Characteristics of phantom limb pain in U.S. civilians and service members.

OBJECTIVES: The population of Americans with limb loss is on the rise, with a different profile than in previous generations (e.g., greater incidence of amputation due to diabetes). This study aimed to identify the key characteristics of phantom limb sensation (PLS) and pain (PLP) in a current sample of Americans with limb loss. METHODS: This cross-sectional study is the first large-scale (n=649) study on PLP in the current population of Americans with limb loss. A convenience sample of military and civilian persons missing one or more major limbs was surveyed regarding their health history and experience with phantom limb phenomena. RESULTS: Of the participants surveyed, 87% experienced PLS and 82% experienced PLP. PLS and PLP typically first occurred immediately after amputation (47% of cases), but for a small percentage (3-4%) onset did not occur until over a year after amputation. Recent PLP severity decreased over time (ß=0.028, 95% CI: -0.05-0.11), but most participants reported PLP even 10 years after amputation. Higher levels of recent PLP were associated with telescoping (ß=0.123, 95% CI: 0.04-0.21) and higher levels of pre-amputation pain (ß=0.104, 95% CI: 0.03-0.18). Those with congenitally missing limbs experienced lower levels of recent PLP (t (37.93)=3.93, p<0.01) but there were no consistent differences in PLP between other amputation etiologies. CONCLUSIONS: Phantom limb phenomena are common and enduring. Telescoping and pre-amputation pain are associated with higher PLP. Persons with congenitally missing limbs experience lower levels of PLP than those with amputation(s), yet PLP is common even in this subpopulation.

Clinical Trial of the Virtual Integration Environment to Treat Phantom Limb Pain With Upper Extremity Amputation.

Background: Phantom limb pain (PLP) is commonly seen following upper extremity (UE) amputation. Use of both mirror therapy, which utilizes limb reflection in a mirror, and virtual reality therapy, which utilizes computer limb simulation, has been used to relieve PLP. We explored whether the Virtual Integration Environment (VIE), a virtual reality UE simulator, could be used as a therapy device to effectively treat PLP in individuals with UE amputation. Methods: Participants with UE amputation and PLP were recruited at Walter Reed National Military Medical Center (WRNMMC) and instructed to follow the limb movements of a virtual avatar within the VIE system across a series of study sessions. At the end of each session, participants drove virtual avatar limb movements during a period of "free-play" utilizing surface electromyography recordings collected from their residual limbs. PLP and phantom limb sensations were assessed at baseline and following each session using the Visual Analog Scale (VAS) and Short Form McGill Pain Questionnaire (SF-MPQ), respectively. In addition, both measures were used to assess residual limb pain (RLP) at baseline and at each study session. In total, 14 male, active duty military personnel were recruited for the study. Results: Of the 14 individuals recruited to the study, nine reported PLP at the time of screening. Eight of these individuals completed the study, while one withdrew after three sessions and thus is not included in the final analysis. Five of these eight individuals noted RLP at baseline. Participants completed an average of 18, 30-min sessions with the VIE leading to a significant reduction in PLP in seven of the eight (88%) affected limbs and a reduction in RLP in four of the five (80%) affected limbs. The same user reported an increase in PLP and RLP across sessions. All participants who denied RLP at baseline (n = 3) continued to deny RLP at each study session. Conclusions: Success with the VIE system confirms its application as a non-invasive and low-cost therapy option for PLP and phantom limb symptoms for individuals with upper limb loss.

Residual Limb Hyperhidrosis and RimabotulinumtoxinB: A Randomized Placebo-Controlled Study.

