RESUMEN
Neuropathic pain is a type of chronic pain caused by an injury or somatosensory nervous system disease. Drugs and exercise could effectively relieve neuropathic pain, but no treatment can completely stop neuropathic pain. The integration of exercise into neuropathic pain management has attracted considerable interest in recent years, and treadmill training is the most used among exercise therapies. Neuropathic pain can be effectively treated if its mechanism is clarified. In recent years, the association between neuroinflammation and neuropathic pain has been explored. Neuroinflammation can trigger proinflammatory cytokines, activate microglia, inhibit descending pain modulatory systems, and promote the overexpression of brain-derived neurotrophic factor, which lead to the generation of neuropathic pain and hypersensitivity. Treadmill exercise can alleviate neuropathic pain mainly by regulating neuroinflammation, including inhibiting the activity of pro-inflammatory factors and over activation of microglia in the dorsal horn, regulating the expression of mu opioid receptor expression in the rostral ventromedial medulla and levels of γ-aminobutyric acid to activate the descending pain modulatory system and the overexpression of brain-derived neurotrophic factor. This article reviews and summarizes research on the effect of treadmill exercise on neuropathic pain and its role in the regulation of neuroinflammation to explore its benefits for neuropathic pain treatment.
RESUMEN
BACKGROUND: The morbidity of knee arthritis is increasing among aged people and total knee arthroplasty has been its mainstream treatment to date. Postoperative rehabilitation is an important part of the procedure. However, the intense pain during the functional exercise involved has always been a challenge for both patients and health care professionals. The aim of this study is to test the analgesic effect of a mixture of nitrous oxide/oxygeb (1:1) inhalation for patients who are doing functional exercise 1 month after total knee arthroplasty. METHODS/DESIGN: This double-blind, randomized, placebo-controlled study will be implemented in the Rehabilitation Department in the General Hospital of Ningxia Medical University. Patients aged between 50 and 75 years who underwent a primary unilateral total knee arthroplasty are eligible for inclusion. The key exclusion criteria include: epilepsy, pulmonary embolism, intestinal obstruction, aerothorax. The treatment group (A) will receive a pre-prepared nitrous oxide/oxygen mixture plus conventional treatment (no analgesics), and the control group (B) will receive oxygen plus conventional treatment (no analgesics). Patients, physicians, therapists, and data collectors are all blind to the experiment. Assessments will be taken immediately after functional exercise begins (T0), 5 min (T1) after functional exercise begins, and 5 min after functional exercise has finished (T2). Patients will be randomly allocated between a treatment group (A) and a control group (B) in a ratio of 1:1. Primary outcome, including pain severity in the procedure, will be taken for each group. Secondary outcomes include blood pressure, heart rate, oxygen saturation, side effects, knee joint range of motion, Knee Society Score (KSS), rescue analgesia need, and satisfaction from both therapists and patients. DISCUSSION: This study will focus on exploring a fast and efficient analgesic for patients who are doing functional exercise after total knee arthroplasty. Our previous studies suggested that the prefixed nitrous oxide/oxygen mixture was an efficacious analgesic for the management of burn-dressing pain and breakthrough cancer pain. The results of this study should provide a more in-depth insight into the effects of this analgesic method. If this treatment proves successful, it could be implemented widely for patients doing functional exercise in the rehabilitation department. TRIAL REGISTRATION: ChiCTR-INR-17012891 . Registered on 6 October 2017.