Phantom-limb pain: characteristics, causes, and treatment

Phantom rectal sensations following abdominoperineal excision of the rectum (APER) and vertical rectus abdominis myocutaneous (VRAM) flap perineal reconstruction

AIM

Phantom rectum is the sensation of an intact and/or functioning rectum, despite excision at surgery. Abdominoperineal excision of the rectum (APER) may be complemented by reconstructive operations and recently it was reported that patients undergoing APER and vertical rectus abdominis myocutaneous (VRAM) flap reconstruction are more prone to develop phantom sensations at an earlier timeframe and have more persistent symptoms than those who do not have perineal repairs. The aim of this study was to determine the prevalence of phantom rectal sensations in a cohort of these patients.

METHOD

Patients who underwent APER and VRAM flap reconstruction for anorectal carcinomas were identified from May 2008 to July 2012. Patients completed a questionnaire evaluating their experience of rectal symptoms post-surgery.

RESULTS

Thirty-four of 47 eligible patients were enrolled in the study. PR sensations were experienced by 50 % of patients, the majority of which (65 %) were present for >1 year. The commonest sensation reported was the feeling of faeces in a normal rectum (24 %). Disturbances in quality of life were apparent in 44 %; notably, sleep was affected, patients expressed increased feelings of stress/sadness, heightened levels of anxiety and limitation of daily activities as consequences of PR symptoms. Few patients sought medical advice.

CONCLUSION

Fifty percent of patients experience PR sensations post-surgery, comparable with reported data for patients who have undergone APER alone. The addition of VRAM reconstruction does not significantly alter the prevalence of PR symptoms. This paper provides further evidence that phantom rectum occurs frequently and thus all patients undergoing excision of the rectum should be counselled appropriately.

A systematic review on the treatment of phantom limb pain with spinal cord stimulation

Phantom limb pain (PLP) is a challenging chronic pain syndrome to treat with pharmacologic agents being first line of management. However, when these agents fail to provide pain relief, other interventions must be considered in a clinical setting. Spinal cord stimulation (SCS) has been shown to provide analgesia in PLP, and should be considered by clinicians.

METHODS

This PRISMA systematic review analyzes the efficacy of SCS for treatment of PLP.

RESULTS

After review of 12 studies, there are mixed results to base a conclusion on.

DISCUSSION

While there is some evidence of efficacy, due to the relatively small number of patients in each study, further research is needed to demonstrate the benefits of SCS for PLP.

Understanding Neuropathic Corneal Pain--Gaps and Current Therapeutic Approaches

The richly innervated corneal tissue is one of the most powerful pain generators in the body. Corneal neuropathic pain results from dysfunctional nerves causing perceptions such as burning, stinging, eye-ache, and pain. Various inflammatory diseases, neurological diseases, and surgical interventions can be the underlying cause of corneal neuropathic pain. Recent efforts have been made by the scientific community to elucidate the pathophysiology and neurobiology of pain resulting from initially protective physiological reflexes, to a more persistent chronic state. The goal of this clinical review is to briefly summarize the pathophysiology of neuropathic corneal pain, describe how to systematically approach the diagnosis of these patients, and finally summarizing our experience with current therapeutic approaches for the treatment of corneal neuropathic pain.

Acupuncture for the treatment of phantom limb syndrome in lower limb amputees: a randomised controlled feasibility study

Background

Post amputation, the complication of phantom limb pain (PLP) is prevalent and difficult to manage. This study aimed to determine whether it was feasible and acceptable to undertake a definitive multicentred randomised controlled trial assessing the effectiveness of acupuncture for treating lower limb amputees with PLP.

Methods

A mixed-methods embedded design, including a randomised controlled trial and semistructured interviews, was undertaken. A total of 15 participants with PLP were randomly assigned to receive either eight pragmatic Traditional Chinese Medicine acupuncture treatments and usual care or usual care alone over 4 weeks. Outcome measures were completed at baseline, weekly throughout the study and at 1 month post completion of the study and included: a numerical pain-rating scale, the Short-Form McGill Pain Questionnaire 2, the EQ-5D-5 L, the Hospital Anxiety and Depression Scale, the Perceived Stress Scale 10-item, the Insomnia Severity Index, and the Patient Global Impression of Change. Post completion of the trial, participants in the acupuncture group were interviewed about their experience. Feasibility-specific data were also collected.

Results

Of 24 amputees meeting the study inclusion criteria, 15 agreed to participate (recruitment rate 62.50 %). Qualitatively, acupuncture was perceived to be beneficial and effective. Quantitatively, acupuncture demonstrated clinically meaningful change in average pain intensity (raw change = 2.69) and worst pain intensity (raw change = 4.00). Feasibility-specific data identified that before undertaking a definitive trial, recruitment, practitioner adherence to the acupuncture protocol, completion of outcome measures at 1 month follow-up and blinding should be addressed. Appropriate outcome measures were identified for use in a definitive trial. Data were generated for future sample size calculations (effect size 0.64). Allowing for a 20 % dropout rate, a sample size of 85 participants per group would be needed in a future definitive trial.

Conclusions

A future definitive trial may be possible if the areas identified in this study are addressed. As acupuncture may be effective at treating PLP, and as this feasibility study suggests that a definitive trial may be possible, a multicentred trial with adequate sample size and blinding is now needed.

Trial registration

ClinicalTrials.gov Identifier: NCT02126436, registered on 4 September 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1639-z) contains supplementary material, which is available to authorized users.

Traumatic neuroma of the superficial peroneal nerve in a patient: a case report and review of the literature

BACKGROUND

Traumatic neuromas are rare benign tumors, which are common in trauma or post-operation and accompanied with obvious symptoms of pain. This study will show the superficial peroneal nerve neuroma occurring after resection of hemangioma.

CASE PRESENTATION

A 44-year-old male had an operation of the right leg cavernous hemangioma resection in 1995. Half a year after the operation, pain around the wound appeared and gradually aggravated. The patient had the lesion exploration resection in 2013, and the pathological result showed traumatic neuroma. Within half a year of the second operation, severe pain showed up again, so neuroma resection proceeded in May 2015. The postoperative pathological and immunohistochemical results showed traumatic neuroma. According to the postoperative follow-up, there were no symptoms of pain appearing again.

LITERATURE REVIEW

The pain is obvious, and B ultrasonography is the most efficient way to find neuromas. Both conservative and operative therapy have their advantages and disadvantages.

CONCLUSIONS

There remain many unanswered questions in relation to the treatment of traumatic neuromas, and further research is required, although we have already had adequate understanding of traumatic neuromas.

