Ultrasound-guided stellate ganglion block for the treatment of migraine in elderly patients: A retrospective and observational study.

OBJECTIVES: This study aimed to assess the effectiveness and safety of ultrasound-guided stellate ganglion block (SGB) in the prophylactic treatment of migraine in the elderly. BACKGROUND: Treatment of migraine in the elderly is often difficult and troublesome due to multiple comorbidities, drug interactions, and adverse effects (AEs). SGB may be an effective treatment approach for migraine in the elderly as its clinical use is rarely limited by concomitant diseases and age-related physiological changes; however, no studies have evaluated the effectiveness of SGB in the treatment of migraine in the elderly population. METHODS: This is a retrospective observational case series study. We retrospectively analyzed patients with migraine aged ≥65 years, who underwent ultrasound-guided SGB for headache management between January 2018 and November 2022. Pain intensity using the numerical rating scale (NRS, 0-10), number of days with headache per month, duration of headache, and the consumptions of acute medications were recorded before SGB treatment, and at 1, 2, and 3 months after the last SGB. Safety assessment included thorough documentation of serious and minor AEs related to SGB. RESULTS: Of 71 patients, 52 were analyzed in this study. After the final SGB, the NRS scores decreased significantly from a mean (± standard deviation [SD]) of 7.3 (1.2) at baseline to 3.3 (1.4), 3.1 (1.6), and 3.6 (1.6) at 1, 2, and 3 months, respectively (vs. baseline, p < 0.001). The mean (SD) number of headache days per month significantly reduced from 23.1 (5.5) to 10.9 (7.1) (p < 0.001), 12.7 (6.5) (p = 0.001), and 14.0 (6.8) days (p = 0.001) at the 1-, 2-, and 3-month follow-ups, respectively. The values of headache duration were also significantly lower at the 1-month (mean [SD] 12.5 [15.8] h, p = 0.001), 2-month (mean [SD] 11.3 [15.9] h, p = 0.001), and 3-month follow-ups (mean [SD] 14.3 [16.0] h, p = 0.001) compared to pre-treatment baseline (mean [SD] 22.7 [17.1] h). There were 33/52 (64%) patients experiencing at least a 50% reduction in acute medications consumption 3 months after the final SGB treatment. The overall AEs rate associated with ultrasound-guided SGB was 9.0% (26/290 SGBs). There were no serious AEs; all reported AEs were minor and transient. CONCLUSIONS: Stellate ganglion block treatment could reduce pain intensity, headache frequency, and duration of migraine, thereby reducing the need for adjunctive medications in elderly patients. Ultrasound-guided SGB might be a safe and effective intervention for the treatment of migraine in elderly patients.

Predictors of the Analgesic Efficacy of CT-Guided Percutaneous Pulsed Radiofrequency Treatment of Gasserian Ganglion in Patients With Idiopathic Trigeminal Neuralgia.

AIMS: Although pulsed radiofrequency (PRF) has few postoperative adverse reactions, its analgesic efficacy for trigeminal neuralgia (TN) is not always guaranteed. The response rate of PRF targeting the Gasserian ganglion for patients with TN varies. This study aims to identify the predictors of the analgesic efficacy of CT-guided percutaneous PRF in patients with idiopathic TN. METHODS: The patients with idiopathic TN who failed to respond to conservative treatment and underwent CT-guided percutaneous PRF treatment of the Gasserian ganglion from July 2008 to August 2018 at our pain clinic were screened. A positive response was defined as a ≥50% reduction in the pain numeric rating scale (NRS) score from baseline. The demographics and other pretreatment clinical data were analyzed by logistic regression analysis to identify the predictors of a positive response. RESULTS: Of the total 102 patients with idiopathic TN who were evaluated in this study, 57 patients (55.9%) were positively responsive to our treatment after 1 year. The binary logistic regression analysis revealed that the positive response to a prior peripheral branch nerve block of the trigeminal nerve with steroid and local anesthetic agents was an independent predictor of the analgesic efficacy of PRF treatment (odds ratio [OR] = 3.685, 95% confidence interval [CI] = 1.583 to 8.577, P = 0.002). The disease duration of TN was also included in the multivariate regression model, although the P value was 0.058 (OR 0.807, 95% CI 0.646 to 1.007). CONCLUSION: For patients who previously had positive responses to peripheral branch nerve block of the trigeminal nerve, PRF is likely to have better efficacy.

Pulsed Radiofrequency Applied to the Sciatic Nerve Improves Neuropathic Pain by Down-regulating The Expression of Calcitonin Gene-related Peptide in the Dorsal Root Ganglion.

