Shock waves as treatment of mouse myofascial trigger points.

INTRODUCTION: An abnormal increase in spontaneous neurotransmission can induce subsynaptic knots in the myocyte called myofascial trigger points. The treatment of choice is to destroy these trigger points by inserting needles. However, 10% of the population has a phobia of needles, blood, or injuries. Therefore, the objective of this study is to verify the usefulness of shock waves in the treatment of myofascial trigger points. METHODS: Two groups of mice have been developed for this: healthy muscles treated with shock waves; trigger points affected muscles artificially generated with neostigmine and subsequently treated with shock waves. Muscles were stained with methylene blue, PAS-Alcian Blue, and labeling the axons with fluorescein and the acetylcholine receptors with rhodamine. Using intracellular recording the frequency of miniature endplate potentials (mEPPs) was recorded and endplate noise was recorded with electromyography. RESULTS: No healthy muscles treated with shock waves showed injury. Twitch knots in mice previously treated with neostigmine disappeared after shock wave treatment. Several motor axonal branches were retracted. On the other hand, shock wave treatment reduces the frequency of mEPPs and the number of areas with endplate noise. DISCUSSION: Shock waves seem to be a suitable treatment for myofascial trigger points. In the present study, with a single session of shock waves, very relevant results have been obtained, both functional (normalization of spontaneous neurotransmission) and morphological (disappearance of myofascial trigger points). Patients with a phobia of needles, blood, or injuries who cannot benefit from dry needling may turn to noninvasive radial shock wave treatment.

Dry Needling Produces Mild Injuries Irrespective to Muscle Stiffness and Tension in Ex Vivo Mice Muscles.

Numerous studies have suggested that the myofascial trigger points are responsible for most of the myofascial pain syndrome, so it seems reasonable that its destruction is a good therapeutic solution. The effectiveness of dry needling (DN) has been confirmed in muscles with myofascial trigger points, hypertonicity, and spasticity. The objective of this study is to analyze the need of repetitive punctures on muscles in different situations. The levator auris longus (LAL) muscle and gastrocnemius muscle from adult male Swiss mice were dissected and maintained alive, while being submerged in an oxygenated Ringer's solution. DN was evaluated under four animal models, mimicking the human condition: normal healthy muscles, muscle fibers with contraction knots, muscles submerged in a depolarizing Ringer solution (KCl-CaCl2), and muscles submerged in Ringer solution with formalin. Thereafter, samples were evaluated with optical microscopy (LAL) and scanning electron microscopy (gastrocnemius). Healthy muscles allowed the penetration of needles between fibers with minimal injuries. In muscles with contraction knots, the needle separated many muscle fibers, and several others were injured, while blood vessels and intramuscular nerves were mostly not injured. Muscles submerged in a depolarizing solution inducing sustained contraction showed more injured muscular fibers and several muscle fibers separated by the needle. Finally, the muscles submerged in Ringer solution with formalin showed a few number of injured muscular fibers and abundant muscle fibers separated by the needle. Scanning electron microscopy images confirm the optical analyses. In summary, dry needling is a technique that causes mild injury irrespective of the muscle tone.

Safety analysis of percutaneous needle electrolysis: a study of needle composition, morphology, and electrical resistance.

BACKGROUND: Percutaneous needle electrolysis (PNE) consists of a galvanic current combined with the insertion of a solid needle into the tissues of the musculoskeletal system. The application of a galvanic current through a needle can alter the morphology and composition during treatment application. This procedure may also provoke a localized temperature increase. AIM: The aim was to evaluate the safety of the PNE procedure by analyzing possible alterations of the needles employed. METHODS: Physio Invasiva® and AguPunt EPI® brand needles, commonly used for the application of this technique, were analyzed in response to three different treatment protocols. Temperature changes were evaluated with the needles immersed in a test tube containing Ringer's solution, and electrical resistance was evaluated with a multimeter. The morphology of the needles, pre- and post-treatment, was examined with a scanning electron microscope (FEI Quanta 600), and the composition of the needles was evaluated using RX diffusion with Oxford Instruments software. RESULTS: Ringer's solution contained in the test tubes examined did not present temperature changes. No changes were observed in the needles under investigation with respect to electrical resistance, morphology, or composition with a protocol applying 3-mA intensity for 3 s and three applications. However, important morphological alterations were observed that affected needle composition after 50 applications (at 3 mA for 3 s). CONCLUSION: PNE, applied according to conventional protocols, appeared to be safe and athermal, and did not provoke a loss of metal particles or modify the morphology of the needles used when studied in vitro.