A proposed psychosomatic etiologic model for rheumatoid arthritis

This model attributes rheumatoid arthritis to reduction or loss of muscle tone. It is hypothesized that tone is maintained via a neurological feedback loop consisting of a spontaneous (fusimotor) signal from the central nervous system (CNS), a return signal from the sensors and a toning signal from the CNS to the muscles. Frequency of return and toning signals are thought to be identical. Arthritis patients believed to react to psychological stress with increased fusimotor frequency (i.e. muscle tension) which over-stretches the sensing tissue. Because of this damage, the lower fusimotor frequency following the stress episode cannot elicit an adequate frequency response from the sensors and this leads to a matching decline in toning pulse frequency and hence muscle tone. Reduced vascular/cardiac tone lowers blood pressure triggering a compensatory hypervolemia. The resulting hypoxia increases vascular leakage causing tissue/lymph edema and pleural/pericardial/joint effusions. Regular ingestion of ephedrine is thought to increase fusimotor frequency and this reactivates the sensors re-establishing muscle tone.