Efficacy and Mechanisms of Virtual Reality Treatment of Phantom Leg Pain
Phantom Limb PainAfter 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.
Epidural Spinal Cord Stimulation for Sensory Restoration and Phantom Limb Pain in Upper-Limb Amputees...
Phantom LimbIndividuals with upper-limb amputation usually have intact nerves within the residual limb, and studies have demonstrated that electrical stimulation of those nerves can produce sensations that appear to emanate from the amputated limb. In this study, investigators will examine the sensations that are produced by electrical stimulation of these nerves at the location where they exit the spinal cord. Stimulation of the spinal cord is commonly used to treat intractable back and limb pain, and the procedure includes a test phase in which electrodes are temporarily placed under the skin near the spinal cord and removed at the end of testing. Similarly, in this study, electrodes will be placed near the spinal cord in the upper back and neck, and stimulation will be applied over the course of multiple testing sessions, lasting less than 30 days. The electrodes will be removed at the last day of testing. During each testing session, electrical stimulation will be applied through the electrodes and a series of tests will be performed to determine the types of sensations produced by stimulation. In addition to producing meaningful sensations with electrical stimulation, this study will also test the effect of stimulation on phantom limb sensations and phantom limb pain.
Psilocybin-assisted Therapy for Phantom Limb Pain
Phantom Limb PainThis double-blind placebo-controlled pilot study seeks to investigate whether psilocybin can be safely administered to people with chronic phantom limb pain (PLP) in a supportive setting with close follow-up, and its effects on pain symptoms and other moods, attitudes, and behaviors. The investigators' primary hypotheses are that psilocybin is safe to administer in people with PLP and that it will reduce scores on measures of pain. The investigators will also assess a number of secondary measures related to the behavioral and neural responses to pain after psilocybin treatment.
Cryoanalgesia to Treat Phantom Limb Pain Following Above-Knee Amputation
AmputationSurgical4 moreWhen a limb is severed, pain perceived in the part of the body that no longer exists often develops and is called "phantom limb" pain. Unfortunately, phantom pain goes away in only 16% of afflicted individuals, and there is currently no reliable definitive treatment. The exact reason that phantom limb pain occurs is unclear, but when a nerve is cut-as happens with an amputation-changes occur in the brain and spinal cord that actually increase with worsening phantom pain. These abnormal changes may often be corrected by putting local anesthetic-called a "nerve block"-on the injured nerve, effectively keeping any "bad signals" from reaching the brain with a simultaneous resolution of the phantom limb pain. However, when the nerve block resolves after a few hours, the phantom pain returns. But, this demonstrates that the brain abnormalities-and phantom pain-that occur with an amputation are not necessarily fixed, and may be dependent upon the "bad" signals being sent from the injured nerve(s), suggesting that a very long peripheral nerve block-lasting many months rather than hours-may permanently reverse the abnormal changes in the brain, and provide definitive relief from phantom pain. A prolonged nerve block lasting a few months may be provided by freezing the nerve using a process called "cryoneurolysis". The ultimate objective of the proposed research study is to determine if cryoanalgesia is an effective treatment for intractable post-amputation phantom limb pain. The proposed pilot study will include subjects with an existing above-knee amputation who experience intractable daily phantom limb pain. A single ultrasound-guided treatment of cryoneurolysis (or sham block-determined randomly like a flip of a coin) will be applied to the major nerves of the thigh. Although not required, each subject may return 4-6 months later for the alternative treatment (if the first treatment is sham, then the second treatment would be cryoneurolysis) so that all participants have the option of receiving the active treatment. Subjects will be followed for a total of 12 months with data collected by telephone.
Surgical Treatments for Postamputation Pain
Residual Limb PainAmputation Neuroma5 moreThis is a double-blind randomised controlled trial (RCT) which compares the effectiveness of three surgical techniques for alleviating residual limb pain (RLP), neuroma pain and phantom limb pain (PLP). The three surgical treatments are Targeted Muscles Reinnervation (TMR), Regenerative Peripheral Nerve Interface (RPNI), and an active control (neuroma excision and muscle burying). Patients will be follow-up for 4 years.
Surgical Treatments for Neuroma Pain in Amputees
PainNeuropathic2 moreAmputees often suffer from relentless pain and disability resulting from symptomatic neuromas within the amputation stumps. When conservative measures fail to address these symptoms, two contemporary surgical approaches to treat symptomatic neuromas have become the most popular. Targeted muscle reinnervation (TMR) is a procedure which involves transferring the injured proximal nerve stump into a terminal nerve branch entering muscle, such that the axons from the proximal nerve stump will regenerate into the muscle and thereby prevent neuroma recurrence. Regenerative peripheral nerve interfaces (RPNIs) are muscle grafts placed on the proximal nerve stumps that serve as targets for the regenerating axons from the proximal nerve stumps. While TMR and RPNIs have demonstrated promise for the treatment of symptomatic neuromas, prospective comparative data comparing outcomes with these two approaches is lacking. The investigators have recently developed a novel approach to treat symptomatic neuromas that provides vascularized, denervated muscle targets (VDMTs) for the axons regenerating from the severed proximal nerve stump to reinnervate. This is accomplished by islandizing a segment of muscle on its blood supply and ensuring complete denervation prior to implanting the neighboring transected nerve stump into this muscle. VDMTs offer theoretical benefits in comparison to RPNIs and TMR that the investigators also aim to test in the proposed study. The investigators' objective is to enroll amputees with symptomatic neuromas into a prospective study in which amputees will be randomized to undergo TMR, RPNI, or VDMT and subsequently monitored for pain and disability for 1-year post-operatively. The investigators' specific aims are as follows: 1) Test the hypothesis that VDMTs are more effective than TMR and RPNIs with regards to treating pain and disability associated with symptomatic neuromas; 2) Provide the first level one, prospective data directly comparing the efficacy of TMR and RPNIs.