OBJECTIVE: To investigate the use of rimabotulinumtoxinB (BoNT/B [Myobloc]) compared with placebo in treating hyperhidrosis in the residual limbs of individuals with amputation. DESIGN: Randomized, double-blind, placebo-controlled pilot study. SETTING: Military medical center. PARTICIPANTS: Male participants (N=9) with 11 major amputations of the lower limbs and who complained of excessive sweating in their residual limbs were enrolled in the study between September 24, 2008 to October 28, 2011. Participants' lower limbs were randomly assigned to receive injections of either BoNT/B (n=7) or placebo (n=4). INTERVENTION: BoNT/B. MAIN OUTCOME MEASURES: The primary efficacy variable was a minimum of 50% reduction in sweat production 4 weeks after the injection as measured via gravimetric sweat analysis after 10 minutes of physical exertion. Secondary analyses were performed on prosthetic function and pain. RESULTS: All volunteers (100%; 7) in the BoNT/B group achieved a minimum of 50% reduction in sweat production as compared with only 50% (2) in the placebo group. The percent reduction was significantly greater for the BoNT/B group than for the placebo group (-72.7%±15.7% vs -32.7%±39.2%; P<.05). Although both groups subjectively self-reported significant sweat reduction and improved prosthetic function (P<.05 for both), objective gravimetric sweat analyses significantly decreased only for the BoNT/B group (2.3±2.3g vs 0.7±1.1g; P<.05). Neither group reported a change in phantom limb pain or residual limb pain (P>.05 for both). CONCLUSIONS: BoNT/B successfully reduces sweat production in individuals with residual limb hyperhidrosis, but does not affect pain. No differences were found in perceived effect on prosthetic use between BoNT/B and placebo groups.

Reliable Change Estimates for Assessing Recovery From Concussion Using the ANAM4 TBI-MIL.

OBJECTIVE: To establish the reliable change parameters for the Automated Neuropsychological Assessment Metrics (ANAM) using a healthy normative sample of active duty service members (SMs) and apply the parameters to sample of recently deployed SMs. METHODS: Postdeployment neurocognitive performance was compared in 1893 US Marines with high rates of combat exposure during deployment. Of the sample, 289 SMs had data for 2 predeployment assessments and were used as a normative subsample and 502 SMs had data for predeployment and postdeployment assessments and were used as a deployed subsample. On the basis of self-report, the deployed subsample were further classified as concussed (n = 238) or as nonconcussed controls (n = 264). Reliable change parameters were estimated from the normative sample and applied data for both deployed groups. Postdeployment performance was quantified using a general linear model (2 group × 2 time) multivariate analysis of variance with repeated measures. RESULTS: Both deployed groups demonstrated a pattern of meaningful decreases in performance over time. CONCLUSIONS: Information from this effort, specifically the reliable change parameters and the base rates of reliable decline, can be used to assist with the identification of postdeployment cognitive issues.

Symptoms of PTSD Associated With Painful and Nonpainful Vicarious Reactivity Following Amputation.

Although the experience of vicarious sensations when observing another in pain have been described postamputation, the underlying mechanisms are unknown. We investigated whether vicarious sensations are related to posttraumatic stress disorder (PTSD) symptoms and chronic pain. In Study 1, 236 amputees completed questionnaires about phantom limb phenomena and vicarious sensations to both innocuous and painful sensory experiences of others. There was a 10.2% incidence of vicarious sensations, which was significantly more prevalent in amputees reporting PTSD-like experiences, particularly increased arousal and reexperiencing the event that led to amputation (φ = .16). In Study 2, 63 amputees completed the Empathy for Pain Scale and PTSD Checklist-Civilian Version. Cluster analyses revealed 3 groups: 1 group did not experience vicarious pain or PTSD symptoms, and 2 groups were vicarious pain responders, but only 1 had increased PTSD symptoms. Only the latter group showed increased chronic pain severity compared with the nonresponder group (p = .025) with a moderate effect size (r = .35). The findings from both studies implicated an overlap, but also divergence, between PTSD symptoms and vicarious pain reactivity postamputation. Maladaptive mechanisms implicated in severe chronic pain and physical reactivity posttrauma may increase the incidence of vicarious reactivity to the pain of others.

Psychometric investigation of the abbreviated concussion symptom inventory in a sample of U.S. Marines returning from combat.

