Pain in an era of armed conflicts: Prevention and treatment for warfighters and civilian casualties

Combat-related peripheral nerve injuries

Active-duty service members (ADSM) and military Veterans represent a population with increased occupational risk for nerve injuries sustained both during training operations and wartime. Mechanisms of war-related nerve injuries have evolved over time, from the musket ball-related traumas described by S.W. Mitchell to complex blast injuries and toxic exposures sustained during Middle East conflicts in the 21st century. Commonly encountered nerve injury etiologies in this population currently include compression, direct trauma, nutritional deficits, traumatic limb amputation, toxic chemical exposures, or blast-related injuries. Expeditious identification and comprehensive, interdisciplinary treatment of combat-associated neuropathies, as well as prevention of these injuries whenever possible is critical to reduce chronic morbidity and disability for service members and to maintain a well-prepared military. However, diagnosis of a combat-associated nerve injury may be particularly challenging due to comorbid battlefield injuries or delayed presentation of neuropathy from military toxic exposures. Advances in imaging for nerve injury, including MRI and ultrasound, provide useful tools to compliment EMG in establishing a diagnosis of combat-associated nerve injury, particularly in the setting of anatomic disruption or edema. Surgical techniques can improve pain control or restoration of function. In all cases, comprehensive interdisciplinary rehabilitation provides the best framework for optimization of recovery. Further work is needed to prevent combat-associated nerve injuries and promote nerve recovery following injury.

Preventing pediatric chronic postsurgical pain: Time for increased rigor

Chronic postsurgical pain (CPSP) results from a cascade of events in the peripheral and central nervous systems following surgery. Several clinical predictors, including the prior pain state, premorbid psychological state (e.g., anxiety, catastrophizing), intraoperative surgical load (establishment of peripheral and central sensitization), and acute postoperative pain management, may contribute to the patient's risk of developing CPSP. However, research on the neurobiological and biobehavioral mechanisms contributing to pediatric CPSP and effective preemptive/treatment strategies are still lacking. Here we evaluate the perisurgical process by identifying key problems and propose potential solutions for the pre-, intra-, and postoperative pain states to both prevent and manage the transition of acute to chronic pain. We propose an eight-step process involving preemptive and preventative analgesia, behavioral interventions, and the use of biomarkers (brain-based, inflammatory, or genetic) to facilitate timely evaluation and treatment of premorbid psychological factors, ongoing surgical pain, and postoperative pain to provide an overall improved outcome. By achieving this, we can begin to establish personalized precision medicine for children and adolescents presenting to surgery and subsequent treatment selection.

Two-Step Resilience-Oriented Intervention for Veterans with Traumatic Brain Injury: A Pilot Randomized Controlled Trial

OBJECTIVE

The present randomized parallel two-arm pilot study aimed to compare the efficacy of two-step resilience-oriented intervention with treatment as usual in veterans with mild to moderate traumatic brain injury.

METHOD

Two-step Resilience-Oriented Intervention (TROI) is a brief psychological intervention that targets cognitive (step 1) and emotional (step 2) factors of resilience and consists of six 1-hour sessions. Overall, 70 Ukrainian veterans serviced in Anti-Terrorist Operation / Joint Forces Operation were randomly assigned to an intervention group (TROI group) or a control group that underwent treatment as usual (TAU group). For pre- (T1) and post-treatment (T2) assessment the Connor-Davidson Resilience Scale (CD-RISC), Hospital Anxiety and Depression Scale (HADS), Montreal Cognitive Assessment Scale (MoCA), Neurobehavioral Symptom Inventory (NSI), Posttraumatic Stress Disorder Checklist 5 (PCL-5), Chaban Quality of Life Scale (CQLS), Positive and Negative Affect Scale (PANAS) were used.

RESULTS

Multivariable linear regression with the treatment group, gender, baseline cognitive performance level and TBI severity as the independent variables revealed statistically significant improvements in the TROI group in resilience (CD-RISC), cognitive performance (MoCA), postconcussive symptoms (NSI), posttraumatic symptoms (PCL-5), positive affect (PANAS) and quality of life (CQLS) comparing to such in TAU group. We found no statistically significant differences between groups in depression, anxiety (HADS) and negative affect (PANAS) outcomes. Additionally, Wilcoxon signed-rank test revealed that participants who completed two-step resilience-oriented intervention had significantly improved scores for all outcomes compared to the baseline (p < 0.05).