The effects of graded motor imagery and its components on phantom limb pain and disability in upper and lower limb amputees: a systematic review protocol

BACKGROUND

Phantom limb pain (PLP) is characterized by the anatomical shifting of neighbouring somatosensory and motor areas into a deafferented cortical area of the brain contralateral to the amputated limb. It has been shown that maladaptive neuroplasticity is positively correlated to the perception of PLP in amputees. Recent studies support the use of graded motor imagery (GMI) and its component to alleviate the severity of PLP and disability. However, there is insufficient collective empirical evidence exploring the effectiveness of these treatment modalities in amputees with PLP. This systematic review will therefore explore the effects of GMI and its individual components on PLP and disability in upper and lower limb amputees.

METHODS

We will utilize a customized search strategy to search PubMed, Cochrane Central register of Controlled Trials, MEDLINE, Embase, PsycINFO, PEDro, Scopus, CINAHL, LILACS, DARE, Africa-Wide Information and Web of Science. We will also look at clinicaltrials.gov ( http://www.clinicaltrials.gov/ ), Pactr.gov ( http://www.pactr.org/ ) and EU Clinical trials register ( https://www.clinicaltrialsregister.eu/ ) for ongoing research. Two independent reviewers will screen articles for methodological validity. Thereafter, data from included studies will be extracted by two independent reviewers through a customized pre-set data extraction sheet. Studies with a comparable intervention and outcome measure will be pooled for meta-analysis. Studies with high heterogeneity will be analysed through random effects model. A narrative data analysis will be considered where there is insufficient data to perform a meta-analysis.

DISCUSSION

Several studies investigating the effectiveness of GMI and its different components on PLP have drawn contrasting conclusions regarding the efficacy and applicability of GMI in clinical practice. This systematic review will therefore gather and critically appraise all relevant data, to generate a substantial conclusion and recommendations for clinical practice and research on this subject.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016036471.

Reversed cortical over-activity during movement imagination following neurofeedback treatment for central neuropathic pain

OBJECTIVE

One of the brain signatures of the central neuropathic pain (CNP) is the theta band over-activity of wider cortical structures, during imagination of movement. The objective of the study was to investigate whether this over-activity is reversible following the neurofeedback treatment of CNP.

METHODS

Five paraplegic patients with pain in their legs underwent from twenty to forty neurofeedback sessions that significantly reduced their pain. In order to assess their dynamic cortical activity they were asked to imagine movements of all limbs a week before the first and a week after the last neurofeedback session. Using time-frequency analysis we compared EEG activity during imagination of movement before and after the therapy and further compared it with EEG signals of ten paraplegic patients with no pain and a control group of ten able-bodied people.

RESULTS

Neurofeedback treatment resulted in reduced CNP and a wide spread reduction of cortical activity during imagination of movement. The reduction was significant in the alpha and beta band but was largest in the theta band. As a result cortical activity became similar to the activity of other two groups with no pain.

CONCLUSIONS

Reduction of CNP is accompanied by reduced cortical over-activity during movement imagination.

SIGNIFICANCE

Understanding causes and consequences mechanism through which CNP affects cortical activity.

Repetitive Transcranial Magnetic Stimulation for Phantom Limb Pain in Land Mine Victims: A Double-Blinded, Randomized, Sham-Controlled Trial

We evaluated the effects of repetitive transcranial magnetic stimulation (rTMS) in the treatment of phantom limb pain (PLP) in land mine victims. Fifty-four patients with PLP were enrolled in a randomized, double-blinded, placebo-controlled, parallel group single-center trial. The intervention consisted of real or sham rTMS of M1 contralateral to the amputated leg. rTMS was given in series of 20 trains of 6-second duration (54-second intertrain, intensity 90% of motor threshold) at a stimulation rate of 10 Hz (1,200 pulses), 20 minutes per day, during 10 days. For the control group, a sham coil was used. The administration of active rTMS induced a significantly greater reduction in pain intensity (visual analogue scale scores) 15 days after treatment compared with sham stimulation (-53.38 ± 53.12% vs -22.93 ± 57.16%; mean between-group difference = 30.44%, 95% confidence interval, .30-60.58; P = .03). This effect was not significant 30 days after treatment. In addition, 19 subjects (70.3%) attained a clinically significant pain reduction (>30%) in the active group compared with 11 in the sham group (40.7%) 15 days after treatment (P = .03). The administration of 10 Hz rTMS on the contralateral primary motor cortex for 2 weeks in traumatic amputees with PLP induced significant clinical improvement in pain.

PERSPECTIVE

High-frequency rTMS on the contralateral primary motor cortex of traumatic amputees induced a clinically significant pain reduction up to 15 days after treatment without any major secondary effect. These results indicate that rTMS is a safe and effective therapy in patients with PLP caused by land mine explosions.

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.

Optimizing Rehabilitation for Phantom Limb Pain Using Mirror Therapy and Transcranial Direct Current Stimulation: A Randomized, Double-Blind Clinical Trial Study Protocol

Background

Despite the multiple available pharmacological and behavioral therapies for the management of chronic phantom limb pain (PLP) in lower limb amputees, treatment for this condition is still a major challenge and the results are mixed. Given that PLP is associated with maladaptive brain plasticity, interventions that promote cortical reorganization such as non-invasive brain stimulation and behavioral methods including transcranial direct current stimulation (tDCS) and mirror therapy (MT), respectively, may prove to be beneficial to control pain in PLP. Due to its complementary effects, a combination of tDCS and MT may result in synergistic effects in PLP.

Objective

The objective of this study is to evaluate the efficacy of tDCS and MT as a rehabilitative tool for the management of PLP in unilateral lower limb amputees.

Methods

A prospective, randomized, placebo-controlled, double-blind, factorial, superiority clinical trial will be carried out. Participants will be eligible if they meet the following inclusion criteria: lower limb unilateral traumatic amputees that present PLP for at least 3 months after the amputated limb has completely healed. Participants (N=132) will be randomly allocated to the following groups: (1) active tDCS and active MT, (2) sham tDCS and active MT, (3) active tDCS and sham MT, and (4) sham tDCS and sham MT. tDCS will be applied with the anodal electrode placed over the primary motor cortex (M1) contralateral to the amputation side and the cathode over the contralateral supraorbital area. Stimulation will be applied at the same time of the MT protocol with the parameters 2 mA for 20 minutes. Pain outcome assessments will be performed at baseline, before and after each intervention session, at the end of MT, and in 2 follow-up visits. In order to assess cortical reorganization and correlate with clinical outcomes, participants will undergo functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) before and after the intervention.

Results

This clinical trial received institutional review board (IRB) approval in July of 2015 and enrollment started in December of 2015. To date 2 participants have been enrolled. The estimate enrollment rate is about 30 to 35 patients per year; thus we expect to complete enrollment in 4 years.

