Alleviate Phantom Limb Pain Research Articles

Robotic-Enhanced Prosthetic Liners for Vibration Therapy: Reducing Phantom Limb Pain in Transfemoral Amputees.

Phantom limb pain, a common challenge for amputees, lacks effective treatment options. Vibration therapy is a promising non-pharmacologic intervention for reducing pain intensity, but its efficacy in alleviating phantom limb pain requires further investigation. This study focused on developing prosthesis liners with integrated vibration motors to administer vibration therapy for phantom limb pain. The prototypes developed for this study addressed previous issues with wiring the electronic components. Two transfemoral amputees participated in a four-week at-home trial, during which they used the vibration liner and rated their initial and final pain intensity on a numeric rating scale each time they had phantom pain. Semi-structured interviews were conducted to gather feedback following the at-home trial. Both participants described relaxing and soothing sensations in their residual limb and phantom limb while using vibration therapy. One participant reported a relaxation of his phantom limb sensations, while both participants noted a decrease in the intensity of their phantom limb pain. Participants said the vibration liners were comfortable but suggested that the vibration could be stronger and that aligning the contacts could be easier. The results of this study highlight the potential effectiveness of using vibration therapy to reduce the intensity of phantom limb pain and suggest a vibration liner may be a feasible mode of administering the therapy. Future research should address optimizing the performance of the vibration liners to maximize their therapeutic benefits.

Restoration of sensory feedback from the foot and reduction of phantom limb pain via closed-loop spinal cord stimulation.

Restoring somatosensory feedback in individuals with lower-limb amputations would reduce the risk of falls and alleviate phantom limb pain. Here we show, in three individuals with transtibial amputation (one traumatic and two owing to diabetic peripheral neuropathy), that sensations from the missing foot, with control over their location and intensity, can be evoked via lateral lumbosacral spinal cord stimulation with commercially available electrodes and by modulating the intensity of stimulation in real time on the basis of signals from a wireless pressure-sensitive shoe insole. The restored somatosensation via closed-loop stimulation improved balance control (with a 19-point improvement in the composite score of the Sensory Organization Test in one individual) and gait stability (with a 5-point improvement in the Functional Gait Assessment in one individual). And over the implantation period of the stimulation leads, the three individuals experienced a clinically meaningful decrease in phantom limb pain (with an average reduction of nearly 70% on a visual analogue scale). Our findings support the further clinical assessment of lower-limb neuroprostheses providing somatosensory feedback.

Phantom Limb Syndrome: An Ayurvedic Perspective

Phantom limb syndrome is a condition in which patients experience sensations, painful or otherwise, in a limb that does not exist. Phantom pain results from a condition called learned paralysis. Learned paralysis affects people who had a stroke or those who had an amputation. In the latter case, the memory of the paralysed limb remains intact while the limb no longer exists. Hence the term- phantom pain. Phantom pain is treated with mirror box therapy. Could there be an Ayurvedic explanation for phantom limb syndrome? We offer the following explanation: Usually, phantom limb syndrome results from amputation. This is because amputation only gets rid of the Sparshanendriya Adhistaana (Tvak) leaving the Sparshanendriya Buddhi intact. This leads to a mismatch between the Sparshanendriya Buddhi and the Sparshanendriya Adhistaana culminating in phantom limb syndrome. The phantom pain emerges from the Smriti of the paralysed limb. Therefore, designing methods that erase this Smriti would alleviate phantom limb pain. This is achieved by using the mirror box. Mirror box therapy involves projecting visual feedback that conflicts with Smriti (learned paralysis). Mirror box therapy is based on the theory of Smriti Kaarana. The Smriti Karana deployed for mirror box therapy includes Roopagrahana, Saadrusyagrahana and Abhyaasa. Mirror box therapy works by projecting the visual feedback such that the aforementioned Smriti Kaarana contradict the Smriti of the paralysed limb. The mirror box therapy illustrates the usefulness of Smriti Kaarana in treating the diseases of Indriya and Manas origin

Efficacy of mirror therapy and virtual reality therapy in alleviating phantom limb pain: a meta-analysis and systematic review

IntroductionAmputations result from trauma, war, conflict, vascular diseases and cancer. Phantom limb pain (PLP) is a potentially debilitating form of chronic pain affecting around 100 million amputees across the world....

