The experience of phantom limb pain in patients with combat-related traumatic amputations

A systematic review of the prevalence of postamputation and chronic neuropathic pain associated with combat injury in military personnel

ABSTRACT

Combat trauma can lead to widespread tissue damage and limb loss. This may result in chronic neuropathic and post amputation pain, including phantom limb pain (PLP) and residual limb pain (RLP). The military population is distinct with respect to demographic, injury, and social characteristics compared with other amputation and trauma cohorts. We undertook a systematic review of studies of military personnel, with a history of combat injury, that reported a prevalence of any type of postamputation pain or chronic neuropathic pain, identified from Embase and MEDLINE databases.Using the inverse variance method with a random-effects model, we undertook a meta-analysis to determine an overall prevalence and performed exploratory analyses to identify the effect of the type of pain, conflict, and time since injury on prevalence. Pain definitions and types of pain measurement tools used in studies were recorded. Thirty-one studies (14,738 participants) were included. The pooled prevalence of PLP, RLP, and chronic neuropathic pain were 57% (95% CI: 46-68), 61% (95% CI: 50-71), and 26% (95% CI: 10-54), respectively. Between-study heterogeneity was high (I 2 : 94%-98%). Characterisation of duration, frequency, and impact of pain was limited. Factors reported by included studies as being associated with PLP included the presence of RLP and psychological comorbidity. The prevalence of postamputation pain and chronic neuropathic pain after combat trauma is high. We highlight inconsistency of case definitions and terminology for pain and the need for consensus in future research of traumatic injury.

The Exploration of the GWOT Combat Amputee's Experience With Longitudinal Care: A Qualitative Study

INTRODUCTION

Contemporary advances in combat medicine have allowed greater numbers of wounded service members to survive their injuries. An estimated 1,705 combat veterans sustained major lower or upper extremity amputations between 2001 and 2017 during the Global War on Terror. This study intends to answer the following question utilizing a qualitative study design: What were the common and abnormal experiences of the Global War on Terror combat amputees relative to their mechanism of injury, perception of injury, and systems of care utilized during their recovery and rehabilitation process?.

METHODS

During the months of December 2022 and January 2023, individual semi-structured interviews were conducted with U.S. Marines that served in the Global War on Terror (total n = 10). Deductive and inductive approaches were employed to identify codes, themes, and meta-themes in the data.

RESULTS

All participants deployed to Afghanistan between the years 2010 and 2014 and were assigned to the following military occupational specialties: Explosive Ordnance Disposal technicians (total n = 2); combat engineers (total n = 2); and infantrymen (total n = 6). Analysis of data collected from interviews highlighted these key observations: (1) Themes in the combat amputee experience include support, systems of care, and mindset and (2) the themes synergistically contribute to the meta-themes mental health and pain and vice versa. As all participants were subjected to a blast mechanism of injury, it is difficult to determine if this played a role in deviating rehabilitation and recovery processes. Perception of injury and how well participants adapted to their new lifestyle, meaning how optimistic they were, appeared to play a significant role in recovery. Participants had mixed feelings about the care they had received but generally spoke favorably of military hospitals and were frustrated with the Veteran Affairs, and there was no clear consensus on their relationship with civilian health care, though most participants chose to seek most of their care through the Veteran Affairs.

CONCLUSION

Based on the research question, this study found an intricate relationship between mental health, pain, and the experiences of the participants regarding their care and rehabilitation. However, the nature of qualitative research makes it impossible to determine generalizations that can be used to create meaningful change to address improving combat amputee veteran care. Further research into long-term health outcomes based on hypotheses not evaluated in existing literature would further improve the ability of health care providers to care for this unique patient population.