Conclusions

This factorial design will provide relevant data to evaluate whether tDCS combined with MT is more effective than each therapy alone, as well as with no intervention (sham/sham) in patients with chronic PLP after unilateral lower limb amputation. In addition, this randomized clinical trial will help to investigate the neurophysiological mechanisms underlying the disease, which could potentially provide relevant findings for further management of this chronic condition and also help to optimize the use of this novel intervention.

Trial Registration

Clinicaltrials.gov NCT02487966; https://clinicaltrials.gov/ct2/show/NCT02487966 (Archived by WebCite at http://www.webcitation.org/6i3GrKMyf)

Tactile feedback for relief of deafferentation pain using virtual reality system: a pilot study

BACKGROUND

Previous studies have tried to relieve deafferentation pain (DP) by using virtual reality rehabilitation systems. However, the effectiveness of multimodal sensory feedback was not validated. The objective of this study is to relieve DP by neurorehabilitation using a virtual reality system with multimodal sensory feedback and to validate the efficacy of tactile feedback on immediate pain reduction.

METHODS

We have developed a virtual reality rehabilitation system with multimodal sensory feedback and applied it to seven patients with DP caused by brachial plexus avulsion or arm amputation. The patients executed a reaching task using the virtual phantom limb manipulated by their real intact limb. The reaching task was conducted under two conditions: one with tactile feedback on the intact hand and one without. The pain intensity was evaluated through a questionnaire.

RESULTS

We found that the task with the tactile feedback reduced DP more (41.8 ± 19.8 %) than the task without the tactile feedback (28.2 ± 29.5 %), which was supported by a Wilcoxon signed-rank test result (p < 0.05).

CONCLUSIONS

Overall, our findings indicate that the tactile feedback improves the immediate pain intensity through rehabilitation using our virtual reality system.

No Telescoping Effect with Dual Tendon Vibration

The tendon vibration illusion has been extensively used to manipulate the perceived position of one's own body part. However, findings from previous research do not seem conclusive sregarding the perceptual effect of the concurrent stimulation of both agonist and antagonist tendons over one joint. On the basis of recent data, it has been suggested that this paired stimulation generates an inconsistent signal about the limb position, which leads to a perceived shrinkage of the limb. However, this interesting effect has never been replicated. The aim of the present study was to clarify the effect of a simultaneous and equal vibration of the biceps and triceps tendons on the perceived location of the hand. Experiment 1 replicated and extended the previous findings. We compared a dual tendon stimulation condition with single tendon stimulation conditions and with a control condition (no vibration) on both 'upward-downward' and 'towards-away from the elbow' planes. Our results show a mislocalisation towards the elbow of the position of the vibrated arm during dual vibration, in line with previous results; however, this did not clarify whether the effect was due to arm representation contraction (i.e., a 'telescoping' effect). Therefore, in Experiment 2 we investigated explicitly and implicitly the perceived arm length during the same conditions. Our results clearly suggest that in all the vibration conditions there was a mislocalisation of the entire arm (including the elbow), but no evidence of a contraction of the perceived arm length.

Experimental tonic hand pain modulates the corticospinal plasticity induced by a subsequent hand deafferentation

Sensorimotor reorganization is believed to play an important role in the development and maintenance of phantom limb pain, but pain itself might modulate sensorimotor plasticity induced by deafferentation. Clinical and basic research support this idea, as pain prior to amputation increases the risk of developing post-amputation pain. The aim of this study was to examine the influence of experimental tonic cutaneous hand pain on the plasticity induced by temporary ischemic hand deafferentation. Sixteen healthy subjects participated in two experimental sessions (Pain, No Pain) in which transcranial magnetic stimulation was used to assess corticospinal excitability in two forearm muscles (flexor carpi radialis and flexor digitorum superficialis) before (T0, T10, T20, and T40) and after (T60 and T75) inflation of a cuff around the wrist. The cuff was inflated at T45 in both sessions and in the Pain session capsaicin cream was applied on the dorsum of the hand at T5. Corticospinal excitability was significantly greater during the Post-inflation phase (p=0.002) and increased similarly in both muscles (p=0.861). Importantly, the excitability increase in the Post-inflation phase was greater for the Pain than the No-Pain condition (p=0.006). Post-hoc analyses revealed a significant difference between the two conditions during the Post-inflation phase (p=0.030) but no difference during the Pre-inflation phase (p=0.601). In other words, the corticospinal facilitation was greater when pain was present prior to cuff inflation. These results indicate that pain can modulate the plasticity induced by another event, and could partially explain the sensorimotor reorganization often reported in chronic pain populations.

Forearm amputees' views of prosthesis use and sensory feedback

STUDY DESIGN

Qualitative descriptive.

INTRODUCTION

The lack of sensory feedback in today's hand prostheses has been in focus recently but the amputees' experiences need to be further investigated.

PURPOSE

To explore forearm amputees' views of prosthesis use and sensory feedback.

METHODS

Thirteen unilateral congenital or traumatic forearm amputees were interviewed. The transcribed text was subjected to content analysis.

RESULTS

Prostheses both facilitate and limit occupational performance. Appearance is important for identity and blending into society. The feeling of agency regarding the prostheses is present but not that of body ownership. Future expectations concerned improved mobility, cosmetics, and sensory feedback.

CONCLUSIONS

This study allows a deeper understanding of the complex relationship between a prosthetic device and the wearer. Today's prostheses allow the wearer to feel agency concerning the artificial limb but the lack of sensory feedback seems to be an important factor still blocking the achievement of body ownership of the prosthesis.

LEVEL OF EVIDENCE

Not applicable.

Parallels between phantom pain and tinnitus

Phantom pain and tinnitus are diseases that cause patients great discomfort. Both are phantom sensations that have many connections with cerebral structures, but their underlying mechanisms are not fully understood. Several therapies have been suggested for these conditions over the years, but there is still no consensus on how to treat either one. Comparison of these two phenomena reveals many similarities, including what is known about their underlying mechanisms, associated brain areas, and responses to therapeutic agents and methods. These similarities need to be evaluated in greater depth, as this could improve our understanding of tinnitus and phantom pain, and thereby improve management strategies for these conditions.

Spinal Cauda Equina Stimulation for Alternative Location of Spinal Cord Stimulation in Intractable Phantom Limb Pain Syndrome: A Case Report

Phantom limb pain is a phenomenon in which patients experience pain in a part of the body that no longer exists. In several treatment modalities, spinal cord stimulation (SCS) has been introduced for the management of intractable post-amputation pain. A 46-year-old male patient complained of severe ankle and foot pain, following above-the-knee amputation surgery on the right side amputation surgery three years earlier. Despite undergoing treatment with multiple modalities for pain management involving numerous oral and intravenous medications, nerve blocks, and pulsed radiofrequency (RF) treatment, the effect duration was temporary and the decreases in the patient's pain score were not acceptable. Even the use of SCS did not provide completely satisfactory pain management. However, the trial lead positioning in the cauda equina was able to stimulate the site of the severe pain, and the patient's pain score was dramatically decreased. We report a case of successful pain management with spinal cauda equina stimulation following the failure of SCS in the treatment of intractable phantom limb pain.

