Efficacy and Mechanisms of Virtual Reality Treatment of Phantom Leg Pain

Efficacy and Mechanisms of Virtual Reality Treatment of Phantom Leg Pain: In-Person Treatment

After amputation of an arm or leg, up to 90% of subjects experience a "phantom limb", a phenomenon characterized by persistent feelings of the missing limb. Many subjects with a phantom limb experience intense pain in the missing extremity that is often poorly responsive to medications or other interventions. The proposed work will contrast the efficacy of two virtual reality treatments for phantom limb pain: a 'Distractor' and an Active VR treatment. In the Distractor treatment, participants are engaged in a visually immersive virtual reality experience that does not require leg movements (REAL i-Series® immersive VR experience). In the Active VR treatment, subjects play a series of VR games using the virtual rendering of both legs.

Study Overview

• Status: Completed
• Conditions: Phantom Limb Pain
• Intervention / Treatment: Behavioral: VR treatment for phantom limb pain

Detailed Description

Almost 2 million people in the US have had an amputation and up to 90% of people with limb amputation experience the persistent sensation of the missing extremity, a phenomenon known as a "phantom limb" (Weeks et al., 2010). Additionally, a significant proportion of individuals with a phantom limb - up to 85% in some studies - experience persistent and debilitating pain in the missing limb, a condition known as phantom limb pain (hereafter PLP). Although existing therapies provide pain relief in some cases, there is widespread agreement that current approaches fall short of bringing relief to most individuals with PLP (Weeks et al., 2010).

The investigators recently completed a proof-of-concept study (Ambron et al., 2021) in which eight subjects with below knee amputations (BKA) underwent two virtual reality (VR) treatments for PLP. In an Active VR treatment, subjects played a variety of active games requiring leg movements while receiving high-quality visual feedback of the missing lower leg. Feedback about leg position was provided via an electromagnetic system using leg sensors (trackSTAR, Ascension Technologies Inc), and the program generated an image of the missing lower leg, visible as a first-person avatar. This treatment was contrasted with a "Distractor" treatment, in which participants were engaged in a visually immersive virtual reality experience that did not require leg movements (Cool!TM). Both treatments were associated with significant reductions in pain intensity, but the Active VR treatment was also associated with reductions in pain interference, depression, and anxiety.

The specific aims of the current study are (i) to replicate our prior observations of efficacy of VR treatment in a larger sample of individuals with BKA; (ii) to test VR therapy in patients with above knee amputations; (iii) to compare the efficacy of Active VR treatment to Distractor VR treatment for PLP on measures of pain as well as psychological health and quality of life.

• Study Type: Interventional
• Enrollment (Actual): 46
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Elkins Park, Pennsylvania, United States, 19027
      • Moss Rehabilitation Research Institute
    • Philadelphia, Pennsylvania, United States, 19104
      • University of Pennsylvania
  • Washington
    • Seattle, Washington, United States, 98104
      • University of Washington-Harborview Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 100 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age 18 - 100 years
2. Capacity to provide Informed Consent
3. Unilateral above or below knee amputation more than 3 months prior to enrollment
4. Absence of cognitive impairment, operationally defined as a Montreal Cognitive Assessment score of 18 or greater
5. Pain averaged over the preceding 1 month in the phantom limb rated as greater than 4 on a scale of 0-10.

Exclusion Criteria:

1. History of significant medical or neurological disorder such as stroke or moderate to severe traumatic brain injury (operationally defined as loss of consciousness for more than 30 minutes)
2. History of significant or poorly controlled psychiatric disorders
3. Current significant depression or anxiety as judged by the Hospital Anxiety and Depression Scale (HADS) (Zigmond & Snaith, 1983).
4. Current abuse of alcohol or drugs, prescription or otherwise
5. Nursing a child, pregnant, or intent to become pregnant during the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active VR treatment; Subjects assigned to the Active VR treatment began by selecting an avatar, with features such as gender and skin color that could be chosen according to preference. During treatment, they participated in a variety of games and activities developed and used by our teams including Kick, Dog Food, Quest for Fire, Chess, Checkers, Sudoku, and surfing the internet. Subjects had substantial flexibility to select games according to their interests but were required to spend at least 30 minutes in each session in games that required forceful, large-amplitude movements of the amputated lower limb (e.g., Quest for Fire, Kick).	Behavioral: VR treatment for phantom limb pain; 8 twice-weekly interventions of virtual reality treatment focused on reducing phantom limb pain.
Experimental: Distractor VR treatment; Subjects assigned to the Distractor VR treatment participated in the REAL i-Series immersive VR experience (REAL system), which had been demonstrated to reduce pain in several studies but lacked the hypothesized "active ingredients" of our Active VR treatment (visual and auditory feedback of movement of an extrapolated amputated limb). Subjects navigated through pleasant and relaxing VR environments; they did not see any rendering of their body and made no movements with their legs.	Behavioral: VR treatment for phantom limb pain; 8 twice-weekly interventions of virtual reality treatment focused on reducing phantom limb pain.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in Pain Intensity	Visual Analogue Scale (VAS) of McGill Short Form Questionnaire (Melzack, 1987); 0 minimum score - 10 maximum score; higher scores indicate higher level of pain (worse outcome)	Baseline versus immediately post-intervention at 4 weeks.
Changes in Pain Quality	McGill Short Form Questionnaire (Melzack, 1987): a series of 4-point scales (0 none - 3 severe) assessing the intensity of 15 qualitative characteristics of pain (e.g., throbbing, shooting, cramping, etc.), where higher scores are worse (more severe). For every participant we computed the total pain score (maximum 45 points indicating severe pain). Then, we computed the difference in the total scores between time points (e.g. post treatment vs baseline). Therefore, negative scores indicate improvement in pain qualitative characteristics.	Baseline versus immediately post-intervention at 4 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in Average Pain	Difference between 8th and 1st treatment session on scaled score measuring "average pain intensity since the previous intervention" on an 11-point numerical rating pain scale; (Scale = 0 - minimum score/no pain to 10 maximum score/pain as bad as participants can imagine); higher scores indicate higher level of pain (worse outcome).	1st treatment versus 8th treatment (4 weeks)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in Daily Activities	The Frenchay Activities Index (FAI) (Holbrook et al., 1983):1983): a scale measuring the physical function and daily activity associated with quality of life in people with amputation. Scale = 0 minimum score to 45 maximum score; higher scores indicate more daily activities (better outcome). We report the average difference between post-intervention (after 4 weeks) and pre-intervention.	Baseline versus immediately post-intervention at 4 weeks.
Changes in Quality of Life	The 12-Item Short Form Health Survey (SF-12) (Ware et al., 1996): a measure of quality of life and functional capacity that has been validated in patients with amputation and phantom limb pain. Scale = 0 minimum score to 100 maximum score. Higher scores indicate poorer physical and mental health (worse outcome).	Baseline versus immediately post-intervention at 4 weeks.
Changes in Pain Interference	The Pain Interference Scale from the Brief Pain Inventory (BPI) (Cleeland & Ryan, 1994): A scale measuring the degree to which pain interferes with daily activities using a 0-10 numeric rating. Scale = 0 minimum score to 10 maximum score. Higher scores indicate greater pain interference (worse outcome). We report the average difference between post-intervention (after 4 weeks) and pre-intervention.	Baseline versus immediately post-intervention at 4 weeks
Changes in Depression and Anxiety	The Hospital Anxiety and Depression Scale (HADS) (Zigmond & Snaith, 1983): This is a 14- item measure with subscales assessing depressive and anxiety symptoms. For each subscale. range = 0 minimum score to 42 maximum score. Higher scores indicate more depression and/or anxiety (worse outcome). We report average differences on the anxiety scale and the depression scales between post-intervention (after 4 weeks) and pre-intervention.	Baseline versus immediately post-intervention at 4 weeks.
Changes in Pain Catastrophizing	The 13-item Pain Catastrophizing Scale (Sullivan et al., 1995): this scale investigates pain catastrophizing, which has been associated with pain severity and disability after amputation. Score range = 0-52; Higher scores indicate higher tendency to catastrophize (worse outcome). We report the average difference between post-intervention (after 4 weeks) and pre-intervention.	Baseline versus immediately post-intervention at 4 weeks.
Changes in Insomnia	Insomnia Severity Index (Bastien et al., 2001): a 7-point scale that measures insomnia, a symptom associated with phantom limb pain. Score range = 0-28; higher scores indicate more insomnia (worse outcome). We report the average difference between post-intervention (after 4 weeks) and pre-intervention.	Baseline versus immediately post-intervention at 4 weeks.
Acceptance of VR System	Technology Acceptance Scale (Morris et al., 1997): this is a 7-point scale that measures level of acceptance of the VR system. 0 minimum score - 133 maximum score; higher scores indicate low level of acceptance (worse score).	Baseline
Usability of the Treatment	System Usability Scale (SUS) (Brooke, 1996); Scale measuring the usability of the each game; minimum score 10 - maximum score 50. Higher scores indicate less usability (worse outcome). For the distractor treatment, participants rated the overall experience; for the active treatment, the average of the two games was computed for each participants.	immediately after the last intervention (session 8 of the intervention), an average of 4 weeks
Cybersickness	Simulator Sickness Questionnaire - SSQ (Kennedy et al., 1993): 4 points (0 - none; 3 - severe) scale assessing the severity of 16 cybersickness motion sickness symptoms, like nausea or dizziness. We computed the average score across items.	1st (week 1) and 8th (week 4) treatment sessions
Presence in VR	Brief Slater-Usoh-Steed Presence Questionnaire (Usoh et al., 2000; Slater et al., 1998; 1994). 0 minimum score - 42 maximum score. Higher scores indicate more presence in the VR (better outcome	1st (week 1) and 8th (week 4) treatment sessions.
Changes in Pain at Its Worst	The Modified Limb Deficiency and Phantom Limb Questionnaire (Goller et al., 2013): a questionnaire and visual analog scale assessing prosthesis usage, phantom limb experiences, and pain severity. The outcome measure used was the score on the visual analogue scale assessing pain severity at its worst (Scale = 0 no pain to 10 unbearable pain). We report the average score difference between post-intervention (after 4 weeks) and pre-intervention.	Baseline versus immediately post-intervention at 4 weeks
Treatment Satisfaction	Visual analogue scale that evaluates treatment satisfaction (Robinson et al., 2004; Smith et al., 2005); 0 minimum score - 10 maximum score; Higher scores indicate more treatment satisfaction (better outcome)	1 week after the end of the intervention, an average of 5 weeks

