Regulation of calcitonin gene-related peptide secretion from trigeminal nerve cells by botulinum toxin type A: implications for migraine therapy

Efficacy of Intra-Articular Botulinum Toxin in Osteoarticular Joint Pain: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

This study was conducted with the aim of evaluating the efficacy of intra-articular injections of botulinum toxin type A (BT-A) into the painful joint diseases through a systematic review of the literature and a meta-analysis of controlled randomized trials. Intra-articular therapies (corticosteroids, hyaluronic acid) have limited efficacy and run a risk of toxicity in patients with joint pain. New therapeutic options are needed to treat painful osteoarticular disease.

METHODS

We searched via Pubmed, American College of Rheumatology, and European League Against Rheumatism congresses, and gray literature for the studies reported until June 2016 and addressing the issue of BT intra-articular injections in patients with refractory joint pain. Randomized trials were included. For the meta-analysis, we compared a numeric rating scale (NRS) from 0 to 10 before treatment and at 1 or 2 months and 6 months after in the BT-A and the control groups for each study. We also compared separately low dose and high dose of BT at 1 or 2 months' evaluation.

RESULTS

In a total of 269 selected articles, 8 were analyzed and 6 studies were included in the meta-analysis involving a total of 382 patients. On comparing the NRS rating for 5 trials, at 1 or 2 months irrespective of the dose of BT, 4 trials showed a positive effect of BT compared with the control on the NRS and 1 found no effect; the overall weighted mean difference [95% confidence interval (CI)] was -1.10 (-1.62, -0.58) (P<0.0001, I=63%). Among the 4 trials with a low dose of BT (100 U), comparing NRS at 1 or 2 months, 3 trials showed significant results with a positive effect of BT-A injection compared with the control on the NRS; the fourth study failed to find any effect. The overall weighted mean difference (95% CI) was -0.95 (-0.02, -1.88) (P=0.05, I=67%). In the 2 trials using a high dose of BT (200 U) comparing NRS at 1 or 2 months, there was an almost zero effect of BT, with an overall weighted mean difference (95% CI) of 0.13 (-0.55, 0.81) (P=0.71, I=0%). In the 3 trials comparing NRS at 6 months there was an overall weighted mean difference (95% CI) of -0.57 (-1.98, 0.83) (P=0.42, I=73%).

CONCLUSIONS

BT-A intra-articular injections have short-term benefits with a statistically significant decrease in the NRS pain score of around 1 point in patients with refractory joint pain. A decrease in the pain score was also observed at 6 months but with a nonsignificant result.

Botulinum Toxin A Injection for Treatment of Chronic Skin Ulcer: A Case Series and Literature Review

Chronic skin ulcer (CSU) often combines with a variety of refractory factors that respond poorly to routine treatments. Botulinum toxin A (BTX-A) can be injected subcutaneously to improve the local blood supply, to reduce pain, and to promote wound healing. At present, few reports have mentioned BTX-A injection for chronic skin ulcer treatment. We observed the effect of four cases that used BTX-A to treat CSU and provided a brief review of the literature. Four cases of CSUs with 4 different causes were treated with BTX-A injection (4 U/cm²). The specific operation is as follows: local, multipoint, cyclic, equidistant, and subcutaneous injections with a depth of 6 to 8 mm. The ulcer area was significantly reduced. Subsequently, the ulcer healed within 20 to 48 days. Botulinum toxin A is recommended as an important treatment for chronic skin ulcer that can improve healing of skin ulcers with various etiologies.

Intra-articular botulinum toxin A (BoNT/A) for pain management in dogs with osteoarthritis secondary to hip dysplasia: A randomized controlled clinical trial

The aim of this study was to evaluate the efficacy and safety of the intra-articular (IA) injection of botulinum toxin type A (BoNT/A) to the management of chronic pain in dogs. In a randomized, controlled, double-blinded study sixteen dogs with osteoarthritis secondary to hip dysplasia were distributed into two groups: 25 IU BoNT/A (BoNT) or saline solution (Control) was administered IA in each affected joint. All dogs received oral supplements (90 days) and carprofen (15 days). The dogs were assessed by a veterinarian on five occasions and the owner completed an assessment form at the same time (baseline to 90 days). The data were analyzed using unpaired-t test, Fisher's exact test, analysis of variance and the Tukey's test (P<0.05). There were no differences between groups in the veterinarian and owner assessments. Lower scores were observed in both groups during 90 days after IA therapy in the owner assessments (P<0.001). Compared with baseline, the Vet score was lower from 15-90 days after IA injection in the BoNT group, and at 15 and 30 days in the Control group (P<0.001). Both treatments were safe and reduced the clinical signs associated with hip osteoarthritis. However, IA BoNT/A (25 IU) did not provide better pain relief than the control treatment.

Evaluation of patient satisfaction after botulinum toxin A injection for the management of masticatory myofascial pain and dysfunction - A pilot study

Objective: To evaluate patient satisfaction with botulinum toxin type A injections for the management of masticatory myofascial pain and dysfunction. Methods: The study group included 25 patients with myofascial pain and dysfunction. Maximum mouth opening (MMO), measured with a ruler, and pain, measured on a 10-cm visual analog scale (VAS), were assessed before treatment and six weeks after treatment. Satisfaction with the treatment, measured on a 10-cm VAS, was obtained six weeks post-treatment. Results: The mean satisfaction score six weeks post-injection was 6.74/10, with a significant improvement in both MMO and pain. Satisfaction was positively correlated with a decrease in pain. Discussion: Botulinum toxin type A injections were well tolerated for the treatment of masticatory myofascial pain and dysfunction in patients with temporomandibular disorder. Improvements were observed in both MMO and pain, with most patients satisfied with the management of pain.