"I did not expect the doctor to treat a ghost": a systematic review of published reports regarding chronic postamputation pain in British First World War veterans

Limb trauma remains the most prevalent survivable major combat injury. In the First World War, more than 700,000 British soldiers received limb wounds and more than 41,000 underwent an amputation, creating one of the largest amputee cohorts in history. Postamputation pain affects up to 85% of military amputees, suggesting that up to 33,000 British First World War veterans potentially reported postamputation pain. This qualitative systematic review explores the professional medical conversation around clinical management of chronic postamputation pain in this patient cohort, its development over the 20th century, and how this information was disseminated among medical professionals. We searched The Lancet and British Medical Journal archives (1914-1985) for reports referring to postamputation pain, its prevalence, mechanisms, descriptors, or clinical management. Participants were First World War veterans with a limb amputation, excluding civilians and veterans of all other conflicts. The search identified 9809 potentially relevant texts, of which 101 met the inclusion criteria. Reports emerged as early as 1914 and the discussion continued over the next 4 decades. Unexpected findings included early advocacy of multidisciplinary pain management, concerns over addiction, and the effect of chronic pain on mental health emerging decades earlier than previously thought. Chronic postamputation pain is still a significant issue for military rehabilitation. Similarities between injury patterns in the First World War and recent Iraq and Afghanistan conflicts mean that these historical aspects remain relevant to today's military personnel, clinicians, researchers, and policymakers.

Haunting of the phantom limb pain abolished by buprenorphine/naloxone

Neuropathic opioid refractory phantom limb pain (PLP) following amputation can be a life long debilitating chronic pain syndrome capable of completely destroying a patient's life. The pain, its associated depression and sleep deprivation can make many patients suicidal. Ever changing and relentless, it is notoriously unresponsive to traditional cocktails of strong opioids, adjuvant pain medications, antidepressants, local anaesthetics, nerve stimulators, hypnotics and psychotropics. Drug effects are seldom more effective than placebo. We describe a successful sustained rescue of a difficult 2-year-long PLP case with sublingual buprenorphine/naloxone using the drug's potent multimodal mechanisms of action: potent long-acting mu agonist/antagonist, kapa receptor antagonist, delta receptor antagonist and novel opioid receptor-like 1 (OR-L1) agonist effects. Traditional escalating pure mu-opioid receptor agonists and adjuvant neuropathic pain cocktails often have disappointing efficacy in the treatment of resistant PLP. We suggest introducing buprenorphine/naloxone as an early effective opioid choice in PLP management.

The prevalence and risk factors for phantom limb pain in people with amputations: A systematic review and meta-analysis

Background

Phantom limb pain (PLP)—pain felt in the amputated limb–is often accompanied by significant suffering. Estimates of the burden of PLP have provided conflicting data. To obtain a robust estimate of the burden of PLP, we gathered and critically appraised the literature on the prevalence and risk factors associated with PLP in people with limb amputations.

Methods

Articles published between 1980 and July 2019 were identified through a systematic search of the following electronic databases: MEDLINE/PubMed, PsycINFO, PsycArticles, Cumulative Index to Nursing and Allied Health Literature, Africa-Wide Information, Health Source: Nursing/Academic Edition, SCOPUS, Web of Science and Academic Search Premier. Grey literature was searched on databases for preprints. Two reviewers independently conducted the screening of articles, data extraction and risk of bias assessment. The meta-analyses were conducted using the random effects model. A statistically significant level for the analyses was set at p<0.05.

Results

The pooling of all studies demonstrated a prevalence estimate of 64% [95% CI: 60.01–68.05] with high heterogeneity [I² = 95.95% (95% CI: 95.10–96.60)]. The prevalence of PLP was significantly lower in developing countries compared to developed countries [53.98% vs 66.55%; p = 0.03]. Persistent pre-operative pain, proximal site of amputation, stump pain, lower limb amputation and phantom sensations were identified as risk factors for PLP.

Conclusion

This systematic review and meta-analysis estimates that six of every 10 people with an amputation report PLP–a high and important prevalence of PLP. Healthcare professionals ought to be aware of the high rates of PLP and implement strategies to reduce PLP by addressing known risk factors, specifically those identified by the current study.