A Non-invasive Intervention (BreEStim) for Management of Phantom Limb Pain (PLP) After Limb Amputation...
Pain ManagementThe purpose of this study is to compare the effectiveness of innovative intervention of breathing controlled electrical stimulation (BreEStim) and conventional electrical stimulation (EStim) in management of neuropathic phantom limb pain in patients after limb amputation.
Pragmatic Trial of Remote tDCS and Somatosensory Training for Phantom Limb Pain With Machine Learning...
Phantom Limb PainThe investigators have designed a pragmatic trial of home-based transcranial direct current stimulation (tDCS) for phantom limb pain (PLP), the PLP-EVEREST trial (PLP-EffectiVEness pRagmatic Stimulation Trial) to test a portable device that would reach underrepresented populations and would validate this therapy in a more pragmatic setting. Subjects will be randomized to home-based tDCS of the primary motor cortex (M1) with somatosensory training or usual care only (including their current pharmacological treatments, physical therapy, and occupational therapy). The investigators will therefore test the effectiveness of home-based tDCS and somatosensory training in a real-world, home-based setting. The Investigator will compare patients randomized to this combined strategy vs. usual care alone (subjects from this group will be offered combined treatment at the end of the trial). The investigators hypothesize that the combined strategy will be associated with a significantly larger Cohen's d effect size (at least 1) compared to the control group.
The Effects of Targeted Phantom Motor Execution on Phantom Limb Control
Phantom LimbMotor Activity2 moreLower limb amputations account for more than 85% of all amputations. In Canada, it has been reported that transtibial amputation (TTA) is the most common level of amputation. Many people with limb amputation have awareness and feel that their missing limb still exists (phantom limb), with perceptions of sensation or pain, and the ability to move the limb with or without intention. Phantom limb sensation (PLS) is defined as all non-painful somatic sensations (e.g. sense of the limb position, touch, pressure, warmth or cold, or movement) in the missing part of the limb. The incidence of PLS is about 60% in adults after 17 months. In addition to PLS, 60-70% of people with amputation experience phantom limb pain (PLP), an intense chronic pain perception in their phantom limb, in the first year after amputation. Although PLP is well known to decrease the quality of life and lessen function, little is known about PLS and phantom limb control (PLC), the ability to intentionally move or control movements of the phantom limb. Enhancing PLS and PLC especially in the immediate months after amputation, could decrease painful perception, facilitate prosthetic control, and improve the function of people with amputations. Keeping this therapeutic and rehabilitative significance in mind, it is hypothesized that a targeted program of phantom motor execution, designed to address phantom limb awareness (PLA), the general knowledge of the presence or existence of the missing limb as one's own, could be associated with improving PLC in people with TTA. Furthermore, prosthetic embodiment, the sense that the prosthesis is accepted as a part of the body with the same functional abilities, may play a role in PLC. Investigating the association of PLC, as one of the phantom phenomena (i.e. PLA, PLS, PLP, and PLC), with surgical, clinical, and demographic characteristics of people with TTA will provide better insight into how phantom phenomena develop. The association of PLC with physical function has significant clinical importance that has never been investigated in people with TTA.
Spinal Cord Stimulation for Restoration of Function in Lower-Limb Amputees, 90-Day
Traumatic Amputation of Lower ExtremityPhantom Limb PainThe goals of this study are to provide sensory information to amputees and reduce phantom limb pain via electrical stimulation of the lumbar spinal cord and spinal nerves. The spinal nerves convey sensory information from peripheral nerves to higher order centers in the brain. These structures still remain intact after amputation and electrical stimulation of the dorsal spinal nerves in individuals with intact limbs and amputees has been demonstrated to generate paresthetic sensory percepts referred to portions of the distal limb. Further, there is recent evidence that careful modulation of stimulation parameters can convert paresthetic sensations to more naturalistic ones when stimulating peripheral nerves in amputees. However, it is currently unclear whether it is possible to achieve this same conversion when stimulating the spinal nerves, and if those naturalistic sensations can have positive effects on phantom limb pain. As a first step towards those goals, in this study, the investigators will quantify the sensations generated by electrical stimulation of the spinal nerves, study the relationship between stimulation parameters and the quality of those sensations, measure changes in control of a prosthesis with sensory stimulation, and quantify the effects of that stimulation on the perception of the phantom limb and any associated pain.