Abstract

Objective

Fibromyalgia syndrome (FS) involves chronic pain accompanied by alteration of cognitive functions, mainly memory and attention. Despite vigilance is a pre-requisite for appropriate performance in most cognitive tasks, it has not been assessed directly in fibromyalgia. The current research aimed to study vigilance in this illness and to explore the potential role of other common symptoms of the syndrome such as pain, sleep quality, anxiety and depression in vigilance performance.

Methods

The Psychomotor Vigilance Task (PVT) was used to assess the vigilance level in a group of fibromyalgia female patients (n=28) compared to a group of healthy women (n=18) matched in age and education level.

Results

The fibromyalgia group reported higher levels of anxiety, depression, negative mood and pain, poorer sleep quality, and lower levels of alertness than the control group. In the PVT, the fibromyalgia group showed slower responses in the PVT as compared to the control group. Fibromyalgia patients further showed high individual differences in vigilance, with a subgroup of them having similar performance in the PVT than the control group. Performance in the PVT showed no relationship with subjective measures.

Conclusion

These findings provided direct support to a vigilance deficit in fibromyalgia as a group. However, there are individual differences suggesting that not all the patients with fibromyalgia necessarily experience vigilance detriment. Since the vigilance state can determine basic functions such as memory and attention, these individual differences should be considered when assessing other cognitive domains in fibromyalgia.

Keywords: Alertness; Sustained attention; Vigilance; Anxiety; Sleep quality; Pain; PVT