Executive function impairments in fibromyalgia syndrome: Relevance of clinical variables and body mass index

PLoS One. 2018 Apr 25;13(4):e0196329. doi: 10.1371/journal.pone.0196329. eCollection 2018.


Background: Several investigations suggest the presence of deterioration of executive function in fibromyalgia syndrome (FMS). The study quantified executive functions in patients with FMS. A wide array of functions was assessed, including updating, shifting and inhibition, as well as decision making and mental planning. Moreover, clinical variables were investigated as possible mediators of executive dysfunction, including pain severity, psychiatric comorbidity, medication and body mass index (BMI).

Methods: Fifty-two FMS patients and 32 healthy controls completed a battery of 14 neuropsychological tests. Clinical interviews were conducted and the McGill Pain Questionnaire, Beck Depression Inventory, State-Trait Anxiety Inventory, Fatigue Severity Scale and Oviedo Quality of Sleep Questionnaire were presented.

Results: Patients performed poorer than controls on the Letter Number Sequencing, Arithmetic and Similarities subtests of the Wechsler Adult Intelligence Scale, the Spatial Span subtest of the Wechsler Memory Scale, an N-back task, a verbal fluency task, the Ruff Figural Fluency Test, the Inhibition score of the Stroop Test, the Inhibition and Shifting scores of the Five Digits Test, the Key Search Test and the Zoo Map Task. Moreover, patients exhibited less steep learning curves on the Iowa Gambling Task. Among clinical variables, BMI and pain severity explained the largest proportion of performance variance.

Conclusions: This study demonstrated impairments in executive functions of updating, shifting inhibition, decision making and planning in FMS. While the mediating role of pain in cognitive impairments in FMS had been previously established, the influence of BMI is a novel finding. Overweight and obesity should be considered by FMS researchers, and in the treatment of the condition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Mass Index
  • Case-Control Studies
  • Cognition / physiology
  • Executive Function / physiology*
  • Female
  • Fibromyalgia / physiopathology*
  • Fibromyalgia / psychology
  • Humans
  • Intelligence Tests
  • Interviews as Topic
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Pain / pathology
  • Pain Measurement
  • Regression Analysis
  • Severity of Illness Index
  • Surveys and Questionnaires

Grant support

This research was supported by a grant from the Spanish Ministry of Economy and Competitiveness, co-financed by European Regional Development Fund (ERDF) (Project PSI2015-69235P).