Cognitive impairment in patients suffering from fibromyalgia. An underestimated problem

The primary symptom of fibromyalgia (FM) is chronic, widespread pain accompanied by diffuse tenderness to light palpation. However, many patients report a multitude of additional complaints and symptoms. Besides fatigue, exhaustibility and stiffness, a decrease in concentration and memory are further complaints that add significantly to the degree of suffering. This complaint, often termed "fibrofog", is increasingly recognised as an independent symptom that has made its way into the medical literature under the term "dyscognition". Nonetheless there are only a few studies that have specifically investigated neuropsychological deficits in FM patients in order to further specify clinical complaints. The studies performed so far have provided increasing evidence that FM patients have attention and working memory deficits, which are most prominent when patients have to cope with an additional source of distraction. With this review we intend to give an overview of the neuropsychological studies in FM performed so far and to assess possible implications for the underlying pathophysiology. In addition, we discuss potential clinical approaches to these symptoms. A systematic literature review up to June 2009 was carried out using the keywords (pairs) "fibromyalgia" and "cognition", "fibromyalgia" and "dyscognition", "fibromyalgia" and "cognitive deficits".