Neural interfacing architecture enables enhanced motor control and residual limb functionality postamputation.

Despite advancements in prosthetic technologies, patients with amputation today suffer great diminution in mobility and quality of life. We have developed a modified below-knee amputation (BKA) procedure that incorporates agonist-antagonist myoneural interfaces (AMIs), which surgically preserve and couple agonist-antagonist muscle pairs for the subtalar and ankle joints. AMIs are designed to restore physiological neuromuscular dynamics, enable bidirectional neural signaling, and offer greater neuroprosthetic controllability compared to traditional amputation techniques. In this prospective, nonrandomized, unmasked study design, 15 subjects with AMI below-knee amputation (AB) were matched with 7 subjects who underwent a traditional below-knee amputation (TB). AB subjects demonstrated significantly greater control of their residual limb musculature, production of more differentiable efferent control signals, and greater precision of movement compared to TB subjects (P < 0.008). This may be due to the presence of greater proprioceptive inputs facilitated by the significantly higher fascicle strains resulting from coordinated muscle excursion in AB subjects (P < 0.05). AB subjects reported significantly greater phantom range of motion postamputation (AB: 12.47 ± 2.41, TB: 10.14 ± 1.45 degrees) when compared to TB subjects (P < 0.05). Furthermore, AB subjects also reported less pain (12.25 ± 5.37) than TB subjects (17.29 ± 10.22) and a significant reduction when compared to their preoperative baseline (P < 0.05). Compared with traditional amputation, the construction of AMIs during amputation confers the benefits of enhanced physiological neuromuscular dynamics, proprioception, and phantom limb perception. Subjects' activation of the AMIs produces more differentiable electromyography (EMG) for myoelectric prosthesis control and demonstrates more positive clinical outcomes.

[Randomized Controlled Trial of the Effects of Repetitive Transcranial Magnetic Stimulation and Mirror Therapy on Phantom Limb Pain in Amputees].

Objective: To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) on phantom limb pain (PLP) in amputees, and to compare the therapeutic effect with that of mirror therapy (MT). Methods: The study was designed as a randomized controlled trial. The evaluators were blinded, while the subjects and the therapists were unblinded. Subjects were randomly assigned to either the rTMS group or the MT group with a computer-generated random number table. From June 2018 to December 2020, from out of 45 amputee patients screened for the study, 30 who met the inclusion criteria were recruited for the study. All patients were recruited from the Rehabilitation Medicine Center, West China Hospital, Sichuan University. In the end, 4 patients withdrew from the study and 26 patients (12 in the rTMS group and 14 in the MT group) completed the prescribed treatment and evaluation. The rTMS group was given rTMS (1 Hz, 15 min, 5 d/week) for 2 weeks in addition to conventional rehabilitation therapy, while the MT group received MT (corresponding movements of limbs, 15 min, 5 d/week) for 2 weeks in addition to conventional rehabilitation therapy. PLP was evaluated by the Visual Analogue Scale (VAS) and Douleur Neuropathique 4 Questions (DN-4). Subjects were assessed before treatment ( t 0), immediately after the completion of the treatment ( t 1) and 3 months after the completion of the treatment ( t 2). Results: The mean age of the 26 patients was 39.73±12.64. There were 15 males and 11 females. According to the reported description of the characteristics of the PLP by the patients, the characteristics with the highest incidence were tingling, stabbing, numbing, electric shocks and burning in descending order. There was no significant difference in the incidence of PLP characteristics between the two groups ( P>0.05). The two groups had comparable baseline data, showing no significant difference in VAS and DN-4 between the two groups at t 0 ( P>0.05). At t 1 and t 2, the VAS and DN-4 scores were decreased from those of t 0, showing statistically significant difference in both groups ( P<0.01 for both scores). In the rTMS group, there was no significant difference between VAS and DN-4 scores at t 1 and those at t 2 ( P>0.05). In the MT group, the VAS and DN-4 scores at t 2 were significantly lower than those of t 1 ( P<0.05). There was no statistically significant difference between the rTMS group and MT group in the changes in pain measurements, i.e., VAS and DN-4 scores, before and after the intervention ( P>0.05). The 26 patients who completed the experiment showed no dizziness, headache, or other abnormalities during the study. Conclusion: The results of this study indicate that repetitive transcranial magnetic stimulation could improve PLP in amputees, and the improvement effect was comparable to that of mirror therapy.