Preoperative state anxiety, acute postoperative pain, and analgesic use in persons undergoing lower limb amputation

OBJECTIVES

The current study examined the relationship between preoperative anxiety and acute postoperative phantom limb pain (PLP), residual limb pain (RLP), and analgesic medication use in a sample of persons undergoing lower limb amputation.

MATERIALS AND METHODS

Participants included 69 adults admitted to a large level 1 trauma hospital for lower limb amputation. Participants' average pain and anxiety during the previous week were assessed before amputation surgery. RLP, PLP, and analgesic medication use were measured on each of the 5 days following amputation surgery.

RESULTS

Results of partial-order correlations indicated that greater preoperative anxiety was significantly associated with greater ratings of average PLP for each of the 5 days following amputation surgery, after controlling for preoperative pain ratings and daily postoperative analgesic medication use. Partial correlation values ranged from 0.30 to 0.62, indicating medium to large effects. Preoperative anxiety was also significantly associated with ratings of average RLP only on postoperative day 1, after controlling for preoperative pain ratings and daily postoperative analgesic medication use (r=0.34, P<0.05). Correlations between preoperative anxiety and daily postoperative analgesic medication dose became nonsignificant when controlling for preamputation and postamputation pain ratings.

DISCUSSION

These findings suggest that anxiety may be a risk factor for acute postamputation PLP and RLP, and indicate that further research to examine these associations is warranted. If replicated, the findings would support research to examine the extent to which modifying preoperative anxiety yields a reduction in postoperative acute PLP and RLP.

Thoracic Outlet Syndrome Causing Phantom Hand Pain in a Person With a Transradial Amputation: A Case Presentation

In this case, a 47-year-old commercial truck driver with a remote right transradial amputation presented with pain in the medial aspect of his right phantom hand. He was diagnosed with thoracic outlet syndrome (TOS). This was attributed to the muscular demands associated with using his body-powered prosthesis for many years. TOS remains a controversial diagnosis in the able-bodied population and a unique diagnostic challenge in a patient with a transradial amputation. In this case, consideration of TOS guided the rehabilitation and treatment plan. His pain improved with a conservative stretching program.

Real-Time Control of a Neuroprosthetic Hand by Magnetoencephalographic Signals from Paralysed Patients

Neuroprosthetic arms might potentially restore motor functions for severely paralysed patients. Invasive measurements of cortical currents using electrocorticography have been widely used for neuroprosthetic control. Moreover, magnetoencephalography (MEG) exhibits characteristic brain signals similar to those of invasively measured signals. However, it remains unclear whether non-invasively measured signals convey enough motor information to control a neuroprosthetic hand, especially for severely paralysed patients whose sensorimotor cortex might be reorganized. We tested an MEG-based neuroprosthetic system to evaluate the accuracy of using cortical currents in the sensorimotor cortex of severely paralysed patients to control a prosthetic hand. The patients attempted to grasp with or open their paralysed hand while the slow components of MEG signals (slow movement fields; SMFs) were recorded. Even without actual movements, the SMFs of all patients indicated characteristic spatiotemporal patterns similar to actual movements, and the SMFs were successfully used to control a neuroprosthetic hand in a closed-loop condition. These results demonstrate that the slow components of MEG signals carry sufficient information to classify movement types. Successful control by paralysed patients suggests the feasibility of using an MEG-based neuroprosthetic hand to predict a patient's ability to control an invasive neuroprosthesis via the same signal sources as the non-invasive method.

The embodiment of assistive devices-from wheelchair to exoskeleton

Spinal cord injuries (SCIs) place a heavy burden on the healthcare system and have a high personal impact and marked socio-economic consequences. Clinically, no absolute cure for these conditions exists. However, in recent years, there has been an increased focus on new robotic technologies that can change the frame we think about the prognosis for recovery and for treating some functions of the body affected after SCIs. This review has two goals. The first is to assess the possibility of the embodiment of functional assistive tools after traumatic disruption of the neural pathways between the brain and the body. To this end, we will examine how altered sensorimotor information modulates the sense of the body in SCI. The second goal is to map the phenomenological experience of using external tools that typically extend the potential of the body physically impaired by SCI. More specifically, we will focus on the difference between the perception of one's physically augmented and non-augmented affected body based on observable and measurable behaviors. We discuss potential clinical benefits of enhanced embodiment of the external objects by way of multisensory interventions. This review argues that the future evolution of human robotic technologies will require adopting an embodied approach, taking advantage of brain plasticity to allow bionic limbs to be mapped within the neural circuits of physically impaired individuals.

Effect of local versus remote tonic heat pain during training on acquisition and retention of a finger-tapping sequence task

Although pain is present in a large proportion of patients receiving rehabilitation, its impact on motor learning is still unclear, especially in the case of neuropathic pain that is not tightly linked to specific movements. The aim of this study was to determine the effect of local and remote tonic cutaneous heat pain applied during training on motor learning of a finger-tapping sequence task. Forty-five healthy participants, randomized to the control, local pain or remote pain groups, were trained to perform an explicit finger motor sequence of five items as fast as possible. During the 10 training blocks (30 s each), local pain and remote pain groups received a heat pain stimulus on the wrist or leg, respectively. Performance was tested in the absence of pain in all groups before (baseline), immediately after (post-immediate), 60 min after (post-60 min) and 24 h after training (post-24 h) to assess both acquisition and next-day retention. Speed increased over time from baseline to post-24 h (p < 0.001), without any significant effect of group (p = 0.804) or time × group interaction (p = 0.385), indicating that the acquisition and retention were not affected by the presence of pain during training. No changes were observed on error rates, which were very low even at baseline. These results with experimental heat pain suggest that the ability to relearn finger sequence should not be affected by concomitant neuropathic pain in neurorehabilitation. However, these results need to be validated in the context of chronic pain, by including pain as a co-variable in motor rehabilitation trials.

The mechanism of neurofeedback training for treatment of central neuropathic pain in paraplegia: a pilot study

Background

Central neuropathic pain has a prevalence of 40 % in patients with spinal cord injury. Electroencephalography (EEG) studies showed that this type of pain has identifiable signatures, that could potentially be targeted by a neuromodulation therapy. The aim of the study was to investigate the putative mechanism of neurofeedback training on central neuropathic pain and its underlying brain signatures in patients with chronic paraplegia.