Visual Capture of a Tactile Sensation is Influenced by Repeated, Structured Exposure of a Visual Stimulus in Virtual Reality

Phantom limb pain is commonly known as a neurological condition, where an amputee will continue to feel a limb that is no longer present in a painful fashion. Virtual mirror therapy (VMT) has been suggested as a method for alleviating phantom limb pain. The inclusion of tactile sensation in VMT has shown to be beneficial; however, delivering a tactile sensation to a phantom limb, without the use of invasive procedures, can be difficult. The current approach for transferring a tactile sensation to a phantom limb is called visual capture. The ability to establish visual capture has been demonstrated in VMT applications. However, there is little research into whether an established visual capture effect can be relocated to a more distal location for phantom limb pain management. This paper investigates whether a passive vibrotactile sensation can be moved to a distal location from its veridical location using a series of distally located lights presented in either a random or a structured fashion. Eight non-amputee participants were tasked with localising a static tactile sensation on a virtual arm. These vibrotactile sensations were presented simultaneously with a visual light stimulus, either co-located or located distally at three different locations. Findings show that a tactile sensation without a visual stimulus was difficult for participants to localise; however, when a visual stimulus was added, they were better able to locate the veridical tactile position. The structured group exhibited a larger range of tactile relocation responses than the random group. However, this result was unreliable, with the majority of the responses situated at the vibrotactile actuator. There was a significant difference between the random and structured group’s ability to retain a visual capture at the veridical vibrotactile location when the lights were located distally. The random group did not express a visual capture response when the lights were presented distally while the structured group did, suggesting the structured group developed a more robust association between the visual stimulus and the vibrotactile stimulus. Findings may be of use where increasing tactile acuity without significant alteration of a veridical location is a desired therapeutic outcome.

Memory-related perceptual illusions directly affect physical activity in humans.

Perceptual illusions help us understand deficits in human perception, but they also have the potential to serve as treatment methods; e.g., to alleviate phantom limb pain. Treatment effects are usually the direct result of a mismatch between false visual feedback and somatosensory/proprioceptive feedback. We aimed to influence physical activity (walking distance) using a memory-related perceptual illusion that relies on a mismatch between a spatially manipulated virtual reality environment and a weakness of memory for a similar, previously experienced environment. Participants' main task was to reproduce a baseline distance three times, by walking on a treadmill while moving through a virtual reality environment. Depending on condition, the environment was either stretched or compressed relative to the previous session, but participants were not informed about these manipulations. Because false, suggestive information can lead to alterations in memory, especially when conveyed through ‘rich’ forms of media such as virtual reality, we expected each manipulation to alter memory for the previous environment(s) and we hypothesized that this would influence walking distance. The results for the first time showed that memory-related perceptual illusions can directly affect physical activity in humans. The effects we found are substantial; stretching previously experienced virtual environments led participants to almost double their initial walking distance, whereas compressing the environments resulted in about half of the initial distance. Possible clinical applications arising from these findings are discussed.

Characteristics of Phantom Limb Pain Alleviated with Virtual Reality Rehabilitation.

Neurorehabilitation techniques using virtual reality (VR) systems have recently become widespread as a rehabilitation method for restoring phantom limb movement and alleviating phantom limb pain (PLP). However, analgesic effects have varied between studies, possibly because of differences in the characteristics of PLP between patients (e.g., cramping, burning, shooting). We aimed to reveal the relationship between VR effects and PLP characteristics using an exploratory factor analysis. PLP characteristics of 19 patients were measured using the Short-Form McGill Pain Questionnaire (SF-MPQ), and all PLP patients performed the VR rehabilitation protocol for 20 minutes. During VR rehabilitation, mirror-reversed computer graphic images of an intact arm (the virtual phantom limb) were presented to patients via a head-mounted display, inducing the perception of voluntary execution of movements of their phantom limb when intending bimanual movements. VR rehabilitation significantly restored movement representation (P < 0.0001) quantified using the bimanual coupling effect and significantly alleviated PLP intensity (P < 0.0001). The factor analysis revealed that PLP characteristics could be divided into two factors: "somatosensory-related pain characteristics" and "kinesthesia-related pain characteristics." PLP alleviation via VR rehabilitation was significantly correlated with "kinesthesia-related pain characteristics" (r = 0.47, P = 0.02) but not "somatosensory-related pain characteristics" (r = 0.22, P = 0.17). The current findings indicate that VR rehabilitation may be particularly effective for PLP associated with distorted phantom limb movement and body representations (e.g., clamping, gnawing), compared with typical neuropathic sensations (e.g., shooting, burning, dysesthesia).

