Learning and memory problems, difficulty paying attention, and inability to control movement are the cognitive problems that fibromyalgia patients experience the most, a study reports.
The dysfunction is worse when patients are anxious or depressed, according to a team whose study involved a review of previous research.
Their study, “Cognitive impairment in fibromyalgia: A meta-analysis of case–control studies,” appeared in the journal Psychosomatic Medicine.
Many fibromyalgia patients complain of fibro fog, or problems with memory, attention and speaking.
And cognitive impairment has been reported in up to 80 percent of fibromyalgia patients.
But neuropsychological tests of cognitive function have yielded inconsistent results. The likely reasons, according to the researchers who did the review, were small sample sizes and the use of multiple neuropsychological tests that make comparison difficult.
The team gathered information from 23 research projects and case studies covering 2,096 participants to try to identify which cognitive problems were the most prevalent in fibromyalgia.
The studies used different neuropsychological tests to compare the cognitive performance of fibromyalgia patients and healthy controls. Some studies included surveys assessing patients’ pain, anxiety and depression.
As expected, researchers found that fibromyalgia patients had more cognitive problems than healthy controls.
The worst dysfunction was in learning and memory, attention, and controlling movement.
Pain and sensory problems are key symptoms of fibromyalgia. The neural pathways involved in cognition and pain processing are closely linked and may influence one another, scientists have said.
But the few studies that looked for links between the severity of patients’ pain and the degree of their cognitive dysfunction failed to find a correlation, according to the researchers who did the review. For instance, memory, attention, and information processing were not significantly associated with pain levels, they found.
The team did discover that patients with more emotional distress, including anxiety and depression, had more cognitive dysfunction, however.
This means that “evaluation of the cognitive function of patients with fibromyalgia must consider mood status and other symptoms,” the team wrote. In fact, anxiety and depression might help to explain the differences in the dysfunction-related research results, they wrote.
“The clinical manifestations of fibromyalgia, including physical, social, and psychological function, along with fatigue and sleep quality, are also associated with cognitive function,” the team wrote.
They also found links between patients’ age and number of years since they were diagnosed with fibromyalgia and their levels of cognitive dysfunction.
“Future experimental research should consider these findings and limitations to explore effective interventions for improving or preventing cognitive dysfunction in fibromyalgia,” the researchers wrote.
The team said a major limitation of their research was that different neuropsychological tests were used in the studies they reviewed.
In addition, the effort that patients put into their neuropsychological testing, and their motivation, could have affected their cognitive performance results, the researchers said.
And another potential limitation, they said, was that none of the studies compared the neuropsychological test results with patients’ subjective view of their cognitive problems.