Sympathetic and Parasympathetic Ganglion Blocks for Treatment of Long COVID-19 Symptoms: A Scoping Review

Long COVID-19 affects approximately 10-30% of individuals who are infected with SARS-CoV-2 and is associated with persistent functional impairment and reduced quality of life. The heterogeneous, multisystemic nature and nonspecific symptomatology of long COVID-19 makes its treatment challenging. This scoping review evaluates existing evidence on sympathetic and parasympathetic ganglion blocks as potential interventions for patients suffering from long COVID-19.

Our primary objective was to assess the effectiveness of sympathetic and parasympathetic ganglion blocks in treating patients with long COVID-19 by identifying the most commonly reported symptoms, symptom response to different block regimens, and any adverse effects associated with these interventions.

A scoping review.

Outpatient clinics where patients received sympathetic blocks or parasympathetic blocks.

A comprehensive search was conducted across PubMed, Embase, Cochrane CENTRAL, Web of Science, Google Scholar, and ClinicalTrials.gov using MeSH and free-text terms related to "long COVID-19," "post-COVID-19 syndrome," and "sympathetic ganglion blocks" and "parasympathetic blocks." Only English-language articles were included. Pre-print repositories and reference lists were also manually screened.

A total of 22 articles covering 505 patients were included in this review. The most frequently studied symptoms were olfactory dysfunction, fatigue, headache, and cognitive disturbances. The most commonly utilized intervention was the stellate ganglion block. The available evidence suggests that the stellate ganglion block could be an effective treatment for dysautonomia symptoms and cognitive dysfunction related to long COVID-19. Sphenopalatine ganglion block may be an effective option to treat headaches in long COVID-19 patients who are refractory to other treatments.

The significant existing variations in treatment regimens precluded our ability to do a quantitative analysis. Reporting bias from case reports and small observational studies should also be considered.

Stellate ganglion blocks may offer therapeutic benefit for the dysautonomia and cognitive dysfunction associated with long COVID-19. Sphenopalatine ganglion blocks have shown promise in managing refractory headache symptoms in this population. Further well-designed, placebo-controlled randomized studies that employ validated outcome measures are required to establish the efficacy of sympathetic ganglion blocks in the treatment of long COVID-19.