Chronic neuropathic pain after traumatic peripheral nerve injuries in the upper extremity: prevalence, demographic and surgical determinants, impact on health and on pain medication

Background and aims Aside from the long term side effects of a nerve injury in the upper extremity with devastating consequences there is often the problem of chronic neuropathic pain. The studies concerning the prevalence of persistent pain of neuropathic origin after peripheral nerve injuries are sparse. The prevalence and risk factors associated with chronic neuropathic pain after nerve injuries in the upper extremity were assessed. Methods A standardized data collection template was employed prospectively and retrospectively for all patients with traumatic nerve injuries accepted at the Hand Surgery Department, Uppsala, Sweden between 2010 and 2018. The template included demographic data, pain diagnosis, type of injured nerve, level of injury, date of the lesion and repair, type of procedure, reoperation, time since the procedure, S-LANSS questionnaire (Self report-Leeds Assessment of Neuropathic Symptoms and Signs), RAND-36 (Item short form health survey), QuickDASH (Disability of Shoulder, Arm and Hand) and additional questionnaires concerned medication, pain intensity were sent to 1,051 patients with nerve injuries. Partial proportional odds models were used to investigate the association between persistent pain and potential predictors. Results More than half of the patients undergoing a surgical procedure developed persistent pain. Prevalence of neuropathic pain was 73% of the patients with pain (S-LANSS ≥ 12 or more). Multivariate analysis indicated that injury of a major nerve OR 1.6 (p = 0.013), years from surgery OR 0.91 (p = 0.01), younger age OR 0.7 (p < 0.001), were the main factors for predicting pain after surgery. The type of the nerve injured was the strongest predictor for chronic pain with major nerves associated with more pain (p = 0.019). Conclusions A high prevalence of chronic pain and neuropathic pain with a negative impact on quality of life and disability were found in patients after traumatic nerve injury. Major nerve injury, younger age and less time from surgery were predictors for chronic pain.

Percutaneous Peripheral Nerve Stimulation for the Treatment of Chronic Pain Following Amputation

Introduction

Chronic pain and reduced function are significant problems for Military Service members and Veterans following amputation. Peripheral nerve stimulation (PNS) is a promising therapy, but PNS systems have traditionally been limited by invasiveness and complications. Recently, a novel percutaneous PNS system was developed to reduce the risk of complications and enable delivery of stimulation without surgery.

Materials and Methods

Percutaneous PNS was evaluated to determine if stimulation provides relief from residual and phantom limb pain following lower-extremity amputation. PNS leads were implanted percutaneously to deliver stimulation to the femoral and/or sciatic nerves. Patients received stimulation for up to 60 days followed by withdrawal of the leads.

Results

A review of recent studies and clinical reports found that a majority of patients (18/24, 75%) reported substantial (≥50%) clinically relevant relief of chronic post-amputation pain following up to 60 days of percutaneous PNS. Reductions in pain were frequently associated with reductions in disability and pain interference.

Conclusions

Percutaneous PNS can durably reduce pain, thereby enabling improvements in quality of life, function, and rehabilitation in individuals with residual or phantom limb pain following amputation. Percutaneous PNS may have additional benefit for Military Service members and Veterans with post-surgical or post-traumatic pain.