Occipital Neuralgia: a noninvasive therapeutic approach

Objective:

to evaluate the application of a noninvasive intervention consisting of a postural modification using personalized models and osteopathy in people with occipital neuralgia.

Method:

retrospective study of the intervention performed in adult population with occipital neuralgia, consisting of postural modification using personalized plantar orthoses and osteopathy, in a study period of four years. The observed variables were: persistence of headache, alignment of the axes, plantar support, center of gravity and center of mass; medical interview data, visual analogue scale, Win-Track gait analysis system and Kinovea software for video analysis (clinical assessment instruments used).

Results:

a total of 34 records of people with occipital neuralgia were studied. A fraction of 58.8% of the patients reported improvement after the intervention. The visual analogue scale data were provided for 64.7% of the records and significant differences (p <0.001) between the means before (8.4 ± 1.7) and after the intervention (2.6 ± 2.7) were found.

Conclusion:

postural modification using personalized orthoses and osteopathy substantially improves the symptomatology of patients with occipital neuralgia.

A Pilot Study to Evaluate the Efficacy and Safety of Treatment with Botulinum Toxin in Patients with Recalcitrant and Persistent Erythematotelangiectatic Rosacea

Background

There are few pharmacologic options to reduce erythema and flushing in patients with recalcitrant erythematotelangiectatic rosacea (ETR). We previously reported two cases of refractory flushing and erythema of rosacea that were successfully treated with intradermal botulinum toxin injection, and additional research is needed to prove the efficacy and safety of this treatment.

Objective

To report the efficacy and safety of botulinum toxin injection as an aid in persistent erythema of rosacea patients.

Methods

A total of 20 Korean patients with recalcitrant ETR were enrolled to receive treatment by injection of botulinum toxin. Patients received one treatment of intradermal botulinum toxin injection and were assessed 1, 2, 4, and 8 weeks after treatment. The severity of erythema and telangiectasia was investigated by a non-treating physician, and the Erythema Index (EI) was assessed by mexameter at each visit. Patient satisfaction and any adverse events were also assessed at each visit.

Results

17 patients completed all follow-up visits and were included in the analysis. Intradermal injection of botulinum toxin significantly reduced erythema severity and EI in ETR patients. Patients reported a satisfaction score of 2.94±0.56 at 8 weeks after treatment. Except for three patients who discontinued the study early due to inconvenience of facial muscle paralysis, 17 patients participating in the final analysis did not report side effects except injection pain at the time of the procedure.

Conclusion

Intradermal injection of botulinum toxin can be used as an effective and relatively safe adjuvant agent for recalcitrant and persistent erythema of ETR patients.

Botulinum toxin type A in the treatment of Raynaud's phenomenon: A three-year follow-up study

Objective

Raynaud’s phenomenon consists of vasospastic disease of the digital arteries after exposure to cold or stress. It causes an important reduction in the patient’s quality of life when severe. The available treatments do not always offer favorable results.

Methods

A 3-year retrospective study was presented. A total of 15 patients with severe Raynaud’s phenomenon who required infiltration with botulinum toxin type A participated in the study. In the first and follow-up visits (30 min, 7 days, 3 months, 6 months, and annual), the overall response by the patient was assessed as was the reduction in the number of weekly episodes of Raynaud’s phenomenon, improvement in pain by means of the Visual Analogue Scale, and resolution of ulcers and necrosis as efficacy variables.

Results

A total of 15 patients were included in the study. After 30 min of infiltration, the immediate results showed a very good perception of response in four patients. After 1 month of treatment, eight patients had obtained and maintained a very good response, persisting throughout the study. A statistically significant reduction in pain was obtained, as well as the number of weekly episodes of Raynaud’s phenomenon. Of the seven patients with basal ulcers, five were completely healed at 3 months. Of the patients, 64.3% showed an overall satisfaction level of >8 at the end of treatment. No serious adverse events were observed.

Conclusion

Botulinum toxin is a useful treatment for severe Raynaud’s phenomenon that is generally well tolerated. Its mechanism of action is not based exclusively on vasodilation. Further studies are necessary to define the ideal patient for this treatment, the most appropriate method of administration, and the number of units and frequency of the infiltrations.

Diagnosis and Treatment of Primary Headache Disorders in Older Adults

OBJECTIVES

To provide a unique perspective on geriatric headache and a number of novel treatment options that are not well known outside of the headache literature.

DESIGN

Review of the most current and relevant headache literature for practitioners specializing in geriatric care.

RESULTS

Evaluation and management of headache disorders in older adults requires an understanding of the underlying pathophysiology and how it relates to age-related physiological changes. To treat headache disorders in general, the appropriate diagnosis must first be established, and treatment of headaches in elderly adults poses unique challenges, including potential polypharmacy, medical comorbidities, and physiological changes associated with aging.

CONCLUSION

The purpose of this review is to provide a guide to and perspective on the challenges inherent in treating headaches in older adults. J Am Geriatr Soc 66:2408-2416, 2018.

