Dolor / Pain

Agosto 1, 2017. No. 2767

Formación reticular y dolor: El pasado y el futuro. Reticular Formation and Pain: The Past and the Future. Martins I1,2,3,4, Tavares I1,2,3,4. Front Neuroanat. 2017 Jul 5;11:51. doi: 10.3389/fnana.2017.00051. eCollection 2017. Abstract The involvement of the reticular formation (RF) in the transmission and modulation of nociceptive information has been extensively studied. The brainstem RF contains several areas which are targeted by spinal cord afferents conveying nociceptive input. The arrival of nociceptive input to the RF may trigger alert reactions which generate a protective/defense reaction to pain. RF neurons located at the medulla oblongata and targeted by ascending nociceptive information are also involved in the control of vital functions that can be affected by pain, namely cardiovascular control. The RF contains centers that belong to the pain modulatory system, namely areas involved in bidirectional balance (decrease or enhancement) of pain responses. It is currently accepted that the imbalance of pain modulation towards pain facilitation accounts for chronic pain. The medullary RF has the peculiarity of harboring areas involved in bidirectional pain control namely by the existence of specific neuronal populations involved in antinociceptive or pronociceptive behavioral responses, namely at the rostroventromedial medulla (RVM) and the caudal ventrolateral medulla (VLM). Furthermore the dorsal reticular nucleus (also known as subnucleus reticularis dorsalis; DRt) may enhance nociceptive responses, through a reverberative circuit established with spinal lamina I neurons and inhibit wide-dynamic range (WDR) neurons of the deep dorsal horn. The components of the triad RVM-VLM-DRt are reciprocally connected and represent a key gateway for top-down pain modulation. The RVM-VLM-DRt triad also represents the neurobiological substrate for the emotional and cognitive modulation of pain, through pathways that involve the periaqueductal gray (PAG)-RVM connection. Collectively, we propose that the RVM-VLM-DRt triad represents a key component of the "dynamic pain connectome" with special features to provide integrated and rapid responses in situations which are life-threatening and involve pain. The new available techniques in neurobiological studies both in animal and human studies are producing new and fascinating data which allow to understand the complex role of the RF in pain modulation and its integration with several body functions and also how the RF accounts for chronic pain. KEYWORDS: analgesics; cognition; connectome; emotions; noradrenaline; opioids; serotonin PDF Avances recientes en la comprensión y manejo del dolor por cáncer. Recent advances in understanding and managing cancer pain. Chwistek M1. F1000Res. 2017 Jun 20;6:945. doi: 10.12688/f1000research.10817.1. eCollection 2017.Abstract Cancer pain remains a significant clinical problem worldwide. Causes of cancer pain are multifactorial and complex and are likely to vary with an array of tumor-related and host-related factors and processes. Pathophysiology is poorly understood; however, new laboratory research points to cross-talk between cancer cells and host's immune and neural systems as an important potential mechanism that may be broadly relevant to many cancer pain syndromes. Opioids remain the most effective pharmaceuticals used in the treatment of cancer pain. However, their role has been evolving due to emerging awareness of risks of chronic opioid therapy. Despite extensive research efforts, no new class of analgesics has been developed. However, many potential therapeutic targets that may lead to the establishment of new pharmaceuticals have been identified in recent years. It is also expected that the role of non-pharmacological modalities of treatment will grow in prominence. Specifically, neuromodulation, a rapidly expanding field, may play a major role in the treatment of neuropathic cancer pain provided that further technological progress permits the development of non-invasive and inexpensive neuromodulation techniques. KEYWORDS: biology of cancer pain; cancer pain; cancer-induced bone pain; cannabis; chemotherapy-induced peripheral neuropathy; intrathecal analgesia; medical marijuana; neuromodulation; opioids; scrambler therapy; spinal cord stimulation PDF  El Comité Ejecutivo de la IASP insta a Venezuela a centrarse en el acceso a medicamentos para el dolor a la luz de escasez crítica IASP Executive Committee Urges Venezuela to Focus on Access to Pain Medications in Light of Critical Shortages As the leading global organization that brings together scientists, clinicians, health-care providers, and policymakers to stimulate and support the study of pain with the goal of improved pain relief worldwide, the International Association for the Study of Pain (IASP) has been made aware that difficult conditions in Venezuela have resulted in inadequate access to pain treatment. Declaración / Statement XIV Congreso Virtual Mexicano de Anestesiología 2017 Octubre 1-Diciembre 31, 2017 Información / Information California Society of Anesthesiologists Reuniones / Events Informacion / Information

Anestesiología y Medicina del Dolor 52 664 6848905 vwhizar@anestesia-dolor.org anestesia-dolor.org

