Cognitive function in fibromyalgia patients

Objective. To evaluate fibromyalgia (FM) patients for the presence of cogni tive deficits and to test the hypothesis that abnormalities would fit a mod el of cognitive aging. Methods. We studied 3 groups of patients: FM patients without concomitant d epression and in the absence of medications known to affect cognitive funct ion (n = 23), age- and education-matched controls (n = 23), and education-m atched older controls who were individually matched to be 20 years older (/-3 years) than the FM patients (n = 22). We measured speed of information processing, working memory function, free recall, recognition memory, verba l fluency, and vocabulary. We correlated performance on cognitive tasks wit h FM symptoms, including depression, anxiety, pain, and fatigue. We also de termined if memory complaints were correlated with cognitive performance. Results. As expected, older controls performed more poorly than younger con trols on speed of processing, working memory, free recall, and verbal fluen cy. FM patients performed more poorly than age-matched controls on all meas ures, with the exception of processing speed. FM patients performed much li ke older controls, except that they showed better speed of processing and p oorer vocabulary. Impaired cognitive performance in FM patients correlated with pain complaints, but not with depressive or anxiety symptoms. FM patie nts reported more memory problems than did the older and younger controls, and these complaints correlated with poor cognitive performance. Conclusion. Cognitive impairment in FM patients, particularly memory and vo cabulary deficits, are documented in this study. Nevertheless, the intact p erformance on measures of information processing speed suggests that the co gnitive deficits are not global. FM patients' complaints about their memory are likely to be legitimate, since their memory function is not age approp riate.