Brain Connectivity Related to Myofascial Pain

Musculoskeletal pain (myofascial) is a frequent complaint in the current population. This discomfort is usually related to excessive use of a limb, bad posture, muscle overload, tension. Little is known about the mechanisms for the perception of this pain by the brain (as well as practically all painful stimuli). Although there are numerous forms of pain diagnosis, almost all of them are subjective, through visual scales or questionnaires, and the vast majority depends on the patient's cognitive state. The aim of this study was to evaluate changes in Brain connectivity using Electroencephalogram (EEG) related to myofascial pain event. EEG signals were acquired from 9 participants with musculoskeletal pain in the trapezius region. During the trials, 4 muscle points were compressed in random order, 2 non-painful in the region of the anterior deltoid muscle and 2 trigger points in the trapezium. The generalized Partial Directed Coherence of the acquired signals showed the presence of more connections between the hemispheres when the pain was in the right side of the body and that there was more connectivity in the left hemisphere. A dense flow of information was found in the frontal and temporal regions of the brain, which is explained in the Pain Matrix. These findings suggested that the myofascial pain is processed in the left hemisphere and influences the connections with the right hemisphere when the painful stimulus is in the right side of the body.