Effects of methylene blue on postoperative low-back pain and functional outcomes after lumbar open discectomy: a triple-blind, randomized placebo-controlled trial

Comparative analysis of renal calculi treatment via different extracorporeal shock wave lithotripsy (ESWL) pathways

OBJECTIVE

To compare the efficacy and safety of Extracorporeal Shock Wave Lithotripsy (ESWL) for treating renal calculi under different shock wave pathways.

METHODS

This study involved a prospective analysis of clinical data obtained from 264 eligible patients with renal stones treated at the Urology Department of Shanxi Bethune Hospital between January 2021 and June 2023. Among these patients, 125 underwent ESWL via the dorsal shock wave pathway (Group A), while 139 patients underwent ESWL via the ipsilateral clavicular midline shock wave pathway (Group B). Preoperatively, all patients underwent non-contrast abdominal CT (NCCT) scans to assess stone count, diameter, CT values, and Skin-to-Stone Distance (SSD). Intraoperatively, ultrasonography was utilized to remeasure SSD and monitor stone fragmentation continuously. The ESWL procedure employed a standardized intermittent stepwise energy escalation technique until treatment completion. Various metrics, including intraoperative Visual Analog Scale (VAS) pain scores, number of shocks, total shock wave energy, stone-free rate (SFR) at 4 weeks post-operation, and postoperative complication rates, were recorded and subjected to statistical analysis.

RESULTS

There were no statistically significant differences between the two groups regarding gender, age, BMI, stone count, stone diameter, stone CT values, intraoperative VAS pain scores, and postoperative complication rates (P>0.05). Preoperative SSD was significantly higher in Group B than in Group A (P<0.05), but there were no significant differences in intraoperative SSD between the groups (P>0.05). Group B showed significantly lower total shock wave energy and number of shocks compared to Group A (P<0.05). The stone-free rate (SFR) after 4 weeks did not exhibit significant differences between the groups (P>0.05). However, when the stone diameter was ≥1.3 cm, the SFR at 4 weeks post-operation in Group B was significantly higher than in Group A (P<0.05).

CONCLUSION

ESWL emerges as a safe and efficacious approach for treating renal calculi. Our findings suggest that utilizing the ipsilateral clavicular midline shock wave pathway in ESWL necessitates less shock wave energy and enhances efficiency, particularly in cases with larger stone burdens.

Evaluation of the Effect of Repetitive Transcranial Magnetic Stimulation of Motor Cortex on Failed Back Surgery Syndrome Pain Control in the Short Term

BACKGROUND

 This study aimed to evaluate the short-term efficacy of repetitive transcranial magnetic stimulation (rTMS) on the treatment of failed back surgery syndrome (FBSS).

METHODS

 In this prospective clinical trial study, 13 patients with FBSS were selected to undergo rTMS, including 5 sessions of stimulation of the primary motor cortex of 90 trains with a frequency of 10 Hz for 2 seconds and an intertrain interval of 20 seconds with a total pulse rate of 1800 per session. The time of each session was 30 minutes with an intensity of 80% of the motor threshold. The severity of pain before and after the intervention was measured by the short-form McGill Pain Questionnaire and visual analog scale (VAS).

RESULTS

 The mean of pain severity was 26.54 ± 6.78 and 14.92 ± 10.1 before and after rTMS, respectively. The severity of pain was significantly decreased after the intervention (p = 0.001). According to the McGill Pain Questionnaire, the severity of pain in the patients was decreased by 44.09 ± 27.32. The mean of the severity of pain according to VAS was 77.31 ± 16.66 before rTMS and 53.46 ± 22.49 after rTMS, which showed that pain intensity was significantly decreased after the intervention (p = 0.006).

CONCLUSIONS

 The use of rTMS of the primary motor cortex in patients who have undergone lumbosacral spine surgery and suffer from pain related to FBSS is associated with a significant reduction in the severity of pain. Because rTMS is a noninvasive treatment method, it can be used as a suitable treatment in these patients.