Mirror Therapy in the Management of Phantom Limb Pain

In this case study, we investigated the efficacy of mirror therapy and online counseling in the management of phantom limb pain. The patient was a 28-year-old woman who experienced phantom limb pain after a traumatic transhumeral amputation three and a half months before initiating therapy. After a 40-minute educational session with a nurse researcher experienced in pain management and surgical nursing, the patient practiced mirror therapy at home for four weeks and kept in contact with the nurse using a mobile chat application. The patient scored the intensity of her pain before and after each practice session on a 0-to-10 numeric pain scale. The first week was difficult for her because of tiredness and the pain. In the second week she experienced less pain during the day than at night but claimed to feel much better than before. In the fourth week, she reported having difficulty sleeping, but she stated that her pain had decreased. The intensity of the pain didn't change following mirror therapy in the first week; however, her average pain score was 1.15 points lower after mirror therapy in the second week (from 4.57 to 3.42), and 1.57 points lower in the third and fourth weeks (from 5.42 to 3.85 and 4.85 to 3.28). Online counseling for mirror therapy is easy, economical, and time-saving for patient and nurse alike. However, physical and physiological problems experienced during this process may reduce the effectiveness of the therapy, highlighting the importance of a multidisciplinary approach to phantom limb pain management, which may include care from a psychologist, massage therapist, physiotherapist, and specialist in alternative therapies for relaxation, in addition to the surgeon and the nurse.

Blast injuries in children: a mixed-methods narrative review

BACKGROUND AND SIGNIFICANCE

Blast injuries arising from high explosive weaponry is common in conflict areas. While blast injury characteristics are well recognised in the adults, there is a lack of consensus as to whether these characteristics translate to the paediatric population. Understanding blast injury patterns in this cohort is essential for providing appropriate provision of services and care for this vulnerable cohort.

METHODS

In this mixed-methods review, original papers were screened for data pertaining to paediatric injuries following blasts. Information on demographics, morbidity and mortality, and service requirements were evaluated. The papers were written and published in English from a range of international specialists in the field.

RESULTS

Children affected by blast injuries are predominantly male and their injuries arise from explosive remnants of war, particularly unexploded ordinance. Blasts show increased morbidity and mortality in younger children, while older children have injury patterns similar to adults. Head and burn injuries represent a significant cause of mortality in young children, while lower limb morbidity is reduced compared with adults. Children have a disproportionate requirement for both operative and non-operative service resources, and provisions for this burden are essential.

CONCLUSIONS

Certain characteristics of paediatric injuries arising from blasts are distinct from that of the adult cohort, while the intensive demands on services highlight the importance of understanding the diverse injury patterns in order to optimise future service provisions in caring for this child blast survivor.

A Pre-clinical Study of the Response Threshold of Intact and Transected Nerves to Stimulation by Transcutaneous Intense Focused Ultrasound

We used diagnostic ultrasound imaging to guide individual bursts (0.1 s) of 2 MHz intense focused ultrasound (iFU) to determine the sensitivity of intact and transected nerves. We found that all nerves had greater sensitivity to iFU stimulation than surrounding muscle. Intact nerves from healthy volunteers had less sensitivity to iFU stimulation (272 ± 35 W/cm² [median ± standard error]) than transected nerves (19 ± 37 W/cm²). Intact, contralateral nerves of amputees dichotomized naturally into two groups-one very sensitive to iFU stimulation (6 ± 2 W/cm²) and one relatively insensitive (539 ± 19 W/cm²), compared with the intact nerves of healthy volunteers. Our study demonstrates the ability of iFU under ultrasound image guidance to stimulate deep, intact and transected peripheral nerves. It also highlights differences in the receptivity to ultrasound stimulation of the peripheral nerves of amputees versus healthy volunteers.

Intense Focused Ultrasound Preferentially Stimulates Transected Nerves Within Residual Limbs: Pilot Study

Objective

Identifying pain generators in tissue deep in the skin can require uncomfortable, complicated, and invasive tests. We describe pilot studies testing the hypothesis that ultrasound image-guided, intense focused ultrasound (ig-iFU) can noninvasively and differentially stimulate the end of transected nerves in the residual limbs of amputee patients.

Design

We applied iFU to the transected nerve ending as individual pulses with a length of 0.1 seconds using a carrier frequency of 2.0 MHz. After targeting, we gradually increased the iFU intensity to reach consistent patient-reported stimulation of the transected nerve ending. We also stimulated the proximal nerve, tissue near the nerve ending, and the intact contralateral nerve. We described the resulting sensations and correlated the results of the study participant's pre-iFU study responses to phantom and residual limb pain questionnaires.