CONCLUSIONS

In summary, we can tentatively conclude that adding TROI to the standard treatment measures may improve the resilience and sustainable symptoms in veterans with TBI when compared with standard treatment. Targeting cognitive and emotional factors like problem-solving, decision-making, positive thinking can promote resilience in veterans with TBI and be useful in facilitating recovery from injury. Results of this pilot study are promising, but the intervention needs to be studied in a larger trial.

Pain stickiness in pediatric complex regional pain syndrome: A role for the nucleus accumbens

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Pain nonresponders have decreased nucleus accumbens (NAc) grey matter density.

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Pain nonresponders have reduced functional connectivity between NAc and dlPFC.

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Connectivity strength between NAc and dlPFC correlates with changes in pain.

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Prediction estimate for pain improvement with grey matter and connectivity was 87%.

Some individuals with chronic pain experience improvement in their pain with treatment, whereas others do not. The neurobiological reason is unclear, but an understanding of brain structure and functional patterns may provide insights into pain’s responsivity to treatment. In this investigation, we used magnetic resonance imaging (MRI) techniques to determine grey matter density alterations on resting functional connectivity (RFC) strengths between pain responders and nonresponders in patients with complex regional pain syndrome. Brain metrics of pediatric patients at admission to an intensive pain rehabilitative treatment program were evaluated. Pain responders reported significant pain improvement at discharge and/or follow-up whereas nonresponders reported no improvements in pain, increases in pain, or emergence of new pain symptoms. The pain (responder/nonresponder) groups were compared with pain-free healthy controls to examine predictors of pain responder status via brain metrics. Our results show: (1) on admission, pain nonresponders had decreased grey matter density (GMD) within the nucleus accumbens (NAc) and reduced RFC strength between the NAc and the dorsolateral prefrontal cortex vs. responders; (2) Connectivity strength was positively correlated with change in pain intensity from admission to discharge; (3) Compared with pain-free controls, grey matter and RFC differences emerged only among pain nonresponders; and (4) Using a discriminative model, combining GMD and RFC strengths assessed at admission showed the highest prediction estimate (87%) on potential for pain improvement, warranting testing in a de novo sample. Taken together, these results support the idea that treatment responsiveness on pain is underpinned by concurrent brain structure and resting brain activity.

Early Pain and Other Somatic Symptoms Predict Posttraumatic Stress Reactions in Survivors of Terrorist Attacks: The Longitudinal Utøya Cohort Study

Survivors of traumatic events commonly suffer from long-term pain and related somatic symptomatology. To test the predominant hypothesis that survivors' pain comprises sequela of persistent posttraumatic stress symptoms (PTSS), we assessed the sequential order of symptom development among young survivors of a terrorist attack. All 490 survivors of the 2011 Utøya (Norway) attacks were invited to the longitudinal Utøya cohort study; 355 (72.4%) participated. The mean survivor age was 19.3 years (SD = 4.6) and 169 were female (47.6%). Somatic symptoms, including headache, other pain and fatigue, and PTSS, were measured 4-5 months (T1), 14-16 months (T2), and 32-33 months (T3) after the attack. Longitudinal associations between somatic symptoms and PTSS were assessed in cross-lagged structural equation model (SEM) analyses, which were adjusted for known confounders. Higher pain levels and other somatic symptoms at T1 consistently predicted PTSS at T2 in SEM analyses, r = .473, p < .001. Beyond this early-to-intermediate posttraumatic phase, somatic symptoms did not significantly predict PTSS: T2-T3, r = .024, p = .831; T1-T3, r = -.074, p = .586. PTSS did not significantly predict later somatic symptomatology at T1-T2, r = .093, p = .455; T2-T3, r = .272, p = .234; or T1-T3, r = -.279, p = .077. The findings indicate that survivors' early pain and related somatic symptoms strongly and consistently predict later psychopathology. After severe psychological trauma, early interventions may need to address individuals' pain to hinder chronification.

Chronic pain among the hospitalized patients after the 22 July 2011 terror attacks in Oslo and at Utøya Island

BACKGROUND

On 22 July 2011, 48 people were hospitalized due to physical injuries from gun shots or explosion, following 2 terror attacks in the Oslo area, Norway. In this study, we have investigated the occurrence of chronic pain, the severity and consequences of chronic pain in these patients, 3 to 4 years after the incidents.

METHODS

Totally 43 eligible terror trauma patients were invited to participate in the study, 30 patients were included. They underwent a consultation with a psychologist and a physician; containing psychological assessment, neuropsychological screening, a standardized clinical interview, medical examination, and a pain protocol.

