Pain-related fear, perceived harmfulness of activities, and functional limitations in complex regional pain syndrome type I.
Numerous studies have shown that pain-related fear is one of the strongest predictors of pain disability in patients with chronic musculoskeletal pain, and there is evidence that the reduction of pain-related fear through an exposure treatment can be associated with restoration of functional abilities in patients with complex regional pain syndrome type I (CRPS-I). These findings suggest that pain-related fear may be associated with functional limitations in neuropathic pain as well. The aim of the current study was to test whether the debilitating role of pain-related fear generalizes to patients with CRPS-I. The results of 2 studies are presented. Study I includes a sample of patients with early CRPS-I referred to an outpatient pain clinic. In Study II, patients with chronic CRPS who are members of a patients' association were invited to participate. The results show that in early CRPS-I, pain severity but not fear of movement/(re)injury as measured with the Tampa Scale for Kinesiophobia was related to functional limitations. In patients with chronic CRPS-I, however, perceived harmfulness of activities as measured with the pictorial assessment method significantly predicted functional limitations beyond and above the contribution of pain severity. Not fear of movement/(re)injury in general, but the perceived harmfulness of activities appears a key factor that might be addressed more systematically in the clinical assessment of patients with CRPS-I. These results support the idea that pain-related fear might be a promising concept in the understanding of pain disability in patients with neuropathic pain.


CONCLUSIONS
This is the first study showing that perceived harmfulness of activities contribute to the functional limitations in CRPS-I. The current findings may help clinicians customizing cognitive-behavioral treatments for patients with chronic neuropathic pain.
Department of Rehabilitation, University Hospital Maastricht, Maastricht, The Netherlands. jeroen.dejong@mumc.nl
Jeroen R
JR
de Jong
Johan W S
JW
Vlaeyen
Jantha M
JM
de Gelder
Jaap
J
Patijn
D000203:Activities of Daily Living / Q000523:psychology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology / Q000523:psychology; D003430:Cross-Sectional Studies; D003627:Data Interpretation, Statistical; D005239:Fear / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D010146:Pain / Q000523:psychology*; D010147:Pain Measurement; D012019:Reflex Sympathetic Dystrophy / Q000523:psychology*; D012044:Regression Analysis; D012727:Sex Characteristics; D012959:Socioeconomic Factors; D055815:Young Adult