Background: Stereotactic radiosurgery is accepted as an alternative for patients with refractory trigeminal neuralgia, but existing evidence is fundamentally based on the Gamma Knife, which is a specific device for intracranial neurosurgery, available in few facilities. Over the last decade it has been shown that the use of linear accelerators can achieve similar diagnostic accuracy and equivalent dose distribution. Objectives: To assess the effectiveness and safety of linear-accelerator stereotactic radiosurgery for the treatment of patients with refractory trigeminal neuralgia. Methods: We carried out a systematic search of the literature in the main electronic databases (PubMed, Embase, ISI Web of Knowledge, Cochrane, Biomed Central, IBECS, IME, CRD) and reviewed grey literature. All original studies on the subject published in Spanish, French, English, and Portuguese were eligible for inclusion. The selection and critical assessment was carried out by 2 independent reviewers based on pre-defined criteria. In view of the impossibility of carrying out a pooled analysis, data were analyzed in a qualitative way. Results: Eleven case series were included. In these, satisfactory pain relief (BIN I-IIIb or reduction in pain ≥ 50) was achieved in 75% to 95.7% of the patients treated. The mean time to relief from pain ranged from 8.5 days to 3.8 months. The percentage of patients who presented with recurrences after one year of follow-up ranged from 5% to 28.8%. Facial swelling or hypoesthesia, mostly of a mild-moderate grade appeared in 7.5% – 51.9% of the patients. Complete anaesthesia dolorosa was registered in only study (5.3%). Cases of hearing loss (2.5%), brainstem edema (5.8%), and neurotrophic keratoplasty (3.5%) were also isolated. Conclusions: The results suggest that stereotactic radiosurgery with linear accelerators could constitute an effective and safe therapeutic alternative for drug-resistant trigeminal neuralgia. However, existing studies leave important doubts as to optimal treatment doses or the therapeutic target, long-term recurrence, and do not help identify which subgroups of patients could most benefit from this technique. Limitations: Paucity of literature and clear lack of clarification for clinical utilization of this technique. Key words: Radiosurgery, trigeminal neuralgia, functional radiosurgery, radiation therapy of benign diseases, stereotactic radiotherapy

Scientific peer review is pivotal in health care research in that it facilitates the evaluation of findings for competence, significance, and originality by qualified experts. While the origins of peer review can be traced to the societies of the eighteenth century, it became an institutionalized part of the scholarly process in the latter half of the twentieth century. This was a response to the growth of research and greater subject specialization. With the current increase in the number of specialty journals, the peer review process continues to evolve to meet the needs of patients, clinicians, and policy makers. The peer review process itself faces challenges. Unblinded peer review might suffer from positive or negative bias towards certain authors, specialties, and institutions. Peer review can also suffer when editors and/or reviewers might be unable to understand the contents of the submitted manuscript. This can result in an inability to detect major flaws, or revelations of major flaws after acceptance of publication by the editors. Other concerns include potentially long delays in publication and challenges uncovering plagiarism, duplication, corruption and scientific misconduct. Conversely, a multitude of these challenges have led to claims of scientific misconduct and an erosion of faith. These challenges have invited criticism of the peer review process itself. However, despite its imperfections, the peer review process enjoys widespread support in the scientific community. Peer review bias is one of the major focuses of today’s scientific assessment of the literature. Various types of peer review bias include content-based bias, confirmation bias, bias due to conservatism, bias against interdisciplinary research, publication bias, and the bias of conflicts of interest. Consequently, peer review would benefit from various changes and improvements with appropriate training of reviewers to provide quality reviews to maintain the quality and integrity of research without bias. Thus, an appropriate, transparent peer review is not only ideal, but necessary for the future to facilitate scientific progress. Key words: Scientific research, peer review process, scientific publications, peer review bias, blinded peer review, scientific misconduct.

