The effect of stellate ganglion block on the atypical facial pain

Local anesthesia nerve block for managing burning mouth syndrome: a scoping review

OBJECTIVE

To assess the clinical scenarios in which nerve blocks are employed in the context of burning mouth syndrome (BMS).

STUDY DESIGN

This scoping review followed the PRISMA-ScR. A protocol was generated on Open Science Framework. Electronic searches were performed in the following databases: PubMed, Scopus, EMBASE, Web of Science, LILACS, and Cochrane, in addition to the grey literature and citations from Grémeau-Richard et al. (2010).

RESULTS

Nerve blocks were used for treatment purposes in all cases. The mandibular nerve and the stellate ganglion were both blocked in 50% studies, while the maxillary nerve and lingual nerve were blocked in 25% study each. The anesthetics used were lidocaine (50%) and bupivacaine (50%). Relief was generally reported after immediate block, and at a mean follow-up of 4.5 weeks, there was considerable improvement compared to the initial conditions when the mandibular and/or maxillary nerve were targeted.

CONCLUSIONS

The use of nerve blocks has been employed in the treatment of patients with refractory BMS. Clinical studies with standardized methodology are necessary to validate and understand the potential role of mandibular and maxillary nerve block in this setting.

Sympathectomy Ameliorates CFA-Induced Mechanical Allodynia via Modulating Phenotype of Macrophages in Sensory Ganglion in Mice

BACKGROUND

The sympathetic nervous system (SNS) is suggested to be involved in some forms of pain, but the mechanisms of which are incompletely known. Moreover, there is a lack of information on the regulatory role of the SNS on macrophages in sensory ganglion, which plays an important role in pain development. The present study aims to investigate the effects of the SNS on orofacial inflammatory pain and examine, if any, how the SNS influences trigeminal ganglion (TG) macrophage responses.

METHODS

Sympathectomy was performed on male C57BL/6 mice before receiving a local injection of Complete Freund's adjuvant (CFA) to induce inflammatory pain. Effects of sympathectomy on orofacial pain were examined by Von Frey test and c-Fos expression. Polarization of TG macrophage was evaluated by immunohistochemistry and the level of norepinephrine (NE) in the TG were determined by liquid chromatography. Sympathetic signaling to TG macrophages were predicted based on single-cell analysis.

RESULTS

CFA injection induced a significant increase in mechanical allodynia, the number of c-Fos-positive neuron, and the level of NE in TG, which were largely reduced by sympathectomy. The number of M1 macrophages was markedly increased by CFA and was largely reduced by sympathectomy from 1 to 14 days post-injection. Single-cell RNA sequencing analysis and immunofluorescence staining showed that TG macrophages mainly express β2 adrenergic receptors for NE. Cell-cell communication analysis predicted sympathetic signaling that may modulate macrophage phenotypes, including Colony-stimulating factor-1, Migration inhibitory factor, Pleiotrophin and Nicotinamide phosphoribosyl transferase.

CONCLUSION

The SNS may involve in CFA-induced mechanical allodynia via modulating macrophage phenotypes in the TG. Targeting sympathetic activation might be useful in treating some painful conditions in the orofacial region.

Stellate ganglion intervention for chronic pain: A review

Stellate ganglion (SG) intervention is currently widely being studied in many kinds of chronic pain. As one of the convenient ways to treat the sympathetic nervous system, the indications for stellate ganglion intervention (SGI) include complex regional pain syndrome, postherpetic neuralgia, cancer pain of different origins, orofacial pain, and so forth. SGI refers to the reversible or irreversible blocking of the cervical sympathetic trunk, cervical sympathetic ganglion, and their innervation range through noninvasive or minimally invasive treatment. Current treatment options include stellate ganglion block (SGB), SG pulsed radiofrequency, continuous radiofrequency treatment, and noninvasive SGB. In particular, SGB continues to be one of the most studied methods in chronic pain management. However, a single SGB usually provides only short-term effects; repeated SGB may result in complications such as hoarseness, light-headedness, and vessel or nerve injury. Meanwhile, the mechanism of SGI is still unclear. This review discusses the research progress of SGI methods, effectiveness, complications, and possible mechanisms in the management of chronic pain.

A Randomized Comparison between 4, 6 and 8 mL of Local Anesthetic for Ultrasound-Guided Stellate Ganglion Block

Background: Because it affords greater accuracy than landmark-based techniques, ultrasound guidance may reduce the volume of local anesthetic required for sympathetic blockade of the upper extremity. We hypothesized that 4 mL would provide a similar clinical effect when compared to larger volumes. Methods: One hundred and two patients with chronic neuropathic pain of the upper extremity or face were randomly assigned to receive an ultrasound-guided (USG) stellate ganglion block (SGB) with either 4 mL (group A), 6 mL (group B) or 8 mL (group C) mL of 1.0% lidocaine. Skin temperatures of the face, hand, and axillary fold were measured bilaterally at baseline, 10, 20, and 30 min after the block. Our primary outcome was the relative increase in hand temperature on the blocked side at 30 min and our non-inferiority margin was −0.6 °C. Secondary outcomes included success rate (as defined by a relative temperature increase of ≥1.5 °C), pain relief, degree of ptosis and side-effects. Results: The 95% confidence intervals for the difference of the means exceeded our non-inferiority margin (A versus B: −0.76 to 0.24; A versus C: −0.89 to 0.11) for temperature changes in the hand; however, success rates were similar (44, 45 and 55% for A, B and C respectively, p = 0.651). No intergroup differences were found in temperature-related outcomes for the other measurement sites (face, axilla). The incidence of minor side-effects was significantly higher in group C and no block-related complications were noted. Conclusions: We were unable to establish the non-inferiority of a 4 mL volume for sympathetic blockade of the hand. The clinical significance of these findings is unclear as success rates were similar between the different groups. In contrast, the 6- and 8 mL volumes were not associated with greater temperature changes in the face and axilla.

Therapeutic potential of stellate ganglion block in orofacial pain: a mini review

Orofacial pain is a common complaint of patients that causes distress and compromises the quality of life. It has many etiologies including trauma, interventional procedures, nerve injury, varicella-zoster (shingles), tumor, and vascular and idiopathic factors. It has been demonstrated that the sympathetic nervous system is usually involved in various orofacial pain disorders such as postherpetic neuralgia, complex regional pain syndromes, and atypical facial pain. The stellate sympathetic ganglion innervates the head, neck, and upper extremity. In this review article, the effect of stellate ganglion block and its mechanism of action in orofacial pain disorders are discussed.