INTRACELLULAR PHOSPHATES IN INCLUSION-BODY MYOSITIS - A 31P MAGNETIC-RESONANCE SPECTROSCOPY STUDY

Muscle phosphorus magnetic resonance spectroscopy was used to study ox idative metabolism at rest and during recovery from exercise in 7 pati ents with sporadic inclusion body myositis (s-IBM), compared with norm al controls (n = 8) and mitochondrial myopathies (n = 20). At rest, 6/ 7 patients had elevated inorganic phosphates. Recovery parameters were not different from controls, in contrast with mitochondrial myopathie s, who showed abnormal rest and recovery. The normal recovery suggests that mitochondrial oxidative capacity is not impaired in s-IBM. (C) 1 998 John Wiley & Sons, Inc.