Direct evidence of EEG coherence in alleviating phantom limb pain by virtual referred sensation: Case report.

Virtual reality (VR) systems have been integrated into rehabilitation techniques for phantom limb pain (PLP). In this case report, we used electroencephalography (EEG) to analyze corticocortical coherence between the bilateral sensorimotor cortices during vibrotactile stimulation in conjunction with VR rehabilitation in two PLP patients. As a result, we observed PLP alleviation and increased alpha wave coherence during VR rehabilitation when stimulation was delivered to the cheek and shoulder (referred sensation areas) of the affected side. Vibrotactile stimulation with VR rehabilitation may enhance the awareness and movement of the phantom hand.

Characteristics of Phantom Limb Pain Alleviated with Virtual Reality Rehabilitation.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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).

Feasibility of a traditional and teletreatment approach to mirror therapy in patients with phantom limb pain: a process evaluation performed alongside a randomized controlled trial.

OBJECTIVE: To evaluate the delivery, acceptance and experiences regarding a traditional and teletreatment approach to mirror therapy as delivered in a randomized controlled trial. DESIGN: Mixed methods, prospective study. SETTING: Rehabilitation centres, hospital and private practices. SUBJECTS: Adult patients with phantom pain following lower limb amputation and their treating physical and occupational therapists. INTERVENTIONS: All patients received 4 weeks of traditional mirror therapy (n = 51), followed by 6 weeks of teletreatment (n = 26) or 6 weeks of self-delivered mirror therapy (n = 25). MAIN MEASURES: Patient files, therapist logs, log files teletreatment, acceptance questionnaire and interviews with patients and their therapists. RESULTS: In all, 51 patients and 10 therapists participated in the process evaluation. Only 16 patients (31%) received traditional mirror therapy according to the clinical framework during the first 4 weeks. Between weeks 5 and 10, the teletreatment was used by 14 patients (56%) with sufficient dose. Teletreatment usage decreased from a median number of 31 (weeks 5-10) to 19 sessions (weeks 11-24). Satisfactory teletreatment user acceptance rates were found with patients demonstrating higher scores (e.g. regarding the usefulness to control pain) than therapists. Potential barriers for implementation of the teletreatment perceived by patients and therapists were related to insufficient training and support as well as the frequency of technical problems. CONCLUSION: Traditional mirror therapy and the teletreatment were not delivered as intended in the majority of patients. Implementation of the teletreatment in daily routines was challenging, and more research is needed to evaluate user characteristics that influence adherence and how technology features can be optimized to develop tailored implementation strategies.

A comparison of the effects of mirror therapy and phantom exercises on phantom limb pain

Background/aim: Although mirror therapy (MT) and phantom exercises (PE) have been shown to reduce pain, the efficacy of these methods in terms of pain, quality of life (QoL), and psychological status (PS) has not been investigated and compared to date. The aim of this study was to determine whether there is any difference between MT and PE in the treatment of phantom limb pain (PLP). Materials and methods: Forty unilateral transtibial amputees (aged 18­45 years) participated in this study. The subjects were randomly divided into 'MT group' and 'PE group'. QoL was assessed using Short-Form 36 (SF-36), psychological status using the Beck depression inventory (BDI), and pain intensity using a visual analog scale (VAS), before and at the end of the program, and on the 3rd and 6th months thereafter. Results: All assessments for all parameters improved significantly in both groups (P < 0.05). Comparison of the two groups revealed a significant difference in changes for VAS and BDI in all measurements, and in pre- and posttreatment scores for all SF-36 parameters (except for Role-Emotional) in favor of the MT group (P < 0.05). Conclusion: While pain intensity decreased and QoL and PS improved in both the MT and PE groups, these improvements were greater in the MT group.

[Cognitive-perceptive approaches in the treatment of chronic pain]. / Kognitiv-perzeptive Ansätze bei chronischen Schmerzen.

