Heterogeneity in chronic fatigue syndrome: evidence from magnetic resonance spectroscopy of muscle

Neuromuscul Disord. 1998 May;8(3-4):204-9. doi: 10.1016/s0960-8966(98)00021-2.


It has been shown previously that some patients with chronic fatigue syndrome show an abnormal increase in plasma lactate following a short period of moderate exercise, in the sub-anaerobic threshold exercise test (SATET). This cannot be explained satisfactorily by the effects of 'inactivity' or 'deconditioning', and patients with abnormal lactate responses to exercise (SATET +ve) have been found to have significantly fewer Type 1 muscle fibres in quadriceps biopsies than SATET -ve patients. We performed phosphorus magnetic resonance spectroscopy on forearm muscles of 10 SATET +ve patients, 9 SATET -ve patients and 13 sedentary volunteers. There were no differences in resting spectra between these groups but at the end of exercise, intracellular pH in the SATET +ve patients was significantly lower than in both the SATET -ve cases and controls (P < 0.03), and the SATET +ve patients also showed a significantly lower ATP synthesis rate during recovery (P < 0.01), indicating impaired mitochondrial oxidative phosphorylation. These observations support other evidence which indicates that chronic fatigue syndrome is a heterogeneous disorder, and confirms the view that some chronic fatigue syndrome patients have a peripheral component to their fatigue.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate / metabolism
  • Adenosine Triphosphate / metabolism
  • Adult
  • Biopsy
  • Fatigue Syndrome, Chronic / diagnosis*
  • Fatigue Syndrome, Chronic / metabolism
  • Female
  • Forearm
  • Genetic Variation*
  • Humans
  • Lactic Acid / metabolism
  • Magnetic Resonance Spectroscopy*
  • Male
  • Middle Aged
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / pathology*
  • Phosphocreatine / metabolism
  • Reference Values


  • Phosphocreatine
  • Lactic Acid
  • Adenosine Diphosphate
  • Adenosine Triphosphate