Effect of Perineural Dextrose Injection on Ulnar Neuropathy at the Elbow: A Randomized, Controlled, Double-Blind Study

Treatment for ulnar neuropathy at the elbow

BACKGROUND

Ulnar neuropathy at the elbow (UNE) is the second most common entrapment neuropathy after carpal tunnel syndrome. Treatment may be conservative or surgical, but optimal management remains controversial. This is an update of a review first published in 2011 and previously updated in 2012 and 2016.

OBJECTIVES

To determine the effectiveness and safety of conservative and surgical treatment for ulnar neuropathy at the elbow (UNE). We intended to test whether: - surgical treatment is effective in reducing symptoms and signs and in increasing nerve function; - conservative treatment is effective in reducing symptoms and signs and in increasing nerve function; - it is possible to identify the best treatment on the basis of clinical, neurophysiological, or nerve imaging assessment.

SEARCH METHODS

We searched the Cochrane Neuromuscular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, four other databases, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform to July 2022.

SELECTION CRITERIA

The review included only randomised controlled clinical trials (RCTs) or quasi-RCTs evaluating people with clinical symptoms suggesting the presence of UNE. We included trials evaluating all forms of surgical and conservative treatments. We considered studies regarding therapy of UNE with or without neurophysiological evidence of entrapment.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed titles and abstracts of references retrieved from the searches and selected all potentially relevant studies. The review authors independently extracted data from included trials and assessed risk of bias. We contacted trial investigators for any missing information. The primary outcome was clinically relevant improvement in function compared to baseline. The secondary outcomes of interest were change in neurological impairment, change from baseline of the motor nerve conduction velocity across the elbow, change from baseline in the nerve diameter/cross-sectional area at the elbow, evaluated by ultrasound or MRI, change in quality of life and adverse events. We used GRADE methodology to assess the certainty of evidence.

MAIN RESULTS

We included 15 RCTs (970 participants), of which six studies were new for this update. Sequence generation was inadequate in one study and not described in six studies; other studies had a low risk of selection bias. We evaluated the clinical outcomes (3 trials, 261 participants) and neurophysiological outcomes (2 trials, 101 participants) of simple decompression versus decompression with submuscular or subcutaneous transposition. Moreover, we evaluated the clinical outcomes of endoscopic versus open decompression surgery (2 trials, 99 participants). We found there was probably little to no difference in clinical improvement in function for simple decompression versus subcutaneous transposition (risk ratio (RR) 0.92, 95% confidence interval (CI) 0.74 to 1.14; 1 study, 147 participants) and simple decompression versus submuscular transposition (RR 0.95, 95% CI 0.77 to 1.17; 2 studies, 114 participants). Compared to simple decompression, we found little to no difference in wound infections for subcutaneous transposition (RR 0.29, 95% CI 0.06 to 1.35; 1 study, 147 participants) and submuscular transposition (RR 0.35, 95% CI 0.10 to 1.21; 2 studies, 114 participants). We found no difference between endoscopic and open decompression in terms of postoperative clinical improvement measured by the Bishop score (RR 0.98, 95% CI 0.84 to 1.14; 2 studies, 99 participants). Among surgical treatments, further single trials investigated postsurgical electrical stimulation after open decompression, nerve decompression and transposition with supercharged end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer. Among conservative treatments for mild or moderate UNE, single trials explored the efficacy of participants' education, night splinting, nerve gliding exercises, corticosteroid and dextrose perineural injection.

AUTHORS' CONCLUSIONS

Low- to moderate-certainty evidence indicates that there is little to no difference in terms of improvement in function or surgical complications between simple decompression and decompression with subcutaneous or submuscular transposition in idiopathic UNE, including when the nerve impairment is severe. Moderate-certainty evidence indicates that there is little to no difference between endoscopic and open decompression in improving clinical function and in terms of procedural complications. Very low-certainty evidence indicates that it is unclear if steroid injections have an effect on clinical improvement, compared to placebo, and if written instructions have an effect on clinical improvement, compared to surgical decompression. Findings from a small RCT on conservative treatment showed that in mild cases, information on movements or positions to avoid may reduce subjective discomfort. One RCT showed that dextrose injection might reduce pain at either short-term (four months) or long-term follow-up (12 months), compared to placebo. Another RCT did not show differences in clinically relevant improvement between dextrose and corticosteroid injection. In clinically severe UNE, findings from a small RCT showed that postsurgical electrical stimulation improves intrinsic muscle reinnervation and strength at 12 months' follow-up.

Rapid Decrease in Dextrose Concentration After Intra-Articular Knee Injection: Implications for Mechanism of Action of Dextrose Prolotherapy

BACKGROUND

D-glucose (dextrose) is used as a 5000-25,000 mg% solution in the injection-based pain therapy known as dextrose prolotherapy (DPT). The number of peer-reviewed clinical trials supporting its use is growing. However, the mechanism of action is unknown, limiting further research. A commonly expressed theory is that hyperosmotic dextrose injection induces inflammation, initiating a healing-specific inflammatory cascade. In vitro study models have used continuous exposure to high concentration dextrose. But the rate of dextrose clearance after intra-articular injection, and, therefore, the duration of exposure of tissues to any particular dextrose concentration, remains unknown. We therefore determined the rate of dextrose concentration diminution in one human participant's knees after intra-articular dextrose knee injection.

METHOD

In this pre-post N-of-1 study, the first author (KDR), a well 70-year-old male without knee-related pathology, injected his own knees with 30 mL of 12,500 mg% dextrose on three occasions; performed serial aspirations of 1.2 mL of intra-articular fluid from 7 to 360 min post-injection; and assessed synovial dextrose concentration. Dextrose clearance kinetics were determined using Minitab and GraphPad Prism software.

