Women with fibromyalgia do not show significant differences compared with healthy women in terms of their overall working memory — the cognitive capacity to store information that needs to be processed — a study shows.
According to the study, “Broad cognitive complaints but subtle objective working memory impairment in fibromyalgia patients,” fibromyalgia patients only presented minor alterations in visuospatial working memory, which could be explained by the intensity of fatigue and depression. Findings were published in the PeerJ Journal of Life and Environmental Sciences.
Cognitive dysfunction, one of the hallmarks of the condition, includes objective cognitive difficulties (the true inability to perform a task) that can be assessed by neuropsychological tests, as well as subjective cognitive complaints (the thought of being unable to perform a task) reported by patients.
“It has been proposed that patients with FM [fibromyalgia] have particular problems in working memory (WM) because they perform poorly in tasks involving distraction or complex and rapidly changing environments,” the investigators wrote.
However, previous study findings have been inconsistent, making it difficult to reach a definitive conclusion on how fibromyalgia affects patients’ working memory as well as its possible relationship with subjective cognitive complaints.
In this study, a group of researchers from the Universidad de Santiago de Compostela in Spain set out to clarify two aspects of this issue: first, whether patients with fibromyalgia show deficits in objective working memory and other subjective cognitive measures compared with healthy individuals; and second, whether there is a possible relationship between objective working memory and self-reported cognitive complaints in patients with fibromyalgia.
The study involved a total of 38 women with fibromyalgia and 33 healthy women of similar age, education, and menopausal status used as controls. All participants completed a series of tests and questionnaires to assess different components of objective working memory, cognitive performance, and subjective perceived cognitive complaints.
Data from tests and questionnaires were collected by an expert psychologist. Clinical and demographic data were obtained during the first study visit, in which patients also provided their informed consent to participate in the study.
No significant differences were found in overall objective working memory performance in women with or without fibromyalgia.
Patients with fibromyalgia performed slightly worse in a single task of visuospatial working memory than healthy controls, which was found to be mediated by the presence of other symptoms of the condition, including pain, fatigue, and depression.
Findings also showed that women with fibromyalgia had a higher level of perception of cognitive dysfunction than healthy women, which was also mediated by fatigue and depression.
However, further analysis showed that self-reported cognitive complaints in patients with fibromyalgia were only linked to lower verbal working memory capacity.
“FM patients have a subtle specific impairment in their working memory functioning, as well as elevated concern about their cognitive status. These findings suggest a disconnection between neuropsychological performance and subjective complaints,” the investigators wrote.
“In FM patients, clinical variables such as pain, fatigue, and depression play an important role in dyscognition [cognitive dysfunction], as assessed by both objective and subjective measures, and should be taken into account in future research,” they added.