In the treatment of difficult chronic pain conditions, cognitive-perceptive approaches offer an alternative to conventional therapies. Especially phantom limb pain and complex regional pain syndrome (CRPS) are frequently treated with these promising modalities. This article provides an overview of the most important cognitive-perceptive therapies and the research results concerning their clinical efficacy. In addition, we discuss their neurobiological foundation and clinical perspectives.

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 Defence Medicine personnel augmented NHS therapy provision, gaining significant experience in rehabilitating complex trauma. Multidisciplinary working was key to delivering this service, with a unique rehabilitation coordinating officer position established to manage the rehabilitation pathway. A military exercise rehabilitation instructor provided daily gym-based rehabilitation, developing exercise tolerance. Emphasis was placed on early independence, reducing pain, eliminating complications and optimising function. Innovative solutions and non-standard combinations of rehabilitation were required, with therapy working practices redesigned that, we believe, exceed provision elsewhere, including novel applications such as unique patient transfers, specialist seating, additional equipment, problem-solving teaching and early upper limb prosthetic provision. Active pain management allowed engagement in rehabilitation. With limited evidence available, therapeutic modalities attempting to alleviate phantom limb pain centred on patients' ability to engage in treatment. Finally, the requirement to measure change in early trauma rehabilitation was identified, leading to the development of the preprosthetic functional outcome measure. This article aims to document advances made, lessons learned, encourage debate and identify priorities for future research for military complex trauma rehabilitation.

The effect of virtual visual feedback on supernumerary phantom limb pain in a patient with high cervical cord injury: a single-case design study.

We characterized the effect of virtual visual feedback (VVF) on supernumerary phantom limb pain (SPLP) in a patient with high cervical cord injury. The subject was a 22-year-old man diagnosed with complete spinal cord injury (level C2) approximately 5 years ago. We applied the ABA'B' single-case design and set phases B and B' as intervention phases for comparison. SPLP significantly improved in comparison of phase A with phase B and phase A with phase B'. We suggest that VVF reduces SPLP and the effect lasts after VVF.

[Neurorehabilitation for Neuropathic Pain].

Deafferentation, like as in limb amputation, brachial plexus avulsion injury and spinal cord injury, is usually followed by neuropathic pain. Neuropathic pain is a debilitating condition and it impairs the quality of life profoundly. Based on recent advances in the cognitive neuroscience, we explain intimate relationships among neuropathic pain, reorganization of primary sensory and motor cortices and the sensorimotor integration of the deafferentated limb. From the standpoint of the sensorimotor integration theory for emerging phantom limb pain, we further discuss the analgesic mechanism of neurorehabilitation techniques such as mirror visual feedback treatment and its related neurorobotics advancement for neuropathic pain.

Outcome of percutaneous osseointegrated prostheses for patients with unilateral transfemoral amputation at two-year follow-up.

OBJECTIVE: To report outcomes regarding general and specific physical health-related quality of life of treatment with percutaneous osseointegrated prostheses. DESIGN: Prospective 2-year case-control study. SETTING: University hospital. PARTICIPANTS: Individuals (N=39; mean age, 44 ± 12.4 y) with unilateral transfemoral amputation as a result of trauma (n=23), tumor (n=11), or other cause (n=5). At baseline, 33 of the 39 participants used socket-suspended prostheses. INTERVENTION: Osseointegrated prosthesis. MAIN OUTCOME MEASURES: Questionnaire for Persons with Transfemoral Amputation (Q-TFA), Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) physical functioning (PF) and physical component summary (PCS), SF-6D, and Physiological Cost Index (PCI). RESULTS: At 2 years postimplantation, 6 of 7 Q-TFA scores improved (P<.0001) compared with baseline (prosthetic use, mobility, problem, global, capability, walking habits). The walking aid subscore did not improve (P=.327). Of the 39 participants, increased prosthesis use was reported by 26, same amount of use by 11, and less use by 2. Improvement was reported in 16 of the 30 separate problem items (P<.05). Unchanged items included problems regarding phantom limb pain and pain from the back, shoulders, and contralateral limb. The PF, PCS, and SF-6D improved a mean of 24.1 ± 21.4 (P<.0001), 8.5 ± 9.7 (P<.0001), and .039 ± .11 (P=.007) points, respectively. Walking energy cost decreased (mean PCI at baseline, .749; mean PCI at follow-up, .61; P<.0001). CONCLUSIONS: Two years after intervention, patients with a unilateral TFA treated with an OPRA implant showed important improvements in prosthetic function and physical quality of life. However, walking aids used and the presence of phantom limb pain and pain in other extremities were unchanged. This information is valuable when considering whether percutaneous osseointegrated prostheses are a relevant treatment option.