RESULTS

In 18 (60%) the injury was severe, as defined by New Injury Severity Score > 15. Twenty-four patients (80%) reported injury-related chronic pain after the trauma, in 22 with consequences on daily life. Analgesics were used by 20 patients, including 5 in need of opioids. Ten patients had unmet needs of further specialist pain care. In 12 patients, the average pain score last week was above three on a 0-10 Numeric Rating Scale. In these patients, clinical signs of neuropathic pain were evident in 10, as tested by the Douleur Neuropathique score. There were significant correlations (P < 0.05) between severity of chronic pain and presence of post-traumatic stress symptoms, reduced quality of life, reduced psychosocial and physical function; but no correlation with pre-injury patient characteristics or the degree of physical injury.

CONCLUSION

Chronic pain was frequent and significant, irrespective of injury severity, in these patients who obtained their physical injuries under extreme psychological conditions.

Evaluating psychosocial contributions to chronic pain outcomes

The biopsychosocial model of pain dominates the scientific community's understanding of chronic pain. Indeed, the biopsychosocial approach describes pain and disability as a multidimensional, dynamic integration among physiological, psychological, and social factors that reciprocally influence one another. In this article, we review two categories of studies that evaluate the contributions of psychosocial factors to the experience of chronic pain. First, we consider general psychosocial variables including distress, trauma, and interpersonal factors. Additionally, we discuss pain-specific psychosocial variables including catastrophizing, expectations, and pain-related coping. Together, we present a diverse array of psychological, social, and contextual factors and highlight the need to consider their roles in the development, maintenance, and treatment of chronic pain conditions.

AAPT Diagnostic Criteria for Peripheral Neuropathic Pain: Focal and Segmental Disorders

Peripheral neuropathic pain is among the most prevalent types of neuropathic pain. No comprehensive peripheral neuropathic pain classification system that incorporates contemporary clinical, diagnostic, biological, and psychological information exists. To address this need, this article covers the taxonomy for 4 focal or segmental peripheral neuropathic pain disorders, as part of the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership and the American Pain Society (APS) collaborative to develop a standardized, evidence-based taxonomy initiative: the ACTTION-APS Pain Taxonomy (AAPT). The disorders-postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia-were selected because of their clinical and clinical research relevance. The multidimensional features of the taxonomy are suitable for clinical trials and can also facilitate hypothesis-driven case-control and cohort epidemiologic studies. PERSPECTIVE: The AAPT peripheral neuropathic pain taxonomy subdivides the peripheral neuropathic pain disorders into those that are generalized and symmetric and those that are focal or segmental and asymmetric. In this article, we cover the focal and segmental disorders: postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia. The taxonomy is evidence-based and multidimensional, with the following dimensions: 1) core diagnostic criteria; 2) common features; 3) common medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors.

When pain gets stuck: the evolution of pain chronification and treatment resistance

It is well-recognized that, despite similar pain characteristics, some people with chronic pain recover, whereas others do not. In this review, we discuss possible contributions and interactions of biological, social, and psychological perturbations that underlie the evolution of treatment-resistant chronic pain. Behavior and brain are intimately implicated in the production and maintenance of perception. Our understandings of potential mechanisms that produce or exacerbate persistent pain remain relatively unclear. We provide an overview of these interactions and how differences in relative contribution of dimensions such as stress, age, genetics, environment, and immune responsivity may produce different risk profiles for disease development, pain severity, and chronicity. We propose the concept of "stickiness" as a soubriquet for capturing the multiple influences on the persistence of pain and pain behavior, and their stubborn resistance to therapeutic intervention. We then focus on the neurobiology of reward and aversion to address how alterations in synaptic complexity, neural networks, and systems (eg, opioidergic and dopaminergic) may contribute to pain stickiness. Finally, we propose an integration of the neurobiological with what is known about environmental and social demands on pain behavior and explore treatment approaches based on the nature of the individual's vulnerability to or protection from allostatic load.

Subliminal (latent) processing of pain and its evolution to conscious awareness

By unconscious or covert processing of pain we refer to nascent interactions that affect the eventual deliverance of pain awareness. Thus, internal processes (viz., repeated nociceptive events, inflammatory kindling, reorganization of brain networks, genetic) or external processes (viz., environment, socioeconomic levels, modulation of epigenetic status) contribute to enhancing or inhibiting the presentation of pain awareness. Here we put forward the notion that for many patients, ongoing sub-conscious changes in brain function are significant players in the eventual manifestation of chronic pain. In this review, we provide clinical examples of nascent or what we term pre-pain processes and the neurobiological mechanisms of how these changes may contribute to pain, but also potential opportunities to define the process for early therapeutic interventions.

