Baseline correlates of the response to the treatment of chronic localized myofascial pain syndrome by injection of local anaesthetic

Abstract

Myofascial pain syndromes (MPS) occur commonly in the community. Treatment by injection of local anaesthetic has met with variable success. We studied 50 out-patients with chronic localized MPS in order to find baseline correlates related to response to treatment. Data collected included sociodemographic and clinical histories as well as psychometric measures of self-efficacy, health locus of control and illness behaviour. Pretreatment pain intensity and scores on the Denial scale of the Illness Behavior Questionnaire (IBQ) were found to be associated with an immediate improvement in pain, while scores on the Affective Inhibition scale of the IBQ were associated with pain relief lasting up to 24 hours. The immediate response was not predictive of the duration of the effect of the treatment. This study shows that the severity of the pain and its role as part of a psychological coping strategy are related to the response to local treatment of MPS.