RESULTS

Dextrose concentration dropped rapidly in all three trials, approximating an exponential or steep S curve. A third order chemical reaction pattern was found, suggesting factors other than dilution or glucose transporter activity, such as rapid diffusion of dextrose across the synovial membrane, may have contributed to the rapid drop in dextrose concentration.

CONCLUSION

This pre-post N-of-1 study shows that, after intraarticular injection of 30 mL of 12,500 mg% dextrose injection into a well knee, the concentration of dextrose diminished rapidly, suggesting that intra-articular cells, tissue, and anatomic structures are exposed to an initially high dextrose concentration for a very short time. This likely affects the mechanism of action of DPT and should inform in vitro study methods.

A systematic review and meta-analysis of the effectiveness of perineural dextrose injection in peripheral compression neuropathies of the upper limbs

Background

Entrapment neuropathies, marked by nerve compression at various anatomical sites, can be effectively managed using conservative approaches like injections. Dextrose 5 % water injection has emerged as a potential therapy by reducing inflammation and promoting tissue regeneration. We aimed to evaluate dextrose injection's efficacy in treating entrapment neuropathies in upper extremities.

Method

We systematically searched EMBASE, Scopus, Web of Science, and PubMed. Our eligibility criteria included participants aged 18 and older who had peripheral upper limb nerve entrapment from non-metabolic and non-traumatic sources. These participants were treated with dextrose injection compared to those receiving other injectables, such as corticosteroids and non-corticosteroid medications. The primary outcome was pain, with secondary outcomes including function, ultrasonographic, and electrodiagnostic findings. The quality of the clinical trials was assessed using Cochrane tools. Random-effect model was employed for meta-analysis.

Results

Thirteen studies, involving 754 patients, were included, with only two showing serious bias risk. Initial findings indicate significant pain relief with dextrose injection within a short time (≤4 weeks) compared to normal saline (MD: -1.30, 95%CI: -2.12; -0.47). Dextrose also demonstrated a significant pain decrease compared to corticosteroids (MD: -0.81, 95 % CI: -1.40; -0.21) with low heterogeneity (I2 = 9 %, P = 0.36), and significantly improved function (MD = -0.46, 95 % CI: -0.76; -0.16) with low heterogeneity (I2 = 17 %, P = 0.31) in mid-term (one to six months).

Conclusion

This meta-analysis suggests dextrose injection as an effective therapy for managing pain and restoring function in entrapment neuropathies. However, further high-quality studies are needed to confirm these findings and establish optimal dosing regimens and injection protocols. Healthcare providers should consider integrating dextrose injection into their treatment strategies for patients with entrapment neuropathies.

Post-traumatic radial nerve neuroma: A case report

Introduction

Radial nerve neuromas (RNNs) are mostly post-traumatic conditions that occur after a complete or partial section of a nerve. Here we report a case of post-traumatic RNN with good functional progression after intense physical rehabilitation.

Case presentation

A 49 years old patient with a post-complete section of the radial nerve underwent intensive physical rehabilitation with two sessions of ultrasound-guided injections of 10 % glucose saline around the neuroma. 12 months later, the patient improved his wrist and hand finger extension functions.

Conclusion

Several surgical and non-surgical therapies have been proposed for the treatment of neuromas. However, no consensus currently exists, and management is frequently adapted to each patient.

The Potential of Glucose Treatment to Reduce Reactive Oxygen Species Production and Apoptosis of Inflamed Neural Cells In Vitro

Neuroinflammation is a key feature in the pathogenesis of entrapment neuropathies. Clinical trial evidence suggests that perineural injection of glucose in water at entrapment sites has therapeutic benefits beyond a mere mechanical effect. We previously demonstrated that 12.5-25 mM glucose restored normal metabolism in human SH-SYFY neuronal cells rendered metabolically inactive from TNF-α exposure, a common initiator of neuroinflammation, and reduced secondary elevation of inflammatory cytokines. In the present study, we measured the effects of glucose treatment on cell survival, ROS activity, gene-related inflammation, and cell cycle regulation in the presence of neurogenic inflammation. We exposed SH-SY5Y cells to 10 ng/mL of TNF-α for 24 h to generate an inflammatory environment, followed by 24 h of exposure to 3.125, 6.25, 12.5, and 25 mM glucose. Glucose exposure, particularly at 12.5 mM, preserved apoptotic SH-SY5Y cell survival following a neuroinflammatory insult. ROS production was substantially reduced, suggesting a ROS scavenging effect. Glucose treatment significantly increased levels of CREB, JNK, and p70S6K (p < 0.01), pointing to antioxidative and anti-inflammatory actions through components of the MAPK family and Akt pathways but appeared underpowered (n = 6) to reach significance for NF-κB, p38, ERK1/2, Akt, and STAT5 (p < 0.05). Cell regulation analysis indicated that glucose treatment recovered/restored function in cells arrested in the S or G2/M-phases. In summary, glucose exposure in vitro restores function in apoptotic nerves after TNF-α exposure via several mechanisms, including ROS scavenging and enhancement of MAPK family and Akt pathways. These findings suggest that glucose injection about entrapped peripheral nerves may have several favorable biochemical actions that enhance neuronal cell function.

Isotonic Glucose Injections for Postherpetic Neuralgia in the Elderly

Postherpetic neuralgia (PHN) is a painful condition which is difficult to treat, especially among the elderly. This clinical case describes the treatment of an 88-year-old patient with PHN who continued to suffer from pain for several months despite oral and transdermal pain treatment. Multiple intradermal glucose 5% injections allowed her to discontinue her pain medication regimen after four sessions. The improvement was sustained at the four-month follow-up after the last procedure. A fifth session was performed because of a flaring up of the pain.