Fibromyalgia syndrome (FMS), the prototypical central pain augmentation syndrome, is characterized by widespread pain and tenderness. Although patients referred to tertiary care pain clinics are recognized as suffering from chronic pain, they are generally considered to have pain attributable to discrete peripheral, nociceptive, or neuropathic etiology.The purpose of the current study was to assess the prevalence of FMS among consecutive patients referred to a tertiary pain clinic and to evaluate the contribution of central pain to the clinical impact upon such patients.
Eighty-five consecutive patients (38 were male, and 47 were female) attending a pain clinic were assessed for the presence of FMS. The presence of FMS was determined according to the 1990 American College of Rheumatology (ACR) classification criteria. Quality of life and physical functioning were assessed, utilizing a structured questionnaire.
The ACR criteria for the classification of FMS were fulfilled by 41.2% of patients. Patients fulfilling FMS criteria ranked significantly lower on all domains of the SF-36, including general health, physical functioning, role limitation due to physical and emotional problems, vitality, social functioning, bodily pain, and mental health. Composite physical and mental health scores were significantly lower among patients fulfilling ACR FMS criteria. Patients fulfilling the ACR criteria for FMS felt significantly more tenderness, based on the mean number of tender points and the mean tenderness threshold, when compared with patients not fulfilling the ACR FMS criteria.
A significant proportion of patients referred to a tertiary pain clinic were found to fulfill the ACR criteria for classification of FMS and thus exhibit an important element of central pain. Central pain augmentation should be actively searched for and therapeutically addressed in the evaluation and management of all patients with chronic pain.