Ultrasound-Guided Nerve Block with Botulinum Toxin Type A for Intractable Neuropathic Pain

The efficacy of botulinum toxin in neuropathic pain: a systematic review

Introduction

Neuropathic pain (NP) is characterised as a lesion or disease directly affecting the somatosensory system. This study aims to analyse the efficacy of botulinum toxin type A (BT-A) in the treatment of neuropathic pain.

Methods

This systematic literature review, guided by PRISMA, applied the PICO strategy with the following criteria: (P = patients with neuropathic pain, I = botulinum toxin, C = placebo or active drug, and O = pain relief).

Results

Fourteen articles, all randomised controlled trials with a placebo control, were included in the review. A total of 645 patients were randomised, with 353 patients receiving treatment with botulinum toxin type A in doses ranging from 25U to 400U. The evaluated studies addressed trigeminal neuralgia, diabetic polyneuropathy, post-herpetic neuralgia, spinal cord injury, phantom limb pain, and peripheral neuropathic pain after trauma or surgery.

Conclusion

BT-A has emerged as a promising treatment for various origins of neuropathic pain. Therefore, future studies should adopt stricter criteria regarding dosage and routes of administration to ensure effective and consistent BT-A application.

Efficacy of Botulinum Type A Injection for the Treatment of Postherpetic Neuralgia and Pruritus Persisting for More Than Four Years-A Case Report

Background: Postherpetic neuralgia (PHN) and postherpetic pruritus (PHP) are common complications of shingles that affect patients' quality of life. PHN and PHP can be managed using various medications and interventional procedures; however, complications persisting for at least six months may hamper recovery. Subcutaneous injections of botulinum toxin type A (BTX-A) can control persistent PHN and PHP. Case presentation: A 71-year-old man presented at our hospital with itching and pain. He had been diagnosed with shingles in the ophthalmic branch of the trigeminal nerve one year previously. As the pain and itching persisted despite medication, a supraorbital nerve block, Gasserian ganglion block, epidural nerve block, and radiofrequency thermocoagulation were performed. A subcutaneous injection of BTX-A was administered into the ophthalmic area of the trigeminal nerve three years after the initial presentation. A decrease of >80% in pain and itching was reported after the injection; however, the left eyelid drooped and the eyeball shifted downward and outward immediately after the injection. No deterioration in vision or pupil dilation was observed, and almost complete resolution of these symptoms occurred spontaneously three months after the injection. Pain and itching continued to improve without further side-effects until six months after the injection. Conclusions: The subcutaneous injection of BTX-A may be an alternative treatment option for chronic and refractory neurological diseases such as PHN and PHP, which persist for four years and are resistant to conventional treatments. Nevertheless, care must be taken to minimize the risk of ptosis.

Peripheral and central neurobiological effects of botulinum toxin A (BoNT/A) in neuropathic pain: a systematic review

ABSTRACT

Botulinum toxin (BoNT), a presynaptic inhibitor of acetylcholine (Ach) release at the neuromuscular junction (NMJ), is a successful and safe drug for the treatment of several neurological disorders. However, a wide and recent literature review has demonstrated that BoNT exerts its effects not only at the "periphery" but also within the central nervous system (CNS). Studies from animal models, in fact, have shown a retrograde transport to the CNS, thus modulating synaptic function. The increasing number of articles reporting efficacy of BoNT on chronic neuropathic pain (CNP), a complex disease of the CNS, demonstrates that the central mechanisms of BoNT are far from being completely elucidated. In this new light, BoNT might interfere with the activity of spinal, brain stem, and cortical circuitry, modulating excitability and the functional organization of CNS in healthy conditions. Botulinum toxins efficacy on CNP is the result of a wide and complex action on many and diverse mechanisms at the basis of the maladaptive plasticity, the core of the pathogenesis of CNP. This systematic review aims to discuss in detail the BoNT's mechanisms and effects on peripheral and central neuroplasticity, at the basis for the clinical efficacy in CNP syndromes.