Results

iFU spatial and temporal average intensity values between 16 W/cm2 and 433 W/cm2 that were applied to the transected nerve ending and proximal nerve elicited sensations, including phantom limb sensations, while the same intensity applied to control tissue centimeters away from the nerve ending, or to the intact nerve on the contralateral limb, did not. Two out of 11 study participants reported only mild and transient pain created by iFU stimulation. Successful iFU intensity values correlated with neither phantom nor residual limb pain scores.

Conclusions

Transected nerves had greater sensitivity to iFU stimulation than ipsilateral and contralateral control tissue, including intact nerve. These results support the view that ig-iFU may one day help physicians identify deep, tender tissue in patients who report experiencing pain.

Correlates of Residual Limb Pain: From Residual Limb Length and Usage to Metabolites and Activity in Secondary Somatosensory Cortex

Most recent studies attribute residual limb pain to peripheral pathological changes of the stump. However, in this paper, we focus on its associations with the residual limb length, usage, as well as the metabolic and functional alterations of the brain. The secondary somatosensory cortex (S2), one important area involved in pain intensity discrimination, was selected as the region of interest. Twenty-two upper-limb amputees were recruited and divided into two groups, i.e., amputees with residual limb pain (9/22) and without residual limb pain (13/22). The residual limb length, usage, as well as the metabolite concentration, resting-state activity and BOLD responses to the tactile stimulation in the contralateral S2, were compared between the two groups and correlated with the pain intensity. The amputees with residual limb pain showed significantly shorter length and less usage of the residual limb than the amputees without residual limb pain, and the pain intensity was significantly negatively correlated with the residual limb length and usage. In addition, the pain intensity was significantly correlated with the tNAA/tCr ratio, resting-state fALFF in the slow-4 band, and BOLD response to the tactile stimulation in the contralateral S2, although there were no significant group differences. Regression analysis suggested that residual limb pain is associated with shorter residual limb length and less residual limb usage.

Combat-related foot injuries: impact on gait and functional outcome

Introduction

Prior to deployment of the Netherlands Army Task Force Urozgan in Afghanistan, the Dutch Military and civilian healthcare systems had limited experience in treating blast injuries and their long-term consequences. This meant that guidelines for treatment and rehabilitation were lacking. The aim of this cohort study was to quantify kinematic and kinetic abnormalities in service members with foot injuries in relation to functional outcome using gait analysis.

Method

In nine service members with combat-related talus, calcaneus and/or navicular bone (TCN) fractures and nine controls, gait parameters were measured using Gait Real-Time Analysis Interactive Lab system. High-level mobility was evaluated by the Comprehensive High-Level Activity Mobility Predictor (CHAMP), and functional ability was assessed by Lower Extremity Functional Scale (LEFS) questionnaire.

Results

Significant differences were found for LEFS and CHAMP scores (P<0.01), comfortable walking speed and ankle joint range of motion (ROM) (P<0.05), all lower in the group with TCN fractures. For this group, a trend (0.1>P>0.05) for higher step width and lower stride duration and peak power was found. A strong correlation (0.6>r>0.79) is shown between LEFS and comfortable walking speed and CHAMP and ankle joint ROM. The correlations between LEFS and stride duration, step width, ankle joint ROM and peak power, and between CHAMP and comfortable walking speed and stride duration, were moderate (0.4>r>0.59).

Conclusions

This study demonstrated that service members with TCN fractures, compared with healthy controls, have altered gait characteristics, specifically lower walking speed and ankle joint ROM, both related to lower physical functioning. Patients with bilateral depressed Böhler’s angle had the worse functional performance, and further research is recommended to evaluate the relationship between Böhler’s angle and physical performance.

