TISSUE OXYGEN MEASUREMENT AND P-31 MAGNETIC-RESONANCE SPECTROSCOPY INPATIENTS WITH MUSCLE TENSION AND FIBROMYALGIA

Muscle tissue oxygen tension was measured by a polarographic oxygen fi ne-needle probe, and inorganic phosphate and creatine phosphate spectr a were recorded using magnetic resonance spectroscopy in patients with chronic low back pain and in patients with fibromyalgia. Results were compared with healthy controls. The tissue oxygen tension was markedl y higher in those with tense muscles than in normal subjects. Magnetic resonance spectra for inorganic phosphate were higher in patients dem onstrating muscle contraction, and intracellular pH was shifted in the alkaline direction in cases with increased muscle tension. Results sh ow that hypoxia is not the result of increased muscle tension, as was thought previously, but results from oversupply of oxygen demanded by the muscle, leading to increased capillary perfusion and rising oxygen tension.