Dolor cronico / Chronic pain

Agosto 2, 2017. No. 2768

Dolor y psicología- Una relación recíproca. Pain and Psychology-A Reciprocal Relationship. Vadivelu N, Kai AM, Kodumudi G, Babayan K, Fontes M, Burg MM. Ochsner J. 2017 Summer;17(2):173-180. Abstract BACKGROUND: Depression typically affects 5% of the general population, but among patients with chronic pain, 30%-45% experience depression. Studies have shown that the relationship between depression and pain is bidirectional: depression is a positive predictor of the development of chronic pain, and chronic pain increases the risk of developing depression. METHODS: This literature review focuses on the relationship between psychology and pain, covering studies that have investigated the association between depression, pain sensitivity, opioid abuse, and gender differences in pain perception. We conducted a PubMed search pairing the word pain with depression, opioid use, and gender differences. RESULTS: The relationship between depression and pain is complex, as suggested by numerous studies that propose depression to be a moderator of the relationship between pain severity, physical functioning, and opioid use. Neuroimaging also suggests an anatomic overlap in the pathway of chronic pain and depression. Positive psychological factors, namely hope, pain acceptance, and optimism, affect the adjustment to persistent pain. CONCLUSION: The intricate relationship between pain and psychology is evidenced by the clinical overlap in their presentations and the overlap between the anatomic regions in the brain associated with the emotional and sensory features of pain and the areas affected by depression. Studies are beginning to improve our understanding of these two systems, but more studies are needed to elucidate the relationship. KEYWORDS: Analgesics-opioid; chronic pain; depression; pain; pain perception; psychology PDF Dolor crónico postoperatorio: hallazgos recientes en la comprensión y el manejo. Chronic postoperative pain: recent findings in understanding and management. Correll D. F1000Res. 2017 Jul 4;6:1054. doi: 10.12688/f1000research.11101.1. eCollection 2017. Abstract Chronic postoperative pain is a poorly recognized potential outcome from surgery. It affects millions of patients every year, with pain lasting for months to years, resulting in patient suffering and ensuing economic consequences. The operations with the highest incidence of chronicpostoperative pain are amputations, thoracotomies, cardiac surgery, and breast surgery. Other risk factors include preoperative pain, psychological factors, demographics, and the intensity of acute postoperative pain. Attempts to prevent chronic postoperative pain have often led to debatable results. This article presents data from recently published studies examining the incidence, risk factors, mechanisms, treatment options, and preventive strategies for chronic postoperative pain in adults. In summary, many of the previously identified risk factors for chronic postoperative pain have been confirmed and some novel ones discovered, such as the importance of the trajectory of acute painand the fact that catastrophizing may not always be predictive. The incidence of chronic postoperative pain hasn't changed over time, and there is limited new information regarding an effective preventive therapy. For example, pregabalin may actually cause more harm in certain surgeries. Further research is needed to demonstrate whether multimodal analgesic techniques have the best chance of significantly reducing the incidence of chronic postoperative pain and to determine which combination of agents is best for given surgical types and different patient populations. KEYWORDS: multimodal analgesia; persistent postoperative pain; surgery PDF El Comité Ejecutivo de la IASP insta a Venezuela a centrarse en el acceso a medicamentos para el dolor a la luz de escasez crítica IASP Executive Committee Urges Venezuela to Focus on Access to Pain Medications in Light of Critical Shortages As the leading global organization that brings together scientists, clinicians, health-care providers, and policymakers to stimulate and support the study of pain with the goal of improved pain relief worldwide, the International Association for the Study of Pain (IASP) has been made aware that difficult conditions in Venezuela have resulted in inadequate access to pain treatment. Declaración / Statement

Anestesiología y Medicina del Dolor 52 664 6848905 vwhizar@anestesia-dolor.org anestesia-dolor.org