Adverse effects of methylene blue in peripheral neurons: An in vitro electrophysiology and cell culture study

Methylene blue (MB) is an effective treatment for methemoglobinemia, ifosfamide-induced encephalopathy, cyanide poisoning, and refractory vasoplegia. However, clinical case reports and preclinical studies indicate potentially neurotoxic activity of MB at certain concentrations. The exact mechanisms of MB neurotoxicity are not known, and while the effects of MB on neuronal tissue from different brain regions and myenteric ganglia have been examined, its effects on primary afferent neurons from dorsal root ganglia (DRG) have not been studied. Mouse DRG were exposed to MB (0.3-10 μM) in vitro to assess neurite outgrowth. Increasing concentrations of MB (0.3-10 μM) were associated with neurotoxicity as shown by a substantial loss of cells with neurite formation, particularly at 10 μM. In parallel experiments, cultured rat DRG neurons were treated with MB (100 μM) to examine how MB affects electrical membrane properties of small-diameter sensory neurons. MB decreased peak inward and outward current densities, decreased action potential amplitude, overshoot, afterhyperpolarization, increased action potential rise time, and decreased action potential firing in response to current stimulation. MB induced dose-dependent toxicity in peripheral neurons, in vitro. These findings are consistent with studies in brain and myenteric ganglion neurons showing increased neuronal loss and altered membrane electrical properties after MB application. Further research is needed to parse out the toxicity profile for MB to minimize damage to neuronal structures and reduce side effects in clinical settings.

Relationships between Paraspinal Muscle and Spinopelvic Sagittal Balance in Patients with Lumbar Spinal Stenosis

OBJECTIVE

To investigate the relationships between measurements of paraspinal muscle and spinopelvic sagittal parameters and the predictive value of lumbar indentation value (LIV) on sagittal balance in patients with lumbar spinal stenosis.

METHODS

It was a retrospective study. We collected the data of 110 patients, who were diagnosed as lumbar spinal stenosis from December 2018 to May 2019. The total cross-sectional area (tCSA), functional cross-sectional area (fCSA), and fatty infiltration (FI) of paraspinal muscle were measured. The spinopelvic sagittal parameters were also measured, including sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), and PI minus LL (PI-LL). Correlations between measurements of paraspinal muscle and sagittal parameters were investigated by Pearson correlation analysis. The multiple linear regression analysis was used to investigate the LIV, age, gender, and BMI for assessing spinopelvic sagittal balance. Receiver-operating characteristic (ROC) curve was used to find out the most optimum cut-off point of LIV for evaluating SVA.

RESULTS

There were 42 males and 68 females in this study and the mean age was 59.9 ± 10.9 years old. By Pearson correlation analysis, MF tCSA showed significant association with LL (r = 0.455, P < 0.01) and PI-LL (r = -0.286, P < 0.01). MF fCSA had a significant correlation with LL (r = 0.326, P < 0.01) and PI-LL (r = -0.209, P < 0.05). LIV was also significantly correlated to spinopelvic sagittal parameters, including SVA (r = -0.226, P < 0.05), LL (r = 0.576, P < 0.01), TK (r = 0.305, P < 0.01), and PI-LL (r = -0.379, P < 0.01). By multiple linear regression analysis, LIV was independently associated with sagittal parameters, including PI-LL and SVA. The cut-off value of LIV for SVA ≤ 50 mm was 10.5 mm (AUC = 0.641). According to the best cut-off value, patients were divided into two groups. For patients with LIV ≤ 10.5 mm, the percentage of SVA ≤ 50 mm was 54.5% (18/33), while it was 83.1% (64/77) for patients with LIV >10.5 mm.

CONCLUSIONS

As a new index to evaluate paraspinal muscle atrophy, the LIV was independently correlated to spinopelvic sagittal balance. Degeneration of paraspinal muscle was associated with spinopelvic sagittal balance.

Effects of adhesion barrier gel on functional outcomes of patients with lumbar disc herniation surgery; A systematic review and meta-analysis of clinical trials

Failed Back Surgery Syndrome (FBSS) is persistent pain and disability following lumbar laminectomy which is associated with decreased quality of life and disability and has been reported in up to 40% of the patients undergoing lumbar laminectomy. Several approaches have been introduced to reduce the rate of the FBSS. Among these, applying anti-adhesive barrier gels have been studied with interest with controversial results. The aim of the current study was to determine the effects of anti-adhesive barrier gels on functional outcome and recurrence of patients undergoing lumbar disc surgery. We searched databases including EMBASE, PUBMED, Web of Science, Scopus, Cochrane Library, and scholar databases until November 2019. To assess the heterogeneity across included studies was used Cochran's Q and I-square (I²) statistics. Standardized mean difference (SMD) and 95% CI between were used to estimate pooled effect sizes. Out of 4507, 10 clinical trials found to be appropriate for current meta-analysis. The pooled results of included clinical trials indicated that adhesion barrier gel significantly decreased leg pain (LP) (SMD = −0.31; 95% CI, −0.60, −0.03; P = 0.032; I²: 59.2%) among patients with lumbar disc herniation surgery. Back pain (BP) (SMD = −0.03; 95% CI, −0.23, 0.16; P = 0.734; I²: 40.2%), and Oswestry disability index (ODI) (SMD = −0.11; 95% CI, −0.27, 0.05; P = 0.178; I²: 0.0%), were not significantly affected following adhesion barrier gel application. Application of adhesion barrier gel in single level lumbar disc surgery is associated with deceased leg pain. However, its application does not affect the low back pain, disability and gate. Further, larger randomized clinical trials are required.

Intradiskal Injection of Methylene Blue for Discogenic Back Pain: A Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

 Intradiskal injection of methylene blue has some potential in alleviating discogenic back pain. This meta-analysis aims to explore the impact of intradiskal injection of methylene blue for discogenic back pain.

METHODS

 Several databases such as PubMed, EMbase, Web of Science, EBSCO, and Cochrane Library databases have been searched through November 2019, and randomized controlled trials (RCTs) assessing the effect of intradiskal injection of methylene blue for discogenic back pain are included.

RESULTS

 Three RCTs are included in the meta-analysis. Overall, compared with control group for discogenic back pain, intradiskal injection of methylene blue remarkably decreased pain scores at 3 months (mean difference [MD] = -0.71; 95% confidence interval [CI] = -0.96 to -0.46; p < 0.00001) and 6 months (MD = -13.92; 95% CI = -22.31 to -5.54; p = 001) and Oswestry Disability Index (ODI) at 4 to 6 weeks (MD = -10.39; 95% CI = -16.95 to -3.83; p = 0.002) and 3 months (MD = -3.66; 95% CI = -4.85 to -2.48; p < 0.00001), but demonstrated no obvious effect on ODI at 6 months (MD = -11.76; 95% CI = -33.33 to 9.80; p = 0.28).

CONCLUSIONS

 Intradiskal injection of methylene blue can substantially decrease pain scores and improve function for discogenic back pain.

Antidepressants in Spine Surgery: A Systematic Review to Determine Benefits and Risks

Antidepressant drugs can be advantageous in treating psychiatric and non-psychiatric illnesses, including spinal disorders. However, spine surgeons remain unfamiliar with the advantages and disadvantages of the use of antidepressant drugs as a part of the medical management of diseases of the spine. Our review article describes a systematic method using the PubMed/Medline database with a specific set of keywords to identify such benefits and drawbacks based on 17 original relevant articles published between January 2000 and February 2018; this provides the community of spine surgeons with available cumulative evidence contained within two tables illustrating both observational (10 studies; three cross-sectional, three case-control, and four cohort studies) and interventional (seven randomized clinical trials) studies. While tricyclic antidepressants (e.g., amitriptyline) and duloxetine can be effective in the treatment of neuropathic pain caused by root compression, venlafaxine may be more appropriate for patients with spinal cord injury presenting with depression and/or nociceptive pain. Despite the potential associated consequences of a prolonged hospital stay, higher cost, and controversial reports regarding the lowering of bone mineral density in the elderly, antidepressants may improve patient satisfaction and quality of life following surgery, and reduce postoperative pain and risk of delirium. The preoperative treatment of preexisting psychiatric diseases, such as anxiety and depression, can improve outcomes for patients with spinal cord injury-related disabilities; however, a preoperative platelet function assay is advocated prior to major spine surgical procedures to protect against significant intraoperative blood loss, as serotonergic antidepressants (e.g., selective serotonin reuptake inhibitors) and bupropion can increase the likelihood of bleeding intraoperatively due to drug-induced platelet dysfunction. This comprehensive review of this evolving topic can assist spine surgeons in better understanding the benefits and risks of antidepressant drugs to optimize outcomes and avoid potential hazards in a spine surgical setting.

Effects of Ho:YAG Laser Ablation on Postoperative Low Back Pain and Functional Status After Transforaminal Endoscopic Lumbar Discectomy: Minimum of 2-Year Follow-Up

OBJECTIVE

To evaluate effects of holmium:yttrium-aluminum-garnet (Ho:YAG) laser ablation on postoperative low back pain and improving functional status in patients with lumbar disc herniation undergoing transforaminal endoscopic lumbar discectomy (TELD).

METHODS

The study enrolled 220 patients with lumbar disc herniation who underwent TELD or TELD with Ho:YAG laser from August 2015 to September 2016. Parameters including operative time, hospitalization, complications, and recurrence were recorded. Clinical outcomes were assessed according to visual analog scale for back pain and leg pain, Oswestry Disability Index for functional status, and modified MacNab criteria for patient satisfaction.

RESULTS

Minimal 2-year follow-up was completed by 186 patients: 76 patients who underwent TELD and 110 patients who underwent TELD with Ho:YAG laser. In the group undergoing TELD, clinical outcomes of back pain and functional status exhibited a V-shaped upward trend after surgery; there were no statistically significant differences in visual analog scale for back pain and Oswestry Disability Index scores at final follow-up compared with preoperatively (P > 0.05). In the group undergoing TELD with Ho:YAG laser, postoperative visual analog scale for back pain and Oswestry Disability Index scores significantly improved compared with preoperatively (P < 0.05) exhibiting relatively consistent improvement after surgery. The only laser-related complication was a burning sensation in the ipsilateral lower limb during the thermal procedure in 2 cases.

CONCLUSIONS

Performing Ho:YAG laser ablation with TELD prolonged low back pain relief and improved functional outcome during 2-year follow-up compared with TELD alone in patients with symptomatic lumbar disc herniation.

Methylene Blue Analogues with Marginal Monoamine Oxidase Inhibition Retain Antidepressant-like Activity

Methylene blue (MB) possesses diverse medical applications. Among these, MB presents with antidepressant-like effects in animals and has shown promise in clinical trials for the treatment of mood disorders. As an antidepressant, MB may act via various mechanisms which include modulation of the nitric oxide cyclic guanosine monophosphate (NO-cGMP) cascade, enhancement of mitochondrial respiration and antioxidant effects. MB is also, however, a high potency inhibitor of monoamine oxidase (MAO) A, which most likely contributes to its antidepressant effect, but also to its adverse effects profile (e.g., serotonin toxicity). The latter has raised the question whether it is possible to design out the MAO inhibition properties of MB yet retaining its clinically useful attributes. This study explores this idea further by characterizing five newly synthesized low MAO-A active MB analogues and examining their antidepressant-like properties in the acute forced swim test (FST) in rats, with comparison to imipramine and MB. The results show that all five analogues exhibit antidepressant-like properties in the FST without confounding effects on locomotor activity. The magnitude of these effects is comparable to those of imipramine and MB. Moreover, these newly synthesized MB analogues are markedly less potent MAO-A inhibitors (IC₅₀ = 0.518-4.73 μM) than MB (IC₅₀ = 0.07 μM). We postulate that such lower potency MAO-A inhibitors may present with a reduced risk of adverse effects associated with MAO-A inhibition. While low level MAO-A inhibition still may produce an antidepressant effect, we posit that other MB-related mechanisms may underlie their antidepressant effects, thereby representing a novel group of antidepressant compounds.

Methylene blue relieves the development of osteoarthritis by upregulating lncRNA MEG3

Methylene blue (MB) is a long-term inhibitor of peripheral nerve axons, thereby alleviating or permanently eliminating pain. However, it remains unknown whether MB is safe and effective method of treating osteoarthritis (OA). MB was injected into the knee joints of rabbits and they were monitored for any histological structural changes. The results revealed no evident changes in the histological structure of the normal knee joint following injection of 1 mg/kg MB at 1, 4, 8 and 24 weeks post-injection. Compared with the vehicle control, MB treatment significantly enhanced the weight distribution and significantly decreased the swelling ratio of the rabbits. Additionally, levels of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) mRNA were significantly increased following treatment with MB, but the protein expression of P2X purinoceptor 3 (P2X3) was significantly suppressed compared with the vehicle control. The levels of interleukin (IL) 6, tumor necrosis factor (TNF)α, IL-1β and IL-8 were significantly suppressed following MB treatment, indicating that MB protects against OA progression. It was also revealed that MEG3 overexpression significantly suppresses levels of P2X3 protein. ELISA indicated that the MEG3-induced reduction of IL-6, TNFα, IL-1β and IL-8 expression was significantly reversed following P2X3 overexpression. Therefore, the results of the present study demonstrated that MB is an effective method of treating OA-associated pain by upregulating lncRNA MEG3 levels. Additionally, lncRNA MEG3 relieves the OA-associated pain and inflammation in a rabbit model of OA by inhibiting P2X3 expression.

