Investigating the effectiveness of visual illusions in treating pain

ISRCTN ISRCTN64093359
DOI https://doi.org/10.1186/ISRCTN64093359
Secondary identifying numbers 14768
Submission date
09/07/2018
Registration date
17/07/2018
Last edited
17/07/2018
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Musculoskeletal Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English Summary

Background and study aims
Complex Regional Pain Syndrome (CRPS) is excruciating pain of unknown origin in a limb. Symptom onset is typically triggered by trauma (soft tissue or a fracture) yet the pain continues well after the injury has healed and extends up the limb far beyond the original injured site. Persistent pain is disproportionate in severity to the resolved trauma and there is no known cure. Pain is accompanied by limb colour and temperature changes in addition to abnormalities in sweating, swelling, skin, hair and nail growth. Altered perceptions of the affected bodily region are described by patients as being distorted in shape and size and different from objective assessment. UK incidence is about 16,000 per year, with one in 60 of the UK population developing CRPS during their lifetime. Up to 26% of cases experience ongoing and unremitting symptoms causing long-term disability and impacting on their ability to work and their general wellbeing. These complex cases do not respond to conventional treatments. A recent small study found that viewing visual illusions that alter the size and shape of the painful hand can provide pain relief for CRPS patients. The aim of this study is to investigate the effects of this intervention on pain and other symptoms, in particular movement performance, in a larger sample of patients.

Who can participate?
Patients aged 18 and over with CRPS in one upper limb

What does the study involve?
The study uses the MIRAGE system developed for the upper limb by Dr Newport at Nottingham University. This system digitally manipulates real-time video of the hands and displays them so that they appear in the same physical and spatial location as the real hands allowing the presentation of a variety of visual illusions. The image of one hand is manipulated in various ways such as enlarging or shrinking the whole hand or specific digits and altering the colour of the hand. These manipulations are performed in real-time so that the participant is able to view their hands moving and can view handling objects within the illusion as though watching their own real hands. Whilst seated, the participant places each arm into one of the two apertures of the MIRAGE system so that their hands rest palm down on a flat surface within the system. Participants view their hands in a ‘window like’ surface above and perpendicular to these apertures. The MIRAGE system operator sits on the opposite side of the system facing the participant. Illusions can be stopped immediately and returned to the real view without moving or withdrawing the hands from the box. The illusions do not require the operator to touch the participant’s hands. Participants are randomly allocated to either the control group or the experimental group. Those allocated to the experimental group view their affected hand within the MIRAGE system and are asked to describe how they would like the appearance of their hand to be changed to represent how they wish their hand to look. The MIRAGE operator changes the appearance of the hand according to the participants’ descriptions. Digital changes in size, colour, and shape are made to suit the specific requests of the participant. Participants are asked to confirm with the operator when the hand image looks correct to them and view the resultant image for a maximum of two minutes. Those allocated to the control group are asked to describe how they would like the appearance of their hand to be changed so that it represents how they wish their hand to look. The MIRAGE operator undertakes a sham procedure as if making these changes but no visual change is made to the hand image. The image is then viewed for a maximum of two minutes. Hand pain is measured before and after the intervention.

What are the possible benefits and risks of participating?
Results from the recent small study showed that the MIRAGE system did help relieve pain in some people with CRPS but not everyone. It is not known whether the MIRAGE device will be helpful or not to symptoms of CRPS. Improving knowledge in this area may help to inform treatments for patients with CRPS and other chronic pain conditions.

Where is the study run from?
1. Royal United Hospitals NHS Trust (UK)
2. The Walton Centre NHS Foundation Trust (UK)

When is the study starting and how long is it expected to run for?
June 2013 to February 2016

Who is funding the study?
National Institute for Health Research (NIHR) (UK)

Who is the main contact?
Dr Jenny Lewis
jenny.lewis8@nhs.net

Contact information

Dr Jenny Lewis
Scientific

The Royal National Hospital for Rheumatic Diseases
Royal United Hospitals NHS Trust
Upper Borough Walls
Bath
BA1 1RL
United Kingdom

ORCiD logoORCID ID 0000-0002-6503-3749
Phone +44 (0)1225 473403
Email jenny.lewis8@nhs.net

Study information

Study designRandomised; Interventional
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Not specified
Study typeTreatment
Participant information sheet ISRCTN64093359_PIS_21May14_v4.doc
Scientific titleAn intervention trial to investigate the effectiveness of visual illusions in manipulating body perception disturbances to reduce chronic pain and improve movement performance
Study hypothesisThis protocol describes an intervention trial to investigate the effectiveness of viewing visual illusions that alter the size and shape of the painful hand to provide pain relief for those with Complex Regional Pain Syndrome (CRPS). Recent pilot findings revealed that visual manipulation of the painful hands in CRPS patients provided pain relief. The proposed controlled study investigates the intervention effectiveness in a larger sample (n=88) on pain and other symptoms, in particular, movement performance. The optimum duration of the intervention to sustain these clinical effects will be determined.
Ethics approval(s)NRES Committee South Central - Berkshire B, 04/06/2013, REC ref: 13/SC/0232
ConditionSpecialty: Musculoskeletal Disorders, Primary sub-specialty: Musculoskeletal Pain Disorders
InterventionStudy intervention
The study intervention utilises the MIRAGE system developed for the upper limb by Dr Newport at Nottingham University. This system digitally manipulates real-time video of the hands and displays them so that they appear in the same physical and spatial location as the real hands allowing the presentation of a variety of visual illusions. The image of one hand will be manipulated in various ways such as enlarging or shrinking the whole hand or specific digits and altering the colour of the hand. These manipulations are performed in real-time so that the participant is able to view their hands moving and can view handling objects within the illusion as though watching their own real hands.