Therapeutic use of botulinum toxin in pain treatment

Botulinum toxin is one of the most potent molecule known to mankind. A neurotoxin, with high affinity for cholinergic synapse, is effectively capable of inhibiting the release of acetylcholine. On the other hand, botulinum toxin is therapeutically used for several musculoskeletal disorders. Although most of the therapeutic effect of botulinum toxin is due to temporary skeletal muscle relaxation (mainly due to inhibition of the acetylcholine release), other effects on the nervous system are also investigated. One of the therapeutically investigated areas of the botulinum neurotoxin (BoNT) is the treatment of pain. At present, it is used for several chronic pain diseases, such as myofascial syndrome, headaches, arthritis, and neuropathic pain. Although the effect of botulinum toxin in pain is mainly due to its effect on cholinergic transmission in the somatic and autonomic nervous systems, research suggests that botulinum toxin can also provide benefits related to effects on cholinergic control of cholinergic nociceptive and antinociceptive systems. Furthermore, evidence suggests that botulinum toxin can also affect central nervous system (CNS). In summary, botulinum toxin holds great potential for pain treatments. It may be also useful for the pain treatments where other methods are ineffective with no side effect(s). Further studies will establish the exact analgesic mechanisms, efficacy, and complication of botulinum toxin in chronic pain disorders, and to some extent acute pain disorders.

Botulinum toxin type A enhances the inhibitory spontaneous postsynaptic currents on the substantia gelatinosa neurons of the subnucleus caudalis in immature mice

Botulinum toxin type A (BoNT/A) has been used therapeutically for various conditions including dystonia, cerebral palsy, wrinkle, hyperhidrosis and pain control. The substantia gelatinosa (SG) neurons of the trigeminal subnucleus caudalis (Vc) receive orofacial nociceptive information from primary afferents and transmit the information to higher brain center. Although many studies have shown the analgesic effects of BoNT/A, the effects of BoNT/A at the central nervous system and the action mechanism are not well understood. Therefore, the effects of BoNT/A on the spontaneous postsynaptic currents (sPSCs) in the SG neurons were investigated. In whole cell voltage clamp mode, the frequency of sPSCs was increased in 18 (37.5%) neurons, decreased in 5 (10.4%) neurons and not affected in 25 (52.1%) of 48 neurons tested by BoNT/A (3 nM). Similar proportions of frequency variation of sPSCs were observed in 1 and 10 nM BoNT/A and no significant differences were observed in the relative mean frequencies of sPSCs among 1-10 nM BoNT/A. BoNT/A-induced frequency increase of sPSCs was not affected by pretreated tetrodotoxin (0.5 µM). In addition, the frequency of sIPSCs in the presence of CNQX (10 µM) and AP5 (20 µM) was increased in 10 (53%) neurons, decreased in 1 (5%) neuron and not affected in 8 (42%) of 19 neurons tested by BoNT/A (3 nM). These results demonstrate that BoNT/A increases the frequency of sIPSCs on SG neurons of the Vc at least partly and can provide an evidence for rapid action of BoNT/A at the central nervous system.

Evaluation of OnabotulinumtoxinA Treatment in Patients with Concomitant Chronic Migraine and Temporomandibular Disorders

Introduction

Migraine and temporomandibular disorders (TMD) are both common diseases and TMD are reported as a risk factor in migraine progression. OnabotulinumtoxinA is used in the treatment of chronic migraine (CM), and also has a potential role in TMD treatment. In this study, it is aimed to compare the efficacy of onabotulinumtoxinA treatment in CM patients with and without TMD.

Methods

In this retrospective study, 30 CM patients (age range: 18-65 years), satisfying the inclusion and follow-up criteria in their medical records were investigated. The PREEMPT injection protocol was taken as reference and onabotulinumtoxinA 155-195 U with fixed-dose has been administered into 31 specific sites within the head/neck muscles in included subjects. Two cycles of treatment were assessed in all patients at the baseline and 12 weeks later. The headache diaries, which were completed routinely one month before, and during 6 months follow-up after the treatment, were assessed. The effect of onabotulinumtoxinA treatment was compared between CM patients with and without TMD/bruxism.

Results

Of 30 female patients, 17 had concomitant TMD. In week 24, there were significant improvement in the groups with and without TMD regarding to the mean change of frequencies in the days with migraine compared to the initial findings (p<0.001). However, there was no significant difference between the two groups.

Conclusions

OnabotulinumtoxinA is an effective and safe treatment for CM. Its efficacy appears to be similar in CM patients with and without TM, speculating that the comorbidity of TMD did not play a role for the treatment response.

Botulinum Toxin for Central Neuropathic Pain

Botulinum toxin (BTX) is widely used to treat muscle spasticity by acting on motor neurons. Recently, studies of the effects of BTX on sensory nerves have been reported and several studies have been conducted to evaluate its effects on peripheral and central neuropathic pain. Central neuropathic pain includes spinal cord injury-related neuropathic pain, post-stroke shoulder pain, multiple sclerosis-related pain, and complex regional pain syndrome. This article reviews the mechanism of central neuropathic pain and assesses the effect of BTX on central neuropathic pain.

Botulinum toxin: A lift for chronic migraines

Chronic migraines are a common condition among patients seen in primary care and management often is a challenge. Despite existing therapies to help manage this condition, many patients continue to experience undue stress and diminished quality of life secondary to pain. This article briefly reviews treatments for migraine and introduces the role of onabotulinumtoxin A (Botox A) in improving the management of chronic migraines.

Botulinum Toxin Type A-A Modulator of Spinal Neuron-Glia Interactions under Neuropathic Pain Conditions

Neuropathic pain represents a significant clinical problem because it is a chronic condition often refractory to available therapy. Therefore, there is still a strong need for new analgesics. Botulinum neurotoxin A (BoNT/A) is used to treat a variety of clinical diseases associated with pain. Glia are in continuous bi-directional communication with neurons to direct the formation and refinement of synaptic connectivity. This review addresses the effects of BoNT/A on the relationship between glia and neurons under neuropathic pain. The inhibitory action of BoNT/A on synaptic vesicle fusion that blocks the release of miscellaneous pain-related neurotransmitters is known. However, increasing evidence suggests that the analgesic effect of BoNT/A is mediated through neurons and glial cells, especially microglia. In vitro studies provide evidence that BoNT/A exerts its anti-inflammatory effect by diminishing NF-κB, p38 and ERK1/2 phosphorylation in microglia and directly interacts with Toll-like receptor 2 (TLR2). Furthermore, BoNT/A appears to have no more than a slight effect on astroglia. The full activation of TLR2 in astroglia appears to require the presence of functional TLR4 in microglia, emphasizing the significant interaction between those cell types. In this review, we discuss whether and how BoNT/A affects the spinal neuron–glia interaction and reduces the development of neuropathy.

