Frequency of Psychosomatic-Prone Myofascial Pain Syndrome in Patients with Incurable Cancer and its Association with the Armchair Sign: A Secondary Analysis of A Prospective, Multicenter, Observational Clinical Study

Abstract

Background Few studies have reported psychosomatic-prone functional damage in cancer patients. Because psychosomatic diseases are pathological conditions, it is difficult to identify their degrees. The armchair sign is a test used to assess voluntary muscle relaxation. This study aimed to evaluate the frequency of psychosomatic-prone functional damage in cancer patients and its association with the armchair sign. Methods This was a secondary analysis of a prospective, multicenter, observational clinical study. We evaluated the frequency of psychosomatic-prone myofascial pain syndrome (MPS) in patients with incurable cancer who were at the start of palliative care and how it is associated with the armchair sign. Moreover, we assessed the usefulness of the armchair sign for the diagnosis of psychosomatic-prone MPS. Results A total of 101 patients were enrolled from March 2018 to December 2018, of whom 44 met MPS diagnostic criteria. Of these, 27 patients (61.3%) had psychosomatic-prone MPS. There was a significant association between the armchair sign and psychosomatic-prone MPS (p = 0.002). Sensitivity and specificity were 40.7% (95% confidence interval: 18.0–63.4) and 100.0%, respectively. The area under the curve score was 0.704 (95% confidence interval: 0.553–0.855). Conclusions MPS in patients with incurable cancer has a high frequency of psychosomatic pathology. The armchair sign may be useful as an ancillary test for the diagnosis of psychosomatic-prone MPS. Trial registration: UMIN000031338. Registered 16 February 2018.