Abstract text (incl. figure legends and references)

Objective: The Coronavirus pandemic has impact on our community far beyond the acute phase, Long COVID-19 is recognized as a new medical entity and resembles fibromyalgia which, likewise, lacks a clear mechanism. Headaches and myofascial pain are common manifestations of COVID-19 and its post-acute sequalae. This work suggests a theoretical model with an organic mechanical mechanism to help explain long COVID-19 headaches and the headaches of functional psychosomatic syndromes such as fibromyalgia, based on cross-disciplinary empirical studies.

Methods: Systematically searched multiple keywords in MEDLINE, EMBASE, COCHRANE, PEDro, and medRxiv, inclusion/exclusion based on title and abstract, then full-text inspection. Additional literature added on relevant side topics.

Results: 831 records included. The theory of "facial-armoring" suggests long COVID-19 and fibromyalgia-like entities may be a disease of connective-tissue driven by myofibroblast-generated-biotensegrity-tension. This mechanism may explain fibromyalgia's pain, distribution of pain, close association with primary headache disorders, decreased pressure-pain threshold, tender spots, fatigue, autonomic abnormalities, absence of clear inflammation, silent imaging investigations, and other phenomena. "Long-COVID-19" is predicted by the model to involve fascial armoring, whereby headaches may arise in part due to a disorder of myofascial tissue, at least in a subset of patients.

Conclusions: long COVID-19 and fibromyalgia-like syndromes resemble a chronic-compartment-like-syndrome-of-the-whole-body and can lead to headaches due to a network of contractile fascial myofibroblasts. Treatments focusing on lifestyle modification and non-pharmacological modalities may be more beneficial in the long term. The body and the mind are one being.

Reference: Plaut S. Scoping review and interpretation of myofascial pain/fibromyalgia syndrome: An attempt to assemble a medical puzzle. PLoS One. 2022;17(2):e0263087.