Background: Clinical studies have shown that applying pulsed radiofrequency (PRF) to the neural stem could relieve neuropathic pain (NP), albeit through an unclear analgesic mechanism. And animal experiments have indicated that calcitonin gene-related peptide (CGRP) expressed in the dorsal root ganglion (DRG) is involved in generating and maintaining NP. In this case, it is uncertain whether PRF plays an analgesic role by affecting CGRP expression in DRG. Methods: Rats were randomly divided into four groups: Groups A, B, C, and D. In Groups C and D, the right sciatic nerve was ligated to establish the CCI model, while in Groups A and B, the sciatic nerve was isolated without ligation. After 14 days, the right sciatic nerve in Groups B and D re-exposed and was treated with PRF on the ligation site. Thermal withdrawal latency (TWL) and hindpaw withdrawal threshold (HWT) were measured before PRF treatment (Day 0) as well as after 2, 4, 8, and 14 days of treatment. At the same time points of the behavioral tests, the right L4-L6 DRG was sampled and analyzed for CGRP expression using RT-qPCR and an enzyme-linked immunosorbent assay (ELISA). Results: Fourteen days after sciatic nerve ligation, rats in Groups C and D had a shortened TWL (P<0.001) and a reduced HWT (P<0.001) compared to those in Groups A and B. After PRF treatment, the TWL of the rats in Group D gradually extended with HWT increasing progressively. Prior to PRF treatment (Day 0), CGRP mRNA expressions in the L4-L6 DRG of Groups C and D increased significantly (P<0.001) and were 2.7 and 2.6 times that of Group A respectively. ELISA results showed that the CGRP content of Groups C and D significantly increased in comparison with that of Groups A and B (P<0.01). After PRF treatment, the mRNA expression in the DRG of Group D gradually decreased and the mRNA expression was 1.7 times that of Group A on the 4th day(P> 0.05). On the 8th and 14th days, the mRNA levels in Group D were restored to those of Groups A and B. Meanwhile, the CGRP content of Group D gradually dropped over time, from 76.4 pg/mg (Day 0) to 57.5 pg/mg (Day 14). Conclusions: In this study, we found that, after sciatic nerve ligation, rats exhibited apparent hyperalgesia and allodynia, and CGRP mRNA and CGRP contents in the L4-L6 DRG increased significantly. Through lowering CGRP expression in the DRG, PRF treatment might relieve the pain behaviors of NP.

Combined Therapy of Paravertebral Nerve Pulsed Radiofrequency and Subcutaneous Block for Acute/Subacute Herpetic Neuralgia: A Retrospective Study.

OBJECTIVES: This retrospective study aimed to investigate the effectiveness and safety of early combined therapy with CT-guided paravertebral nerve (PVN), pulsed radiofrequency (PRF), and subcutaneous block on acute/subacute herpes zoster (HZ). METHODS: A total of 98 medical records were analyzed. All patients underwent CT-guided PRF on PVN immediately followed by a single subcutaneous block with lidocaine and dexamethasone in acute/subacute phase. The therapy efficacy was evaluated by pain numeric rating scale (NRS) and effective rate, which was defined as a percent of cases with a reduction in pain NRS>50% at day 1, week 2, 4, 12, and 24 after the procedure. The incidences of medication reduction and postherpetic neuralgia (PHN) were also retrieved. Further comparison was conducted between acute group (disease duration<30 days from HZ onset) and subacute group (30 day50% in prior medications amounted to 83% and the incidence of clinically meaningful PHN decreased to 23%. The clinical efficacy was more profound in acute group than in subacute group at every time points ( P <0.05). No severe complications occurred. DISCUSSION: Our data revealed surprising levels of pain relief by combination therapies of PRF and subcutaneous block targeting different sites of pain pathway, thus suggesting a valuable treatment option for acute/subacute herpetic neuralgia.

Outcomes and Predictors of Response of Duloxetine for the Treatment of Persistent Idiopathic Dentoalveolar Pain: A Retrospective Multicenter Observational Study.

