The Rubber Hand Illusion (RHI) in Patients With CRPS

Completed

• Conditions: CRPS; Unilateral Limb Pain of Origin Other Than CRPS
• Interventions: Procedure: rubber hand illusion

• Registration Number: NCT01618578
• Lead Sponsor: Ruhr University of Bochum

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 Description

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.

Study Timeline

• Study Start: 2010-05
• Primary Completion: 2011-11
• Study Completion: 2011-11
• Status Verified: 2012-06
• Study First Submitted: 2012-06-11
• Study First Submitted QC: 2012-06-12
• Study First Posted: 2012-06-13
• Last Update Submitted: 2012-06-24
• Last Update Posted: 2012-06-26

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 69

Inclusion Criteria

every participant:

• aged > 18 years
• written informed consent
• free to withdraw participation at any time
• adequate understanding of the german language

Patients with CRPS:

• patients with CRPS type 1 of the upper limb
• clinical symptoms were diagnosed on the basis of the recently modified diagnostic research criteria (Harden, Bruehl et al., 2007)
• proved by typical enhancement in the late phase of the 99m-technetium-triple-phase bone skeleton scintigraphy (Wüppenhorst, Maier et al., 2010)

Patients with unilateral pain of the upper limb:

• unilateral pain
• pain of origin other than CRPS

Healthy subjects:

• age and sex matched to patients with CRPS
• checked by the DFNS IMI questionnaire

Exclusion Criteria

every participant:

• inadequate understanding of the german language
• missing informed consent
• diabetes mellitus

Patients with CRPS:

-CRPS Type 2

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Patients with CRPS	rubber hand illusion	24 patients with CRPS of the upper limb type 1 were included into the study.
Patients with unilateral upper limb pain	rubber hand illusion	21 patients with unilateral upper limb pain served as controls.
healthy subjects	rubber hand illusion	24 healthy subjects were age- and sex matched to patients with CRPS.

Primary Outcome Measures

Name	Time	Method
subjective illusion strength by a validated questionnaire	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.

Secondary Outcome Measures

Name	Time	Method
objectified illusion strength by measure of skin conductance response (SCR)	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	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).

Trial Locations

Locations (1)

Pain clinic of the Bergmannsheil University Hospital; 🇩🇪 Bochum, Germany