Phantom Limb Pain
Conditions
Brief summary
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.
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.
Interventions
BEHAVIORALVR treatment for phantom limb pain
8 twice-weekly interventions of virtual reality treatment focused on reducing phantom limb pain.
Sponsors
Albert Einstein Healthcare Network
University of Pennsylvania
University of Washington
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Forty individuals with above (AKA) or below (BKA) knee amputation suffering from chronic phantom limb pain (PLP) were recruited and quasi-randomly assigned to Active VR versus Distractor VR treatments.
Eligibility
Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in Pain Intensity | Baseline versus immediately post-intervention at 4 weeks. | 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) |
| Changes in Pain Quality | Baseline versus immediately post-intervention at 4 weeks. | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes in Average Pain | 1st treatment versus 8th treatment (4 weeks) | 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). |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORLaurel Buxbaum, PsyD
Albert Einstein Healthcare Netork
Participant flow
Recruitment details
Participants were recruited over a period of approximately 3 years at one of our study sites. Recruitment methods included mail, email, and/or telephone contact with potential participants identified through our databases; monthly invitation emails to patients listed in the Jefferson database; advertisements on the Amputee Coalition website and Facebook amputee groups; outreach through amputee support group meetings; and distribution of flyers at prosthetic clinics.
Pre-assignment details
The mismatch between the number of participants in the Protocol Enrollment and Total Participants is due to the fact that three participants withdrew prior to randomization and cannot be inserted in the columns related to one of the two treatments.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 59 years STANDARD_DEVIATION 10.7 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 14 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Pain Intensity score on VAS | 2.4 score on a scale STANDARD_DEVIATION 2.6 |
| Pain quality at baseline | 19.9 score on a scale STANDARD_DEVIATION 7.7 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 6 Participants |
| Race (NIH/OMB) More than one race | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 18 Participants |
| Sex: Female, Male Female | 10 Participants |
| Sex: Female, Male Male | 11 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 21 | 1 / 15 |
| other Total, other adverse events | 1 / 21 | 1 / 15 |
| serious Total, serious adverse events | 0 / 21 | 1 / 15 |
Outcome results
None listed