Methods

Patients’ EEG activity was modulated from the sensory-motor cortex, electrode location C3/Cz/C4/P4 in up to 40 training sessions Results. Six out of seven patients reported immediate reduction of pain during neurofeedback training. Best results were achieved with suppressing Ɵ and higher β (20–30 Hz) power and reinforcing α power at C4. Four patients reported clinically significant long-term reduction of pain (>30 %) which lasted at least a month beyond the therapy. EEG during neurofeedback revealed a wide spread modulation of power in all three frequency bands accompanied with changes in the coherence most notable in the beta band. The standardized low resolution electromagnetic tomography analysis of EEG before and after neurofeedback therapy showed the statistically significant reduction of power in beta frequency band in all tested patients. Areas with reduced power included the Dorsolateral Prefrontal Cortex, the Anterior Cingulate Cortex and the Insular Cortex.

Conclusions

Neurofeedback training produces both immediate and longer term reduction of central neuropathic pain that is accompanied with a measurable short and long term modulation of cortical activity. Controlled trials are required to confirm the efficacy of this neurofeedback protocol on treatment of pain. The study is a registered UKCRN clinical trial Nr 9824.

The body fades away: investigating the effects of transparency of an embodied virtual body on pain threshold and body ownership

The feeling of “ownership” over an external dummy/virtual body (or body part) has been proven to have both physiological and behavioural consequences. For instance, the vision of an “embodied” dummy or virtual body can modulate pain perception. However, the impact of partial or total invisibility of the body on physiology and behaviour has been hardly explored since it presents obvious difficulties in the real world. In this study we explored how body transparency affects both body ownership and pain threshold. By means of virtual reality, we presented healthy participants with a virtual co-located body with four different levels of transparency, while participants were tested for pain threshold by increasing ramps of heat stimulation. We found that the strength of the body ownership illusion decreases when the body gets more transparent. Nevertheless, in the conditions where the body was semi-transparent, higher levels of ownership over a see-through body resulted in an increased pain sensitivity. Virtual body ownership can be used for the development of pain management interventions. However, we demonstrate that providing invisibility of the body does not increase pain threshold. Therefore, body transparency is not a good strategy to decrease pain in clinical contexts, yet this remains to be tested.

Transcutaneous electrical nerve stimulation (TENS) for phantom pain and stump pain following amputation in adults

BACKGROUND

This is the first update of a Cochrane review published in Issue 5, 2010 on transcutaneous electrical nerve stimulation (TENS) for phantom pain and stump pain following amputation in adults. Pain may present in a body part that has been amputated (phantom pain) or at the site of amputation (stump pain), or both. Phantom pain and stump pain are complex and multidimensional and the underlying pathophysiology remains unclear. The condition remains a severe burden for those who are affected by it. The mainstay treatments are predominately pharmacological, with increasing acknowledgement of the need for non-drug interventions. TENS has been recommended as a treatment option but there has been no systematic review of available evidence. Hence, the effectiveness of TENS for phantom pain and stump pain is currently unknown.

OBJECTIVES

To assess the analgesic effectiveness of TENS for the treatment of phantom pain and stump pain following amputation in adults.

SEARCH METHODS

For the original version of the review we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, AMED, CINAHL, PEDRO and SPORTDiscus (February 2010). For this update, we searched the same databases for relevant randomised controlled trials (RCTs) from 2010 to 25 March 2015.

SELECTION CRITERIA

We only included RCTs investigating the use of TENS for the management of phantom pain and stump pain following an amputation in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We planned that where available and appropriate, data from outcome measures were to be pooled and presented as an overall estimate of the effectiveness of TENS.

MAIN RESULTS

In the original review there were no RCTs that examined the effectiveness of TENS for the treatment of phantom pain and stump pain in adults. For this update, we did not identify any additional RCTs for inclusion.

AUTHORS' CONCLUSIONS

There were no RCTs to judge the effectiveness of TENS for the management of phantom pain and stump pain. The published literature on TENS for phantom pain and stump pain lacks the methodological rigour and robust reporting needed to confidently assess its effectiveness. Further RCT evidence is required before an assessment can be made. Since publication of the original version of this review, we have found no new studies and our conclusions remain unchanged.

Dorsal Root Ganglion (DRG) Stimulation in the Treatment of Phantom Limb Pain (PLP)

OBJECTIVES

Phantom limb pain (PLP) is a neuropathic condition in which pain is perceived as arising from an amputated limb. PLP is distinct from, although associated with, pain in the residual limb and nonpainful phantom sensations of the missing limb. Its treatment is extremely challenging; pharmaceutical options, while commonly employed, may be insufficient or intolerable. Neuromodulatory interventions such as spinal cord stimulation have generated mixed results and may be limited by poor somatotopic specificity. It was theorized that dorsal root ganglion (DRG) neuromodulation may be more effective.

MATERIALS AND METHODS

Patients trialed a DRG neurostimulation system for their PLP and were subsequently implanted if results were positive. Retrospective chart review was completed, including pain ratings on a 100-mm visual analogue scale (VAS) and patient-reported outcomes.

RESULTS

Across eight patients, the average baseline pain rating was 85.5 mm. At follow-up (mean of 14.4 months), pain was rated at 43.5 mm. Subjective ratings of quality of life and functional capacity improved. Some patients reduced or eliminated pain medications. Patients reported precise concordance of the paresthesia with painful regions, including in their phantom limbs; in one case, stimulation eliminated PLP as well as nonpainful phantom sensations. Three patients experienced a diminution of pain relief, despite good initial outcomes.

CONCLUSIONS

DRG neuromodulation may be an effective tool in treating this pain etiology. Clinical outcomes in this report support recent converging evidence suggesting that the DRG may be the site of PLP generation and/or maintenance. Further research is warranted to elucidate mechanisms and optimal treatment pathways.

An Investigation of the Effects of Different Pulse Patterns of Transcutaneous Electrical Nerve Stimulation (TENS) on Perceptual Embodiment of a Rubber Hand in Healthy Human Participants With Intact Limbs

OBJECTIVE

The aim of this study was to investigate the strength of perceptual embodiment achieved during an adapted version of the rubber hand illusion (RHI) in response to a series of modified transcutaneous electrical nerve stimulation (TENS) pulse patterns with dynamic temporal and spatial characteristics which are more akin to the mechanical brush stroke in the original RHI.

MATERIALS AND METHODS

A repeated-measures counterbalanced experimental study was conducted where each participant was exposed to four TENS interventions: continuous pattern TENS; burst pattern TENS (fixed frequency of 2 bursts per second of 100 pulses per second); amplitude-modulated pattern TENS (intensity increasing from zero to a preset level, then back to zero again in a cyclical fashion); and sham (no current) TENS. Participants rated the intensity of the RHI using a three-item numerical rating scale (each item was ranked from 0 to 10). Friedman's analysis of ranks (one-factor repeated measure) was used to test the differences in perceptual embodiment between TENS innervations; alpha was set at p ≤ 0.05.

