Botulinum toxin in the treatment of rare head and neck pain syndromes: a systematic review of the literature

Botox (OnabotulinumtoxinA) for Treatment of Migraine Symptoms: A Systematic Review

Background. Migraine is one of the most common types of headache, and it is the second most common cause of neurological disorders, with an annual prevalence of about 15% of the population. This study aimed to evaluate the effect of BoNT-A on the duration and intensity of migraine attacks. In addition, we investigated the effective injection sites. Methods. According to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, we searched online databases, including Web of Science, PubMed, EMBASE, Scopus, Cochrane Library, ProQuest, ClinicalTrials.gov, and Google Scholar from 2011 to 2021. Results. A total of 24 articles were included in the study. The use of BoNT-A in individuals suffering from chronic migraine (CM) decreases the frequency of migraine attacks per month, pain intensity, medication use, emergency visits, and migraine-related disabilities. The BoNT-A was well tolerated and leads to improved performance and better quality of life (QoL). Overall, treatment with BoNT-A in adults with CM is beneficial. In addition, the use of BoNT-A in individuals with vestibular migraine (VM) reduces the frequency of migraines and brings about the improvement of disability status caused by migraine headaches. Meanwhile, the use of BoNT-A reduces the frequency of migraine attacks per month among individuals with chronic refractory migraine (CRM). Conclusions. The use of BoNT-A is a low-cost option for the treatment of various kinds of migraines, including chronic, episodic, unilateral, and vestibular types. BoNT-A can reduce the frequency of migraine attacks per month and diminish the severity of pain.

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.

Re-engineering clostridial neurotoxins for the treatment of chronic pain: current status and future prospects

Clostridial neurotoxins from the botulinum neurotoxin (BoNT) family are protein complexes, derived from the bacterium Clostridium botulinum, which potently inhibit acetylcholine release and result in a reversible blockade of the neuromuscular junction. This feature led to the clinical development of BoNT-A for a number of neuromuscular disorders. BoNT-A toxins are commercially available as three different preparations: Dysport/Azzalure, Botox/Vistabel, and Xeomin/Bocouture. Although BoNT-A preparations have not yet been approved for the treatment of pain, a substantial body of preclinical and clinical evidence shows that BoNT-A is effective in treating a number of different types of pain. It is thought to exert an analgesic effect both via muscle-relaxant properties and also directly, via inhibition of nociceptive neuropeptides. This review explores the mechanistic basis of this analgesic effect, summarizing current knowledge of the structure-function relationship of BoNT and discussing effects on both motor and pain neurons. For a complete picture of the analgesic properties of BoNT-A, clinical evidence of efficacy in myofascial pain and neuropathic pain is considered in tandem with a mechanistic rationale for activity. Patients experiencing chronic pain are clear candidates for treatment with a modified clostridial endopeptidase that would provide enduring inhibition of neurotransmitter release. A strong preclinical evidence base underpins the concept that re-engineering of BoNT could be used to enhance the analgesic potential of this neurotoxin, and it is hoped that the first clinical studies examining re-engineered BoNT-A will confirm this potential.

Botulinum toxin therapy for osteoarticular pain: an evidence-based review

Botulinum (BoNT) toxin has been used for its muscle-paralyzing action in conditions such as treatment of wrinkles, cervical dystonia and blephrospasm. There is preclinical and emerging clinical evidence of another mechanism of action of BoNT, namely, an antinociceptive action. In this review, we provide an evidence-based review of clinical studies of BoNT in osteoarticular conditions, such as osteoarthritis, tennis elbow, low back pain, and hand pain. Many randomized controlled trials (RCTs) found evidence of short-term efficacy of an injection of BoNT in relief of pain, and in some cases, improvement of function and quality of life. However, more clinical trials are needed to better define the clinical use of BoNT for treatment of refractory osteoarticular pain.