This study describes the psychometric investigation of an 11-item symptom checklist, the Abbreviated Concussion Symptom Inventory (ACSI). The ACSI is a dichotomously scored list of postconcussive symptoms associated with mild traumatic brain injury. The ACSI was administered to Marines (N = 1,435) within the 1st month of their return from combat deployments to Afghanistan. Psychometric analyses based upon nonparametric item response theory supported scoring the ACSI via simple summation of symptom endorsements; doing so produced a total score with good reliability (α = .802). Total scores were also found to significantly differentiate between different levels of head injury complexity during deployment, F(3, 1,431) = 100.75, p < .001. The findings support the use of the ASCI in research settings requiring a psychometrically reliable measure of postconcussion symptoms.

Observation of limb movements reduces phantom limb pain in bilateral amputees.

BACKGROUND: Mirror therapy has been demonstrated to reduce phantom limb pain (PLP) experienced by unilateral limb amputees. Research suggests that the visual feedback of observing a limb moving in the mirror is critical for therapeutic efficacy. OBJECTIVE: Since mirror therapy is not an option for bilateral lower limb amputees, the purpose of this study was to determine if direct observation of another person's limbs could be used to relieve PLP. METHODS: We randomly assigned 20 bilateral lower limb amputees with PLP to visual observation (n = 11) or mental visualization (n = 9) treatment. Treatment consisted of seven discrete movements which were mimicked by the amputee's phantom limbs moving while visually observing the experimenter's limbs moving, or closing the eyes while visualizing and attempting the movements with their phantom limbs, respectively. Participants performed movements for 20 min daily for 1 month. Response to therapy was measured using a 100-mm visual analog scale (VAS) and the McGill Short-Form Pain Questionnaire (SF-MPQ). RESULTS: Direct visual observation significantly reduced PLP in both legs (P < 0.05). Amputees assigned to the mental visualization condition did not show a significant reduction in PLP. INTERPRETATION: Direct visual observation therapy is an inexpensive and effective treatment for PLP that is accessible to bilateral lower limb amputees.

Analysis of post-deployment cognitive performance and symptom recovery in U.S. Marines.

BACKGROUND: Computerized neurocognitive testing (NCAT) has been proposed to be useful as a screening tool for post-deployment cognitive deficits in the setting of mild traumatic brain injury (mTBI). We assessed the clinical utility of post-injury/post-deployment Automated Neurocognitive Assessment Metric (ANAM) testing, using a longitudinal design to compare baseline ANAM tests with two post-deployment ANAM tests in a group of Marines who experienced combat during deployment. METHODS AND FINDINGS: Post-deployment cognitive performance and symptom recovery were compared in a subsample of 1324 U.S. Marines with high rates of combat exposure during deployment. Of the sample, 169 Marines had available baseline and twice repeated post-deployment ANAM results. A retrospective analysis of the ANAM data, which consisted of a self-report questionnaire about deployment-related blast exposure, recent history of mTBI, current clinical symptoms, and cognitive performance. Self-reported concussion sustained anytime during deployment was associated with a decrease in cognitive performance measured between 2-8 weeks post-deployment. At the second post-deployment test conducted on average eight months later, performance on the second simple reaction time test, in particular, remained impaired and was the most consistent and sensitive indicator of the cognitive decrements. Additionally, post-concussive symptoms were shown to persist in injured Marines with a self-reported history of concussion for an additional five months after most cognitive deficits resolved. Results of this study showed a measurable deployment effect on cognitive performance, although this effect appears to resolve without lasting clinical sequelae in those without history of deployment-related concussion. CONCLUSIONS: These results highlight the need for a detailed clinical examination for service members with history of concussion and persistent clinical symptoms. Reliance solely upon computerized neurocognitive testing as a method for identifying service members requiring clinical follow-up post-concussion is not recommended, as cognitive functioning only slowly returned to baseline levels in the setting of persistent clinical symptoms.

Teleneurology applications: Report of the Telemedicine Work Group of the American Academy of Neurology.

