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.

Mg/kg/d) every other day 6 times over 2 weeks for a total dose of 13.8 mg/kg. Thermal escape latencies, mechanical allodynia using von Frey hairs, and observation of behavior/morbidity and body weights were assessed. After onset of allodynia, we examined the actions of intraperitoneal gabapentin (100 mg/kg), etanercept (20 and 40 mg/kg), ketorolac (15 mg/kg), and morphine (1, 3, and 10 mg/kg). Additionally, using the conditioned place preference (CPP) paradigm, we examined the effects of gabapentin and ketorolac on the presumed pain state initiated by cisplatin. Additionally, we examined the spinal cord and dorsal root ganglia (DRG) of cisplatin-treated mice. RESULTS: Cisplatin, but not saline treatment, produced persistent hindpaw tactile allodynia, which persisted 46 days with no effect on thermal escape. Gabapentin and morphine, but neither etanercept nor ketorolac, produced a complete but transient (2-hour) reversal of the allodynia. Etanercept (40 mg/kg) pretreatment resulted in a delay in onset of mechanical allodynia. Using CPP, gabapentin, but not ketorolac, in cisplatin animals resulted in a significant preference for the drug-associated treatment compartment. There was no place preference in non–cisplatin-treated (nonallodynic) mice after gabapentin injection. Immunohistochemistry in cisplatin-treated mice showed no change in glial fibrillary acidic protein (astrocyte) or Iba1 (ionized calcium binding adaptor molecule 1) (microglia) activation states, but a significant increase in activated transcription factor 3 was observed in the DRG. CONCLUSIONS: Cisplatintreated mice display allodynia and an activation of DRG activated transcription factor 3, which is paralleled by its effects on behavior in the CPP system, wherein gabapentin, but not ketorolac, in the presence of the cisplatin polyneuropathy, is positively rewarding, confirming that this neuropathy is an aversive (painful) state that is ameliorated by gabapentin....

Objective: To investigate the incidence of postoperative sore throat (POST) in Korean patients undergoing general anaesthesia with endotracheal intubation and to assess potential risk factors. Methods: This prospective study enrolled patients who underwent all types of elective surgical procedures with endotracheal intubation and general anaesthesia. The patients were categorized into group S (those with a POST) or group N (those without a POST). The demographic, clinical and anaesthetic characteristics of each group were compared. Results: This study enrolled 207 patients and the overall incidence of POST was 57.5% ( n = 119). Univariate analysis revealed that significantly more patients in group S had a cough at emergence and hoarseness in the postanaesthetic care unit compared with group N. Receiver operating characteristic curve analysis showed that an intracuff pressure ≥17 cmH₂O was associated with POST. Multivariate analysis identified an intracuff pressure ≥17 cmH₂O and cough at emergence as risk factors for POST. At emergence, as the intracuff pressure over ≥17 cmH₂O increased, the incidence of hoarseness increased. Conclusions: An intracuff pressure ≥17 cmH₂O and a cough at emergence were risk factors for POST in Korean patients. Intracuff monitoring during anaesthesia and a smooth emergence are needed to prevent POST.

There is little evidence regarding the effectiveness of intervention methods in the treatment of zoster-related pain (ZAP) after the acute phase of zoster. Generally, if ZAP remains after more than 180 days from its onset, the likelihood of pain reduction is very low; this condition is considered as a “well established” post-herpetic neuralgia (PHN). Although the clinical efficacy of intrathecal steroid injection and spinal cord stimulation (SCS) for ZAP management has been reported, these interventions are not widely used due to inherent disadvantages. Continuous epidural block is widely used in clinical practice, and the effectiveness of pulsed radiofrequency (PRF) to the dorsal root ganglion (DRG) in the treatment of ZAP already has been reported. The purpose of this study was to compare the clinical efficacy of continuous epidural block and DRG PRF beyond acute phase of zoster, bur before PHN was well established (from 30 days to180 days after zoster onset). Retrospective comparative study. A total of 42 medical records were analyzed. Patients were divided into two groups according to the type of procedure utilized: continuous epidural block (continuous epidural group) and DRG PRF (PRF group). The clinical efficacy of the procedure was evaluated using a numeric rating scale (NRS) and the medication dose before and 1 to 6 months after the procedure. There was a significant decrease in the NRS value with time in both groups. However, this decrease was more significant in the PRF group than in the continuous epidural group. The medication doses decreased significantly in the PRF group over time, but not in the continuous epidural group. The rate of clinically meaningful PHN (NRS≥3) was also lower in the PRF group than in the continuous epidural group. This study revealed that DRG PRF was more effective than a continuous epidural block in treating ZAP after the acute phase of zoster. A neuromodulation method such as DRG PRF may be a useful option for reducing the progression of neuropathic changes caused by the persistent transmission of a pain signal after the acute phase of zoster.