Muscle disorders and dentition-related aspects in temporomandibular disorders: controversies in the most commonly used treatment modalities

This review explores the aetiology of temporomandibular disorders and discusses the controversies in variable treatment modalities.Pathologies of the temporomandibular joint (TMJ) and its' associated muscles of mastication are jointly termed temporomandibular disorders (TMDs).TMDs present with a variety of symptoms which include pain in the joint and its surrounding area, jaw clicking, limited jaw opening and headaches. It is mainly reported by middle aged females who tend to recognize the symptoms more readily than males and therefore more commonly seek professional help.Several aetiological factors have been acknowledged including local trauma, bruxism, malocclusion, stress and psychiatric illnesses. The Research Diagnostic Criteria of the Temporomandibular Disorders (RDC/TMD) is advanced to other criteria as it takes into consideration the socio-psychological status of the patient.Several treatment modalities have been recommended including homecare practices, splint therapy, occlusal adjustment, analgesics and the use of psychotropic medication; as well as surgery, supplementary therapy and cognitive behavioural therapy. Although splint therapy and occlusal adjustment have been extensively used, there is no evidence to suggest that they can be curative; a number of evidence-based trials have concluded that these appliances should not be suggested as part of the routine care.Surgery, except in very rare cases, is discouraged since it is the most invasive alternative; recent studies have shown healthier outcome with cognitive behavioural therapy.

The methodological quality of systematic reviews comparing temporomandibular joint disorder surgical and non-surgical treatment

BACKGROUND

Temporomandibular joint disorders (TMJD) are multifactor, complex clinical problems affecting approximately 60-70% of the general population, with considerable controversy about the most effective treatment. For example, reports claim success rates of 70% and 83% for non-surgical and surgical treatment, whereas other reports claim success rates of 40% to 70% for self-improvement without treatment. Therefore, the purpose of this study was to (1) identify systematic reviews comparing temporomandibular joint disorder surgical and non-surgical treatment, (2) evaluate their methodological quality, and (3) evaluate the evidence grade within the systematic reviews.

METHODS

A search strategy was developed and implemented for MEDLINE, Cochrane Library, LILACS, and Brazilian Dentistry Bibliography databases. Inclusion criteria were: systematic reviews (+/- meta-analysis) comparing surgical and non-surgical TMJD treatment, published in English, Spanish, Portuguese, Italian, or German between the years 1966 and 2007(up to July). Exclusion criteria were: in vitro or animal studies; narrative reviews or editorials or editorial letters; and articles published in other languages. Two investigators independently selected and evaluated systematic reviews. Three different instruments (AMSTAR, OQAQ and CASP) were used to evaluate methodological quality, and the results averaged. The GRADE instrument was used to evaluate the evidence grade within the reviews.

RESULTS

The search strategy identified 211 reports; of which 2 were systematic reviews meeting inclusion criteria. The first review met 23.5 +/- 6.0% and the second met 77.5 +/- 12.8% of the methodological quality criteria (mean +/- sd). In these systematic reviews between 9 and 15% of the trials were graded as high quality, and 2 and 8% of the total number of patients were involved in these studies.

CONCLUSION

The results indicate that in spite of the widespread impact of TMJD, and the multitude of potential interventions, clinicians have expended sparse attention to systematically implementing clinical trial methodology that would improve validity and reliability of outcome measures. With some 20 years of knowledge of evidence-based healthcare, the meager attention to these issues begins to raise ethical issues about TMJD trial conduct and clinical care.

Cervicogenic headache

The relationship of the neck to headache has been recognized by physicians for over a century. However, whether the neck is the cause of a separate diagnostic entity, cervicogenic headache or simply a part of other headache complexes is the source of controversy. In recent years, there has been an increasing awareness of neck symptoms associated with headache. Various criteria for the diagnosis of cervicogenic headache have been put forward, but a clear consensus is lacking. Unfortunately, this has resulted in reports of varying prevalence, varying treatment recommendations and literature reports that require scrutiny for diagnostic criteria used in selecting patients to be treated. Review of the literature shows many older uncontrolled studies and later literature reports describe only small numbers of patients. Cervicogenic headache or headache related to the neck afflicts many persons and research with adequate patient inclusion is needed. This paper describes cervicogenic headache and treatment options.

Botulinum toxin occipital nerve block for the treatment of severe occipital neuralgia: a case series

