The Rubber Hand Illusion (RHI) in Patients With CRPS

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

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.

Study Overview

• Status: Completed
• Conditions: CRPS; Unilateral Limb Pain of Origin Other Than CRPS
• Intervention / Treatment: Procedure: rubber hand illusion

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 Type: Observational
• Enrollment (Actual): 69

Contacts and Locations

Study Locations

• Germany
  • Bochum, Germany, 44789
    • Pain clinic of the Bergmannsheil University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

The study sample consists of three groups:

1. Patients with CRPS of the upper limb type 1 ( n=24)
2. Patients with unilateral pain of the upper limb origin other than CRPS (n=21)
3. Healthy subjects, age and sex-matched to patients with CRPS Patients with unilateral pain of the upper limb of origin other than CRPS serve as controls. Recruitment for all CRPS and the majority of patients in the control group took place in the pain clinic of the Bergmannsheil University Hospital in Bochum. The remaining patients were recruited from the Neurological respectively Surgical department of the Bergmannsheil University Hospital.

Description

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 Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients with CRPS; 24 patients with CRPS of the upper limb type 1 were included into the study.	Procedure: rubber hand illusion; There were three consecutive trials of the RHI: one control trial: asynchronous condition (3 Min.); two experimental trials (conducted on both hands):synchronous condition (3 Min.),additionally watching the prosthesis being threatened (20 sec.)
Patients with unilateral upper limb pain; 21 patients with unilateral upper limb pain served as controls.	Procedure: rubber hand illusion; There were three consecutive trials of the RHI: one control trial: asynchronous condition (3 Min.); two experimental trials (conducted on both hands):synchronous condition (3 Min.),additionally watching the prosthesis being threatened (20 sec.)
healthy subjects; 24 healthy subjects were age- and sex matched to patients with CRPS.	Procedure: rubber hand illusion; There were three consecutive trials of the RHI: one control trial: asynchronous condition (3 Min.); two experimental trials (conducted on both hands):synchronous condition (3 Min.),additionally watching the prosthesis being threatened (20 sec.)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
subjective illusion strength by a validated questionnaire	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.	1 hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
objectified illusion strength by measure of skin conductance response (SCR)	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).	1 hour
Measurement of influences of the illusion strength	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).	half an hour

Collaborators and Investigators

• Sponsor: Ruhr University of Bochum

Study record dates

Study Major Dates

• Study Start: May 1, 2010
• Primary Completion (ACTUAL): November 1, 2011
• Study Completion (ACTUAL): November 1, 2011

Study Registration Dates

• First Submitted: June 11, 2012
• First Submitted That Met QC Criteria: June 12, 2012
• First Posted (ESTIMATE): June 13, 2012

Study Record Updates

• Last Update Posted (ESTIMATE): June 26, 2012
• Last Update Submitted That Met QC Criteria: June 24, 2012
• Last Verified: June 1, 2012

More Information

Terms related to this study

• Keywords: CRPS; body image; rubber hand illusion; body ownership
• Additional Relevant MeSH Terms: Nervous System Diseases; Neurologic Manifestations; Neurobehavioral Manifestations; Perceptual Disorders; Illusions
• Other Study ID Numbers: RHI2010