Local Injection of Methylcobalamin Combined with Lidocaine for Acute Herpetic Neuralgia

Low Trend for VZV-Associated Disease Patients to Visit Neurologists

Background

Herpes zoster (HZ) is a skin disease that can also cause virus-infectious peripheral neuropathies. Despite this, there is limited information on patient preferences for seeking medical attention for HZ and zoster-associated pain (ZAP). Our study aimed to evaluate how frequently patients with ZAP choose to visit neurologists for their symptoms.

Methods

This study conducted a retrospective review of electronic health records in three general hospitals from January 2017 to June 2022. Using association rule mining, the study analyzed referral behaviors.

Results

We identified 33,633 patients with 111,488 outpatient visits over 5.5 years. The study found that the majority of patients (74.77-91.22%) visited dermatologists during their first outpatient visit, while only a small percentage (0.86-1.47%) preferred to consult a neurologist. The proportion of patients referred to a specialist during their medical visit varied significantly between different specialties within the same hospital (p <0.05) and even within the same specialty (p<0.05). There was a weak association (Lift:1.00-1.17) of referral behaviors between dermatology and neurology. Across the three hospitals, the average number of visits to a neurologist for ZAP was 1.42-2.49, with an average electronic health record duration of 11-15 days per patient. After consulting with a neurologist, some patients were referred to other specialists.

Conclusion

It was observed that patients with HZ and ZAP tended to visit a variety of specialists, with only a small number seeking the assistance of neurologists. However, from the perspective of neuroprotection, it is the duty of neurologists to provide more means.

Infusion Therapy in the Treatment of Neuropathic Pain

PURPOSE OF REVIEW

Neuropathic pain is a prevalent and burdensome condition. While oral medical therapies are the first-line treatment for refractory neuropathic pain, in some cases, infusion therapy may be employed. This article is a systematic review of recent publications regarding epidemiologic, pathophysiologic, diagnostic, and therapeutic advancements in the treatment of neuropathic pain using intravenous infusion therapy. Special consideration will be given to relevant and practically used agents and available information on outcomes.

RECENT FINDINGS

Individuals with neuropathic pain from various etiologies (e.g. trigeminal neuralgia, post-herpetic neuralgia, diabetic neuropathy) often find short-term relief from infusion therapies. However, it is difficult to generalize the findings of these studies to form a standard treatment regimen. The purpose of this paper is to provide clinicians an up-to-date summary of recent literature regarding several infusion therapies in treating neuropathic pain.

B Vitamins and One-Carbon Metabolism: Implications in Human Health and Disease

Vitamins B9 (folate) and B12 are essential water-soluble vitamins that play a crucial role in the maintenance of one-carbon metabolism: a set of interconnected biochemical pathways driven by folate and methionine to generate methyl groups for use in DNA synthesis, amino acid homeostasis, antioxidant generation, and epigenetic regulation. Dietary deficiencies in B9 and B12, or genetic polymorphisms that influence the activity of enzymes involved in the folate or methionine cycles, are known to cause developmental defects, impair cognitive function, or block normal blood production. Nutritional deficiencies have historically been treated with dietary supplementation or high-dose parenteral administration that can reverse symptoms in the majority of cases. Elevated levels of these vitamins have more recently been shown to correlate with immune dysfunction, cancer, and increased mortality. Therapies that specifically target one-carbon metabolism are therefore currently being explored for the treatment of immune disorders and cancer. In this review, we will highlight recent studies aimed at elucidating the role of folate, B12, and methionine in one-carbon metabolism during normal cellular processes and in the context of disease progression.

B12 as a Treatment for Peripheral Neuropathic Pain: A Systematic Review

Neuropathic pain describes a range of unpleasant sensations caused by a lesion or disease of the somatosensory nervous system. The sensations caused by neuropathic pain are debilitating and improved treatment regimens are sought in order to improve the quality of life of patients. One proposed treatment for neuropathic pain is vitamin B12, which is thought to alleviate pain by a number of mechanisms including promoting myelination, increasing nerve regeneration and decreasing ectopic nerve firing. In this paper, the evidence for B12 as a drug treatment for neuropathic pain is reviewed. Twenty four published articles were eligible for inclusion in this systematic review in which a range of treatment regimens were evaluated including both B12 monotherapy and B12 in combination with other vitamins or conventional treatments, such as gabapentinoids. Overall, this systematic review demonstrates that there is currently some evidence for the therapeutic effect of B12 in the treatment of post-herpetic neuralgia (level II evidence) and the treatment of painful peripheral neuropathy (level III evidence).

Intra-Venous Lidocaine to Relieve Neuropathic Pain: A Systematic Review and Meta-Analysis

Background: The prevalence of neuropathic pain is estimated to be between 7 and 10% in the general population. The efficacy of intravenous (IV) lidocaine has been studied by numerous clinical trials on patients with neuropathic pain. The aim of this systematic review and meta-analysis was to evaluate the efficacy of IV lidocaine compared with a placebo for neuropathic pain and secondly to assess the safety of its administration. Methods: A literature search on PubMed, Scopus, CENTRAL (Cochrane Central Register of Controlled Trials), and Google scholar databases was performed for relevant studies published up to February 2019. Randomized controlled trials (RCTs) evaluating IV lidocaine treatment for pain relief in patients with neuropathic pain were included. Results: 26 articles met the inclusion criteria. Patients with varied etiology of neuropathic pain were among the patient samples of these studies. Fifteen articles were included for quantitative analysis. Lidocaine was superior to a placebo in relieving neuropathic pain in the early post-infusion period [Mean Difference (MD) = -11.9; 95% Confidence interval (CI): -16.8 to -7; p < 0.00001]. Multiple infusions of lidocaine over a period of 4 weeks, however, had no significant effect on reliving neuropathic pain (MD = -0.96; 95% CI: -2.02 to 0.11; p = 0.08). IV lidocaine was also associated with a significant number of adverse events compared to a placebo [Odds Ratio (OR) = 7.75; 95% CI: 3.18-18.92; p < 0.00001]. Conclusion: Our study indicates that while IV lidocaine is effective in pain control among patients with neuropathic pain in the immediate post-infusion period, it does not have a long-lasting, persistent effect. IV infusions of the drug are associated with an increased risk of side effects compared to a placebo. However, the risk of serious adverse events is negligible. Further, well-designed RCTs evaluating the effects of various dosages and infusion periods of IV lidocaine are required to provide clear guidelines on its clinical use.