[Mirror therapy for the treatment of phantom limb pain after bilateral thigh amputation. A case report]. / Spiegeltherapie zur Behandlung von Phantomschmerzen nach beidseitiger Oberschenkelamputation. Ein Fallbericht.

This case study is the first to report successful treatment of bilateral phantom limb pain (PLP) in a patient with bilateral thigh amputation and inefficacious medical treatment using a protocol of graded interventions including mirror therapy (MT). MT is a common treatment for PLP but requires the induction of a visual illusion of an intact limb in the mirror, usually achieved by mirroring the healthy extremity. Here, we illustrate how application of a unilateral prosthesis sufficed to induce the necessary illusion. After sequential imagery, then lateralization training, which alleviated pain attacks, the patient received a further 3-week treatment of mirror treatment. Pain intensity was reduced by more than 85 %; the number of attacks were decreased by more than 90% per day. The analgesic efficacy lasted until the unexpected death of the patient several months later. This case illustrates the mechanisms of MT through overcoming the sensory incongruences underlying the distorted body schema and its efficacy in patients with bilateral amputation.

An augmented reality home-training system based on the mirror training and imagery approach.

Mirror training and movement imagery have been demonstrated to be effective in treating several clinical conditions, such as phantom limb pain, stroke-induced hemiparesis, and complex regional pain syndrome. This article presents an augmented reality home-training system based on the mirror and imagery treatment approaches for hand training. A head-mounted display equipped with cameras captures one hand held in front of the body, mirrors this hand, and displays it in real time in a set of four different training tasks: (1) flexing fingers in a predefined sequence, (2) moving the hand into a posture fitting into a silhouette template, (3) driving a "Snake" video game with the index finger, and (4) grasping and moving a virtual ball. The system records task performance and transfers these data to a central server via the Internet, allowing monitoring of training progress. We evaluated the system by having 7 healthy participants train with it over the course of ten sessions of 15-min duration. No technical problems emerged during this time. Performance indicators showed that the system achieves a good balance between relatively easy and more challenging tasks and that participants improved significantly over the training sessions. This suggests that the system is well suited to maintain motivation in patients, especially when it is used for a prolonged period of time.

Content analyses of a priori qualitative phantom limb pain descriptions and emerging categories in mid-southerners with limb loss.

PURPOSE: The purposes of this descriptive study were (a) to identify the relative frequencies of a priori categories of phantom limb pain (PLP) quality descriptors reported by Mid-Southerners with limb loss, (b) to analyze their descriptions for emerging categories of PLP, and (c) to identify the relative frequencies of the emerging categories. DESIGN: This cross-sectional descriptive verbal survey assessed PLP descriptors. A content analyses determined relative frequencies of a priori PLP descriptors as well as emerging categories that were identified. FINDINGS: The most common a priori PLP quality descriptors reported by 52 amputees with PLP were intermittent, tingling/needles/numb, sharp, cramping, burning, and stabbing. The most common emerging categories reported were pain compared to illness/injury, electrical cyclical, and manipulated/positional. CONCLUSION: The detailed descriptions of PLP provide insight into the vivid experiences of PLP. CLINICAL RELEVANCE: Rehabilitation nurses can use this information with PLP assessment, patient teaching, and counseling.

Distinct patterns of metabolic motor cortex activity for phantom and residual limb pain in people with amputations: A functional near-infrared spectroscopy study.