Clinical Trial

The Dutch Ministry of Defence (MOD) and the Institutional Review Board and Medical Ethics Review Committee Brabant, The Netherlands, approved this study (P1550).

Home-Based Tactile Discrimination Training Reduces Phantom Limb Pain

BACKGROUND

Phantom limb pain (PLP) affects a high percentage of amputees. Since treatment options are limited, low quality of life and addiction to pain medication frequently occur. New treatments, such as mirror therapy or electrical sensory discrimination training, make use of the brain's plasticity to alleviate this centrally derived pain.

AIM

This pilot study assessed the question of whether home-based tactile discrimination training (TDT) leads to a stronger decrease in PLP levels compared to standard massage treatment.

DESIGN

Controlled study.

SETTING

Outpatient.

POPULATION

Amputees (upper/lower extremity) with a PLP score of 4 or higher out of a possible 10 points on the visual analog scale.

METHODS

Eight patients participated in the study. The treatment phase comprised 2 weeks (15 minutes daily). Subjects were examined at baseline, after treatment, 2 weeks after completing treatment, and 4 weeks after completing treatment. Pain was assessed using the West Haven-Yale Multidimensional Pain Inventory.

RESULTS

There was a significantly stronger reduction in PLP in the treatment group receiving TDT. PLP intensity ratings were significantly reduced at the end of therapy, and at 2 and 4 weeks after completing treatment compared to pretreatment.

CONCLUSIONS

TDT seems to be an easy, cheap, time-effective, and safe method to achieve sustained alleviation of PLP and also brings about a positive change in body image.

REHABILITATION IMPACT

Home-based TDT could achieve a sustained reduction in PLP and should be considered as a possible alternative to established treatment methods.

Treating individuals with amputations in therapeutic massage and bodywork practice: A qualitative study

INTRODUCTION

Best practices for massage therapy and bodywork (TMB) treatment of individuals with amputations are not well established. Although anecdotal observations are available, they have limited applicability for informing effective massage therapy and bodywork approaches for individuals with amputations. This study is part of a multifaceted research program seeking to establish a foundation for education and investigation of TMB for amputation related conditions/symptomology. The purpose of this study was to understand how TMB practitioners approach and treat individuals with amputations and their perceptions of outcomes. The TMB practitioner perspective is important in informing the development of a TMB practice framework for people with amputation.

METHODS

The methodology of this study was informed by the phenomenological approach to qualitative inquiry. Semi-structured telephone interviews were conducted between June and September 2015, recorded and transcribed. Analysis consisted of descriptive coding and themes emerged through an iterative process. Codes and themes were discussed and verified with the research team. Participants were invited to review developed themes to indicate the extent to which results accurately encompassed their experiences as TMB practitioners.

RESULTS

Twenty-five community practicing, professional TMB practitioners from 16 states consented to participate and all completed one interview. Analysis identified four themes which indicated TMB practitioners: value touch and consider it a core aspect of treatment for individuals with amputations; operate under a core belief that individuals with amputations greatly benefit from TMB; and consider relief that stems from TMB to be multidimensional, including physical, mental, and emotional aspects; and, certain components of treatment approach are unique to amputation clients.

CONCLUSIONS

Findings support that individuals with amputation benefit from TMB, at least from the perspective of TMB practitioners. Findings of this exploratory research identify important questions regarding approaches to treatment and potential TMB effectiveness hypotheses for amputation populations. Next steps will consider TMB approach and effects from the perspective of those with amputation(s).

Veterans and chronic pain

1. Musculoskeletal problems are the commonest reason for medical discharge in all the British armed forces. By definition, these problems are chronic and resistant to treatment. 2. Pain is also common in veterans who have experienced severe injuries (polytrauma), often accompanied by post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI) orpostconcussive syndrome. 3. In veterans seeking treatment for chronic pain, PTSD is common. There is also evidence for elevated levels of alcohol misuse in veterans who have been deployed to conflict. However, most veterans do not have pain, PTSD or alcohol problems. 4. Pain clinicians would benefit from training in meeting veterans' needs, in order to promote their engagement and successful treatment. This should include countering stereotypes, information about the military and support for the assessment and onward referral of PTSD and alcohol problems.