The headache of terror

Objective

To elaborate the risk of headache among adolescent survivors exposed to terror.

Methods

On July 22, 2011, a lone man opened gunfire, killing 69 people at a summer camp for adolescents on the Utøya islet in Norway. All 358 adolescent survivors 13 to 20 years of age were invited to participate in the Utøya interview study. Among the 213 (59%) respondents, half (49%) were male, the mean age was 17.7 years, and 13 (6%) were severely injured. For each survivor, 8 matched controls were drawn from the population-based Young-HUNT3 Study, conducted between 2006 and 2008, with a participation rate of 73%. Recurrent migraine and tension-type headache (TTH) over the past 3 months served as main outcomes and were measured 4 to 5 months after the mass shooting with a validated headache interview, in accordance with the International Classification of Headache Disorders.

Results

After exposure to terror, the odds ratio for migraine was 4.27 (95% confidence interval 2.54–7.17) and for TTH was 3.39 (95% confidence interval 2.22–5.18), as estimated in multivariable logistic regression models adjusted for injury, sex, age, family structure and economy, prior exposure to physical or sexual violence, and psychological distress. The observed increased risk of headache in survivors was related largely to an increase in weekly and daily headaches.

Conclusions

Exposure to terror increases risk of persistent weekly and daily migraine and TTH in adolescent survivors, above expected levels. The terrors of other violence may similarly increase the risk of frequent headaches. After severe psychological traumas, interventions may need to address survivors' pain to hinder chronification.

Enfermedades crónicas en población afectada por el conflicto armado en Colombia, 2015

Objetivo. El propósito de este estudio fue identificar las enfermedades crónicas no mentales, más frecuentes en la población colombiana afectada por el conflicto armado.

Metodología. Este es un estudio transversal, que usa datos de la Encuesta Nacional de Salud Mental 2015. La población estudiada se estratificó por sexo y edad y se extrajeron otros datos generales como: nivel educativo y grado de pobreza, medido por el Índice Multidimensional de Pobreza. Se analizaron datos de personas que reportaron haber sido víctimas del conflicto armado colombiano en algún momento de la vida la vida y se reportó como medida de riesgo relativo indirecto la frecuencia de presentación de enfermedades crónicas no mentales.

Resultados. Se describió información de 10 764 personas mayores de 18 años siendo una muestra representativa a nivel nacional. Se encontró que 10,4 % de los sujetos afectados por el conflicto armado tienen un nivel educativo superior (técnico o universitario), así como 43,6 % se encuentran en estado de pobreza o en estado de vulnerabilidad. Las enfermedades crónicas no mentales identificadas fueron: hipertensión arterial 20,4 % (IC95% 15,7–26,1), diabetes 6,7 % (IC95% 4,4–10,3), enfermedades reumatológicas 10,4 % (IC95% 7,1–14,9), enfermedades gastrointestinales 19,1 % (IC95% 14,5–24,7), y dolor crónico 6,9 % (IC95% 4,2–11)

Conclusiones. La población afectada por el conflicto armado tiene aparentemente mayor riesgo de presentar enfermedades crónicas no mentales, tales como hipertensión arterial y diabetes, lo que evidencia la situación de vulnerabilidad de estas comunidades.

Physical Injury and Somatic Complaints: The Mediating Role of Posttraumatic Stress Symptoms in Young Survivors of a Terror Attack

Physically injured trauma survivors have particularly high risk for later somatic complaints and posttraumatic stress symptoms (PTSS). However, the potential mediating role of PTSS linking injury to later somatic complaints has been poorly investigated. In this study, survivors (N = 255) were interviewed longitudinally at 2 timepoints after the terror attack on Utøya Island, Norway, in 2011. Assessments included injury sustained during the attack, PTSS (after 4-5 months), somatic complaints (after 14-15 months), and background factors. Causal mediation analysis was conducted to evaluate the potential mediating role of PTSS in linking injury to somatic complaints comparing 2 groups of injured survivors with noninjured survivors. For the nonhospitalized injured versus the noninjured survivors, the mediated pathway was significant (average causal mediation effect; ACME = 0.09, p = .028, proportion = 55.8%). For the hospitalized versus the noninjured survivors, the mediated pathway was not significant (ACME = 0.04, p = .453, proportion = 11.6%). PTSS may play a significant mediating role in the development of somatic complaints among nonhospitalized injured trauma survivors. Intervening health professionals should be aware of this possible pathway to somatic complaints.