BACKGROUND: Phantom pain limb (PLP) has gained more attention due to the large number of people with amputations around the world and growing knowledge of the pain process, although its mechanisms are not completely understood. OBJECTIVES: The aim of this study was to understand, in patients with amputations, the association between PLP and residual limb pain (RLP), and the brain metabolic response in cortical motor circuits, using functional near-infrared spectroscopy (fNIRS). METHODS: Sixty participants were recruited from the rehabilitation program in São Paulo, Brazil. Included patients were aged over 18 years, with traumatic unilateral lower-limb amputation, with PLP for at least 3 months after full recovery from amputation surgery. PLP and RLP levels were measured using visual analogue scales. fNIRS was performed during motor execution and motor mirror tasks for 20 s. In order to highlight possible variables related to variation in pain measures, univariate linear regression analyses were performed for both experimental conditions, resulting in four fNIRS variables (two hemispheres x two experimental conditions). Later, in order to test the topographic specificity of the models, eight multivariate regression analyses were performed (two pain scales x two experimental conditions x two hemispheres), including the primary motor cortex (PMC) related channel as an independent variable as well as five other channels related to the premotor area, supplementary area, and somatosensory cortex. All models were controlled for age, sex, ethnicity, and education. RESULTS: We found that: i) there is an asymmetric metabolic activation during motor execution and mirror task between hemispheres (with a predominance that is ipsilateral to the amputated limb), ii) increased metabolic response in the PMC ipsilateral to the amputation is associated with increased PLP (during both experimental tasks), while increased metabolic response in the contralateral PMC is associated with increased RLP (during the mirror motor task only); ii) increased metabolic activity of the ipsilateral premotor region is associated with increased PLP during the motor mirror task; iii) RLP was only associated with higher metabolic activity in the contralateral PMC and lower metabolic activity in the ipsilateral inferior frontal region during motor mirror task, but PLP was associated with higher metabolic activity during both tasks. CONCLUSION: These results suggest there is both task and region specificity for the association between the brain metabolic response and the two different types of post-amputation pain. The metabolic predominance that is ipsilateral to the amputated limb during both tasks was associated with higher levels of PLP, suggesting a cortical motor network activity imbalance due to potential interhemispheric compensatory mechanisms. The present work contributes to the understanding of the underlying topographical patterns in the motor-related circuits associated with pain after amputations.

Motor and sensory rehabilitation after lower limb amputation: state of art and perspective of change.

The rehabilitation of the amputated patient is based on a coordinated sequence of diagnostic, prognostic and therapeutic procedures carried out by an interdisciplinary rehabilitation team, that works globally on all patient problems. The objectives of the different phases of the rehabilitation treatment were reviewed. Due to their relevance in conditioning the final outcome of the treatment, aspects requiring further studies and remarks, were also reviewed. Among these the psychological aspects, the alterations of all sensory inputs, the secondary alterations at the bone, articular and muscular level, pain of the residual limb and the phantom limb. Finally, the basic criteria to be used to choose the kind of prosthesis in relation to the characteristics and expectations of the amputated person, and the results of the recovery of the autonomy and walking ability, will be schematically described.

Imaginative resonance training (IRT) achieves elimination of amputees' phantom pain (PLP) coupled with a spontaneous in-depth proprioception of a restored limb as a marker for permanence and supported by pre-post functional magnetic resonance imaging (fMRI).

Non-pharmacological approaches such as mirror therapy and graded motor imagery often provide amelioration of amputees' phantom limb pain (PLP), but elimination has proved difficult to achieve. Proprioception of the amputated limb has been noted in studies to be defective and/or distorted in the presence of PLP, but has not, apparently, been researched for various stages of amelioration up to the absence of PLP. Previous studies using functional magnetic resonance imaging (fMRI) suggested that pathological cortical reorganisation after amputation may be the underlying neurobiological correlate of PLP. We report two cases of permanent elimination of PLP after application of imaginative resonance training. The patients, 69 years and 84 years old, reported freedom from PLP together with in-depth achievement of proprioception of a restored limb at the end of the treatment, which may thus be taken as an indication of permanence. Pre/post fMRI for the first case showed, against a group of healthy controls, analogous changes of activation in the sensorimotor cortex.

Strategies for graded motor imagery for clients with phantom limb pain and cognitive impairment.

