[Neuropsychological performance in patients with fibromyalgia syndrome: relation to pain and anxiety].

Previous studies have revealed the presence of cognitive impairment in patients with fibromyalgia syndrome (FMS). However, they have not determined the possible influence of the diverse clinical variables in these disturbances. The first aim of the current study is to compare the cognitive function of 81 patients with FMS and 35 healthy controls by means of a neuropsychological battery. The second aim is to determine the influence of anxiety and pain in the cognitive impairment of patients with FMS. The results of our study show that patients with FMS display a significantly lower cognitive performance and a significantly higher anxiety level than the healthy controls in all the parameters assessed. The neuropsychological performance in patients with FMS is associated with pain, and this relation was independent of the anxiety level. The relationship between cognitive performance and anxiety level was also significant. Therefore, we conclude that cognitive performance is primarily affected by pain. The level of anxiety explains part of the variability in neuropsychological tests that is not explained by pain.