Collaborators and Investigators

• Sponsor: Albert Einstein Healthcare Network
• Collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD); University of Pennsylvania; University of Washington
• Investigators: Principal Investigator: Laurel Buxbaum, PsyD, Albert Einstein Healthcare Netork

Publications and helpful links

General Publications

• Ware J Jr, Kosinski M, Keller SD. A 12-Item Short-Form Health Survey: construction of scales and preliminary tests of reliability and validity. Med Care. 1996 Mar;34(3):220-33. doi: 10.1097/00005650-199603000-00003.
• Zigmond AS, Snaith RP. The hospital anxiety and depression scale. Acta Psychiatr Scand. 1983 Jun;67(6):361-70. doi: 10.1111/j.1600-0447.1983.tb09716.x.
• Bastien CH, Vallieres A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Med. 2001 Jul;2(4):297-307. doi: 10.1016/s1389-9457(00)00065-4.
• Suresh K. An overview of randomization techniques: An unbiased assessment of outcome in clinical research. J Hum Reprod Sci. 2011 Jan;4(1):8-11. doi: 10.4103/0974-1208.82352.
• Cleeland CS, Ryan KM. Pain assessment: global use of the Brief Pain Inventory. Ann Acad Med Singap. 1994 Mar;23(2):129-38.
• Melzack R. The short-form McGill Pain Questionnaire. Pain. 1987 Aug;30(2):191-197. doi: 10.1016/0304-3959(87)91074-8.
• Robinson LR, Czerniecki JM, Ehde DM, Edwards WT, Judish DA, Goldberg ML, Campbell KM, Smith DG, Jensen MP. Trial of amitriptyline for relief of pain in amputees: results of a randomized controlled study. Arch Phys Med Rehabil. 2004 Jan;85(1):1-6. doi: 10.1016/s0003-9993(03)00476-3.
• Smith DG, Ehde DM, Hanley MA, Campbell KM, Jensen MP, Hoffman AJ, Awan AB, Czerniecki JM, Robinson LR. Efficacy of gabapentin in treating chronic phantom limb and residual limb pain. J Rehabil Res Dev. 2005 Sep-Oct;42(5):645-54. doi: 10.1682/jrrd.2005.05.0082.
• Holbrook M, Skilbeck CE. An activities index for use with stroke patients. Age Ageing. 1983 May;12(2):166-70. doi: 10.1093/ageing/12.2.166.
• Goller AI, Richards K, Novak S, Ward J. Mirror-touch synaesthesia in the phantom limbs of amputees. Cortex. 2013 Jan;49(1):243-51. doi: 10.1016/j.cortex.2011.05.002. Epub 2011 Jun 22.
• Slater M, Steed A, McCarthy J, Maringelli F. The influence of body movement on subjective presence in virtual environments. Hum Factors. 1998 Sep;40(3):469-77. doi: 10.1518/001872098779591368.
• Ambron E, Buxbaum LJ, Miller A, Stoll H, Kuchenbecker KJ, Coslett HB. Virtual Reality Treatment Displaying the Missing Leg Improves Phantom Limb Pain: A Small Clinical Trial. Neurorehabil Neural Repair. 2021 Dec;35(12):1100-1111. doi: 10.1177/15459683211054164. Epub 2021 Oct 27.

Study record dates

Study Major Dates

• Study Start (Actual): May 10, 2022
• Primary Completion (Actual): March 16, 2025
• Study Completion (Actual): April 6, 2025

Study Registration Dates

• First Submitted: February 9, 2022
• First Submitted That Met QC Criteria: March 24, 2022
• First Posted (Actual): March 25, 2022

Study Record Updates

• Last Update Posted (Actual): September 9, 2026
• Last Update Submitted That Met QC Criteria: August 17, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Neurobehavioral Manifestations; Perceptual Disorders; Pain, Postoperative; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Phantom Limb
• Other Study ID Numbers: 2022-775.; 5R01HD104158-05 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: After de-identification, individual participant data to be shared included descriptors of clinical status (e.g., time since amputation, level of amputation), background test battery results, and outcome measures results.
• IPD Sharing Time Frame: Immediately following publication. No end date.
• IPD Sharing Access Criteria: Researchers who provide a sound rationale.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No