BACKGROUND: Individuals with amputations often experience phantom limb pain (PLP) that can limit their participation in rehabilitation, prosthesis training, desired activities, and roles. One nonpharmacological rehabilitation intervention for PLP is graded motor imagery (GMI). There are several components to GMI, including right/left discrimination or laterality, motor imagery, sensory retraining, and mirror therapy. Successful implementation of GMI requires a range of cognitive skills, such as attention span, working memory, abstract reasoning, and planning. For individuals with PLP who concurrently display cognitive impairments, GMI protocols can be adapted using strategies derived from clinical practice. OBJECTIVES: The purpose of this technical clinical report was to discuss the application of clinically implemented cognitive compensation techniques to GMI instruction. STUDY DESIGN: Not applicable. METHODS: Clinical expert opinion to explore adaptations for GMI. TECHNIQUE: Graded motor imagery can be an effective tool for pain treatment; however, some clients may need greater clinician support due to existing cognitive difficulties. RESULTS: For clients to be successful, active engagement in learning about and implementing GMI techniques is necessary. CONCLUSIONS: When serving the lifetime amputation care needs of patients with cognitive deficits, we find that targeted learning strategies and accommodations can be helpful when introducing GMI concepts and skill development. Enhanced patient education techniques support client learning.

A scoping review of current non-pharmacological treatment modalities for phantom limb pain in limb amputees.

PURPOSE: Phantom limb pain (PLP) is a chronic neuropathic pain condition of a missing limb following amputation. Pain management is multi-modal, including various non-pharmacological therapies. The purpose of this scoping review was to investigate the evidence surrounding current non-pharmacological treatment modalities for PLP and provide insight into their clinical feasibility. METHOD: A systematic search was conducted using four databases (Medline, Embase, PsychInfo, and CINAHL) following the PRISMA-ScR method. Results from papers meeting the inclusion criteria were charted to summarize findings, demographics, and use of neuroimaging. RESULTS: A total of 3387 papers were identified, and full texts of 142 eligible papers were assessed. Eleven treatment modalities for PLP were identified with varying levels of evidence. Overall, there were 25 RCTs, 58 case reports, and 59 a combination of pilot, quasi-experimental, observational, and other study designs. CONCLUSIONS: Currently, the evidence surrounding most treatment modalities is limited and only a fraction of studies are supported by strong evidence. The findings of this review demonstrated a clear need to conduct more rigorous research with diverse study designs to better understand which modalities provide the most benefit and to incorporate neuroimaging to better determine the neural correlates of PLP and mechanisms of various treatments.Implications for RehabilitationPhantom limb pain (PLP) is a prevalent and debilitating condition following amputation and health care professionals should incorporate an evidence-based pain management protocol into their rehabilitation program.There exist a number of different non-pharmacological therapies to address PLP, however the scientific rigor and levels of evidence vary across modalities.Prescription of interventions for PLP should consider individual patient differences, accessibility to the patient, and quite possibly, a multi-modal approach, particularly for those who also experience residual limb pain.Imagery-based therapies provide the highest level of current evidence based on robust and large randomized control trials, are readily accessible, and are thus most recommended for relief of PLP.

Supernumerary phantom limbs in spinal cord injury.

STUDY DESIGN AND OBJECTIVES: Case report and review of supernumerary phantom limbs in patients suffering from spinal cord injury (SCI). SETTING: SCI rehabilitation centre. CASE REPORT: After a ski accident, a 71-year-old man suffered an incomplete SCI (level C3; AIS C, central cord syndrome), with a C3/C4 dislocation fracture. From the first week after injury, he experienced a phantom duplication of both upper limbs that lasted for 7 months. The supernumerary limbs were only occasionally related to painful sensation, specifically when they were perceived as crossed on his trunk. Although the painful sensations were responsive to pain medication, the presence of the illusory limb sensations were persistent. During neurological recovery, the supernumerary limbs gradually disappeared. A rubber hand illusion paradigm was used twice during recovery to monitor the patient's ability to integrate visual, tactile and proprioceptive stimuli. CONCLUSION: Overall, the clinical relevance of supernumerary phantom limbs is not clear, specific treatment protocols have not yet been developed, and the underlying neural mechanisms are not fully understood. Supernumerary phantom limbs have been previously reported in patients with (sub)cortical lesions, but might be rather undocumented in patients suffering from traumatic SCI. For the appropriate diagnosis and treatment after SCI, supernumerary phantoms should be distinguished from other phantom sensations and pain syndromes after SCI.