Effectiveness of Botulinum Toxin in the Treatment of Neuropathic Pain: A Literature Review

Neuralgia is characterized by chronic pain resulting from damage or diseases in the somatosensory system, including nerves responsible for transmitting sensory information. Current treatments for neuropathic pain, which is a type of neuralgia, have limited success rates and can cause unwanted side effects. Since 1989, botulinum toxin-A (BTX-A), derived from the potent neurotoxin Clostridium botulinum, has been used to treat neuropathic pain in humans. BTX-A has shown analgesic effects by inhibiting the release of neurotransmitters involved in pain transmission. This review aims to evaluate the effectiveness of BTX-A in various types of neuralgia. The research question guiding this review is whether BTX-A is safe and effective in reducing pain in different types of neuralgias. To conduct this review, a literature search was performed using the PubMed, Medline, and PubMed Central databases. The search strategy included relevant keywords related to BTX-A, neuralgia, and neuropathic pain. After screening titles, abstracts, and full texts, a total of 30 articles were included in the review. These studies examined the efficacy of BTX-A in various conditions such as postherpetic neuralgia (PHN), auriculotemporal neuralgia (ATN), occipital neuralgia (ON), leprosy-induced neuropathic pain (LIN), focal painful neuropathies, complex regional pain syndrome (CRPS), trigeminal neuralgia (TN), and neuropathic pain associated with spinal cord injury. However, further research is needed to enhance our understanding of the optimal use of BTX-A in specific neuralgias. It is important to acknowledge the limitations of the included studies. Nevertheless, BTX-A might be considered a viable treatment option for neuralgia.

Analgesic Effect of Perineural Injection of BoNT/A on Neuropathic Pain Induced by Chronic Constriction Injury of Sciatic Nerve in Rats

This study was designed to investigate the analgesic effect of perineural injection of BoNT/A on neuropathic pain induced by sciatic nerve chronic constriction injury (CCI) and possible mechanisms. SD rats were randomly divided into Sham group, CCI group and BoNT/A group. Paw mechanical withdrawal threshold (pMWT) and paw thermal withdrawal latency (pTWL) of each group were detected at different time points after surgery. The expression of myelin markers, autophagy markers and NLRP3 inflammasome-related molecules in injured sciatic nerves were examined at 12 days after surgery. Moreover, C-fiber evoked potential in spinal dorsal horn was recorded. The expression of SNAP-25, neuroinflammation and synaptic plasticity in spinal dorsal horn of each group were examined. Then rats treated with BoNT/A were randomly divided into DMSO group and Wnt agonist group to further explore the regulatory effect of BoNT/A on Wnt pathway. We found that pMWT and pTWL of ipsilateral paw were significantly decreased in CCI group compared with Sham group, which could be improved by perineural injection of BoNT/A at days 7, 9 and 12 after surgery. The peripheral analgesic mechanisms of perineural injection of BoNT/A might be related to the protective effect on myelin sheath by inhibiting NLRP3 inflammasome and promoting autophagy flow, while the central analgesic mechanisms might be associated with inhibition of neuroinflammation and synaptic plasticity in spinal dorsal horn due to inhibiting SNAP-25 and Wnt pathway. As a new route of administration, perineural injection of BoNT/A can relieve CCI induced neuropathic pain probably via both peripheral and central analgesic mechanisms.

