Our study shows that there was no difference between the effect of small doses of botulinum toxin A and those of physiological saline in the treatment of myofascial pain syndrome.

Simple but objective measurement of soft tissue consistency would be advantageous in the assessment of many neurological, lymphostatic and venous disorders. The aim of the present study was to evaluate the feasibility of using a novel hand-held computerized soft tissue stiffness meter (STSM). The STSM describes the soft tissue stiffness (STS) in the form of the instantaneous force (N) by which the tissue resists the constant deformation produced by a cylindrical intender. Firstly, the STSM was used to test elastomer samples with known mechanical properties. In the in vivo assessment, 12 healthy, nondisabled adults (age range, 24-57 years) and 16 subjects with chronic myofascial neck pain syndrome (age range, 27-55 years) were studied. To study the reproducibility (coefficient of variation (CV(%))) of the method, the measurement sites were either marked with a marker pen (marked points) or localized anatomically (unmarked points). Measurements were made from the dorsal forearm (Arm), trapezius (Tra), levator scapulae (Lev), infraspinatus (Inf) and deltoideus (Del) muscle areas. STS in the forearm was studied during different types of short-term relative isometric loading of the muscle as well as during venous occlusion. STS values of the myofascial trigger points in the Lev muscles were evaluated bilaterally. A linear, positive relationship was found between the indenter force (N) and the dynamic compressive modulus (MPa) of elastomer stiffness (r(2) = 0.90, n = 9). Intra- and interrater CVs of marked and unmarked sites varied between 4.31% and 12.06%. STS increased linearly along the relative muscle load (r(2) = 0.96) and nonlinearly during the venous occlusion (r(2) = 0.97). Statistically significant regional variation of STS was found between the different measurement sites (p < 0.05). In conclusion, STSM can evaluate tissue stiffness quantitatively and yield reproducible data.

No abstract

Objectives: Evaluate the electromyographic findings in the trigger points [TrPs] of 31 patients, suffering from myofascial pain syndrome in the neck-shoulder area, before and after injection treatment.Methods: One hundred and seventy-two TrPs and 31 reference points were studied with needle-electromyography and then the TrPs were injected via the same needle with small doses of either botulinum toxin A [BTA] or saline in a double-blind study.Results: In the baseline, the occurrence of spontaneous electrical activity containing endplate spikes [EPS] was 23.3 percent in all the TrPs and 9.7 percent in the reference points. This difference did not reach statistical significance, but the difference was statistically significant in the TrPs of upper trapezius [P = 0.02 on the left and 0.04 on the right side]. We found complex repetitive discharges in 3.5 percent of studied TrPs, but not at any of the reference points. At four weeks after the BTA treatment, fibrillation potentials were found in 31.3 percent of the TrPs against none in the saline group [P < 0.001]. Injections of BTA reduced the mean prevalence of EPS in TrPs significantly [P < 0.05] when compared with saline injections. The change of EPS prevalence correlated with the subjective result of treatment assessed on verbal scale, but not with other pain measurements.

No abstract