Background: We previously published on the pressure effect using a rheumatoid animal model (Pain Physician in 2013 and 2014). However, we do not know how long the pressure effect lasts after exposure to high pressure. Objective: We evaluated the duration of the pressure effect in a day for a given study period. Study Design: Laboratory animal study. Methods: Following injection of Complete Freund’s Adjuvant (CFA) into one side of the knee joint, 8 rats were assigned to 1.5 atmospheres absolute (ATA) hyperbaric chamber 3 hours per day for one or 2 weeks (1WPG or 2WPG). Pain levels were assessed daily for 2 weeks according to weight bearing force (WBF) of the affected limb. In addition, the levels of gelatinase, MMP-2, and MMP-9 expression in synovial fluids of the knees were analyzed. Results: The reduction of WBF was high at one day after injection and then increased spontaneously up to 2 weeks in 1WPG and 2WPG. The pressure effects lasted for a given day and did not exceed the pressure effects of the next day in all study periods. Improvement of WBF in 2WPG was significantly greater than that of 1WPG during 8~14 days. The gelatinase expression ratio was significantly reduced in 1WPG and 2WPG, and 2WPG showed the lowest gelatinase ratio at 2 weeks. Limitation: Although enough samples were used for the study, more samples will be needed to raise the reliability. Conclusion: The 3 hours of 1.5 ATA pressure effect lasted for more than a day. Longer pressure exposure time appears to yield a greater therapeutic effect in an RA animal model up to a given study period. Continuous application of high pressure might be beneficial for achievement of a better therapeutic effect in clinical application. Key words: Pressure effect, arthritic knee, arthritic pain, long-term effect of pressure, biophysiologic assessment, pain behavior assessment, arthritis treatment

Background: Stellate ganglion block (SGB) has been reported to be effective in the treatment of breast cancer-related lymphedema (BCRL). Objective: To determine the effects of SGB in BCRL patients and the efficacy of corticosteroids in SGB. Study Design: A double-blinded, randomized, controlled trial. Setting: A single academic hospital, outpatient setting. Methods: In total, 32 patients with BCRL were recruited. Patients were divided randomly into 3 groups (Group A: 0.5% bupivacaine 5 mL, n = 12; Group B: 0.5% bupivacaine 4.5 mL + 20 mg of triamcinolone 0.5 mL, n = 10; and Group C: 0.5% bupivacaine 4 mL + 40 mg of triamcinolone 1 mL, n = 10). All patients received 3 consecutive SGBs, every 2 weeks. The primary outcomes were changes in forearm and upper arm circumference. Circumference was measured at baseline, 2 weeks (before the second injection), 4 weeks (before the third injection), and 8 weeks (one month follow-up after 3 consecutive SGBs). Moreover, subjective data were collected using EORTC C-30 at baseline and 8 weeks. Results: After 3 consecutive SGBs, forearm and upper arm circumferences were decreased significantly from baseline in all groups (P < 0.05/3). The upper arm circumference of group C was reduced significantly more than that of group A (P < 0.05/3). The subjective data by EORTC-C30 at baseline and one month after 3 consecutive SGBs revealed no statistically significant difference. Limitations: Relatively few patients were enrolled. We did not compare SGB with any other BCRL treatment, such as complex decongestive therapy. Conclusions: This study suggests that SGB may be an effective treatment for BCRL. Furthermore, it appears that corticosteroids could have an additive effect in SGB. Key words: Stellate ganglion block, breast cancer, lymphedema:

Multiple myeloma is a hematologic malignancy associated with destructive bone loss. Lytic lesions, a hallmark of this cancer, can result in significant morbidity because of associated pain and structural osseous compromise. Osteoplasty has demonstrated efficacy in the treatment of myelomatous pain within the axial skeleton; however, there is limited evidence supporting the utility of osteoplasty to treat extra-spinal lesions. We describe a 67 year-old woman with stable IgA lambda multiple myeloma with sentinel bilateral greater trochanteric lytic lesions that was referred to our interventional pain management clinic for evaluation of bilateral lateral hip pain. Conservative treatment options including physical therapy, non-steroidal anti-inflammatory drugs (NSAIDs), oral opiates, and local corticosteroid injections to bilateral trochanteric bursae failed to offer pain relief. The patient underwent minimally invasive percutaneous trochanteroplasty with concomitant core biopsy of her bilateral trochanteric lytic lesions. The intended goals of this novel procedure were to determine the cause of the suspected lytic lesions, provide pain relief, and offer structural stability by safely implanting bone cement as part of a fracture prevention strategy. At 12 month followup, the patient’s pain improved by 70% and she no longer required the use of pain medication. The patient also displayed a significant improvement in her day-to-day functioning and quality of life. Key words: Pain, osteoplasty, trochanteroplasty, multiple myeloma, greater trochanter, percutaneous