An academic debate: OnabotulinumtoxinA for chronic migraine: PREEMPT-derived vs "customized" dosing/injection paradigm

In 2010 onabotulinumtoxinA (OnabotA) was approved by the United States Food and Drug Administration for the treatment of chronic migraine (CM). Data supporting approval were derived primarily from two parallel placebo-controlled trials, the PREEMPT studies. Many clinicians and research investigators critical of those data have recommended that the dosing/injection paradigm for treating CM be "customized" to the needs of the individual patient rather than administered in a uniform fashion conforming to the methodology utilized in the PREEMPT studies. In this paper the authors debate the issue of whether treatment of CM with OnabotA should be standardized versus customized.

A Study and Review of Effects of Botulinum Toxins on Mast Cell Dependent and Independent Pruritus

Pruriceptive itch originates following activation of peripheral sensory nerve terminals when pruritogens come in contact with the skin. The ability of botulinum neurotoxins (BoNTs) to attenuate transmitter release from afferent terminals provides a rationale for studying its effect on pruritus. This study investigated the effects of BoNT/A1 and BoNT/B1 on mast cell dependent (Compound 48/80:48/80) and independent (Chloroquine:CQ) scratching. C57Bl/6 male mice received intradermal injection of 1.5 U of BoNT/A1, BoNT/B1 or saline 2, 7, 14 and 21 days prior to ipsilateral 48/80 or CQ at the nape of the neck. Ipsilateral hind paw scratching was determined using an automated recording device. The effect of BoNTs on 48/80 mediated mast cell degranulation was analyzed in human and murine mast cells and the presence of SNAREs was determined using qPCR, immunostaining and Western blot. Pre-treatment with BoNT/A1 and BoNT/B1 reduced 48/80 and CQ induced scratching behavior starting on day 2 with reversal by day 21. Both serotypes inhibited 48/80 induced mast cell degranulation. qPCR and immunostaining detected SNAP-25 mRNA and protein, respectively, in mast cells, however, Western blots did not. This study demonstrates the long-lasting anti-pruritic effects of two BoNT serotypes, in a murine pruritus model using two different mechanistically driven pruritogens. These data also indicate that BoNTs may have a direct effect upon mast cell degranulation.

Neurogenic inflammation and its role in migraine

The etiology of migraine pain involves sensitized meningeal afferents that densely innervate the dural vasculature. These afferents, with their cell bodies located in the trigeminal ganglion, project to the nucleus caudalis, which in turn transmits signals to higher brain centers. Factors such as chronic stress, diet, hormonal fluctuations, or events like cortical spreading depression can generate a state of "sterile inflammation" in the intracranial meninges resulting in the sensitization and activation of trigeminal meningeal nociceptors. This sterile inflammatory phenotype also referred to as neurogenic inflammation is characterized by the release of neuropeptides (such as substance P, calcitonin gene related peptide) from the trigeminal innervation. This release leads to vasodilation, plasma extravasation secondary to capillary leakage, edema, and mast cell degranulation. Although neurogenic inflammation has been observed and extensively studied in peripheral tissues, its role has been primarily investigated in the genesis and maintenance of migraine pain. While some aspects of neurogenic inflammation has been disregarded in the occurrence of migraine pain, targeted analysis of factors have opened up the possibilities of a dialogue between the neurons and immune cells in driving such a sterile neuroinflammatory state in migraine pathophysiology.

The Effect of Botulinum Neurotoxin Serotype a Heavy Chain on the Growth Related Proteins and Neurite Outgrowth after Spinal Cord Injury in Rats

(1) Background: The botulinum toxin A (BoNT-A) heavy chain (HC) can stimulate the growth of primary motor neurites. (2) Methods: A recombinant BoNT/A HC was injected locally plus interval intrathecal catheter of BoNT/A HC to rats with ipsilateral semi-dissociated lumbar spinal cord injuries (SCIs). First, 2D gel with a silver nitrate stain was applied to detect the general pattern of protein expression. Growth associated protein 43 (GAP-43) and superior cervical ganglion 10 (SCG10) were chosen to represent the altered proteins, based on their molecular weight and pI, and were used to further detect their expression. Meanwhile, the neuronal processes were measured. The measurements of thermal hyperalgesia and grasp power at the ipsilateral hindlimb were used to evaluate spinal sensory and motor function, respectively. (3) Results: The local injection of BoNT/A HC followed by its intrathecal catheter intervally altered the spinal protein expression pattern after an SCI; protein expression was similar to normal levels or displayed a remarkable increase. The changes in the expression and distribution of phosphorylated growth associated protein 43(p-GAP 43) and superior cervical ganglion 10 (SCG 10) indicated that the administration of BoNT/A HC to the SCI significantly amplified the expression of p-GAP43 and SCG10 (p < 0.05). Meanwhile, the positive immunofluorescent staining for both p-GAP43 and SCG10 was mainly present near the rostral aspect of the injury, both in the cytoplasm and the neuronal processes. Moreover, the outgrowth of neurites was stimulated by the BoNT/A HC treatment; this was evident from the increase in neurite length, number of branches and the percentage of cells with neuronal processes. The results from the spinal function tests suggested that the BoNT/A HC did not affect sensation, but had a large role in improving the ipsilateral hindlimb grasp power (p < 0.05). (4) Conclusions: The local injection with the intermittent intrathecal administration of BoNT/A heavy chain to rats with SCI increased the local expression of GAP-43 and SCG 10, which might be affiliated with the regeneration of neuronal processes surrounding the injury, and might also be favorable to the relief of spinal motor dysfunction.