Management of Trigeminal Neuralgia with Botulinum Toxin Type A: Report of Two Cases

Trigeminal neuralgia is a chronic pain condition associated with sharp, shock-like pain in one or more divisions of the trigeminal nerve. For patients who do not respond well to pharmacotherapy, there is growing evidence that Botulinum toxin type A injections into the trigeminal ganglion provide pain relief for several weeks up to several months at a time. One option is to administer injections into the trigeminal ganglion in Meckel's cave by inserting a needle through the Pterygopalatine Fossa using fluoroscopy to guide and confirm the proper needle placement. However, there is evidence that Botulinum toxin travels across nerve synapses; thus, injecting directly into the trigeminal ganglion may not be necessary. We present two patients with a confirmed diagnosis of trigeminal neuralgia who were treated by injecting Botulinum toxin type A intraorally into the mental foramen which resulted in 6 months or longer of pain relief. Injections into the mental foramen are much easier to administer than those administered directly into the trigeminal ganglion, and both patients treated with this technique experienced comparable results to what can be expected from traditional fluoroscopy-guided botulinum toxin injections. Though more research is needed, these cases potentially imply that a less-invasive injection may be sufficient in managing trigeminal neuralgia-related pain.

A comparative study of Botulinum toxin type A versus conventional oral therapy as a second-line treatment of diabetic neuropathy

Background

Diabetes mellitus is commonly complicated by diabetic peripheral neuropathy. Poor adherence to medication is common in diabetic peripheral neuropathy mainly due to common side effects and poor tolerance to medication. Botulinum toxin A intradermal injection has proved efficacy in cases of diabetic peripheral neuropathy, however there is a need to compare its effect to other lines of treatment. The aim of the study was to compare Botulinum toxin type A versus conventional oral treatment as a second-line treatment of painful diabetic peripheral neuropathy. The current study was a comparative study on 30 patients with type 2 diabetes mellitus. Diabetic peripheral neuropathy was proved by nerve conduction study. All patients were on carbamazepine. Patients were divided randomly into three groups. First group was add-on duloxetine, second group was add-on gabapentin and the third group was injected intradermal with Botulinum toxin A.

Results

Our study showed that Botulinum A intradermal injection, gabapentin and duloxetine add-on therapy decreased the VAS and PSQI over a 12-week study period and this was statistically significant at p < 0.001*. Botulinum A intradermal injection also decreased the mean of PSQ1 from 17.3 ± 1.8 to 10.9 ± 3.1 in 12 weeks constituting the highest decline in PSQ1 among the three groups and this was statistically significant at p < 0.001*.

Conclusion

Botulinum toxin A injection had a comparable if not superior efficacy to duloxetine and gabapentin as a second-line treatment of diabetic peripheral neuropathy.

The Mechanisms of Action of Botulinum Toxin Type A in Nociceptive and Neuropathic Pathways in Cancer Pain

BACKGROUND

Botulinum toxin type A (BoNT-A) is widely employed for cosmetic purposes and in the treatment of certain diseases such as strabismus, hemifacial spasm and focal dystonia among others. BoNT-A effect mainly acts at the muscular level by inhibiting the release of acetylcholine at presynaptic levels consequently blocking the action potential in the neuromuscular junction. Despite the great progress in approval and pharmaceutical usage, improvement in displacing BoNT-A to other pathologies has remained very limited. Patients under diagnosis of several types of cancer experience pain in a myriad of ways; it can be experienced as hyperalgesia or allodynia, and the severity of the pain depends, to some degree, on the place where the tumor is located. Pain relief in patients diagnosed with cancer is not always optimal, and as the disease progresses, transition to more aggressive drugs, like opioids is sometimes unavoidable. In recent years BoNT-A employment in cancer has been explored, as well as an antinociceptive drug; experiments in neuropathic, inflammatory and acute pain have been carried out in animal models and humans. Although its mechanism has not been fully known, evidence has shown that BoNT-A inhibits the secretion of pain mediators (substance P, Glutamate, and calcitonin gene related protein) from the nerve endings and dorsal root ganglion, impacting directly on the nociceptive transmission through the anterolateral and trigeminothalamic systems.

AIM

The study aimed to collect available literature regarding molecular, physiological and neurobiological evidence of BoNT-A in cancer patients suffering from acute, neuropathic and inflammatory pain in order to identify possible mechanisms of action in which the BoNT-A could impact positively in pain treatment.