Background: There has been a recent surge in the literature highlighting the association of fentanyl as precipitating serotonin syndrome in patients on a serotonergic agent. Objective: The purpose of our study was to understand the incidence of serotonin syndrome in patients who receive fentanyl while on serotonergic agents. Study Design: This retrospective analysis was conducted from 2012 to 2013 after approval from the Institutional Review Board. We searched for all patients that had received a serotonergic agent and were admitted to the hospital during the study period. Next, we split these patients into 2 groups by placing all patients who had received fentanyl and a serotonergic agent into one group. We then searched for any of the Hunter Serotonin Toxicity Criteria in the records of patients that had received both fentanyl and a serotonergic agent. Further, we searched for all patients with serotonin syndrome mentioned in their records. Setting: This study was conducted at a 900 bed tertiary care academic center. Results: Over the 2 year study period, 112,045 patients were on a serotonergic agent, and 4,538 of these patients were treated with both fentanyl and a serotonergic agent. A search for Hunter’s Criteria through the records of the patients receiving both fentanyl and a serotonergic agent revealed 23 patients had been documented with some of these symptoms. On detailed chart review, only 4 [95% CI 1 – 10] of these patients truly met Hunter’s Criteria for serotonin syndrome. We then searched all admissions for a diagnosis code of serotonin syndrome during the study period. Five additional cases of serotonin syndrome were found, but none of these patients were treated with fentanyl. Limitations: Some of the limitations of our study include that it represents a single institution, although it is a large academic center. An inherent limitation may be the under diagnosis of serotonin syndrome. Conclusion: The incidence of serotonin syndrome in patients who receive both fentanyl and a serotonergic agent is low. Key words: Fentanyl, serotonin syndrome, serotonergic drugs, opioids, SSRI, antidepressant

Background: The superior hypogastric plexus (SHGP) carries afferents from the viscera of the lower abdomen and pelvis. Neurolytic block of this plexus is used for reducing pain resulting from malignancy in these organs. The ganglion impar (GI) innervats the perineum, distal rectum, anus, distal urethra, vulva, and distal third of the vagina. Different approaches to the ganglion impar neurolysis have been described in the literature. Objectives: To assess the feasibility, safety, and efficacy of combining the block of the SHGP through the postero-median transdiscal approach with the GI block by the transsacro-coccygeal approach for relief of pelvic and/or perineal pain caused by pelvic and/or perineal malignancies or any cancer related causes. Methods: Fifteen patients who had cancer-related pelvic pain, perineal pain, or both received a combined SHGP neurolytic block through the postero-median transdiscal approach using a 20-gauge Chiba needle and injection of 10 mL of 10% phenol in saline plus a GI neurolytic block by the trans-sacro-coccygeal approach using a 22-gauge 5 cm needle and injection of 4 – 6 mL of 8% phenol in saline. Pain intensity (measured using a visual analogue scale) and oral morphine consumption pre- and post-procedure were measured. Results: All patients presented with cancer-related pelvic, perineal, or pelviperineal pain. Pain scores were reduced from a mean (± SD) of 7.87 ± 1.19 pre-procedurally to 2.40 ± 2.10 one week post-procedurally (P < 0.05). In addition, the mean consumption of morphine (delivered via 30 mg sustained-release morphine tablets) was reduced from 98.00 ± 34.89 mg to 32.00 ± 28.48 mg after one week (P < 0.05). No complications or serious side effects were encountered during or after the block. Limitations: This study is limited by its small sample size and non-randomized study. Conclusion: A combined neurolytic SHGP block with GI block is an effective and safe technique for reducing pain in cancer patients presented with pelvic and/or perineal pain. Also, a combined SHGP block through a posteromedian transdiscal approach with a GI block through a trans-sacrococcygeal approach may be considered more effective and easier to perform than the recently invented bilateral inferior hypogastric plexus neurolysis through a transsacral approach. Key words: Superior hypogastric plexus block, ganglion impar block, cancer pain, pelvic pain, perineal pain

Chronic post thoracotomy pain (CPTP) was a common complication after thoracotomy, while spontaneous muscle contraction (SMC) was very rare. Neuropathic pain components appeared in some CPTP patients. The patients with neuropathic pain (NPP) often suffered from more severe pain.We presented a case of a 57 year- old Chinese male, suffering from SMC with extreme chronic pain after thoracotomy for 2 years. The patient was treated by pulsed radiofrequency (PRF). Then we reviewed the related progresses including recent view on NPP in CPTP, the possible mechanism of SMC, treatments for CTPT, and peripheral nerve treatments in NPP.Case report and review of the literature.The patient was diagnosed as CPTP with SMC. After the experimental intercostal nerve block provided short-term analgesia, we performed PRF through the angulus costae on intercostal nerves under x-ray guidance. We performed PRF for 3 times in all, at an interval of 2 weeks. Then we had followed up the pain intensity, frequency and amplitude of SMC of this patient during the 2 years.The pain intensity decreased from 8 to 2 on the visual analogue scale (VAS). The frequency of muscle contraction was decreased by 90%, and the amplitude was decreased by 60%. The treatment also improved the patient's sleep quality. These improvements were stable in 2 years' follow-up. In our review of the literature, the SMC may be based on the pain-spasm-pain model.Single case report.Pulsed radiofrequency provided good efficacy in CPTP with SMC in this case.