Fibrofog and fibromyalgia: a narrative review and implications for clinical practice

Patients with fibromyalgia often report forgetfulness as well as declines in cognitive function, memory, and mental alertness-symptoms that have been termed "fibrofog" in popular and electronic media as well as in professional literature. "Fibrofog" is the subjectively experienced cognitive dysfunction associated with fibromyalgia and is a clinically important yet comparatively less well-studied aspect of the disorder; it includes loss of mental clarity (mental fogginess) as well as attention and memory impairment. Although until recently cognitive symptoms have been largely ignored, these symptoms can be more disturbing than the widespread pain and can change these patients' lives, sometimes dramatically so. Whereas widespread musculoskeletal pain, tenderness, and fatigue may be the hallmark symptoms of fibromyalgia, patients rank cognitive dysfunction highly in terms of disease impact. This review addresses (1) the prevalence of self-reported cognitive disturbances in fibromyalgia, (2) the clinical presentation of fibrofog, (3) neuropsychological test performance, with particular attention to discrepancies between self-report and test results, (3) clinical correlates of impaired cognitive function in fibromyalgia, (4) neurobiology relevant to cognitive disturbances in fibromyalgia, and (5) clinical management of fibrofog. Although the pathophysiology of fibromyalgia remains an enigma, evidence suggests that it may be a brain disorder, with cognitive deficits ("fibrofog") reflecting disturbed centrally mediated processes.