Electrical nerve stimulation for xerostomia: A meta-analysis of randomised controlled trials

Rosmarinic acid Ameliorates neuronal regeneration in the bridging silicone rubber conduits of the sciatic nerve in taxol-treated rats

Background and aim

Taxol modulates local inflammatory conditions in peripheral nerves, which may impair their regeneration and recovery when injured. This study aimed to determine the effects of rosmarinic acid (RA, a polyphenol constituent of many culinary herbs) on the regeneration of the sciatic nerves in the bridging conduits.

Experimental procedure

In the cell study, RA decreased nuclear factor (NF)-κB activity induced by taxol in a dose dependency. In the animal model, taxol-treated rats were divided into 3 groups (n = 10/group): taxol (2 mg/kg body weight for 4 times) and taxol + RA (3 times/week for 4 weeks at 20 and 40 mg/kg body weight) groups. Macrophage infiltration, calcitonin gene-related peptide (CGRP) expression levels, neuronal connectivity, animal behavior, and neuronal electrophysiology were evaluated.

Results and conclusion

At the end of 4 weeks, macrophage density, CGRP expression level, and axon number significantly increased in the RA group compared with the taxol group. The RA administration unaffected heat, cold plate licking latencies, and motor coordination. Moreover, the 40 mg/kg RA group had significantly larger nerve conduction velocity and less latency compared to the taxol group. This study suggested that RA could ameliorate local inflammatory conditions to augment the recovery of regenerating nerves by accelerating their regrowth and improving electrophysiological function in taxol-treated peripheral nerve injury repaired with the silicone rubber conduit.

Salivary Electrostimulation in the Treatment of Radiation Therapy-Induced Xerostomia (LEONIDAS-2): A Multicenter, Randomized, Double-Masked, Sham-Controlled, Phase 3 Trial

PURPOSE

Radiation therapy-induced xerostomia significantly affects quality of life in head and neck cancer survivors. Neuro-electrostimulation of the salivary glands may safely increase natural salivation and reduce dry mouth symptoms.

METHODS AND MATERIALS

This multicenter, double-masked, randomized, sham-controlled clinical trial assessed the long-term effects of a commercially available intraoral neuro-electrostimulating device in lessening xerostomia symptoms, increasing salivary flow, and improving quality of life in individuals with radiation therapy-induced xerostomia. Using a computer-generated randomization list, participants were assigned (1:1) to an active intraoral custom-made removable electrostimulating device or a sham device to be used for 12 months. The primary outcome was the proportion of patients reporting a 30% improvement on the xerostomia visual analog scale at 12 months. A number of secondary and exploratory outcomes were also assessed through validated measurements (sialometry and visual analog scale) and quality-of-life questionnaires (EORTC QLQ-H&N35, OH-QoL16, and SF-36).

RESULTS

As per protocol, 86 participants were recruited. Intention-to-treat analyses showed no statistical evidence of a difference between the study groups with respect to the primary outcome or for any of the secondary clinical or quality-of-life outcomes. Exploratory analyses showed a statistically significant difference in the changes over time of the dry mouth subscale score of the EORTC QLQ-H&N35 in favor of the active intervention.

CONCLUSIONS

LEONIDAS-2 did not meet the primary and secondary outcomes.

The Impact of Xerostomia on Food Choices-A Review with Clinical Recommendations

Xerostomia and hyposalivation are highly prevalent conditions in old age, particularly among multimorbid elders, and are often attributed to the use of multiple medications. These conditions negatively affect oral functions, such as chewing, swallowing, speech, and taste. Additionally, the lack of lubrication of the oral mucosa frequently leads to super-infections with candida. Denture retention and comfort may also be compromised. The risk of dental caries and erosion of natural teeth increases since saliva, which is essential for repairing initial lesions in tooth structures, is insufficient. The dry sensation in the mouth also impacts the emotional and social well-being of elderly individuals. Patients experiencing xerostomia often avoid certain foods that are uncomfortable or difficult to consume. However, some foods may alleviate the symptoms or even stimulate salivation. This review discusses the limited available evidence on nutritional advice for patients with xerostomia and aims to provide insight into the patient's perspective while offering clinical recommendations. Future studies should focus on investigating the nutritional intake of individuals suffering from xerostomia or hyposalivation in order to ensure oral health comfort, prevent malnutrition, and minimize the impact on their quality of life.

Salivary stimulatory effect of novel low level transcutaneous electro neurostimulator in geriatric patients with xerostomia

BACKGROUND

Xerostomia (dryness of the mouth) is one of the most common long-term consequences of ageing, and it causes a tremendous impact on the function and morphology of the salivary ductal system. As a consequence, it leads to a decrease in the amount of salivary output and also affects the overall quality of life. The purpose of this study was to determine whether electrostimulation using a custom designed transcutaneous electrical nerve stimulation (TENS) device will help to improve the quality of secreted saliva following electrostimulation.

METHODS

One hundred thirty-five participants underwent the intervention for three months, twice daily (80 Hz). Pre-intervention and post-intervention unstimulated saliva were collected. Parameters such as salivary pH, cortisol level, salivary antioxidants, total protein, the viscosity of saliva, and microbial carriage were analysed.

RESULTS

Salivary pH, cortisol, microbial cultures, viscosity, and antioxidants showed a significant difference at the end of the 3rd month (p < 0.05). Irrespective of the patient's age, gender, and common underlying systemic illnesses (diabetes and hypertension), a significant change in the quality of the salivary analytes was observed.