Agency over Phantom Limb Enhanced by Short-Term Mirror Therapy.

Most amputees experience phantom limb, whereby they feel that the amputated limb is still present. In some cases, these experiences include pain that can be alleviated by “mirror therapy.” Mirror therapy consists of superimposing a mirrored image of the moving intact limb onto the phantom limb. This therapy provides a closed loop between the motor command to the amputated limb and its predicted visual feedback. This loop is also involved in the sense of agency, a feeling of controlling one’s own body. However, it is unclear how mirror therapy is related to the sense of agency over a phantom limb. Using mirror therapy, we investigated phantom limb pain and the senses of agency and ownership (i.e., a feeling of having one’s own body) of the phantom limb. Nine upper-limb amputees, five of whom reported recent phantom limb pain, underwent a single 15-min trial of mirror therapy. Before and after the trial, the participants completed a questionnaire regarding agency, ownership, and pain related to their phantom limb. They reported that the sense of agency over the phantom limb increased following the mirror therapy trial, while the ownership slightly increased but not as much as did the agency. The reported pain did not change; that is, it was comparably mild before and after the trial. These results suggest that short-term mirror therapy can, at least transiently, selectively enhance the sense of agency over a phantom limb, but may not alleviate phantom limb pain.

Lessons learned from early rehabilitation of complex trauma at the Royal Centre for Defence Medicine

During the recent conflicts in Iraq and Afghanistan, substantial numbers of service personnel survived devastating injuries, presenting significant challenges for early rehabilitation at Queen Elizabeth Hospital Birmingham. Royal Centre for...

Restoring movement representation and alleviating phantom limb pain through short-term neurorehabilitation with a virtual reality system.

We developed a quantitative method to measure movement representations of a phantom upper limb using a bimanual circle-line coordination task (BCT). We investigated whether short-term neurorehabilitation with a virtual reality (VR) system would restore voluntary movement representations and alleviate phantom limb pain (PLP). Eight PLP patients were enrolled. In the BCT, they repeatedly drew vertical lines using the intact hand and intended to draw circles using the phantom limb. Drawing circles mentally using the phantom limb led to the emergence of an oval transfiguration of the vertical lines ('bimanual-coupling' effect). We quantitatively measured the degree of this bimanual-coupling effect as movement representations of the phantom limb before and immediately after short-term VR neurorehabilitation. This was achieved using an 11-point numerical rating scale (NRS) for PLP intensity and the Short-Form McGill Pain Questionnaire (SF-MPQ). During VR neurorehabilitation, patients wore a head-mounted display that showed a mirror-reversed computer graphic image of an intact arm (the virtual phantom limb). By intending to move both limbs simultaneously and similarly, the patients perceived voluntary execution of movement in their phantom limb. Short-term VR neurorehabilitation promptly restored voluntary movement representations in the BCT and alleviated PLP (NRS: p=0.015; 39.1±28.4% relief, SF-MPQ: p=0.015; 61.5±48.5% relief). Restoration of phantom limb movement representations and reduced PLP intensity were linearly correlated (p<0.05). VR rehabilitation may encourage patient's motivation and multimodal sensorimotor re-integration of a phantom limb and subsequently have a potent analgesic effect. There was no objective evidence that restoring movement representation by neurorehabilitation with virtual reality alleviated phantom limb pain. This study revealed quantitatively that restoring movement representation with virtual reality rehabilitation using a bimanual coordination task correlated with alleviation of phantom limb pain.

Reflections on Mirror Therapy

Background. Mirror visual feedback (MVF), a phenomenon where movement of one limb is perceived as movement of the other limb, has the capacity to alleviate phantom limb pain or promote motor recovery of the upper limbs after stroke. The tool has received great interest from health professionals; however, a clear understanding of the mechanisms underlying the neural recovery owing to MVF is lacking. Objective. We performed a systematic review to assess the effect of MVF on brain activation during a motor task. Methods. We searched PubMed, CINAHL, and EMBASE databases for neuroimaging studies investigating the effect of MVF on the brain. Key details for each study regarding participants, imaging methods, and results were extracted. Results. The database search yielded 347 article, of which we identified 33 suitable for inclusion. Compared with a control condition, MVF increases neural activity in areas involved with allocation of attention and cognitive control (dorsolateral prefrontal cortex, posterior cingulate cortex, S1 and S2, precuneus). Apart from activation in the superior temporal gyrus and premotor cortex, there is little evidence that MVF activates the mirror neuron system. MVF increases the excitability of the ipsilateral primary motor cortex (M1) that projects to the “untrained” hand/arm. There is also evidence for ipsilateral projections from the contralateral M1 to the untrained/affected hand as a consequence of training with MVF. Conclusion. MVF can exert a strong influence on the motor network, mainly through increased cognitive penetration in action control, though the variance in methodology and the lack of studies that shed light on the functional connectivity between areas still limit insight into the actual underlying mechanisms.

