Detection of peripheral and central sensitisation at acupoints in patients with unilateral shoulder pain in Beijing: a cross-sectional matched case–control study

Abstract

ObjectiveTo investigate the pattern of experimental pain responses at acupoints in patients with unilateral shoulder pain.DesignA cross-sectional matched study.SettingAcupuncture and Moxibustion Department, Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University.ParticipantsVolunteer samples of 60 participants (30 patients with unilateral shoulder pain, 30 healthy controls).InterventionsNot applicable.Main outcome measuresPressure pain thresholds (PPTs) were measured at four acupoints—namely, Tianzong (SI 11), Jianliao (SJ 14), Jianyu (LI 15) and Jianzhen (SI 9), on the painful/non-painful side in patients with unilateral shoulder pain or healthy controls, respectively. The correlations between the Peripheral Sensitisation Index (PSI) and Central Sensitisation Index (CSI) were compared.ResultsAnalysis showed significantly lower PPT values at acupoints on the painful side compared with the non-painful side in patients with shoulder pain (p<0.025). Meanwhile, PPTs on the non-painful side of these patients were lower than those on the ipsilateral side of healthy controls (p<0.025). No significant differences in PPT values were found between the non-acupoint of the painful/non-painful side in patients with shoulder pain and the ipsilateral side of healthy controls (p>0.05). Additionally, it was observed that the pressure pain assessment acupoints have a strong association with PSI and CSI; three acupoints, in particular, SJ 14, LI 15 and SI 9, showed a correlation with PSI and CSI.ConclusionThe results suggest the presence of peripheral and central sensitisation at acupoints in participants with unilateral shoulder pain. There exists an obvious relationship among the three acupoints SJ 14, LI 15 and SI 9, which are usually chosen to treat shoulder pain. The results provide evidence for the selection of acupoints to treat shoulder pain by acupuncture.

Mast cells are important regulator of acupoint sensitization via the secretion of tryptase, 5-hydroxytryptamine, and histamine

“…Therefore, acupoint sensitization is an important prerequisite that enables it to perceive and respond to outside stimuli, allowing it to contribute to the restoring of body functions weakened by disease. In addition, as disease indicators located on the body surface, sensitized acupoints can be used in clinical prognosis and disease monitoring practices [ 13 – 14 ].…”

Acupuncture for chronic neck pain with sensitive points: study protocol for a multicentre randomised controlled trial

“…The pressure pain threshold (PPT) is a semiobjective method used to quantify localised pain 22 23. Clinical studies have confirmed that the sensitivity (PPT) at acupoints changes when patients are in a diseased state, such as shoulder pain,24 knee osteoarthritis,25 primary dysmenorrhea26 and premenstrual syndrome 27. The degree of change in the PPT may objectively reflect the intensity of acupoint sensitisation and it may be related to the disease status 28.…”

Lack of association between acupoint sensitization and microcirculatory structural changes in a mouse model of knee osteoarthritis: A pilot study

“…Acupoint sensitization significantly affects the receptive field size and the sensitivity of an acupoint and thus enhances its therapeutic function , which includes receiving stimuli and regulating body function. In addition, as a reflection of disease activity on the body surface, a sensitized acupoint can hold high clinical value . Therefore, the structural changes and functional characteristics of microcirculation during acupoint sensitization need to be clarified to improve diagnostic and treatment capabilities, as well as better understand of acupoint connotation.…”