Persistent occipital neuralgia can produce severe headaches that are difficult to control by conservative or surgical approaches. We retrospectively describe a series of six patients with severe occipital neuralgia who received conservative and interventional therapies, including oral antidepressants, membrane stabilizers, opioids, and traditional occipital nerve blocks without significant relief. This group then underwent occipital nerve blocks using the botulinum toxin type A (BoNT-A) BOTOX Type A (Allergan, Inc., Irvine, CA, U.S.A.) 50 U for each block (100 U if bilateral). Significant decreases in pain Visual Analog Scale (VAS) scores and improvement in Pain Disability Index (PDI) were observed at four weeks follow-up in five out of six patients following BoNT-A occipital nerve block. The mean VAS score changed from 8 +/- 1.8 (median score of 8.5) to 2 +/- 2.7 (median score of 1), while PDI improved from 51.5 +/- 17.6 (median 56) to 19.5 +/- 21 (median 17.5) and the duration of the pain relief increased to an average of 16.3 +/- 3.2 weeks (median 16) from an average of 1.9 +/- 0.5 weeks (median 2) compared to diagnostic 0.5% bupivacaine block. Following block resolution, the average pain scores and PDI returned to similar levels as before BoNT-A block. In conclusion, BoNT-A occipital nerve blocks provided a much longer duration of analgesia than diagnostic local anesthetics. The functional capacity improvement measured by PDI was profound enough in the majority of the patients to allow patients to resume their regular daily activities for a period of time.

Neck pain in chronic whiplash syndrome treated with botulinum toxin. A double-blind, placebo-controlled clinical trial

OBJECTIVES

Neck pain in chronic whiplash syndrome is a major burden for patients, healthcare providers and insurance companies. Randomized data on treatment of botulinum toxin in chronic whiplash syndrome are scarce. We conducted a randomized, placebo-controlled clinical trial to prove efficacy of botulinum toxin for neck pain in chronic whiplash syndrome.

METHODS

40 patients with chronic whiplash syndrome (whiplash associated disorders grade 1 and 2) were randomly assigned to receive botulinum toxin (maximum 100 units) or placebo (saline) in muscles with increased tenderness.

RESULTS

After 12 weeks there was no significant difference between the two treatment groups in decrease of neck pain intensity on VAS (-7.0 mm, 95% confidence interval (CI) [-20.7 to +6.7]), mean number of neck pain days (-1%; 95% CI [-15% to +13%]), neck pain hours per day (-0.14; 95% CI [-3.0 to +2.7]), days on which symptomatic treatment was taken (-0.7%; 95% CI [-15% to +13%]) number of analgesics taken per day (-0.14; 95% CI [-0.6 to +0.4]) and total cervical range of motion (-11 degrees; 95% CI [-40 to +17]). There also was no significant difference in patient's assessment of improvement after week 4, 8 and 12.

CONCLUSIONS

Botulinum toxin was not proven effective in treatment of neck pain in chronic whiplash syndrome. Increased muscle tenderness alone might not be the major cause of neck pain in whiplash syndrome.

Progressive Cervical Kyphosis Associated with Botulinum Toxin Injection

Weakness of the neck extensors can lead to "dropped head syndrome", a condition of progressive cervical kyphosis in which a patient is unable to hold their head up against the force of gravity. This condition can be associated with structural abnormalities of the spine as found in ankylosing spondylitis and vertebral fractures. Neuromuscular disorders, such as myasthenia gravis, muscular dystrophies, inflammatory myopathies, and motor neuron disorders such as amyotrophic lateral sclerosis (ALS) have also been reported as etiologies of dropped head syndrome. In this article, we describe an elderly woman with rapidly progressive cervical kyphosis following an injection of botulinum toxin A into her neck extensor musculature.

A Lack of Antinociceptive or Antiinflammatory Effect of Botulinum Toxin A in an Inflammatory Human Pain Model

Several in vitro and in vivo investigations have shown that botulinum toxin A (BoNT/A) can inhibit the release of substance P and excitatory amino acids. Recently, a marked antinociceptive effect of BoNT/A and inhibition of glutamate release was observed in an animal pain model with inflammatory sensitization. In the present study, we tested the antiinflammatory and antihyperalgetic effect of BoNT/A in a well-characterized human inflammatory pain model. Using a randomized, double-blind, paired study design, we compared the effects of 100 mouse units of BoNT/A versus pure saline. Thermal and mechanical pain testings and superficial skin blood flow measurements were performed at baseline, at 48 h (in normal skin), and at 72 h (in inflamed skin) thereafter. Ultraviolet B irradiation resulted in a local inflammation with significant primary and secondary hyperalgesia. However, despite the evidence of efficacy on sudomotor function, BoNT/A had no effect on pain measures in either normal or inflamed skin. Signs of inflammation and primary and secondary hyperalgesia were found to be unaffected by BoNT. We have confirmed that BoNT/A has no direct effect on acute, noninflammatory pain. Furthermore, despite highly promising data from animal research, we have not observed antiinflammatory or antinociceptive effects of BoNT/A in human inflammatory pain.