CONCLUSION

The study emphasises the use of a custom designed TENS device in improving the quality of secreted saliva among old patients with oral dryness.

A Computational Text Mining-Guided Meta-Analysis Approach to Identify Potential Xerostomia Drug Targets

Xerostomia (subjective complaint of dry mouth) is commonly associated with salivary gland hypofunction. Molecular mechanisms associated with xerostomia pathobiology are poorly understood, thus hampering drug development. Our objectives were to (i) use text-mining tools to investigate xerostomia and dry mouth concepts, (ii) identify associated molecular interactions involving genes as candidate drug targets, and (iii) determine how drugs currently used in clinical trials may impact these genes and associated pathways. PubMed and PubMed Central were used to identify search terms associated with xerostomia and/or dry mouth. Search terms were queried in pubmed2ensembl. Protein-protein interaction (PPI) networks were determined using the gene/protein network visualization program search tool for recurring instances of neighboring genes (STRING). A similar program, Cytoscape, was used to determine PPIs of overlapping gene sets. The drug-gene interaction database (DGIdb) and the clinicaltrials.gov database were used to identify potential drug targets from the xerostomia/dry mouth PPI gene set. We identified 64 search terms in common between xerostomia and dry mouth. STRING confirmed PPIs between identified genes (CL = 0.90). Cytoscape analysis determined 58 shared genes, with cytokine-cytokine receptor interaction representing the most significant pathway (p = 1.29 × 10-23) found in the Kyoto encyclopedia of genes and genomes (KEGG). Fifty-four genes in common had drug interactions, per DGIdb analysis. Eighteen drugs, targeting the xerostomia/dry mouth PPI network, have been evaluated for xerostomia, head and neck cancer oral complications, and Sjögren's Syndrome. The PPI network genes IL6R, EGFR, NFKB1, MPO, and TNFSF13B constitute a possible biomarker signature of xerostomia. Validation of the candidate biomarkers is necessary to better stratify patients at the genetic and molecular levels to facilitate drug development or to monitor response to treatment.

A Stimulator of the Salivary Excretion Based on Physical Vibration of the Parotid Glands

Oral dryness causes significant health problems both functional (difficulty speaking, chewing and swallowing) and structural in teeth (increased number of infections) and oral mucosa. The main objective of this study is to show an alternative treatment to help stimulate the salivary secretion thus improving the quality of life of the patient. In this study, a salivary stimulation equipment using vibrotactile stimuli is shown. The system has been placed bilaterally in the parotid glands and assessed the efficacy of the salivary secretion by sialometry before and after the stimulation. The new proposal is capable of stimulating salivary secretion, in a significative way after 7 minutes of use, at least in the cases analyzed, and fulfills low-cost, easy-to-use, and safe technical restrictions. In this setting, this paper suggests the performance of a deep clinical trial to measure the exact efficacy of the prototype and the times and frequencies needed to state the optimal treatment depending in each case.

Transcutaneous Electrical Nerve Stimulation: A Review of Dental Applications

Transcutaneous electrical nerve stimulation or TENS is a nonpharmacologic method that is used to alleviate pain from various acute and chronic conditions. TENS works through activation of descending inhibitory neurons of the central nervous system. In dentistry, TENS has applications for pain reduction in temporomandibular disorders and postherpetic neuralgia. It has also been studied for its role in increasing salivary secretion in subjects with xerostomia and as a local anesthetic agent in pediatric dentistry. Its wide applications in the orofacial region make it an important treatment modality. The purpose of the present review was to describe the general principles and its applications in dentistry along with its indications, advantages, and disadvantages. A web-based search was conducted using the keywords “transcutaneous electrical nerve stimulation,” “temporomandibular joint,” “TENS,” “TMJ,” “orofacial pain,” and “Management.” The manuscripts thus obtained were evaluated and used for compiling the present narrative review. The present review focuses on the mechanism of action, applications, and effectiveness of TENS in the management of diseases of the maxillofacial region.

The efficacy of vitamin D in multiple sclerosis: A meta-analysis

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory demyelination disorder in the central nervous system (CNS) leading to a high level of neurological disability. The pathogenesis of MS remains largely unknown, which explains the lack of significant efficacy of therapy in MS. Vitamin D deficiency is widely considered to be an environmental risk factor for MS. Many studies investigating the therapeutic effects of vitamin D on MS have been applied. The objective of this systematic review and meta-analysis was to evaluate the effectiveness of vitamin D in MS patients.

METHODS

To obtain a more comprehensive estimate of the efficacy of vitamin D on MS patients, we conducted a meta-analysis to determine the role of vitamin D in MS. The PubMed, EMBASE and Cochrane databases were searched in October 2017. Randomized, double-blind, placebo-controlled clinical trials recorded within the three main databases were considered. The analysis was conducted for two specific outcomes: Expanded Disability Status Scale (EDSS) score and annual relapse rate (ARR).

RESULTS

Vitamin D₃ as add-on treatment had no significant therapeutic effect on MS according to EDSS score (mean difference -0.01 [95% CI -0.34 to 0.33]). The ARR was higher in the vitamin D group than in the placebo group (mean difference 0.05 [95% CI 0.01 to 0.1]).

CONCLUSION

Our findings suggest that vitamin D appeared to have no therapeutic effect on EDSS score or ARR in the patients with MS.