Chronic fatigue syndrome differs from fibromyalgia. No evidence for elevated substance P levels in cerebrospinal fluid of patients with chronic fatigue syndrome

Pain. 1998 Nov;78(2):153-155. doi: 10.1016/S0304-3959(98)00134-1.


Levels of substance P were determined in the cerebrospinal fluid (CSF) in 15 patients with chronic fatigue syndrome (CFS). All values were within normal range. This is in contrast to fibromyalgia (FM). The majority of patients with FM have increased substance P values in the CSF. The results support the notion that FM and CFS are different disorders in spite of overlapping symptomatology.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Fatigue Syndrome, Chronic / cerebrospinal fluid*
  • Female
  • Fibromyalgia / cerebrospinal fluid*
  • Humans
  • Male
  • Reference Values
  • Substance P / cerebrospinal fluid*


  • Substance P