RESULTS

There were statistically significant differences in the intensity of misattribution and perceptual embodiment between sham and active TENS interventions, but no significant differences between the three active TENS conditions (amplitude-modulated TENS, burst TENS, and continuous TENS). Amplitude-modulated and burst TENS produced significantly higher intensity scores for misattribution sensation and perceptual embodiment compared with sham (no current) TENS, whereas continuous TENS did not.

CONCLUSION

The findings provide tentative, but not definitive, evidence that TENS parameters with dynamic spatial and temporal characteristics may produce more intense misattribution sensations and intense perceptual embodiment than parameters with static characteristics (e.g., continuous pulse patterns).

Systematic review and meta-analysis of the efficacy of perineural local anaesthetic catheters after major lower limb amputation

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the effects of using an intraoperatively placed perineural catheter (PNC) with a postoperative local anaesthetic infusion on immediate and long-term outcomes after lower limb amputation.

METHODS

A systematic review of key electronic journal databases was undertaken from inception to January 2015. Studies comparing PNC use with either a control, or no PNC, were included. Meta-analysis was performed for postoperative opioid use, pain scores, mortality, and long-term incidence of stump and phantom limb pain. Sensitivity analysis was performed for opioid use. Quality of evidence was assessed using the GRADE system.

RESULTS

Seven studies reporting on 416 patients undergoing lower limb amputation with PNC usage (n = 199) or not (n = 217) were included. Approximately 60% were transtibial amputations PNC use reduced postoperative opioid consumption (standardised mean difference: -0.59, 95% CI -1.10 to -0.07, p = .03), maintained on sensitivity analysis for large (p = .03) and high-quality (p = .003) studies, but was marginally lost (p = .06) on studies enrolling patients with peripheral arterial disease only. PNC treatment did not affect postoperative pain scores (p = .48), in-hospital mortality (p = .77), phantom limb pain (p = .28) or stump pain (p = .37). GRADE quality of evidence for all outcomes was very low.

CONCLUSION

There is poor-quality evidence that PNC usage significantly reduces opioid consumption following lower limb amputation, without affecting other short- or long-term outcomes. Well-performed randomised studies are required.

Phantom Eye Syndrome: Patient Experiences after Enucleation for Uveal Melanoma

PURPOSE

Patients undergoing enucleation for uveal melanoma need to be informed of the possibility of phantom eye syndrome (PES). The number with uveal melanoma in PES studies has been small. Aims were to: (1) determine the prevalence, symptoms, and characteristics of PES and to test associations of PES symptoms with sociodemographic and clinical characteristics; (2) examine the interrelatedness of PES symptoms; and (3) explore the emotional valence of PES and the relationship to anxiety and depression.

DESIGN

Cross-sectional questionnaire.

PARTICIPANTS

Patients (n = 179) with uveal melanoma enucleated 4 to 52 months previously.

METHODS

Questionnaire on PES. Responses to a routine audit of mood obtained from clinical records.

MAIN OUTCOME MEASURES

Patients were asked about 3 symptoms: pain, visual sensations, and a feeling of seeing through the removed eye. Mood was assessed by the Hospital Anxiety and Depression Scale.

RESULTS

Of 179 respondents, 108 (60.3%) experienced symptoms: 86 reported (48%) visual sensations, 50 reported (28%) seeing, and 42 reported (23%) pain; 14 (7.8%) reported all 3 symptoms. At the time of the questionnaire, 31 (17%) experienced 1 or more symptoms daily. Women were more likely to report pain (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.08-4.40). Younger patients at enucleation were more likely to report pain (t = 4.13; degrees of freedom (df), 177; P < 0.001) and visual sensations (t = 2.11; df, 177; P < 0.05). Patients studied sooner after enucleation were more likely to report seeing (Mann-Whitney U, 2343; P < 0.05). Pain and seeing were intercorrelated (chi-square, 5.47; Φ = 0.18; df, 1; P < 0.05), pain with visual sensations (chi-square, 3.91; Φ = 0.15; df, 1; P < 0.05) and seeing with visual sensations (chi-square, 34.22; Φ = 0.45; df, 1; P < 0.001). Twenty of 108 patients (18.5%) found symptoms disturbing, and 21 of 108 (19.4%) pleasurable. Patients reporting pain were more anxious (OR, 3.53; 95% CI, 1.38-9.03) and depressed (OR, 13.26; 95% CI, 3.87-46.21).

CONCLUSIONS

Patients should be informed of PES symptoms. Pain may indicate anxiety or depression; this needs research to determine cause and effect.

Tactile, thermal, and electrical thresholds in patients with and without phantom limb pain after traumatic lower limb amputation

Purpose

To examine whether there is central sensitization in patients with phantom limb pain (PLP) after traumatic limb amputation.

Methods

Seventeen patients after unilateral lower limb amputation secondary to trauma were enrolled. Ten patients had chronic PLP, while the other seven patients had no PLP. Tactile-sensation threshold, cold- and warm-sensation thresholds, cold- and heat-pain thresholds, electrical-sensation threshold (EST), and electrical-pain threshold on the distal residual limb and the symmetrical site on the sound limb were measured in all tested patients. Their thresholds were compared within the PLP and non-PLP group, and between the groups.

Results

The novel findings included: 1) electrical-pain threshold was only decreased in the sound limb in the PLP group and there was no difference between two limbs in the non-PLP group, suggesting central sensitization in patients with PLP; and 2) EST was increased on the affected limb as compared to the sound limb within the PLP group, but there were no significant differences in EST between the PLP and non-PLP group. There were in general no significant differences in other tested thresholds within the groups and between groups.

Conclusion

Our results demonstrate central sensitization in the patients with PLP after traumatic limb amputation.

Short-term effect on pain and function of neurophysiological education and sensorimotor retraining compared to usual physiotherapy in patients with chronic or recurrent non-specific low back pain, a pilot randomized controlled trial

BACKGROUND

Non-specific chronic low back pain (NSCLBP) is a major health problem. Identification of subgroups and appropriate treatment regimen was proposed as a key priority by the Cochrane Back Review Group. We developed a multimodal treatment (MMT) for patients with moderate to severe disability and medium risk of poor outcome. MMT includes a) neurophysiological education on the perception of pain to decrease self-limitation due to catastrophizing believes about the nature of NSCLBP, b) sensory training of the lower trunk because these patients predominantly show poor sensory acuity of the trunk, and c) motor training to regain definite movement control of the trunk. A pilot study was conducted to investigate the feasibility of MMT, prior to a larger RCT, with focus on patients' adherence and the evaluation of short-term effects on pain and disability of MMT when compared to usual physiotherapy.