Whilst seated, the participant places each arm into one of the two apertures of the MIRAGE system so that their hands rest palm down on a flat surface within the system. Participants view their hands in a ‘window like’ surface above and perpendicular to these apertures. The MIRAGE system operator sits the opposite side of the system facing the participant. Illusions can be stopped immediately and returned to the real view without moving or withdrawing the hands from the box. The illusions do not require the operator to touch the participant’s hands.

Trial arm allocation
Following written consent participants will be randomly allocated to either the control or intervention arm by the MIRAGE operator in a 1:1 ratio. The clinical assessor will be blinded to this procedure.

Experimental arm
Those allocated to the experimental arm will undertake the experimental intervention. Whilst viewing their affected hand within the MIRAGE system the participant will be asked to describe how they would like the appearance of their hand to be changed to represent how they wish their hand to look i.e. desired appearance. The operator will change the appearance of the hand according to the participants’ descriptions. Digital changes in size, colour, and shape will be made to suit the specific requests of the individual. Participants will be asked to confirm with the operator when the hand image looks correct to them and view the resultant image for a maximum of two minutes.

Control arm
Those allocated to the control arm will undertake the control condition. Participants will be asked to describe how they would like the appearance of their hand to be changed so that it represents how they wish their hand to look i.e. desired appearance. The MIRAGE operator will undertake a sham procedure as if making these changes yet no visual change will be made to the hand image. The image will be subsequently viewed for a maximum of two minutes.

Session 1
Consent, baseline outcome measures, allocation to trial arm, control or experimental intervention, dependent on trial arm, post intervention measures. Approximate total session duration is two hours.

Sessions 2 to 4
Control or experimental intervention
The approximate total duration for each session is one and a half hours which involves a maximum intervention time of 30 minutes. Data will be collected within these intervention sessions.
Intervention typeOther
Primary outcome measureMeasured at baseline, post intervention where stated and follow up in session 5:
1. Pain specific to the hand will be verbally captured using a 0-10 numerical rating scale (NRS) where 0 is no pain and 10 is worst pain imaginable, undertaken pre-post intervention
2. Pain assessed using the Neuropathic Pain Symptom Inventory at baseline
3. Body perception disturbance measured using the Bath CRPS body perception disturbance scale
Secondary outcome measuresTactile acuity, measured using a two-point discrimination test pre and post intervention
Overall study start date16/06/2013
Overall study end date16/02/2016

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participantsPlanned Sample Size: 88; UK Sample Size: 88
Participant inclusion criteria1. Participants meet the Budapest criteria for CRPS (Harden 2010) in one upper limb and may have lower limb involvement (unilateral or bilateral)
2. >/= 18 years
3. Male or female
4. Describe an altered perception of their painful body
5. Able to understand verbal and written English
6. Willing to participate and provide written informed consent
Participant exclusion criteria1. Serious ill health
2. Bilateral upper limb involvement
3. Dystonia
4. Co-morbidity that may influence CRPS symptoms i.e. stroke, diabetic peripheral neuropathy, progressive neurological disease such as multiple sclerosis, Parkinson’s disease
5. Currently participating in an intervention trial
Recruitment start date16/06/2013
Recruitment end date16/02/2016

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centres

The Royal National Hospital for Rheumatic Diseases, Royal United Hospitals NHS Trust
Upper Borough Walls
Bath
BA1 1RL
United Kingdom
The Walton Centre NHS Foundation Trust
Lower Lane
Fazakerley
Liverpool
L9 7LJ
United Kingdom

Sponsor information

Royal United Hospitals Bath NHS Foundation Trust
Hospital/treatment centre

c/o Jane Carter, R&D Manager
Royal National Hospital of Rheumatic Diseases
Bath
BA1 1RL
England
United Kingdom

ROR logo "ROR" https://ror.org/058x7dy48

Funders

Funder type

Government

NIHR Trainees Co-ordinating Centre (TCC); Grant Codes: CAT-CL-03-2012-019

No information available

Results and Publications

Intention to publish date17/10/2018
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryOther
Publication and dissemination planPreliminary findings from this study have been presented at the European Pain Congress (EFIC) Vienna 2015 and IASP CRPS Special interest group conference, Zurich 2015. Future presentations are confirmed for British Pain Society annual congress, Harrogate April 2016, and Allied Health Professional conferences in Belfast and Liverpool in the summer. An abstract was submitted to IASP biannual congress, Japan in September 2016. A manuscript has been written for submission to an international peer-reviewed journal - Pain. Furthermore, this data has formed the basis of a larger grant application to Arthritis Research UK which has been successful that includes brain imaging to better understand the therapeutic mechanisms of action of visual illusions in chronic pain to help improve central targets for future treatment.
IPD sharing planThe datasets generated and/or analysed during the current study during this study will be included in the subsequent results publication.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Participant information sheet version v4 21/05/2014 17/07/2018 No Yes
HRA research summary 28/06/2023 No No

Additional files

ISRCTN64093359_PIS_21May14_v4.doc
Uploaded 17/07/2018