Intense focused ultrasound preferentially stimulates subcutaneous and focal neuropathic tissue: preliminary results

OBJECTIVE

Potential peripheral sources of pain from subcutaneous tissue can require invasive evocative tests for their localization and assessment. Here, we describe studies whose ultimate goal is development of a noninvasive evocative test for subcutaneous, painful tissue.

DESIGN

We used a rat model of a focal and subcutaneous neuroma to test the hypothesis that intense focused ultrasound can differentiate focal and subcutaneous neuropathic tissue from control tissue. To do so, we first applied intense focused ultrasound (2 MHz, with individual pulses of 0.1 second in duration) to the rat's neuroma while the rat was under light anesthesia. We started with low values of intensity, which we increased until intense focused ultrasound stimulation caused the rat to reliably flick its paw. We then applied that same intense focused ultrasound protocol to control tissue away from the neuroma and assayed for the rat's response to that stimulation.

RESULTS

Intense focused ultrasound of sufficient strength (I(SATA) of 600 +/- 160 W/cm(2) ) applied to the neuroma caused the rat to flick its paw, while the same intense focused ultrasound applied millimeters to a centimeter away failed to induce a paw flick.

CONCLUSION

Successful stimulation of the neuroma by intense focused ultrasound required colocalization of the neuroma and intense focused ultrasound supporting our hypothesis.

Phantom limb pain in daily practice--still a lot of work to do!

OBJECTIVES

Effective treatment of phantom limb pain (PLP, pain felt in the part of the body of an amputated limb) is still difficult to achieve, and improved treatment is needed. It is therefore of paramount interest to understand the current practice of PLP therapy outside pain centers.

DESIGN

As a part of a nationwide survey, 537 amputees were asked 11 questions related to their treatment experiences and the pain relief. Furthermore, the patients' opinion about the quality of medical care was also asked.

RESULTS

Five hundred thirty-seven out of 1088 amputees returned the questionnaire (49.4%). Four hundred (74.5%) suffered from PLP. The patients rated their caregivers' knowledge about PLP lower than their own. Many (41.6%) of PLP patients had never been informed about the possibility of occurrence and mechanisms of PLP. The vast majority of the PLP patients did not try any treatment. Among those treated, more than 30% consulted more than three physicians for beneficial treatment. A >50% pain reduction was achieved in only 12.7% of PLP patients. The most successful treatments were opioids (67.4%) and anticonvulsants (51.7%). Surgery was performed in 46.4% of all PLP patients and in 29.7% due to a clinically suspected neuroma. After surgery, pain was worse or unchanged in 50% and improved in 41.6%, and 7.4% were pain-free.

CONCLUSIONS

Our results suggest that there are primary needs for better information about PLP pathophysiology and treatment not only for patients but also for caregivers. Limited therapeutic success reveals a further need for increased research in PLP management.

Battlefield analgesia: a brief review of current trends and concepts in the treatment of pain in US military casualties from the conflicts in Iraq and Afghanistan

SUMMARY Battlefield analgesia and post-injury pain management is a high priority within the military medical community. The combined military services of the USA have developed a Pain Task Force and clinical practice guidelines to ensure that adequate analgesia is provided to our wounded soldiers as far forward as the point of injury on the battlefield. As a result of this emphasis, novel analgesic techniques and equipment have led to improved pain management. Continuous peripheral nerve blocks, intranasal ketamine, battlefield acupuncture and other adjuncts have all been utilized safely and successfully. The ability to provide rapid analgesia as early in the course of injury as possible not only helps with the immediate pain of the soldier, but potentially minimizes the risk of developing chronic postinjury pain. During the long medical evacuation system the risks of both undertreatment and overtreatment of pain are very real. Future studies and observation will help to delineate best treatment regimens and pave the way for the next generation of medical providers to positively impact a soldier’s recovery. This article is written from the perspective of the USA with a focus on the conflicts in Afghanistan (Operation Enduring Freedom) and Iraq (Operation Iraqi Freedom).