METHOD

We conducted a randomised controlled trial (RCT) in a primary care physiotherapy centre in Switzerland. Outcome assessment was 12 weeks after baseline. Patients with NSCLBP, considerable disability (five or more points on the Roland and Morris Disability Questionnaire (RMDQ) and medium or high risk of poor outcome on the Keele Start Back Tool (KSBT) were randomly allocated to either MMT or usual physiotherapy treatment (UPT) by an independent research assistant. Treatment included up to 16 sessions over 8 to 12 weeks. Both groups were given additional home training of 10 to 30 minutes to be performed five times per week. Adherence to treatment was evaluated in order to assess the feasibility of the treatment. Assessments were conducted by an independent blinded person. The primary outcome was pain (NRS 0-10) and the secondary outcome was disability (RMDQ). Between-group effects with Student's t-test or the Mann-Whitney U test and the standardized mean difference of the primary outcome were calculated.

RESULTS

Twenty-eight patients (46% male, mean age 41.5 years (SD 10.6)) were randomized to MMT (n = 14) or UPT (n = 14). Patients' adherence to treatment was >80% in both groups. Pain reduction (NRS; [95% CI]) was 2.14 [1.0 to 3.5] in the MMT and 0.69 [-2.0 to 2.5.] in the UPT. The between-group difference was 1.45 [0.0 to 4.0] (p = 0.03), representing a moderate effect size of 0.66 [-0.1 to 1.5]. Reduction in disability on the RMDQ was 6.71 [4.2 to 9.3] in MMT and 4.69 [1.9 to 7.4] in UPT, with a non-significant between-group difference of 2.02 [-1.5 to 5.6] (p = 0.25). The required sample size for a RCT with six months follow-up was estimated at 170 patients.

CONCLUSIONS

MMT was found to be feasible and to significantly reduce pain in the short term when compared with UPT. A future RCT with a six-month follow-up would require approximately 170 patients.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN66262199. Registered 8 January 2014.

Immediate and Sustained Effects of 5-Day Transcranial Direct Current Stimulation of the Motor Cortex in Phantom Limb Pain

The study explored the analgesic effects of transcranial direct current stimulation (tDCS) over the motor cortex on postamputation phantom limb pain (PLP). Eight subjects with unilateral lower or upper limb amputation and chronic PLP were enrolled in a crossover, double-blind, sham-controlled treatment program. For 5 consecutive days, anodal (active or sham) tDCS was applied over the motor cortex for 15 minutes at an intensity of 1.5 mA. The 5-day treatment with active, but not sham, tDCS induced a sustained decrease in background PLP and in the frequency of PLP paroxysms, which lasted for 1 week after the end of treatment. Moreover, on each day of active tDCS, patients reported an immediate PLP relief, along with an increased ability to move their phantom limb. Patients' immediate responses to sham tDCS, on the contrary, were variable, marked by an increase or decrease of PLP levels from baseline. These results show that a 5-day treatment of motor cortex stimulation with tDCS can induce stable relief from PLP in amputees. Neuromodulation targeting the motor cortex appears to be a promising option for the management of this debilitating neuropathic pain condition, which is often refractory to classic pharmacologic and surgical treatments.

PERSPECTIVE

The study describes sustained and immediate effects of motor cortex stimulation by tDCS on postamputation PLP, whose analgesic action seems linked to the motor reactivation of the phantom limb. These results are helpful for the exploitation of tDCS as a therapeutic tool for the management of neuropathic pain.

Developing An Acupuncture Protocol for Treating Phantom Limb Pain: A Delphi Consensus Study

Background

Little is known about how a Traditional Chinese Medicine (TCM) approach could be used to treat phantom limb pain (PLP). There is currently no standard acupuncture protocol in the literature to treat this syndrome.

Objectives

To achieve consensus among a group of acupuncture practitioners on the pathology and recommended treatment of PLP and devise an acupuncture protocol for the treatment of this condition.

Methods

A classical Delphi approach was used using two parallel online Delphi studies. One study focused on participants with past experience of treating PLP (TPLP, n=7) and the other on practitioners with no past experience (NTPLP, n=16). Two hypothetical case studies were provided and participants were asked for responses on how they would treat these patients. Three rounds were included. Participants were also invited to rate and comment on the finalised protocol. Round 1 data were analysed using content analysis. In subsequent rounds an a priori criterion for defining consensus was set at ≤1.75 IQR. A group median of 5–6 was considered to mean ‘agree’.

Results

19 participants completed all Delphi rounds (12 NTPLP, 7 TPLP). 108 NTPLP and 76 TPLP statements were generated and circulated in round 2; 53% of the NTPLP statements and 62% of the TPLP statements met consensus in round 2 and 45% of the NTPLP statements and 44% of the TPLP statements met consensus in round 3. Participants all agreed with the final protocol developed.

Conclusions

The protocol developed does not claim to be best practice but provides a preliminary consensus from practitioners practising acupuncture for the treatment of PLP.

The influence of central neuropathic pain in paraplegic patients on performance of a motor imagery based Brain Computer Interface

•

Motor imagery based BCI-classifier built on EEG data of paraplegic patients, gives higher classification accuracy in patients with central neuropathic pain compared to patients with no chronic pain.

•

Higher BCI classification accuracy in paraplegic patients with central neuropathic pain is accompanied with stronger event related desynchronisation during motor imagery.

•

BCI classification accuracy between feet and a hand was comparable with classification accuracy between hands, in all three groups of participants.

Objective

The aim of this study was to test how the presence of central neuropathic pain (CNP) influences the performance of a motor imagery based Brain Computer Interface (BCI).

Methods

In this electroencephalography (EEG) based study, we tested BCI classification accuracy and analysed event related desynchronisation (ERD) in 3 groups of volunteers during imagined movements of their arms and legs. The groups comprised of nine able-bodied people, ten paraplegic patients with CNP (lower abdomen and legs) and nine paraplegic patients without CNP. We tested two types of classifiers: a 3 channel bipolar montage and classifiers based on common spatial patterns (CSPs), with varying number of channels and CSPs.

Results

Paraplegic patients with CNP achieved higher classification accuracy and had stronger ERD than paraplegic patients with no pain for all classifier configurations. Highest 2-class classification accuracy was achieved for CSP classifier covering wider cortical area: 82 ± 7% for patients with CNP, 82 ± 4% for able-bodied and 78 ± 5% for patients with no pain.

Conclusion

Presence of CNP improves BCI classification accuracy due to stronger and more distinct ERD.

Significance

Results of the study show that CNP is an important confounding factor influencing the performance of motor imagery based BCI based on ERD.