CONCLUSION

BoNT-A could be an important neo-adjuvant and coadjuvant in the treatment of several types of cancer, to diminish pro-tumor activity and secondary pain.

Combination of Botulinum Toxin and minocycline Ameliorates Neuropathic Pain Through Antioxidant Stress and Anti-Inflammation via Promoting SIRT1 Pathway

Neuropathic pain (NP) is one of the intractable complications of spinal cord injury (SCI), with poor prognosis and seriously affects the quality of life of patients. This study aims to determine the treatment effect and mechanism of multimodal therapies in a rat model of SCI-induced NP by combining treatment with the anti-inflammatory agent minocycline (MC) and botulinum toxin (BoNT). The combined utilization alleviated SCI-induced NP and reduced apoptosis, inflammation, and oxidative stress of SCI by activating SIRT1 and dampening pAKT, P53, and p-NF-KB. BoNT with a concentration of 0.1 nm and MC with a concentration of 20 uM were selected for the experiment in the primary microglia and astrocytes treated with LPS. It was found that the combination of BoNT and MC obviously inhibits the inflammatory response and oxidative stress of glial cells, and notably activates SIRT1 and restrains pAKT, P53, and p-NF-KB. Therefore, in the treatment of SCI-induced NP, the combination of BoNT and MC markedly improves the therapeutic effect of NP by promoting the SIRT1 expression, thereby inactivating NF-KB, P53, and PI3K/AKT signaling pathway, inhibiting inflammation and oxidative stress as well as relieving SCI-induced NP.

Therapeutic Use of Botulinum Neurotoxins in Dermatology: Systematic Review

Botulinum toxin is a superfamily of neurotoxins produced by the bacterium Clostridium Botulinum with well-established efficacy and safety profile in focal idiopathic hyperhidrosis. Recently, botulinum toxins have also been used in many other skin diseases, in off label regimen. The objective of this manuscript is to review and analyze the main therapeutic applications of botulinum toxins in skin diseases. A systematic review of the published data was conducted, following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Botulinum toxins present several label and off-label indications of interest for dermatologists. The best-reported evidence concerns focal idiopathic hyperhidrosis, Raynaud phenomenon, suppurative hidradenitis, Hailey–Hailey disease, epidermolysis bullosa simplex Weber–Cockayne type, Darier’s disease, pachyonychia congenita, aquagenic keratoderma, alopecia, psoriasis, notalgia paresthetica, facial erythema and flushing, and oily skin. Further clinical trials are still needed to better understand the real efficacy and safety of these applications and to standardize injection and doses protocols for off label applications.

The Lateral Decubitus Body Position Might Improve the Safety of Ultrasound-Guided Supraclavicular Brachial Plexus Nerve Block

Background

To investigate whether body mass index (BMI) and changes in body positioning have any correlation with the distance from the pleura to the inferior trunk of the supraclavicular brachial plexus.

Patients and Methods

Twenty stroke patients with upper limb spasticity and complex regional pain syndrome were recruited for this study. Distance from the pleura to the inferior trunk was measured in the supine position, body turned sideways at 45 °, and in the lateral decubitus position. Correlations between BMI and measured distances in these body positions were evaluated. A linear musculoskeletal ultrasound transducer was used to conduct these distance measurements.

Results

The distance from the pleura to the inferior trunk in the supine position was calculated to have an average of 0.42 ± 0.06 cm (D1), 0.44 ±0.05 (D2) when lying sideways at 45 °, and 0.87 ± 0.08 cm (D3) in the lateral decubitus position. The Kruskal–Wallis test revealed significant differences when comparing D3 with D1, and D3 with D2 (p < 0.001). Positive correlations were observed between BMI and D1 (Spearman’s rho = 0.62, p = 0.004, two-tailed), and between BMI and D2 (Spearman’s rho = 0.61, p = 0.005, two-tailed). The strongest positive correlation was observed between BMI and D3 (Spearman’s rho = 0.78, p < 0.001, two-tailed).