OBJECTIVE: To review current literature on neurology telemedicine and to discuss its application to patient care, neurology practice, military medicine, and current federal policy. METHODS: Review of practice models and published literature on primary studies of the efficacy of neurology telemedicine. RESULTS: Teleneurology is of greatest benefit to populations with restricted access to general and subspecialty neurologic care in rural areas, those with limited mobility, and those deployed by the military. Through the use of real-time audio-visual interaction, imaging, and store-and-forward systems, a greater proportion of neurologists are able to meet the demand for specialty care in underserved communities, decrease the response time for acute stroke assessment, and expand the collaboration between primary care physicians, neurologists, and other disciplines. The American Stroke Association has developed a defined policy on teleneurology, and the American Academy of Neurology and federal health care policy are beginning to follow suit. CONCLUSIONS: Teleneurology is an effective tool for the rapid evaluation of patients in remote locations requiring neurologic care. These underserved locations include geographically isolated rural areas as well as urban cores with insufficient available neurology specialists. With this technology, neurologists will be better able to meet the burgeoning demand for access to neurologic care in an era of declining availability. An increase in physician awareness and support at the federal and state level is necessary to facilitate expansion of telemedicine into further areas of neurology.

Neurology and the military: Five new things.

The current Iraq and Afghanistan conflicts have seen the highest survival rates in US service members ever, despite staggering numbers of traumatic brain injury and limb loss cases. The improvement in survival can be attributed at least in part to advances in far-forward, rapid medical treatment, including the administration of hypertonic saline solutions and decompressive craniectomies to manage elevated intracranial pressure. After evacuation to military hospitals in the continental United States, service members who have had limb loss face extensive rehabilitation. The growing amputee population has led to a burgeoning interest in the treatment of phantom limb pain and in the development of advanced prostheses.

Use of a virtual integrated environment in prosthetic limb development and phantom limb pain.

Patients face two major difficulties following limb loss: phantom limb pain (PLP) in the residual limb and limited functionality in the prosthetic limb. Many studies have focused on decreasing PLP with mirror therapy, yet few have examined the same visual ameliorating effect with a virtual or prosthetic limb. Our study addresses the following key questions: (1) does PLP decrease through observation of a 3D limb in a virtual integration environment (VIE) and (2) can consistent surface electromyography (sEMG) signals from the VIE drive an advanced modular prosthetic limb (MPL)? Recorded signals from the residual limb were correlated to the desired motion of the phantom limb, and changes in PLP were scored during each VIE session. Preliminary results show an overall reduction in PLP and a trend toward improvement in signal-to-motion accuracy over time. These signals allowed MPL users to perform a wide range of hand motions.

Outcomes from a US military neurology and traumatic brain injury telemedicine program.

OBJECTIVE: This study evaluated usage of the Army Knowledge Online (AKO) Telemedicine Consultation Program for neurology and traumatic brain injury (TBI) cases in remote overseas areas with limited access to subspecialists. We performed a descriptive analysis of quantity of consults, response times, sites where consults originated, military branches that benefitted, anatomic locations of problems, and diagnoses. METHODS: This was a retrospective analysis that searched electronic databases for neurology consults from October 2006 to December 2010 and TBI consults from March 2008 to December 2010. RESULTS: A total of 508 consults were received for neurology, and 131 consults involved TBI. For the most part, quantity of consults increased over the years. Meanwhile, response times decreased, with a mean response time of 8 hours, 14 minutes for neurology consults and 2 hours, 44 minutes for TBI consults. Most neurology consults originated in Iraq (67.59%) followed by Afghanistan (16.84%), whereas TBI consults mainly originated from Afghanistan (40.87%) followed by Iraq (33.91%). The most common consultant diagnoses were headaches, including migraines (52.1%), for neurology cases and mild TBI/concussion (52.3%) for TBI cases. In the majority of cases, consultants recommended in-theater management. After receipt of consultant's recommendation, 84 known neurology evacuations were facilitated, and 3 known neurology evacuations were prevented. CONCLUSIONS: E-mail-based neurology and TBI subspecialty teleconsultation is a viable method for overseas providers in remote locations to receive expert recommendations for a range of neurologic conditions. These recommendations can facilitate medically necessary patient evacuations or prevent evacuations for which on-site care is preferable.