Background: Duloxetine has been reported to significantly relieve the pain of persistent idiopathic dentoalveolar pain (PIDP); however, the number of studies available is scarce and no study has identified the predictors of response of duloxetine for the treatment of PIDP. Objective: To report the efficacy, safety, and identification of positive predictors of duloxetine for PIDP patients through a retrospective multicenter observational study. Methods: We retrospectively reviewed the clinical database of PIDP patients who were prescribed duloxetine at 3 hospitals between January 2018 and November 2021. Demographic and pain-related baseline data, efficacy of patients after 3 months of medication by visual analog scale (VAS) scores for pain and adverse events were extracted and analyzed. The predictors of pain-relieving effect of duloxetine were identified by logistic regression analysis. Results: A total of 135 patients were included in this study. Side effects occurred immediately after taking duloxetine in 24 (17.8%) patients, and the treatment with duloxetine was discontinued on 13 of them because they could not tolerate the side effects. Other 11 (8.1%) patients gradually tolerated the side effects within 2 weeks. Ninety-four out of 122 (77.0%) patients obtained pain relief with VAS significantly decreased (p < 0.01) and the other 28 (23.0%) patients stopped taking the drug because of weak efficacy. Binary logistic regression analysis showed that short disease duration (OR = 1.017, 95% CI = 1.004-1.030, P = 0.012) was an independent predictor of the positive response of duloxetine. Conclusion: This study confirmed that duloxetine can significantly improve chronic pain of PIDP patients, and the safety was tolerable. Patients with shorter disease duration had more benefit from duloxetine. Limitations: This is a retrospective observational study. Long-term efficacy and safety of duloxetine in the treatment of PIDP patients were not evaluated.

Clinical Efficacy of a Spiral CT-Guided Balloon Compression Day-Surgery Operation for the Treatment of Trigeminal Neuralgia.

Objective: This study aimed to investigate the clinical efficacy of a balloon compression day-surgery operation under the guidance of spiral computed tomography (CT) three-dimensional (3D) reconstruction for the treatment of trigeminal neuralgia. Methods: The clinical efficacy and related indexes of 380 patients with trigeminal neuralgia treated by a spiral CT-guided balloon compression day-surgery operation in the pain department of Beijing TianTan Hospital, from October 2017 to March 2021, were retrospectively analyzed. Results: Five patients failed due to foramen ovale puncture or in placing the balloon; two patients had ineffective results after the operation and re-entered the hospital for secondary balloon compression. The initial effective rate of the operation in the 380 patients was 98.16%. All patients were discharged on the day of the operation, the average operation time was 26.46 ± 12.15 min, and the average interval from the completion of the operation to discharge was 2.67 ± 0.95 h. During the follow-up period (1-41 months), 12 patients had pain recurrence, and a Kaplan-Meier analysis revealed that the cumulative pain-free recurrence survival rate at 41 months after the operation was 80.64%. No complications related to foramen ovale puncture occurred. Conclusion: The spiral CT-guided balloon compression day-surgery operation is safe, effective, and worthy of clinical promotion.

REDUCE trial: the effects of perineural dexamethasone on scalp nerve blocks for relief of postcraniotomy pain-a study protocol for a randomized controlled trial.

BACKGROUND: Pain is common in the first 2 days after major craniotomy. Inadequate analgesia may lead to an increased risk of postoperative complications. Most pain following craniotomy arises from the pericranial muscles and soft tissues of the scalp. Scalp nerve blocks with local anesthesia seem to provide effective, safe, however, transient postoperative analgesia which does not seem to meet the requirements of craniotomy. Currently, peripheral dexamethasone has been observed to significantly prolong the duration of analgesia of nerve blocks (e.g., saphenous nerve block, adductor canal block, thoracic paravertebral block, brachial plexus nerve block). On the contrary, a study reported that perineural dexamethasone did not appear to prolong the analgesic time after supratentorial craniotomy. However, all patients in this study were given 24 mg of oral or intravenous dexamethasone regularly for at least 7 days during the perioperative period, which possibly masked the role of single local low doses of perineural dexamethasone. Therefore, the analgesic effect of single dexamethasone for scalp nerve blocks without the background of perioperative glucocorticoid deserves further clarification. METHODS: The REDUCE trial is a prospective, single-center, parallel-group randomized controlled trial involving a total of 156 adults scheduled for elective craniotomy with general anesthesia. Patients will be randomly divided among two groups: the control group (n = 78) will receive scalp nerve blocks with 0.5% bupivacaine, plus normal saline with epinephrine at 1:200,000; the DEX4mg group (n = 78) will receive scalp nerve blocks with 0.5% bupivacaine, plus 4 mg dexamethasone with epinephrine at 1:200,000. The primary outcome will be the duration of analgesia, defined as the time between the performance of the block and the first analgesic request. DISCUSSION: The REDUCE trial aims to further assess the analgesic effect of single dexamethasone as an adjuvant to scalp nerve blocks for relief of postcraniotomy pain without the background of perioperative glucocorticoid. TRIAL REGISTRATION: ClinicalTrials.gov NCT04648358 . Registered on November 30, 2020.

Pre-emptive scalp infiltration with ropivacaine plus methylprednisolone versus ropivacaine alone for relief of postoperative pain after craniotomy in children (RP/MP vs RP): a study protocol for a randomised controlled trial.