Botulinum toxin treatment of pain syndromes -an evidence based review

This review evaluates the existing level of evidence for efficacy of BoNTs in different pain syndromes using the recommended efficacy criteria from the Assessment and Therapeutic Subcommittee of the American Academy of Neurology. There is a level A evidence (effective) for BoNT therapy in post-herpetic neuralgia, trigeminal neuralgia, and posttraumatic neuralgia. There is a level B evidence (probably effective) for diabetic neuropathy, plantar fasciitis, piriformis syndrome, pain associated with total knee arthroplasty, male pelvic pain syndrome, chronic low back pain, male pelvic pain, and neuropathic pain secondary to traumatic spinal cord injury. BoNTs are possibly effective (Level C -one class II study) for female pelvic pain, painful knee osteoarthritis, post-operative pain in children with cerebral palsy after adductor release surgery, anterior knee pain with vastus lateralis imbalance. There is a level B evidence (one class I study) that BoNT treatment is probably ineffective in carpal tunnel syndrome. For myofascial pain syndrome, the level of evidence is U (undetermined) due to contradicting results. More high quality (Class I) studies and studies with different types of BoNTs are needed for better understanding of the role of BoNTs in pain syndromes.

Management of Pediatric Migraine: Current Therapies

Migraine is one of the most common neurologic conditions in pediatrics. It can be a significant stressor, causing absences from school and interruption of parents' work and family schedules. The mainstay of treatment remains educating patients about healthy lifestyle practices and the influences of sleep, stressors, and hydration on triggering migraine attacks. Psychological therapies such as biofeedback or cognitive-behavioral therapy may be beneficial in some patients, especially those with prominent psychological comorbidities. New advances in the pathophysiology of migraine and additional pediatric approval of abortive therapy with triptans have led to significant advances in the management of migraine in children. Some challenges to preventive therapy were recently noted with the negative results obtained in the Childhood and Adolescent Migraine Prevention Study, which compared prescription drugs to placebo. Inherent differences between adult and pediatric headaches, with shorter duration of pediatric migraine and prominent placebo effect, present recurring challenges for clinicians. [Pediatr Ann. 2018;47(2):e55-e60.].

Assessing adverse effects of intra-articular botulinum toxin A in healthy Beagle dogs: A placebo-controlled, blinded, randomized trial

OBJECTIVE

To investigate the clinical, cytological, and histopathological adverse effects of intra-articularly injected botulinum toxin A in dogs and to study whether the toxin spreads from the joint after the injection.

METHODS

A longitudinal, placebo-controlled, randomized clinical trial was conducted with six healthy laboratory Beagle dogs. Stifle joints were randomized to receive either 30 IU of onabotulinum toxin A or placebo in a 1:1 ratio. Adverse effects and spread of the toxin were examined by evaluating dynamic and static weight-bearing of the injected limbs, by assessing painless range of motion and pain on palpation of joints, and by performing synovial fluid analysis, neurological examination, and electrophysiological recordings at different examination time-points in a 12-week period after the injections. The dogs were then euthanized and autopsy and histopathological examination of joint structures and adjacent muscles and nerves were performed.

RESULTS

Intra-articular botulinum toxin A did not cause local weakness or injection site pain. Instead, static weight-bearing and painless range of motion of stifle joints decreased in the placebo limbs. No clinically significant abnormalities associated with intra-articular botulinum toxin A were detected in the neurological examinations. Electrophysiological recordings showed low compound muscle action potentials in two dogs in the botulinum toxin A-injected limb. No significant changes were detected in the synovial fluid. Autopsy and histopathological examination of the joint and adjacent muscles and nerves did not reveal histopathological adverse effects of the toxin.

CONCLUSION

Intra-articular botulinum toxin A does not produce significant clinical, cytological, or histopathological adverse effects in healthy dogs. Based on the electrophysiological recordings, the toxin may spread from the joint, but its clinical impact seems to be low.

Evidence and experience with onabotulinumtoxinA in chronic migraine: Recommendations for daily clinical practice

OnabotulinumtoxinA has been demonstrated to be effective as a preventive treatment in patients with chronic migraine (CM). Five years after the approval of onabotulinumtoxinA in Spain, the Headache Study Group of the Spanish Society of Neurology considered it worthwhile to gather a group of experts in treating patients with CM in order to draw up, based on current evidence and our own experience, a series of guidelines aimed at facilitating the use of the drug in daily clinical practice. For this purpose, we posed 12 questions that we ask ourselves as doctors, and which we are also asked by our patients. Each author responded to one question, and the document was then reviewed by everyone. We hope that this review will constitute a practical tool to help neurologists treating patients with CM.

The binding of botulinum neurotoxins to different peripheral neurons

Botulinum neurotoxins are the most potent toxins known. The double receptor binding modality represents one of the most significant properties of botulinum neurotoxins and largely accounts for their incredible potency and lethality. Despite the high affinity and the very specific binding, botulinum neurotoxins are versatile and multi-tasking toxins. Indeed they are able to act both at the somatic and at the autonomic nervous system. In spite of the preference for cholinergic nerve terminals botulinum neurotoxins have been shown to inhibit to some extent also the noradrenergic postganglionic sympathetic nerve terminals and the afferent nerve terminals of the sensory neurons inhibiting the release of neuropeptides and glutamate, which are responsible of nociception. Therefore, there is increasing evidence that the therapeutic effect in both motor and autonomic disorders is based on a complex mode of botulinum neurotoxin action modulating the activity of efferent as well as afferent nerve fibres.

