NCT06483035

Treatment of Phantom Limb Pain by Intensive Visual Simulation Therapy

Intensive Visual Simulation as Treatment for Chronic Phantom Limb Pain in Persons With Upper or Lower Limb Amputation - A Randomized Controlled Trial

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 38 (estimated)
• Sponsor: Oslo Metropolitan University · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

Phantom limb pain (PLP) is reported by as much as 80 % of patients following an amputation. There is increasing knowledge of the relation between PLP and maladaptive changes in brain cortical regions. Research has shown that the sight of an "intact arm" moving in a mirror may reverse maladaptions (Mirror-therapy, MT) and reduce PLP. The current project will implement a digital and modernized version of MT, i.e. Intensive Visual Simulation Therapy (IVS-T). Pilot studies have shown promising results on pain reduction in people with phantom limb pain when using IVS-T. However, there is a lack of RCT studies on this patient population. This study is a 2-arm randomized controlled trial (RCT) investigating the effectiveness of IVS-T compared with usual care in person with unilateral upper- or lower limb amputation with chronic phantom limb pain. The primary aim of the study is to investigate if IVS treatment is superior to usual care in reducing phantom limb pain intensity after 2 months of treatment in unilateral amputees with moderate to severe PLP. The study will furthermore explore quality of life, analgesic consumption, phantom pain characteristics, mobility, and disability. In addition, the study utilizes brain imagery during treatments to investigate neural plasticity and the association between PLP and maladaptive cortical changes.

Detailed description

Phantom limb pain is pain experienced to arise from and reside in the amputated limb, hence the name, phantom limb pain. PLP is experienced by about 50-80 % after acquired limb loss. The pain can be excruciating, and chronic phantom limb pain (PLP) can have a truly devastating effect on a persons' life, affecting both physical function and quality of life. Unfortunately, phantom limb pain has proven difficult to treat both by pharmacological and non-pharmacological methods. Several treatment options have been suggested, but without showing strong research evidence for effect on PLP. Over time, several mechanisms have been proposed to explain the occurrence of PLP, but the most cited reasons for the existence or development of phantom limb pain are theories connected to neuroplasticity, cortical reorganization and maladaptive changes due to loss of sensory input and motor control (e. g. Pons. Science, 1991). Several studies have observed that phantom limb pain is closely associated with neuroplastic changes in the somatosensory and motor cortex of the brain. Although these are maladaptive changes, the fact that the adult brain retains a neuroplastic capacity also opens a therapeutic widow of opportunity, i. e. it makes it possible to envision non-invasive therapies that exploits the principles of brain plasticity in the treatment of phantom limb pain by designing treatments that conceivably may reverse maladaptive changes and possibly reduce PLP. Relating to this, functional activity of the affected limb, including the use of a prosthesis, has been seen to have a positive effect on PLP, and this effect is believed to be partly explained by an effect of motor activity of the remaining stump on brain cortical activity and possibly cortical reorganization (Mosely and Floor Neurorehabilitation and Neural Repair, 2012). This is also the rationale behind classical interventions such as "mirror therapy", first proposed by Ramachandran (Nature, 1995). The present study will investigate the effect of a novel method for treatment of phantom limb pain that extends the concept of mirror therapy. This new method entails viewing a virtual limb (phantom limb) on a large screen, that "substitute" the missing limb. In short, the treatment starts with making a videorecording of the intact limb of the patient performing different predetermined movements. This recording is then digitally "flipped" and two "intact" limbs are then displayed on a large screen in front of the patient. The amputated limb is hidden below the screen. The patient is then asked to execute a set of movements with the (hidden) amputated limb, and at the same time the person will observe the phantom limb on the screen perform the exact same (prerecorded) movements. This treatment protocol is called Intensive Visual Simulation Therapy (IVS) and extends the concept of mirror therapy, where only the intact and healthy limb is performing movements and there is no motor planning or motor execution of the amputated limb. In this project, the effect of the IVS method on reduction of phantom limb pain will be compared to "Usual Care" (UC), which will be considered the standard treatment. Persons with either unilateral upper or lower limb amputation will be included in this study. In conjunction with use of these two therapeutic approaches, advanced, neuroimaging tools (functional near-infrared spectroscopy; fNIRS) will be implemented with the purpose of investigating the neurological responses to IVS treatment. As opposed to functional magnetic resonance imaging (fMRI), the fNIRS system allows the measurement of brain activity in a more "naturalistic" setting, like when the participants "execute" movements with the phantom limb in the IVS system. Participants in this study will be randomized to either IVS or UC treatment. Measurement of PLP and other outcome measures will be performed at baseline, after eight weeks of IVS or UC and at 2 months follow-up. Persons in the UC group shall continue with their standard treatment for this entire period (8+8 weeks). Persons in the IVS group will receive two treatment sessions per week for eight weeks and then no treatment in the follow-up period (8 weeks). The UC group will have the opportunity to receive IVS treatment after terminating their follow-up period.

Conditions

• Phantom Limb Pain

Interventions

Type	Name	Description
DEVICE	Intensive Visual Simulation (IVS)	The IVS system initially makes a video-recording of the intact body part (arm or leg) executing a set of specific movements. These video recordings will be digitally reversed and projected onto a large screen in front of the patient. On the screen, the patient will monitor an intact, life-like extremity in place of the amputated extremity. This digital extremity will then execute the recorded movements in a pre-planned manner. Simultaneously, the patient will follow the digital virtual limb moving on the screen with his/hers amputated arm/leg, which is hidden below the screen. Hence, IVS therapy comprises elements of both movement perception, motor planning, motor execution and visual feedback of two intact limbs moving which are distinctive from classical Mirror-Therapy.
OTHER	Usual Care (UC)	After allocation to UC, the participants continue with their normal treatment as prescribed by their medical doctor or other health professionals. All control participants are offered to complete IVS treatment after the end of the study period. The participants in the control group will therefore be placed on a fictitious "waiting list" during the study period.

Timeline

• Start date: 2024-09-05
• Primary completion: 2026-09-01
• Completion: 2026-10-01
• First posted: 2024-07-01
• Last updated: 2025-03-21

Locations

1 site across 1 country: Norway