Neurological diseases and pain

Chronic pain is a frequent component of many neurological disorders, affecting 20-40% of patients for many primary neurological diseases. These diseases result from a wide range of pathophysiologies including traumatic injury to the central nervous system, neurodegeneration and neuroinflammation, and exploring the aetiology of pain in these disorders is an opportunity to achieve new insight into pain processing. Whether pain originates in the central or peripheral nervous system, it frequently becomes centralized through maladaptive responses within the central nervous system that can profoundly alter brain systems and thereby behaviour (e.g. depression). Chronic pain should thus be considered a brain disease in which alterations in neural networks affect multiple aspects of brain function, structure and chemistry. The study and treatment of this disease is greatly complicated by the lack of objective measures for either the symptoms or the underlying mechanisms of chronic pain. In pain associated with neurological disease, it is sometimes difficult to obtain even a subjective evaluation of pain, as is the case for patients in a vegetative state or end-stage Alzheimer's disease. It is critical that neurologists become more involved in chronic pain treatment and research (already significant in the fields of migraine and peripheral neuropathies). To achieve this goal, greater efforts are needed to enhance training for neurologists in pain treatment and promote greater interest in the field. This review describes examples of pain in different neurological diseases including primary neurological pain conditions, discusses the therapeutic potential of brain-targeted therapies and highlights the need for objective measures of pain.

21. Phantom pain

Phantom pain is pain caused by elimination or interruption of sensory nerve impulses by destroying or injuring the sensory nerve fibers after amputation or deafferentation. The reported incidence of phantom limb pain after trauma, injury or peripheral vascular diseases is 60% to 80%. Over half the patients with phantom pain have stump pain as well. Phantom pain can also occur in other parts of the body; it has been described after mastectomies and enucleation of the eye. Most patients with phantom pain have intermittent pain, with intervals that range from 1 day to several weeks. Even intervals of over a year have been reported. The pain often presents itself in the form of attacks that vary in duration from a few seconds to minutes or hours. In most cases, the pain is experienced distally in the missing limb, in places with the most extensive innervation density and cortical representation. Although there are still many questions as to the underlying mechanisms, peripheral as well as central neuronal mechanisms seem to be involved. Conservative therapy consists of drug treatment with amitriptyline, tramadol, carbamazepine, ketamine, or morphine. Based on the available evidence some effect may be expected from drug treatment. When conservative treatment fails, pulsed radiofrequency treatment of the stump neuroma or of the spinal ganglion (DRG) or spinal cord stimulation could be considered (evidence score 0). These treatments should only be applied in a study design.

Neuropathic pain: a maladaptive response of the nervous system to damage

Neuropathic pain is triggered by lesions to the somatosensory nervous system that alter its structure and function so that pain occurs spontaneously and responses to noxious and innocuous stimuli are pathologically amplified. The pain is an expression of maladaptive plasticity within the nociceptive system, a series of changes that constitute a neural disease state. Multiple alterations distributed widely across the nervous system contribute to complex pain phenotypes. These alterations include ectopic generation of action potentials, facilitation and disinhibition of synaptic transmission, loss of synaptic connectivity and formation of new synaptic circuits, and neuroimmune interactions. Although neural lesions are necessary, they are not sufficient to generate neuropathic pain; genetic polymorphisms, gender, and age all influence the risk of developing persistent pain. Treatment needs to move from merely suppressing symptoms to a disease-modifying strategy aimed at both preventing maladaptive plasticity and reducing intrinsic risk.