The Effect of Interactive Neurostimulation Therapy on Myofascial Trigger Points Associated with Mechanical Neck Pain: A Preliminary Randomized, Sham-Controlled Trial

Objectives: This trial was conducted to assess the effectiveness of interactive neurostimulation (INS) therapy on the treatment of pain associated with myofascial trigger points (MTPs) in adults with mechanical neck pain. Design: This was a preliminary, randomized, sham-controlled trial. Setting: The trial was conducted in a tertiary-care institution. Subjects: The participants were 23 adults with pain and MTPs in the neck or shoulder lasting >2 weeks. Interventions: INS (active or sham) was delivered for 10 minutes in a single session over the MTP area in each patient. Outcome measures: Immediately following the intervention, subjects were tested for pressure pain thresholds (PPTs) and 10-cm visual analogue scale score (VAS) for pain intensity. At the 5 day follow-up, two additional tests were performed: the neck disability index (NDI) and the patient specific functional scale (PSFS) for function. Results: Improvements in function (PSFS) were observed in the treatment group, which were of clinical significance in selected subjects. These effects were statistically greater than those obtained in the sham group but were overall not at a level of clinical significance in this small population. Improvements in pain intensity (VAS) and neck disability (NDI) were observed in both the treatment and sham groups, indicating that INS had no greater benefit using these measures. There was no change in PPTs following either the active or sham treatment. Conclusions: INS is a new and emerging therapy, which may be efficacious for managing musculoskeletal conditions, such as myofascial pain syndrome. This study demonstrated improvements in function in individuals with MTPs following INS therapy, which may be of clinical significance in certain patients with neck or shoulder pain. Further large-scale clinical trials are required to confirm this effect and to determine if INS also reduces pain and neck disability.