Discussion

In the lateral decubitus body position, the distance from the pleura to the inferior trunk increased significantly by 2-fold and was positively correlated with BMI. The increased distance may improve the safety of the nerve block procedure. As a result, it is recommended that patients be placed in the lateral decubitus body position when performing ultrasound-guided supraclavicular brachial plexus nerve block of the inferior trunk.

Evaluation of Botulinum Toxin Type A Injection in the Treatment of Localized Chronic Pruritus

BACKGROUND: Botulinum toxin is a neurotoxin produced by the bacterium Clostridium botulinum that causes a flaccid muscle paralysis. It is currently used for aesthetic procedures and to treat focal hyperhidrosis. The botulinum toxin has also been used experimentally in many other dermatological conditions with positive results. OBJECTIVE: We sought to evaluate the efficacy and safety of intradermal injection of botulinum toxin A in the treatment of localized recalcitrant chronic pruritus in lichen simplex, inverse psoriasis, post-burn itching, lichen planus (hypertrophic), and postherpetic neuralgia. METHODS: This was a clinical trial study of 32 patients (12 with lichen simplex chronicus [LSC], 4 with inverse psoriasis, 4 with post-burning itch, 4 with lichen planus, 4 with hypertrophic lichen planus, and 4 with post-herpetic neuralgia). We used 2 to 3mL of unpreserved saline to dilute each vial (50 units) of botulinum toxin A. This led to a final concentration of 2 to 2.5U/0.1cc; injections were typically made into the dermis. RESULTS: The ages of patients in the group studied ranged from 13 to 85 years, with a mean of 37.38 years, and 59.4 percent were female. There were statistical reductions in visual analog scale in all the studied cases. CONCLUSION: Botulinum toxin A appears to be a safe and effective therapy for the improvement of localized recalcitrant itching in LSC, inverse psoriasis, burns, hypertrophic lichen planus, lichen planus, and symptoms of postherpetic neuralgia.

Alternative Clinical Indications of Botulinum Toxin

Botulinum toxin type A (BoNTA) is a powerful neurotoxin that inhibits acetylcholine release from presynaptic vesicles. The potency and safety profile of BoNTA grant the toxin vast therapeutic potential. It has been used off-label for a variety of dermatologic conditions. This review aims to analyze published literature regarding the benefits and risks of the off-label use of BoNTA beyond facial lines, including eccrine hidrocystomas, enlarged pores, keloids and hypertrophic scars, hidradenitis suppurativa, hyperhidrosis, masseter muscle hypertrophy, and salivary gland hypertrophy, among others. A MEDLINE search from January 2000 to December 2019 was conducted on the off-label uses of botulinum toxin in dermatology.

Perineural injection of botulinum toxin-A in painful peripheral nerve injury - a case series: pain relief, safety, sensory profile and sample size recommendation

Objectives: Subcutaneous injection of botulinum toxin-A (sBONT-A) is a novel treatment for peripheral neuropathic pain. While its analgesic effects are well documented, this treatment is often not comfortable and fails in patients who show signs of sensory loss but rarely allodynia. There are some case reports about perineural BONT-A injection (pBONT-A) which could be an alternative approach. Here we present a retrospective, open label case series of pBONT-A's efficacy and safety regarding neurological consequences involving changes in somatosensory profiles of both responders and non-responders. Methods: Sixty patients (53 ± 13years, 77% males) with PNI were treated with pBONT-A after a test injection with a local anesthetic, which prompted distinctive pain relief. Quantitative sensory testing (QST; DFNS protocol) and pain intensity were assessed before and ≥7 days post pBONT-A injection. Definition of response: satisfactory pain reduction of ≥30% NRS (numerical rating scale: 0 = no pain, 10 = worst pain) for ≥4 days. Statistics: Paired t-test, Mann-Whitney U-test, χ² test. Results: A temporary weak paresis in one case was clinically verified. The QST -parameters remained unchanged, but patients with more frequent hyperalgesia signs reported less analgesia (p = .04). The pBONT-A injection prompted pain relief by 24.8% (NRS: 6.0 ± 1.7 vs. 4.5 ± 2.1; p < .0001); 57% (n = 34) were responders (NRS: 6.0 ± 1.6 vs. 3.4 ± 1.6, relief of 43.4%; p < .0001). Based on these results, we suggest that future parallel design trials on pBONT-A need to include at least 84 patients. Discussion: Ultrasound-guided pBONT-A injection seems to be a safe treatment leading to a sufficient pain relief for some months without sensory changes. Surprisingly, pBONT-A showed a pronounced analgesic effect also in patients without signs of hyperalgesia.