Methylene Blue: The Long and Winding Road From Stain to Brain: Part 2

Methylene blue was the first synthetic drug ever used in medicine, having been used to treat clinical pain syndromes, malaria, and psychotic disorders more than one century ago. Methylene blue is a cationic thiazine dye with redox-cycling properties and a selective affinity for the nervous system. This drug also inhibits the activity of monoamine oxidase, nitric oxide synthase, and guanylyl cyclase, as well as tau protein aggregation; increases the release of neurotransmitters, such as serotonin and norepinephrine; reduces amyloid-beta levels; and increases cholinergic transmission. The action of methylene blue on multiple cellular and molecular targets justifies its investigation in various neuropsychiatric disorders. Investigations of methylene blue were instrumental in the serendipitous development of phenothiazine antipsychotic drugs. Although chlorpromazine is heralded as the first antipsychotic drug used in psychiatry, methylene blue is a phenothiazine drug that had been used to treat psychotic patients half a century earlier. It has also been studied in bipolar disorder and deserves further investigation for the treatment of unipolar and bipolar disorders. More recently, methylene blue has been the subject of preclinical and clinical investigations for cognitive dysfunction, dementia, and other neurodegenerative disorders. [Journal of Psychosocial Nursing and Mental Health Services, 54(10), 21-26.].

Unilateral lag screw fixation of isolated non-union atlas lateral mass fracture: a new technical note

We describe a novel and new technique of posterior unilateral lag screw fixation of non-union atlas lateral mass fracture. A 46-year-old man presented with cervical pain and tenderness after a vehicle turn over accident and he was diagnosed to have left atlas lateral mass fracture. He was initially treated by immobilization using Minerva orthosis. About 2 months later, he developed severe neck pain and limitation of motion and thus he was scheduled for operation due to non-union atlas lateral mass fracture. A 28 mm lag screw was inserted under anterior-posterior and lateral fluoroscopic views. The entrance point was at the dorsal aspect of left atlas posterior arc at its junction to the lateral mass, and by using the trajectory of 10 degrees medial and 22 degrees cephalad fracture reduction was achieved. Unilateral lag screw fixation of atlas fractures is an appropriate, safe and effective surgical technique for the management of unilateral atlas fractures.

Clinical and radiological outcomes after decompression and posterior fusion in patients with degenerative scoliosis

OBJECTIVE

The prevalence of degenerative scoliosis (DS) increases with age and an overall increase is seen due to the aging population. This study aims to evaluate the clinical and radiological outcomes after decompression and posterior fusion in patients with DS.

METHODS

In this is prospective study, 43 patients with DS, aged 37 to 70 years, were eligible to undergo decompression and posterior fusion. Primary outcomes were low back pain (LBP) with or without radicular pain, which was evaluated preoperatively and at 12 and 24 months after surgery with the use of a visual analog scale (VAS), and the quality of life (QOL), which was assessed at the same time periods by the Oswestry Disability Index (ODI) questionnaire. The Cobb's method was used to measure the degree of scoliosis in each patient preoperatively and at 24 hours, 12 and 24 months after the surgery.

RESULTS

VAS scores improved significantly from a mean of 8.18 preoperatively to 4.48 at 12 months and 3.07 at 24 months postoperatively (P < .001). The mean radicular pain scores also decreased significantly (P < .001). At postoperative 12 months, the mean ODI score was significantly lower than the mean preoperative ODI score (47.81 ± 16.06 vs. 72.18 ± 12.28; P = .001). ODI score at 24 months postoperatively was significantly better than the preoperative ODI (15.53 ± 7.21 vs. 72.18 ± 12.28; P = .016). The mean Cobb angle changed significantly from 31.4° ± 4.88 preoperatively to 3.28° ± 2.10 at 24 months postoperatively (P < .001).

CONCLUSIONS

Our findings suggest that decompression and posterior fusion in the patients with DS is an effective surgical method which is associated with satisfying clinical results in terms of improvement of postoperative LBP, radicular pain, and QOL, and correction of Cobb angle at 12 and 24 months after the surgery and restoration of sagittal alignment at 2 months postoperatively.

Nitric Oxide and Related Aspects Underlying Angina

Increased number of patients affected by metabolic syndrome (MS) has prompted the necessity of better understanding what is involved in such syndrome. Nevertheless, the establishment of promising therapies depends on the knowledge about the interaction of molecules within MS. In such context, Nitric Oxide (NO) emerges from a bulk of works relating its roles on aspects of MS, including cardiovascular diseases, their symptoms and comorbidities, which are thought to be triggered by similar sources. NO, nitric oxide synthase and enzymatic chains are keys for those disease and symptoms processes. NO has been separately described as part of hypertensive, ischemic and pain signaling. Although there are similar pathways likely shared for generating cardiovascular symptoms such angina, they are barely associated to NO in literature. The present review aims to clarify the patterns of NO alteration in metabolic syndrome directly concerned to cardiovascular symptoms, especially angina.