Relationship between pain and neuropathic symptoms in chronic musculoskeletal pain.

OBJECTIVE: The present study aimed to assess neuropathic symptoms, their stability over time and relationship to pain intensity, pain distribution, and emotional distress in patients with musculoskeletal disorders.

DESIGN: This is a prospective study.

SETTING: The study was done at the Department of Physical Medicine and Rehabilitation at Ulleval University Hospital.

PATIENTS: Eighty-six subjects between 18 years and 70 years with chronic musculoskeletal pain participated. Forty-nine subjects had widespread pain and 39 subjects fulfilled the American College of Rheumatology (ACR) criteria for fibromyalgia.

OUTCOME MEASURES: McGill pain drawing, pain intensity (visual analog scales), emotional distress (Hopkins Symptom Checklist v 25), and fibromyalgia impact questionnaire were the recorded predictors, and neuropathic symptoms (Leeds assessment of neuropathic symptoms and signs-LANSS) were the main outcome variable which was assessed over 4 months.

RESULTS: The mean LANSS score was 6.7 (standard deviation 5.6). Thirteen percent of the subjects had a score of 12 or more. Self-reported LANSS symptoms did not change over the 4 months follow-up, and the reliability of measurements as evaluated by intraclass correlation coefficient was 0.78. In a backward multiple regression analysis, the presence of fibromyalgia diagnosis and emotional distress remained the final predictors for neuropathic symptoms.

CONCLUSIONS: Our study demonstrates that neuropathic symptoms are prominent features of chronic musculoskeletal pain and are stable over time. These symptoms were closely related to emotional distress and to the diagnosis of fibromyalgia. The results lend support to the theory that neuropathic symptoms represent an underlying sensitization.