The Role of Botulinum Toxin A in the Treatment of Raynaud Phenomenon

Raynaud phenomenon (RP) is a transient digital ischemia that occurs after exposure to cold temperature or emotional distress. It presents with a triphasic course: the initial white phase is followed by cyanotic discoloration and, subsequently, erythema. The attacks may be associated with pain, paresthesia, and complicate with nonhealing ulceration often leading to amputation. To date, there are no clear-cut therapeutic guidelines and many medications are used off-label. Encouraging results were reported with the use of botulinum neurotoxin-A (BoNT-A). However, there is still ongoing debate regarding indications, contraindications, best injection technique, and mechanism of action. The aim of this study was to address these issues by providing an up-to-date and detailed overview of the use of BoNT-A in RP.A PubMed database search was conducted. The available studies and techniques were evaluated and compared.The search yielded a total of 29 studies. Ten papers, published between 2004 and 2014, were considered relevant. A total of 128 patients underwent BoNT-A injections. Seventy-five percent to 100 % of the patients reported pain reduction after treatment. Healing of ulcers was reported in 75% to 100% of the affected patients. The most common complication was temporary hand weakness, with an average incidence of 14.1%. Injections targeting the neurovascular bundle at or slightly proximal to the A1 pulley were the most commonly performed.Botulinum neurotoxin-A injection proved to be a valid approach in both primary and secondary RP. The available evidence shows the achievement of both symptomatic and functional improvements in this debilitating condition. However, the patient should be adequately informed about the risk of transient hand weakness.

Botulinum toxin in the treatment of trigeminal neuralgia: 6-Month follow-up

BACKGROUND

Botulinum toxin type-A (BTX-A) has been successfully utilized to treat trigeminal neuralgia. In this study, through the use of a new technique, the efficacy of the injection of BTX-A to the maxillary and mandibular nerves was evaluated.

METHODS

A total of 27 patients were injected with 100 Units of BTX-A to the maxillary and mandibular nerves. Visual analogue scale score and pain frequency were assessed before treatment and at the first week, second month, and sixth month after treatment. Patients with ≥50% reduction in mean pain score at the second and sixth month were defined as responders.

RESULTS

A total of 27 patients were included in the study. BTX-A significantly reduced pain intensity and pain attack frequency at the first week, second month, and sixth month after treatment. At the second month, 74.1% of patients, at the sixth month, 88.9% of patients responded to treatment. Forty-four percent of patients did not experience any pain at the sixth month. The mean recurrence period was 87.7 ± 20.4. BTX-A was well tolerated and showed few treatment-related adverse events.

CONCLUSION

Injection to the maxillary and mandibular roots seems to be a highly effective method. In the event of recurrence, after each injection, the pain severity and attack frequency decreased.

Cluster Headache Associated with Secondary Unilateral Blepharospasm: A Case Report and Review of the Literature

Purpose:

Cluster headache is one of the most serious types of headache that is accompanied by autonomic parasympathetic symptoms. Its association with hemifacial spasm in the same side had been rarely reported. The aim of this report is describing a case with this association and treatment strategies.

Case Report:

Here we report a 37-year-old female with cluster headache associated with secondary unilateral blepharospasm that was successfully treated with combination therapy including botulinum toxin injection.

Conclusion:

Hemifacial spasm associated with cluster headache needs special attention and can be treated successfully.

The effect of intra-articular botulinum toxin A on substance P, prostaglandin E2, and tumor necrosis factor alpha in the canine osteoarthritic joint

Background

Recently, intra-articular botulinum toxin A (IA BoNT A) has been shown to reduce joint pain in osteoarthritic dogs. Similar results have been reported in human patients with arthritis. However, the mechanism of the antinociceptive action of IA BoNT A is currently not known. The aim of this study was to explore this mechanism of action by investigating the effect of IA BoNT A on synovial fluid (SF) and serum substance P (SP), prostaglandin E₂ (PGE₂), and tumor necrosis factor alpha (TNF-α) in osteoarthritic dogs. Additionally, the aim was to compare SF SP and PGE₂ between osteoarthritic and non-osteoarthritic joints, and investigate associations between SP, PGE₂, osteoarthritic pain, and the signalment of dogs. Thirty-five dogs with chronic naturally occurring osteoarthritis and 13 non-osteoarthritic control dogs were included in the study. Osteoarthritic dogs received either IA BoNT A (n = 19) or IA placebo (n = 16). Serum and SF samples were collected and osteoarthritic pain was evaluated before (baseline) and 2 and 8 weeks after treatment. Osteoarthritic pain was assessed with force platform, Helsinki Chronic Pain Index, and joint palpation. Synovial fluid samples were obtained from control dogs after euthanasia. The change from baseline in SP and PGE₂ concentration was compared between the IA BoNT A and placebo groups. The synovial fluid SP and PGE₂ concentration was compared between osteoarthritic and control joints. Associations between SP, PGE₂, osteoarthritic pain, and the signalment of dogs were evaluated.

Results

There was no significant change from baseline in SP or PGE₂ after IA BoNT A. Synovial fluid PGE₂ was significantly higher in osteoarthritic compared to control joints. Synovial fluid PGE₂ correlated with osteoarthritic pain. No associations were found between SP or PGE₂ and the signalment of dogs. The concentration of TNF-α remained under the detection limit of the assay in all samples.

Conclusions

The results suggest that the antinociceptive effect of IA BoNT A in the joint might not be related to the inhibition of SP nor PGE₂. Synovial fluid PGE₂, but not SP, could be a marker for chronic osteoarthritis and pain in dogs.

Neuronal entry and high neurotoxicity of botulinum neurotoxin A require its N-terminal binding sub-domain

Botulinum neurotoxins (BoNTs) are the most toxic proteins known, due to inhibiting the neuronal release of acetylcholine and causing flaccid paralysis. Most BoNT serotypes target neurons by binding to synaptic vesicle proteins and gangliosides via a C-terminal binding sub-domain (H_CC). However, the role of their conserved N-terminal sub-domain (H_CN) has not been established. Herein, we created a mutant form of recombinant BoNT/A lacking H_CN (rAΔH_CN) and showed that the lethality of this mutant is reduced 3.3 × 10⁴-fold compared to wild-type BoNT/A. Accordingly, low concentrations of rAΔH_CN failed to bind either synaptic vesicle protein 2C or neurons, unlike the high-affinity neuronal binding obtained with ¹²⁵I-BoNT/A (K_d = 0.46 nM). At a higher concentration, rAΔH_CN did bind to cultured sensory neurons and cluster on the surface, even after 24 h exposure. In contrast, BoNT/A became internalised and its light chain appeared associated with the plasmalemma, and partially co-localised with vesicle-associated membrane protein 2 in some vesicular compartments. We further found that a point mutation (W985L) within H_CN reduced the toxicity over 10-fold, while this mutant maintained the same level of binding to neurons as wild type BoNT/A, suggesting that H_CN makes additional contributions to productive internalization/translocation steps beyond binding to neurons.

Botulinum toxin type A reduces inflammatory hypernociception induced by arthritis in the temporomadibular joint of rats

OBJECTIVE

This study aimed to investigate the antinociceptive effects of Botulinum toxin type A (BoNT-A) on persistent inflammatory hypernociception induced by arthritis in the temporomandibular joint (TMJ) of rats.

MATERIAL AND METHODS

Wistar rats were induced to persistent inflammatory hypernociception in the left TMJ. Then, animals were treated with intra-TMJ injections of BoNT-A, using doses of 3.5, 7 and 14 U/kg. Saline was used as control group. Behavioral tests were applied to evaluated the effect of BoNT-A in the inflammatory hypernociception. After that, animals were euthanized and samples from peri-articular tissues and trigeminal ganglia were obtained for further analyses.

RESULTS

BoNT-A reduced the persistent inflammatory hypernociception induced by arthritis in the TMJ of rats. BoNT-A significantly reduced the peripheral release of the neurotransmitters Substance P and Calcitonin gene related peptide; and the pro-inflammatory cytokine IL-1β. Otherwise, BoNT-A had no effect in the peripheral release of glutamate and the cytokine TNF-α.

CONCLUSION

These results demonstrate that intra-articular injection of BoNT-A reduces the albumin-induced arthritis persistent hypernociception in TMJ of rats by peripheral inhibition of neuropeptides release.

Diverse Physiological Roles of Calcitonin Gene-Related Peptide in Migraine Pathology: Modulation of Neuronal-Glial-Immune Cells to Promote Peripheral and Central Sensitization

The neuropeptide calcitonin gene-related peptide (CGRP) is implicated in the underlying pathology of migraine by promoting the development of a sensitized state of primary and secondary nociceptive neurons. The ability of CGRP to initiate and maintain peripheral and central sensitization is mediated by modulation of neuronal, glial, and immune cells in the trigeminal nociceptive signaling pathway. There is accumulating evidence to support a key role of CGRP in promoting cross excitation within the trigeminal ganglion that may help to explain the high co-morbidity of migraine with rhinosinusitis and temporomandibular joint disorder. In addition, there is emerging evidence that CGRP facilitates and sustains a hyperresponsive neuronal state in migraineurs mediated by reported risk factors such as stress and anxiety. In this review, the significant role of CGRP as a modulator of the trigeminal system will be discussed to provide a better understanding of the underlying pathology associated with the migraine phenotype.

Botulinum toxin in the management of chronic migraine: clinical evidence and experience

Chronic migraine (CM) is a severely disabling neurological condition characterized by episodes of pulsating unilateral or bilateral headache. The United States Food and Drug Administration (FDA) approved onabotulinumtoxinA (Botox®) for the prophylactic treatment of CM in 2010. It has been shown that onabotulinumtoxinA is effective in the reduction of headache frequency and severity in patients with CM. Treatment is well tolerated by the patients. This review reports on the history of botulinum neurotoxin (BoNT) in CM and presents the current clinical evidence for the use of onabotulinumtoxinA in the treatment of CM.

Abobotulinum Toxin A in the Treatment of Chronic Low Back Pain

Chronic low back pain is a debilitating condition with a complex and multifactorial pathophysiology. Botulinum neurotoxins (BoNTs) have strong analgesic effects, as shown in both animal models of pain and in human beings. A randomized, double-blind, placebo-controlled, parallel format study to investigate the efficacy of abobotulinum toxin A (aboA) in chronic low back pain was conducted. The study cohort consisted of 18 patients who received 100 units of aboA into each of the five lumbar extensor spinae muscles unilaterally or bilaterally (total dose 500 to 1000 units), and 19 who received normal saline of the same volume. The level of pain and quality of life were assessed using the visual analogue scale (VAS) and three questionnaires including the Oswestry Low Back Pain Disability Questionnaire (OLBPDQ). Patients’ perception of improvement was recorded via patient global impression of change (PGIC). The primary outcome measure, the proportion of responders with VAS of <4 at 6 weeks, was not met, but the data was significantly in favor of aboA at 4 weeks (p = 0.008). The total Oswestry score representing quality of life improved in the aboA group compared to the placebo group (p = 0.0448). Moreover, significantly more patients reported their low back pain as “much improved” in the abobotulinum toxin A group (0.0293).

