The prevalence and clinical impact of reported cognitive difficulties (fibrofog) in patients with rheumatic disease with and without fibromyalgia

J Clin Rheumatol. 2004 Apr;10(2):53-8. doi: 10.1097/01.rhu.0000120895.20623.9f.


Cognitive dysfunction in patients with rheumatic disease encompasses a range of impairment. Their prevalence, co-occurrence, and impact on symptom severity were assessed in 57 patients with fibromyalgia (FMS) and 57 patients with rheumatic disease without FMS. Information pertaining to memory decline, mental confusion, and speech difficulty was extracted from questions embedded in a health questionnaire and a blind retrospective chart review. Pain, morning stiffness, fatigue, and sleep difficulty were established on a 0- to 100-mm visual analog scale. Variables of mental confusion, fatigue, tension, depression, anger, and vigor were assessed using the Profile of Mood States.Compared with the non-FMS sample, patients with FMS complained more often of memory decline (70.2-24.6%), mental confusion (56.1-12.3%), and speech difficulty (40.4-3.5%). Memory decline and mental confusion were coupled more often in patients with FMS (50.9-8.8%). Patients with FMS with this combination of cognitive problems reported more pain (76.0-45.4%), stiffness (79.7-43.7%), fatigue (79.6-52.6%), and disturbed sleep (59.2-36.6%) compared with patients with FMS with memory problems alone. Patients with rheumatic disease substantially differ in cognitive vulnerability, with patients with FMS at considerably higher risk for cognitive difficulty. More importantly, the prevalence of a combined disturbance in memory and mental clarity is high and closely associated with the perception of increased illness severity and diminished mental health in FMS. That this linkage has the possibility of having a great deal to do with an important clinical variant of FMS underscores the need for greater clinical recognition of this underrecognized pattern and for further research.Patients with fibromyalgia frequently report memory and concentration problems, especially if asked about them. Clinicians could judge these complaints as similar to adult attention deficit syndrome and reassure the patient. Trying medication to improve attention and concentration is sensible but untested in fibromyalgia.