Phantom eye syndrome: a review of the literature

The purpose of this literature review was to describe the main features of phantom eye syndrome in relation to their possible causes, symptoms, treatments, and influence of eye amputation on quality of life of anophthalmic patients. For this, a bibliographical research was performed in Pubmed database using the following terms: “eye amputation,” “eye trauma,” “phantom eye syndrome,” “phantom pain,” and “quality of life,” associated or not. Thirteen studies were selected, besides some relevant references contained in the selected manuscripts and other studies hallowed in the literature. Thus, 56 articles were included in this review. The phantom eye syndrome is defined as any sensation reported by the patient with anophthalmia, originated anophthalmic cavity. In phantom eye syndrome, at least one of these three symptoms has to be present: phantom vision, phantom pain, and phantom sensations. This syndrome has a direct influence on the quality of life of the patients, and psychological support is recommended before and after the amputation of the eyeball as well as aid in the treatment of the syndrome. Therefore, it is suggested that, for more effective treatment of phantom eye syndrome, drug therapy should be associated with psychological approach.

A review of hyperacusis and future directions: part I. Definitions and manifestations

PURPOSE

Hyperacusis can be extremely debilitating, and at present, there is no cure. We provide an overview of the field, and possible related areas, in the hope of facilitating future research.

METHOD

We review and reference literature on hyperacusis and related areas. We have divided the review into 2 articles. In Part I, we discuss definitions, epidemiology, different etiologies and subgroups, and how hyperacusis affects people. In Part II, we review measurements, models, mechanisms, and treatments, and we finish with some suggestions for further research.

RESULTS

Hyperacusis encompasses a wide range of reactions to sound, which can be grouped into the categories of excessive loudness, annoyance, fear, and pain. Many different causes have been proposed, and it will be important to appreciate and quantify different subgroups. Reasonable approaches to assessing the different forms of hyperacusis are emerging, including psychoacoustical measures, questionnaires, and brain imaging.

CONCLUSIONS

Hyperacusis can make life difficult for many, forcing sufferers to dramatically alter their work and social habits. We believe this is an opportune time to explore approaches to better understand and treat hyperacusis.

Outcomes of ultrasound-guided extracorporeal shock wave therapy for painful stump neuroma

OBJECTIVE

To investigate the effect of extracorporeal shock wave therapy (ESWT) on painful stump neuroma.

METHODS

Thirty patients with stump neuroma at the distal end of an amputation site were assigned randomly to the ESWT group (n=15) and the transcutaneous electrical nerve stimulation (TENS)+desensitization+pharmacological treatment group (n=15). For 3 weeks, the ESWT group received a weekly session involving 1,500 pulses at 0.10 mJ/mm(2), while the control group was treated 10 times each, 40 minutes per day with TENS and desensitization treatment, and daily medication for 3 weeks. ESWT stimulation was given by focusing on the area at the neuroma site clearly identified by ultrasound.

RESULTS

The changes in the McGill pain questionnaire were 38.8±9.0 prior to treatment and 11.8±3.1 following the treatment. The corresponding values for the control group were 37.2±7.7 and 28.5±10.3. The changes between groups were significantly different (p=0.035). The change in visual analog scale prior to and after treatment was 7.0±1.5 and 2.8±0.8 in the ESWT group, respectively, and 7.2±1.4 and 5.8±2.0 in the control group. These changes between the groups were also significantly different (p=0.010). The outcome in the pain rating scale also showed significant differences between groups (p<0.001). Changes in neuroma size and pain pressure threshold (lb/cm(2)) were not significantly different between groups (p>0.05).

CONCLUSION

The study findings imply that ESWT for stump neuroma is superior to conventional therapy.

Phantom limb pain: an energy/trauma model

Phantom limb pain (PLP) is a form of chronic neuropathic pain that responds poorly to treatment interventions derived from the neuroanatomic understanding of pain and analgesia. Several new psychological and behavioral treatments that have proven more effective have been explained by invoking neural plasticity as their mechanism of action. Other novel treatments that are based on an "energy medicine" model also appear to be quite effective, especially when addressing the psychological trauma of the amputation itself, a factor that is generally overlooked in the standard surgical approach to limb amputation. A speculative trauma/energy model for the etiology of PLP is proposed. This model is developed in some detail, and its utility in explaining several anomalous aspects of PLP, as well as the clinical efficacy of energy therapies, is outlined. This model is proposed as a step in the development of simple and effective energy/trauma treatment protocols for this widespread and largely treatment-resistant disorder.

Continuous regional anaesthesia provides effective pain management and reduces opioid requirement following major lower limb amputation

OBJECTIVES

Postoperative stump pain after major lower limb amputation is a significant impediment to the recovery of amputees. The vast majority of patients require opioid analgesics following surgery, which are associated with opioid-related side-effects. Here, we investigate whether intraoperative placement of a peripheral nerve stump catheter followed by continuous infusion of local anesthetic is as effective at pain control as current analgesic practices. If beneficial, this procedure could potentially reduce post-amputation opioid consumption and opioid-related adverse effects.

METHODS

A retrospective chart review was conducted of 198 patients over a 4-year period who had undergone a major lower limb amputation for indications related to peripheral vascular disease. Postoperatively, 102 patients received a perineural catheter were compared to 96 patients who did not. The primary outcomes of this study were the amount of morphine equivalents used in the first 72 hours postoperatively and postoperative pain intensity in the first 24 hours.

RESULTS

A total of 198 lower-limb amputations were selected for analyses. Multiple regression analyses indicated that perineural catheter use was associated with a lower cumulative postoperative opioid consumption over the first 72 hours but not postoperative pain scores at 24 hours. Perineural catheter use led to a 40% reduction in opioid use during the first 72 hours postoperatively. Mixed model repeated measures analysis demonstrated that this opioid reduction was consistent over time. Other variables related to total opioid use included age, pre-surgical chronic pain, pre-surgical opioid use, patient-controlled analgesia.

CONCLUSIONS

Continuous perineural infusions of local anesthetic are a safe and effective method for reducing post-amputation opioid analgesic medications after major lower limp amputation.

Introduction to neuropathic pain syndromes

Chronic pain impairs the quality of life for millions of individuals and therefore presents a serious ongoing challenge to clinicians and researchers. Debilitating chronic pain syndromes cost the US economy more than $600 billion per year. This article provides an overview of the epidemiology, clinical presentation, and treatment outcomes for craniofacial, spinal, and peripheral neurologic pain syndromes. Although the authors recognize that the diagnosis and treatment of the chronic forms of neuropathic pain syndromes represent a clinical challenge, there is an urgent need for standardized classification systems, improved epidemiologic data, and reliable treatment outcomes data.