[Long-term effectiveness of topical analgesics]

BACKGROUND

Neuropathic pain consistently presents a significant therapeutic challenge. Topically applied analgesics have the advantage of showing low systemic side effects, but data on long-term effectiveness are lacking. Consequently, interviews were carried out with all patients being treated with topical analgesics in hospital.

METHODS

Ethics 16-5690, German Clinical Trials Register (DRKS) 00011877. Between 2008 and 2017 a total of 265 patients were treated at least once with either capsaicin 8% (C), lidocaine 5% (L) and/or perineural botulinum toxin type A (B). From this sample, 205 patients (77%) were interviewed by telephone for feedback on pain reduction (first/last treatment: low/moderate/very good), the possible reduction of analgesic prescription and if applicable the reasons for discontinuation of use (time of interview C: 26 ± 19 months, L: 61 ± 23 months, B: 11 ± 6 months after start). Further pretreatment data and diagnoses were obtained from the in-house documentation system. Responders or long-term responders were defined as patients with at least one moderate pain reduction after the first or last treatment, as long as the effect was adequately maintained.

RESULTS

In all treatment groups (56 ± 13 years, 62% male, C: 80, L: 84, B: 58 patients) patients with a long history of pain (C: 60 ± 73 months, L: 59 ± 66 months, B: 67 ± 71 months) and high pain intensity (numeric rating scale, NRS, C: 7 ± 2, L: 7 ± 2, B: 6 ± 2), were predominant. The highest primary and long-term responder rates were exhibited by L (57%/60%, B: 52%/37%, C: 23%/15%). With B, long-term responders were most frequently able to reduce analgesic use (74%, C: 58%, L: 38%).

DISCUSSION

Despite the long duration of the disease, the most used off-label topical drugs L and B demonstrated a high primary response rate (in contrast to C), with most benefiting from long-term treatment.

The effects of botulinum toxin type A injection on pain symptoms, quality of life, and sleep quality of patients with diabetic neuropathy: A randomized double-blind clinical trial

Background: Neuropathic pain is one of the most common problems in patients with diabetes mellitus (DM). In this study, the effect of botulinum toxin type A (BTX-A) on neuropathic pain, quality of sleep, and quality of life of diabetic patients with sensorimotor polyneuropathy was studied. Methods: This randomized placebo-controlled trial study was carried out in a double-blind (patient-researcher) method. The study was performed on 32 patients with type 2 DM. Neuropathy was confirmed by Douleur Neuropathique 4 (DN4) Questionnaire and nerve conduction study (NCS). The patients were randomly assigned to two intervention and control groups based on the random numbers table. After selecting the subjects, we used 36-Item Short Form Health Survey (SF-36), Neuropathic Pain Scale (NPS), Visual Analogue Scale (VAS), and Pittsburgh Sleep Quality Index (PSQI) questionnaires before and after 3 months of 100 units BTX-A injection (as intervention group) or same amount of chloride sodium (as control group) to the subjects' feet. The data were analyzed by SPSS software using independent two-sample t-test, chi-square test, and one-way repeated measures analysis of variance (ANOVA). Results: 12 male and 20 female patients participated in this study. There was a significant difference in the mean VAS, PSQI, physical dimension of the SF-36, and some NPS indices over time (12 weeks) (P < 0.001). Conclusion: The results of this study showed that BTX-A reduced neuropathic pain and improved the quality of life and sleep in people with diabetic neuropathy.

