The Therapeutic Effects of Dextrose Injection for Myofascial Pain Syndrome

Patients with an myofascial trigger point (MTrP) in their upper trapezius will be divided into three groups: Group A receiving MTrP injection with normal saline (control group), Group B with hypo-osmolar dextrose (5% dextrose), and Group C with hyper-osmolar dextrose (15% dextrose). Clinical outcomes and morphological changes will be measured before the injection, one hour after, one week after, two weeks after, and one month after the injection to delineate the therapeutic effects of dextrose injection for an MTrP.

Inclusion Criteria: * 1). Patients should be 20 years of age or older; * 2). They are able to communicate freely; * 3). Patients have the diagnosis of myofascial pain syndrome (MPS) with a definite myofascial trigger point (MTrP) in the neck base and upper back regions (the upper trapezius muscle). The MTrP is identified based on the following criteria, as recommended by Simons \[Simons et al., 1999\]: * (a). a localized tender spot in a palpable taut band of muscle fibers, * (b). recognized pain (as the usual clinical complaint) when the tender spot is compressed, * (c). characteristic and consistent referred pain. * 4). Symptoms of MPS should be more than 3 weeks. Exclusion Criteria: * (1). acute or serious medical problems; * (2). cognitive impairment or psychiatric disorder; * (3). coagulopathy or any other bleeding disorder; * (4). taking medication of anticoagulation or antithrombolytics; * (5). sensory deficiency over the body part where MTrPs located; * (6). serum hepatitis B or acquired immunodeficiency syndrome; * (7). malignancy; * (8). pregnant or likely to be pregnant. * (9). diabetes mellitus