Body perception distortions correlate with neuropathic features in Italian fibromyalgic patients: Findings from a self-administered online survey

Background: Recent studies found that fibromyalgia may underly neuropathic conditions affecting the peripheral nervous system. Moreover, clinical observations and preliminary reports suggest the existence of body perceptions distortions (BPD) like "phantom" feelings of swollen hands and feet, similar to those complained by patients with other neuropathic conditions or subjected to experimental procedures affecting the peripheral nervous system. Objectives: To investigate the prevalence of self-reported BPD in Italian people with fibromyalgia through an online survey administered with the help of the associations of patients distributed nationwide.Design: cross-sectional study.Method: A nationwide sample of 854 patients out of 1173 subjects enrolled was analyzed after the exclusion of comorbidities and incomplete answers. We additionally performed a post-hoc analysis comparing data of patients who entirely fulfilled the Fibromyalgia Research Criteria (FRC) (2011) for epidemiological studies with respect to those only partially responding to the FRC (FM-).Results: Nearly 90% of subjects reported neuropathic pain, symptoms potentially indicative for small-fiber pathology, and at least 1 BPD, while 2 or more BPD was reported in 64.1% of cases. Phantom feelings of "heaviness", "constriction", and "swelling" were the most frequently self-reported perceptual distortions. BPD were significant correlated with symptoms potentially indicative for small-fiber pathology, neuropathic pain, disability, painful sites, and severity of fibromyalgia (0.20<0.33).Conclusions: Our preliminary findings highlighted that the phenomenon of self-reported BPD in patients with fibromyalgia correlated with neuropathic symptoms. If these results will be confirmed in future studies BPD may be potentially considered as part of the clinical picture of fibromyalgia.