Ropivacaine mesylate exerts neurotoxicity via up-regulation of Fas/FasL expression in rat pheochromocytoma PC12 cells

It has been shown that local anesthetics have potential neurotoxicity, but the exact mechanism remains unclear. In this study, PC12 cells were treated with different concentrations of ropivacaine mesylate (0.1, 0.5, 1, 2 and 4 mmol/L) for 24 h, the cell viability was assessed by CCK-8 assay. Then, cells in 0.5 mmol/L ropivacaine group, 2 mmol/L ropivacaine group and control group were subjected to morphological observation under a light microscope, assessment of cell necrosis by Hoechst33342/PI staining and apoptosis by Annexin V-FITC/PI staining, and the detection of Fas and FasL expression by qPCR, immunofluorescence and Western blot. Results showed that the cell viability decreased significantly (P<0.05), necrosis and apoptosis rate increased markedly (P<0.05), and the expression of Fas, FasL, caspase-3 and caspase-8 increased dramatically (P<0.05) with the increase in the concentration of ropivacaine mesylate. Therefore, ropivacaine mesylate may induce the apoptosis of PC12 cells, which may be related to the up-regulation of Fas/FasL.

Botulinum Toxin for the Treatment of Neuropathic Pain

Botulinum toxin (BoNT) has been used as a treatment for excessive muscle stiffness, spasticity, and dystonia. BoNT for approximately 40 years, and has recently been used to treat various types of neuropathic pain. The mechanism by which BoNT acts on neuropathic pain involves inhibiting the release of inflammatory mediators and peripheral neurotransmitters from sensory nerves. Recent journals have demonstrated that BoNT is effective for neuropathic pain, such as postherpetic neuralgia, trigeminal neuralgia, and peripheral neuralgia. The purpose of this review is to summarize the experimental and clinical evidence of the mechanism by which BoNT acts on various types of neuropathic pain and describe why BoNT can be applied as treatment. The PubMed database was searched from 1988 to May 2017. Recent studies have demonstrated that BoNT injections are effective treatments for post-herpetic neuralgia, diabetic neuropathy, trigeminal neuralgia, and intractable neuropathic pain, such as poststroke pain and spinal cord injury.

Subcutaneous Botulinum Toxin Injection for Post-Thoracotomy Pain Syndrome in Palliative Care: A Case Report

Post-thoracotomy pain syndrome (PTPS) is a traumatic neuropathy that can affect as many as 50% of patients undergoing thoracotomy. Patients are often refractory to conservative management and may require multiple analgesics for adequate pain control. Botulinum toxin, derived from Clostridium botulinum, has many uses in treating conditions involving spasticity, dystonia, chronic migraine, and a variety of pain disorders including neuropathies. Botulinum toxin type A injections may provide an alternative or adjunct to improve symptom management in patients with PTPS.

Botulinum Toxin Off-Label Use in Dermatology: A Review

BACKGROUND

Botulinum toxin is a neurotoxin produced by the bacterium Clostridium botulinum which causes a flaccid muscle paralysis. It is currently used for aesthetic treatments and in the focal hyperhidrosis. Recently, botulinum toxin has also been used experimentally in many other dermatological conditions with good results.

OBJECTIVE

To review and analyze the possible botulinum toxin off-label applications published.

METHODS

A retrospective review of the published data was conducted.

CONCLUSIONS

this potent drug can lead to several off-label indications of interest for dermatologists. Further clinical trials are still needed to better understand the real efficacy and safety of these applications and to standardize injection and dose protocols.