Chronic Migraine: An Update on Physiology, Imaging, and the Mechanism of Action of Two Available Pharmacologic Therapies

Several lines of research support the hypothesis that migraine is a spectrum of illness, with clinical symptoms that vary along a continuum from episodic migraine to chronic migraine. Physiologic changes may result in episodic migraine evolving into chronic migraine over months to years in susceptible individuals. With chronification, headache frequency increases, becoming more disabling and less responsive to therapy. Neurophysiologic and functional imaging research has reported that chronic migraine may be associated with severity‐specific metabolic, functional, and structural abnormalities in the brainstem. Without longitudinal studies, it is unclear whether these changes may represent a continuum of individual progression and/or are reversible. Furthermore, chronic migraine is associated with larger impairments in cortical processing of sensory stimuli when compared with episodic migraine, possibly caused by more pronounced cortical hyperexcitability.

Progressive changes in nociceptive thresholds and subsequent central sensitization due to recurrent migraine attacks in vulnerable individuals contribute to the chronic migraine state. This may result in changes to baseline neurologic function between headache attacks, evident in both electrophysiological and functional imaging research. Patients experiencing migraine chronification may report increased non‐headache pain, fatigue, psychiatric disorders (eg, depression, anxiety), gastrointestinal complaints, and other somatic conditions associated with their long‐term experience with migraine pain.

Recent research provides a foundation for differentiating episodic and chronic migraine based on neurophysiologic and neuroimaging tools. In this literature review, we consider these findings in the context of models designed to explain the physiology and progression of episodic migraine into chronic migraine, and consider treatment of chronic migraine in susceptible individuals. Advances in pharmacotherapy provide treatment options for chronic migraine. Of the currently available treatment options, only onabotulinumtoxinA and topiramate have received regulatory approval and have demonstrated efficacy in patients with chronic migraine, although the exact mechanisms of action are not fully elucidated.

Anatomy and immunochemical characterization of the non-arterial peptidergic diffuse dural innervation of the rat and Rhesus monkey: Implications for functional regulation and treatment in migraine

Objective

The interplay between neuronal innervation and other cell types underlies the physiological functions of the dura mater and contributes to pathophysiological conditions such as migraine. We characterized the extensive, but understudied, non-arterial diffuse dural innervation (DDI) of the rat and Rhesus monkey.

Methods

We used a comprehensive integrated multi-molecular immunofluorescence labeling strategy to extensively profile the rat DDI and to a lesser extent that of the Rhesus monkey.

Results

The DDI was distributed across a dense, pervasive capillary network and included free nerve endings of peptidergic CGRP-expressing C fibers that were closely intertwined with noradrenergic (NA) sympathetic fibers and thin-caliber nonpeptidergic “C/Aδ” fibers. These newly identified C/Aδ fibers were unmyelinated, like C fibers, but expressed NF200, usually indicative of Aδ fibers, and uniquely co-labeled for the CGRP co-receptor, RAMP1. Slightly-larger caliber NF200-positive fibers co-labeled for myelin basic protein (MBP) and terminated as unbranched corpuscular endings. The DDI peptidergic fibers co-labeled for the lectin IB4 and expressed presumably excitatory α1-adrenergic receptors, as well as inhibitory 5HT1D receptors and the delta opioid receptor (δOR), but rarely the mu opioid receptor (µOR). Labeling for P2X3, TRPV1, TRPA1, and parasympathetic markers was not observed in the DDI.

Interpretation

These results suggest potential functional interactions, wherein peptidergic DDI fibers may be activated by stress-related sympathetic activity, resulting in CGRP release that could be detected in the circulation. CGRP may also activate nonpeptidergic C/Aδ fibers that are likely mechanosensitive or polymodal, leading to activation of post-synaptic pain transmission circuits. The distribution of α1-adrenergic receptors, RAMP1, and the unique expression of the δOR on CGRP-expressing DDI fibers suggest strategies for functional modulation and application to therapy.

Botulinum Toxin A for Bladder Pain Syndrome/Interstitial Cystitis

Botulinum neurotoxin A (BoNT-A), derived from Clostridium botulinum, has been used clinically for several diseases or syndrome including chronic migraine, spasticity, focal dystonia and other neuropathic pain. Chronic pelvic or bladder pain is the one of the core symptoms of bladder pain syndrome/interstitial cystitis (BPS/IC). However, in the field of urology, chronic bladder or pelvic pain is often difficult to eradicate by oral medications or bladder instillation therapy. We are looking for new treatment modality to improve bladder pain or associated urinary symptoms such as frequency and urgency for patients with BPS/IC. Recent studies investigating the mechanism of the antinociceptive effects of BoNT A suggest that it can inhibit the release of peripheral neurotransmitters and inflammatory mediators from sensory nerves. In this review, we will examine the evidence supporting the use of BoNTs in bladder pain from basic science models and review the clinical studies on therapeutic applications of BoNT for BPS/IC.

Primary and Secondary Red Ear Syndrome: Implications for Treatment

Approximately 57 patients with red ear syndrome have been reported in the literature since it was initially described in 1994. The clinical phenotype therefore continues to be defined and no consistent treatment response has been described. We report three new cases of red ear syndrome and suggest that the disorder may exist as a primary trigeminal or cervical autonomic cephalalgia, coexist with other rare trigeminal autonomic cephalalgias, or may be secondary. The pathogenesis in these different circumstances may be distinct, the triggers specific and, when secondary, the disorder may be more resistant to treatment.