Are the mechanisms driving somatosensory reorganization cortical or subcortical?

Are the mechanisms driving somatosensory reorganization cortical or subcortical?

Treatment of phantom limb pain (PLP) based on augmented reality and gaming controlled by myoelectric pattern recognition: a case study of a chronic PLP patient

A variety of treatments have been historically used to alleviate phantom limb pain (PLP) with varying efficacy. Recently, virtual reality (VR) has been employed as a more sophisticated mirror therapy. Despite the advantages of VR over a conventional mirror, this approach has retained the use of the contralateral limb and is therefore restricted to unilateral amputees. Moreover, this strategy disregards the actual effort made by the patient to produce phantom motions. In this work, we investigate a treatment in which the virtual limb responds directly to myoelectric activity at the stump, while the illusion of a restored limb is enhanced through augmented reality (AR). Further, phantom motions are facilitated and encouraged through gaming. The proposed set of technologies was administered to a chronic PLP patient who has shown resistance to a variety of treatments (including mirror therapy) for 48 years. Individual and simultaneous phantom movements were predicted using myoelectric pattern recognition and were then used as input for VR and AR environments, as well as for a racing game. The sustained level of pain reported by the patient was gradually reduced to complete pain-free periods. The phantom posture initially reported as a strongly closed fist was gradually relaxed, interestingly resembling the neutral posture displayed by the virtual limb. The patient acquired the ability to freely move his phantom limb, and a telescopic effect was observed where the position of the phantom hand was restored to the anatomically correct distance. More importantly, the effect of the interventions was positively and noticeably perceived by the patient and his relatives. Despite the limitation of a single case study, the successful results of the proposed system in a patient for whom other medical and non-medical treatments have been ineffective justifies and motivates further investigation in a wider study.

Training With Virtual Visual Feedback to Alleviate Phantom Limb Pain

Background. Performing phantom movements with visual virtual feedback, or mirror therapy, is a promising treatment avenue to alleviate phantom limb pain. However the effectiveness of this approach appears to vary from one patient to another. Objective. To assess the individual response to training with visual virtual feedback and to explore factors influencing the response to that approach. Methods. Eight male participants with phantom limb pain (PLP) resulting from either a traumatic upper limb amputation or a brachial plexus avulsion participated in this single case multiple baseline study. Training was performed 2 times per week for 8 weeks where a virtual image of a missing limb performing different movements was presented and the participant was asked to follow the movements with his phantom limb. Results. Patients reported an average 38% decrease in background pain on a visual analog scale (VAS), with 5 patients out of 8 reporting a reduction greater than 30%. This decrease in pain was maintained at 4 weeks postintervention in 4 of the 5 participants. No significant relationship was found between the long-term pain relief and the duration of the deafferentation or with the immediate pain relief during exposure to the feedback. Conclusions. These results support the use of training with virtual feedback to alleviate phantom limb pain. Our observations suggest that between-participant differences in the effectiveness of the treatment might be related more to a difference in the susceptibility to the virtual visual feedback, than to factors related to the lesion, such as the duration of the deafferentation.

Effectiveness of phantom exercises for phantom limb pain: A pilot study

To investigate the effects of phantom limb exercises on phantom limb pain. A total of 20 traumatic amputees participated in the study. Ten received phantom exercises and prosthetic training, and 10 were treated with routine prosthetic training and a general exercise programme. Intensity of pain was evaluated using a 10-cm visual analogue scale before therapy and after 4 weeks of therapy. Baseline scores on the visual analogue scale were similar between the groups. Pain intensity decreased in all subjects after 4 weeks of treatment in both groups. According to the visual analogue scale scores at the end of 4 weeks, the phantom exercises group differed significantly from the general exercise group (p < 0.05). Phantom exercises appear to be effective in reducing phantom pain, but further research is required to confirm this.The results of this study indicate that phantom exercises can be used safely to alleviate phantom limb pain in lower and upper limb amputees.