The Importance of Electromyographic Findings in Determining the Etiology of Mastalgia

Aim: The etiology of mastalgia is not fully understood. We evaluated the relationship between electromyography (EMG) measurements of the pectoralis major (PM) muscle and mastalgia in patients with non-cyclic unilateral mastalgia. Methods: Thirty-one patients who were admitted to the breast surgery outpatient clinic due to the complaints of intermittent or continuous unilateral non-cyclic mastalgia for at least one month were included in the study. Data on age, family history, age of menarche, body mass index (BMI), physical examination, breast ultrasonography and mammography findings and amplitudes, latency and cutaneous silent period (CSP) in EMG of the right and left PM muscles were noted. Results: The mean age of the patients was 43.3 (20-65) years; mastalgia affected the left breast and the right breast in 22 (71%) and nine (29%), respectively. Twenty-three patients (74.1%) had a BMI of ≥25 kg/m2. There was a size difference between the two breasts in eleven patients. The EMG results of PM muscles in healthy and mastalgia sides were compared and there was no significant difference observed between the amplitude and resistance parameters. The mastalgia side had significantly higher CSP values. Conclusion: Prolonged CSP suggests that unilateral mastalgia may be associated with pain modulating mechanisms of the central nervous system.