title: Characterizing "fibrofog": Subjective appraisal, objective performance, and task-related brain activity during a working memory task.
abstract: The subjective experience of cognitive dysfunction ("fibrofog") is common in fibromyalgia. This study investigated the relation between subjective appraisal of cognitive function, objective cognitive task performance, and brain activity during a cognitive task using functional magnetic resonance imaging (fMRI). Sixteen fibromyalgia patients and 13 healthy pain-free controls completed a battery of questionnaires, including the Multiple Ability Self-Report Questionnaire (MASQ), a measure of self-perceived cognitive difficulties. Participants were evaluated for working memory performance using a modified N-back working memory task while undergoing Blood Oxygen Level Dependent (BOLD) fMRI measurements. Fibromyalgia patients and controls did not differ in working memory performance. Subjective appraisal of cognitive function was associated with better performance (accuracy) on the working memory task in healthy controls but not in fibromyalgia patients. In fibromyalgia patients, increased perceived cognitive difficulty was positively correlated with the severity of their symptoms. BOLD response during the working memory task did not differ between the groups. BOLD response correlated with task accuracy in control subjects but not in fibromyalgia patients. Increased subjective cognitive impairment correlated with decreased BOLD response in both groups but in different anatomic regions. In conclusion, "fibrofog" appears to be better characterized by subjective rather than objective impairment. Neurologic correlates of this subjective experience of impairment might be separate from those involved in the performance of cognitive tasks.
authors.affiliation: National Center for Complementary and Integrative Health (NCCIH), NIH, Bethesda, MD, United States; MedStar Washington Hospital Center, Division of Rheumatology, Washington, DC, United States. Electronic address: Brian.walitt@nih.gov.
authors.forename: Brian
authors.initials: B
authors.lastname: Walitt
authors.affiliation: National Center for Complementary and Integrative Health (NCCIH), NIH, Bethesda, MD, United States.
authors.forename: Marta
authors.initials: M
authors.lastname: Čeko
authors.affiliation: Georgetown University Medical Center, Department of Neurology, Center for Functional and Molecular Imaging, Washington, DC, United States.
authors.forename: Manish
authors.initials: M
authors.lastname: Khatiwada
authors.affiliation: National Center for Complementary and Integrative Health (NCCIH), NIH, Bethesda, MD, United States.
authors.forename: John L
authors.initials: JL
authors.lastname: Gracely
authors.affiliation: Georgetown University Medical Center, Department of Medicine, Division of Rheumatology, Immunology and Allergy, Washington, DC, United States.
authors.forename: Rakib
authors.initials: R
authors.lastname: Rayhan
authors.affiliation: Georgetown University Medical Center, Department of Neurology, Center for Functional and Molecular Imaging, Washington, DC, United States.
authors.forename: John W
authors.initials: JW
authors.lastname: VanMeter
authors.affiliation: Center for Pain Research and Innovation, University of North Carolina, School of Dentistry, Chapel Hill, NC, United States.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Gracely
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging*; D003072:Cognition Disorders / Q000209:etiology* / Q000473:pathology*; D005260:Female; D005356:Fibromyalgia / Q000150:complications*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010147:Pain Measurement; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
chemical_list: D010100:Oxygen
keywords: Cognitive dysfunction; Cognitive testing; Fibromyalgia; Neuroimaging