VISUALIZATION OF CHRONIC NECK-SHOULDER PAIN - IMPAIRED MICROCIRCULATION IN THE UPPER TRAPEZIUS MUSCLE IN CHRONIC CERVICO-BRACHIAL PAIN

This study pertains to the 71 patients who had received a diagnosis of cervico-brachial pain syndrome after thorough clinical examination of a total series of 300 patients, who had been referred to the National Insurance Hospital in Tranas because of chronic neck pain that interf ered with their ability to work. Changes in trapezius muscle blood flo w and EMG were examined and related to the anamnesis and physical find ings. The microcirculation in the upper part of the right and left tra pezius muscles was examined simultaneously by using optical laser-Dopp ler single-fibres after insertion into the muscle directly via the ski n. Continuous recordings were made during stepwise increased static co ntraction determined electro-myographically. Signal processing was per formed on-line by computer. MRT of the cervical spine was performed in 12 patients. None showed nerve root affliction. in showed a bulging i ntervertebral disc and two, a narrowed nerve hole (lateral stenosis). The muscle blood flow (LDF) was significantly lower in the most painfu l side compared with the opposite side in the group of 41 patients wit h predominantly unilateral pain (21 women and 20 men). A lowered blood flow was also found when the 21 females in this group was compared wi th a normal control group of 20 healthy women. The patients had lower rms-EMG and EMG mean power frequency (MPF) in the painful side compare d with the opposite side. A further lowering cf the MPF was observed w ith induced fatigue. It was concluded that the chronic neck pain in ce rvico-brachial syndrome can become visualized by the finding of lowere d blood flow of the trapezius muscle which seems to be an expression o f the chronic neck pain.