific evidence for a treatment recommendation of migraine with botulinum toxin. Further studies are needed for a definite evaluation of subgroups with probable benefit from such a treatment and for the comparison of botulinum toxin with other migraine prophylactic drugs.