Symptoms of autonomic dysfunction in chronic fatigue syndrome

QJM. 2007 Aug;100(8):519-26. doi: 10.1093/qjmed/hcm057. Epub 2007 Jul 7.


Background: Chronic fatigue syndrome (CFS) is common and its cause is unknown.

Aim: To study the prevalence of autonomic dysfunction in CFS, and to develop diagnostic criteria.

Design: Cross-sectional study with independent derivation and validation phases.

Methods: Symptoms of autonomic dysfunction were assessed using the Composite Autonomic Symptom Scale (COMPASS). Fatigue was assessed using the Fatigue Impact Scale (FIS). Subjects were studied in two groups: phase 1 (derivation phase), 40 CFS patients and 40 age- and sex-matched controls; phase 2 (validation phase), 30 CFS patients, 37 normal controls and 60 patients with primary biliary cirrhosis.

Results: Symptoms of autonomic dysfunction were strongly and reproducibly associated with the presence of CFS or primary biliary cirrhosis (PBC), and correlated with severity of fatigue. Total COMPASS score >32.5 was identified in phase 1 as a diagnostic criterion for autonomic dysfunction in CFS patients, and was shown in phase 2 to have a positive predictive value of 0.96 (95%CI 0.86-0.99) and a negative predictive value of 0.84 (0.70-0.93) for the diagnosis of CFS.

Discussion: Autonomic dysfunction is strongly associated with fatigue in some, but not all, CFS and PBC patients. We postulate the existence of a 'cross-cutting' aetiological process of dysautonomia-associated fatigue (DAF). COMPASS >32.5 is a valid diagnostic criterion for autonomic dysfunction in CFS and PBC, and can be used to identify patients for targeted intervention studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Autonomic Nervous System Diseases / diagnosis*
  • Autonomic Nervous System Diseases / epidemiology
  • Cross-Sectional Studies
  • Fatigue Syndrome, Chronic / complications*
  • Female
  • Heart Rate
  • Humans
  • Male
  • Middle Aged
  • Prevalence
  • Reproducibility of Results
  • Severity of Illness Index