INTRODUCTION: Pre-emptive scalp infiltration with local anaesthetics is the simplest and most effective method to prevent postoperative incisional pain. However, local infiltration of an anaesthetic only provides relatively short-term pain relief. Methylprednisolone (MP) treatment, administered as an adjuvant at the wound site, has been shown to provide satisfactory pain management after lumbar laminectomy. However, there is no evidence regarding the efficacy of MP infiltration for the relief of postoperative pain after craniotomy. Currently, postoperative pain after craniotomy in children is undertreated. Therefore, we aim to investigate whether pre-emptive scalp infiltration with ropivacaine (RP) plus MP is superior to RP alone to improve postoperative pain after craniotomy in children. METHODS AND ANALYSIS: The RP/MP versus RP trial is a prospective, single-centre, randomised, parallel-group study of 100 children aged 8-18 years undergoing intracranial surgery. Participants will be randomly allocated to receive pre-emptive scalp infiltration with either RP plus MP or RP alone. The primary outcome will be the cumulative fentanyl dose administered by patient-controlled intravenous analgesia within 24 hours postoperatively. The secondary outcomes will include postoperative Numerical Rating Scale scores, pain control satisfaction scores, length of stay and adverse events. Data will be analysed by the intention-to-treat principle. ETHICAL APPROVAL AND DISSEMINATION: The study protocol has been approved by the Institutional Review Board of Beijing Tiantan Hospital Affiliated to Capital Medical University (Approval Number: KY 2018-066-02). The results will be disseminated in international academic meetings and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03636165; Pre-results.

Pulsed Radiofrequency Reduced Neuropathic Pain Behavior in Rats Associated with Upregulation of GDNF Expression.

BACKGROUND: Pulsed radiofrequency (PRF) is a novel nondestructive interventional technique for the treatment of neuropathic pain (NP). However, this intervention is still lack of relevant regulation and the mechanism of action is insofar not clear. Historically, most studies have reported that PRF can relieve reduce hyperalgesia in multiple NP animal models by acting on the dorsal root ganglion. However, a few recent studies have shown that PRF can effectively treat hyperalgesia in pain models by a direct application on injured peripheral nerves. OBJECTIVES: To observe changes in pain behavior and the pathology of the sciatic nerve (SN) after applying PRF at the ligation site in a chronic constriction injury (CCI) rat model and to investigate the effect of PRF on the expression of glia cell line-derived neurotrophic factor (GDNF) in nervous tissue. STUDY DESIGN: A randomized, experimental trial. SETTING: Experimental Animal Center, Beijing Tiantan Hospital, Capital Medical University. METHODS: Thirty-six adult Sprague-Dawley rats were randomly divided into 3 groups: Sham-Sham (SS), CCI-Sham (CS), and CCI-PRF (CP). The right SNs of the rats in the CS and CP groups were ligated to create a CCI model. For the SS group, the right SN was separated without ligation. On the 14th fourteenth day after surgery, PRF treatment was applied at the ligation site of the SN for the rats in the CP group using a 45 V output voltage at 42 °C for 3 minutes. The electrode was placed in rats in the SS and CS groups without electricity applied. The hindpaw withdrawal threshold (HWT) and thermal withdrawal latency (TWL) were measured at various time points before and after the treatments in each group. Optical microscopic scores and electron microscopic observation were given to the right SN ligation sites of the rats in each group 14 days after the treatment. Meanwhile, the GDNF expression levels in the ligation site of the SN and in the L4-L6 spinal cord segments were determined for each group by enzyme-linked immunosorbent assay (ELISA). RESULTS: Fourteen days after PRF treatment, the HWT and TWL values in the CP group were significantly increased compared to those of the CS group (P < 0.01). Under the optical microscope, the axonal number, axonal diameter, and myelin sheath thickness in the CP group were significantly increased compared to those of the CS group 14 days after PRF treatment (P < 0.01). Under the electron microscope, the degeneration at the SN ligation site was significantly improved in the CP group compared to the CS group. The GDNF expression levels at the ligation site of the SN and the L4-L6 spinal segments in the CP and CS groups were increased compared to those of the SS group (P < 0.01). In addition, the GDNF expression in the CP group was significantly higher than that in the CS group (P < 0.01). LIMITATIONS: GDNF expression was only measured at day 14 after the treatment rather than at various time points during the experiment. CONCLUSIONS: The findings suggest that the application of PRF at the impaired SN relieved reduced the CCI-induced NP by through regulating the upregulation of the GDNF expression in the nervous tissues.