Muscle injections with lidocaine improve resting fatigue and pain in patients with chronic fatigue syndrome

A Review of Stellate Ganglion Block as an Adjunctive Treatment Modality

Peripheral nerve blocks are becoming increasingly used as adjunctive treatment modalities for a variety of conditions refractory to medical management. Right or left stellate ganglion blocks (SGB) are a specific type of peripheral nerve block that target the sympathetic blockade of neuronal impulses using the injection of local anesthetic and steroids into nerve bundles in the cervical area. This review article is intended to summarize the common uses of stellate ganglion blocks and explain the procedural technique, which has evolved with technological advances in ultrasonography. The similarities between these disease processes are centered around sympathetic hyperactivity. This sympathetic overdrive state is created by increased levels of nerve growth factor (NGF), which causes a cascade of sympathetic sprouting resulting in increased norepinephrine (NE) systemically. Reversal of this cascade by local anesthetic injection into the stellate ganglion thereby reduces NGF and sympathetic sprouting subsequently lowering overall norepinephrine levels. This is the unifying theory by which SGB is able to provide resolution for the varied clinical conditions described in this article.  This review article discusses the physiology of several conditions where stellate ganglion blocks are being investigated as an adjunct treatment modality, including anosmia, PTSD, long-COVID, chronic fatigue syndrome, menopausal hot flashes, and ventricular tachyarrhythmias. Overall, the current literature supporting the use of stellate ganglion blocks for several esoteric conditions is limited; however, case reports to date have shown promising evidence-based results supporting their use as an adjunctive treatment among patients with refractory symptoms to existing treatment algorithms. In conclusion, SGB should be considered among patients with refractory symptoms for medical management in the conditions discussed in this article. Further research is needed to delineate which patients will benefit from the use of SGB, the use of subsequent blocks and timelines in between injections, and unilateral versus bilateral blockade.

Local anesthetics as a therapeutic tool for post COVID-19 patients: A case report

BACKGROUND

Post COVID-19 syndrome (PC-19S) appears to be independent of acute illness severity and humoral response. The involvement of the autonomic nervous system (ANS), expressed by dysautonomia, has been hypothesized as a contributor. Several studies have associated the therapeutic effects of local anesthetics (LA) to their action on the ANS. To the best of our knowledge, this is the first report of therapeutic injections with LA linked to clinical improvement in a patient with PC-19S.

PATIENT CONCERNS AND DIAGNOSES

This was a 54-year-old-man with postCOVID-19 symptoms lasting 14 weeks, including fatigue, breathlessness, diarrhea, muscle pain, and emotional lability.

INTERVENTIONS AND OUTCOME

Injections of 0.5% procaine in the stellate ganglion (SG) and sphenopalatine ganglion (SPG), and in clinically relevant points in the scalp, thorax, and abdomen were performed 3 times over 3 months. The patient reported progressive improvement and was asymptomatic upon completing the treatment. Prescribed medications were discontinued. The 36-Item Short Form Health Survey (SF-36) score showed significant improvement across all SF-36-domains.

CONCLUSION

Subanesthetic doses of LA injected in clinically relevant points led to rapid and complete symptom resolution in this patient with PC-19S. Targeted LA injections may have therapeutic benefits in PC-19S and in other chronic diseases linked to stress and inflammation.

Animal Models of Peripheral Pain: Biology Review and Application for Drug Discovery

Pain is a complex constellation of cognitive, unpleasant sensory, and emotional experiences that primarily serves as a survival mechanism. Pain arises in the peripheral nervous system and pain signals synapse with nerve tracts extending into the central nervous system. Several different schemes are used to classify pain, including the underlying mechanism, tissues primarily affected, and time-course. Numerous animal models of pain, which should be employed with appropriate Institutional Animal Care and Use approvals, have been developed to elucidate pathophysiology mechanisms and aid in identification of novel therapeutic targets. The variety of available models underscores the observations that pain phenotypes are driven by several distinct mechanisms. Pain outcome measurement encompasses both reflexive (responses to heat, cold, mechanical and electrical stimuli) and nonreflexive (spontaneous pain responses to stimuli) behaviors. However, the question of translatability to human pain conditions and potential treatment outcomes remains a topic of continued scrutiny. In this review we discuss the different types of pain and their mechanisms and pathways, available rodent pain models with an emphasis on type of pain stimulations and pain outcome measures and discuss the role of pathologists in assessing and validating pain models.