Más de insensibilidad congénita al dolor / Congenital insensitivity to pain

Agosto 5, 2017. No. 2771

Trastornos de la reactividad al dolor L. Vicente-Fatela, Mª S. Acedo Rev. Soc. Esp. Dolor 11: 31-37, 2004 RESUMEN La función protectora del dolor es bien conocida. Existen algunas enfermedades que cursan con la ausencia de la percepción dolorosa y conllevan a múltiples problemas para los pacientes afectados. En los trastornos de la reactividad al dolor se pueden distinguir trastornos congénitos y adquiridos. Dentro de los congénitos se incluyen dos cuadros clínicos bien diferenciados: la insensibilidad congénita al dolor o analgesia congénita y la indiferencia congénita al dolor. En el primer caso el estímulo doloroso no es transmitido adecuadamente al sistema nervioso central debido a un defecto en las vías sensitivas; mientras que en el segundo la vía sensorial está integra, pero el paciente no identifica el estímulo doloroso como desagradable. Actualmente la insensibilidad congénita al dolor se encuadra dentro de un grupo de neuropatías hereditarias llamadas sensitivo-autonómicas, con afectación de la sensibilidad dolorosa, en relación con la implicación de las fibras nerviosas mielínicas pequeñas y amielínicas, vehículos de la mayor parte de la sensibilidad dolorosa, así como de las fibras autonómicas. Se distinguen cinco tipos de neuropatía hereditaria sensitivo-autonómica, que se describen en el texto, existiendo alteración de la percepción dolorosa en todas ellas, aunque con mayor grado en alguna de ellas como en el caso de la neuropatía hereditaria sensitivo-autonómica tipo IV o insensibilidad congénita al dolor con anhidrosis. Clínicamente en estas neuropatías se pueden producir lesiones a diversos niveles como consecuencia de la pérdida de la sensibilidad dolorosa. Las alteraciones que se asocian con mayor frecuencia son: fracturas múltiples, articulaciones de Charcot, dismetría de extremidades inferiores, osteomielitis, artritis séptica, luxaciones, autoamputaciones, automutilaciones y escoliosis progresiva. Es necesario un tratamiento multidisciplinar y especializado junto con la colaboración paterna para minimizar las complicaciones de esta enfermedad potencialmente grave. En ausencia de tratamiento etiológico, el tratamiento sintomático adquiere una gran importancia. Se evitarán en lo posible los procesos de riesgo, producción de fracturas, mordeduras, roces, infecciones y mutilaciones. Cuando se producen lesiones en áreas del cerebro que sustentan el procesamiento del estímulo doloroso, pueden tener lugar déficits en uno o varios componentes de la percepción dolorosa, y pueden producirse situaciones clínicas similares a la insensibilidad congénita al dolor. Dentro de los trastornos adquiridos se describen la asimbolia dolorosa, la analgotimia y la hemianopsia dolorosa. Palabras clave: Insensibilidad congénita al dolor. Analgesia congénita. Asimbolia dolorosa. Neuropatía hereditaria sensitivo-autonómica. PDF Insensibilidad congénita al dolor; sufriendo sin dolor Francisco Pimienta      Francisco Mercado Angélica Almanza Elementos 101, 2016, pp. 13-20 PDF Revisión de la actualización y presentación clínica en la insensibilidad congénita al dolor y a la anhidrosis. Update Review and Clinical Presentation in Congenital Insensitivity to Pain and Anhidrosis. Pérez-López LM1, Cabrera-González M1, Gutiérrez-de la Iglesia D1, Ricart S2, Knörr-Giménez G1. Case Rep Pediatr. 2015;2015:589852. doi: 10.1155/2015/589852. Epub 2015 Oct 22. Abstract Introduction. Congenital insensitivity to pain and anhidrosis (CIPA) or hereditary sensory and autonomic neuropathy type IV is an extremely rare syndrome. Three clinical findings define the syndrome: insensitivity to pain, impossibility to sweat, and mental retardation. This pathology is caused by a genetic mutation in the NTRK1 gene, which encodes a tyrosine receptor (TrkA) for nerve growth factor (NGF). Methods. The consultation of a child female in our center with CIPA and a tibia fracture in pseudoarthrosis encouraged us to carefully review literature and examine the therapeutic possibilities. A thorough review of literature published in Pubmed was done about CIPA and other connected medical issues mentioned in the paper. Conclusions. The therapeutic approach of CIPA remains unclear. The preventive approach remains the only possible treatment of CIPA. We propose two new important concepts in the therapeutic approach for these patients: (1) early surgical treatment for long bone fractures to prevent pseudoarthrosis and to allow early weight bearing, decreasing the risk of further osteopenia, and (2) bisphosphonates to avoid the progression of osteopenia and to reduce the number of consecutive fractures. PDF Insensibilidad congénita al dolor (HSNA tipo IV) Congenital Insensitivity to Pain (HSNA type IV). Millichap JG. Pediatr Neurol Briefs. 2015 Apr;29(4):31. doi: 10.15844/pedneurbriefs-29-4-6. Abstract Investigators from New York University, NY, studied 14 patients with congenital insensitivity to pain with anhidrosis (CIPA), compared to 10 patients with chronically deficient sympathetic activity (pure autonomic failure), and 15 normal age-matched controls. KEYWORDS: Anhidrosis; Congenital; Norepinephrine; Pain PDF XIV Congreso Virtual Mexicano de Anestesiología 2017 Octubre 1-Diciembre 31, 2017 Información / Information California Society of Anesthesiologists Reuniones / Events Informacion / Information

Anestesiología y Medicina del Dolor 52 664 6848905 vwhizar@anestesia-dolor.org anestesia-dolor.org