Clinical Trial: The Rubber Hand Illusion (RHI) in Patients With CRPS

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Comparable Induction of the Rubber Hand Illusion (RHI) in Complex Regional Pain Syndrome Type 1 (CRPS 1) and Healthy Subjects

Brief Summary: The present study investigates by means of the rubber hand illusion body image stability and sense of body ownership in patients with CRPS of the upper limb compared to patients with unilateral pain of origin other than CRPS and age and sex-matched healthy subjects.

Detailed Summary: In patients with CRPS of the upper limb distortions of body representation and impairments of sense of body ownership are well-known. To investigate the body schema and body image stability of these patients in comparison to patients with upper limb pain of origin other than CRPS and healthy subjects, we conducted a series of rubber hand illusions. This well - established paradigm is elicited by visuo-tactile stimulation of one´s own real hand and a visible hand and forearm prosthesis. The present study investigates 1) if and how far patients with CRPS are susceptible to experience the illusion 2) how far the illusion strength differs between CRPS and patients with unilateral pain of the upper limb of other origin and healthy subjects 3) how far parameters, e.g. neglect-like severity symptoms, body plasticity, empathy, duration of disease and pain intensity influence the illusion strength.
Sponsor: Ruhr University of Bochum

Current Primary Outcome: subjective illusion strength by a validated questionnaire [ Time Frame: 1 hour ]

The illusion strength was measured subjectively by a validated questionnaire on a 7- point Likert scale,ranging from 0 (= disagree strongly) to 7 (= agree strongly). The questionnaire encompassed five slightly modified items of the German-translated questionnaire by Ocklenburg et al.(2011), following Botvinick & Cohen (1998).In the experimental conditions the questionnaire was additionally augmented by three further statements regarding the perception of the needle threat.


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • objectified illusion strength by measure of skin conductance response (SCR) [ Time Frame: 1 hour ]
    The SCR represents an objective measure of participant´s identification with the artificial limb, indicating the autonomic nervous system arousal in anticipation of pain, while watching the prosthesis being harmed (Armel & Ramachandran, 2003; Ehrsson, Wiech, Weiskopf, Dolan & Passingham, 2007). In every trial, the SCR was recorded with Ag-AgCl electrodes from the thenar and hypothenar eminence of the non-tested hand. Conductivity was measured in micro-Siemens (1/Ohm).
  • Measurement of influences of the illusion strength [ Time Frame: half an hour ]
    Several questionnaires were used to assess current and average pain intensity (NRS 0-10), neglect-like severity symptoms (Frettloeh et al. 2006), Handedness (Oldfield,1971), body plasticity (TABP) (Desmond, Horgan et al., 2001), empathy (IRI) ( Davis, 1980) and DASH-score (German, Wind et al. 1999).


Original Secondary Outcome: Same as current

Information By: Ruhr University of Bochum

Dates:
Date Received: June 11, 2012
Date Started: May 2010
Date Completion:
Last Updated: June 24, 2012
Last Verified: June 2012