Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.
Fibromyalgia with and without Comorbid Positional Cervical Cord Compression (PC3): An Iron-Clad Difference.
Wood2, Patrick B., Schmidt-Wilcke3, Tobias, Holman1, Andrew J.
Fibromyalgia (FM) is associated with abnormalities of dopaminergic neurotransmission. Because iron is an important cofactor for dopamine metabolism, we investigated whether FM symptom severity might correlate with iron stores as indicated by serum ferritin level (FE). Positional cervical cord compression (PC3) has also been recently identified as a common abnormality among FM patients (J Pain 2008;9:613-22). We therefore investigated whether FM patients with (FM/PC3+) or without (FM/PC3-) this cervical abnormality might differ with regard to symptom severity or their potential relationship to FE.
A convenience sample of 150 patients referred to a community-based FM specialty clinic was analyzed. All subjects met ACR 1990 diagnostic criteria for FM. Among these, 50% (n=75) were randomly selected from a pool of patients with: (1) a clinical history of cervical trauma and/or exacerbation of symptoms on cervical extension; and (2) PC3 on dynamic magnetic resonance imaging (dMRI). The other 50% (n=75) were randomly selected from among patients who either (1) denied a history of cervical trauma and had no exacerbation of symptoms on cervical extension, or (2) had undergone cervical dMRI and had no evidence of cord compromise. FE was drawn on all patients at intake and processed at the same clinical reference laboratory. All patients completed a comprehensive series of medical questionnaires, including a scaled review of systems and Adult ADHD Self-Report Scale (ASRS). Categorical indices of symptom severity were derived by summation of scaled symptoms from the intake review of systems (05 scale: 0 = none; 1 = minimal; 2 = mild; 3 = moderate; 4 = severe; 5 = extreme). Student's t-test for non-paired samples was used to compare FE and symptom severity between groups. Pearson's correlation was used to evaluate potential correlations between FE and symptom severity within each group.
There were no significant differences between groups concerning FE (FM/PC3- vs. FM/PC3+, mean ± SD: 49.4 ± 33.8 ng/ml vs. 56.4 ± 35.9 ng/ml, p =.22) or the severity of any clinical index. However, among FM/PC3- significant negative correlations were found between FE and the severity of several measures, including ASRS score (rho =-.377, p =.001), dyscognition (rho =-.488, p <.001), dys-coordination (rho =-.392, p =.001), affective disturbance (rho =-.384, p =.001), and clinical pain (rho =-.231, p =.047). Conversely, among FM/PC3+, no significant correlations were found between FE and the severity of any symptoms.
Among FM patients without comorbid PC3, negative correlations exist between FE and the severity of symptoms ostensibly linked to dopaminergic neurotransmission, including dyscognition, dys-coordination, affective disturbance, and clinical pain. These remarkable differences among FM patients suggest distinct pathophysiological subtypes within the greater 'FM construct'. Further research is needed to determine whether FM might be associated with abnormal iron metabolism and to evaluate for potential correlations between FE and objective measures of dopaminergic neurotransmission.
To cite this abstract, please use the following information:
Wood, Patrick B., Schmidt-Wilcke, Tobias, Holman, Andrew J.; Fibromyalgia with and without Comorbid Positional Cervical Cord Compression (PC3): An Iron-Clad Difference. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :102