Enrique Reig

Pulsed Radiofrequency in Lumbar Radicular Pain: Clinical Effects in Various Etiological Groups

Background:  The purpose of this study was to evaluate the effectiveness of pulsed radiofrequency (PRF) applied to the lumbar dorsal root ganglion (DRG).

Cost Effectiveness of Intrathecal Therapy for Pain

Successful management of chronic cancer and nonmalignant pain remains a challenge to clinicians, and cost effectiveness is an important consideration for clinical decision making. Although the oral route was previously considered the optimal method of chronic opioid administration, emerging evidence demonstrates a therapeutic advantage to intrathecal opioid delivery compared to alternative modalities. Intrathecal drug delivery uses an implantable drug infusion system to deliver very low doses of opioids and other analgesics directly into the intrathecal space. Although the initial costs of surgical implantation of an intrathecal pump appear to be substantial, maintenance costs of intrathecal drug delivery over time are significantly lower than other routes of administration, including oral and intravenous drug delivery. Cost analyses of alternate routes of opioid administration indicate that intrathecal delivery is the most cost‐effective route of opioid administration for patients who require long‐term management of cancer (≥ 3–6 months) or nonmalignant pain (≥ 11–22 months).

Neurologic Sequelae of Intraspinal Drug Delivery Systems: Results of a Survey of American Implanters of Implantable Drug Delivery Systems

OBJECTIVES. The development of neurological sequelae subsequent to the placement of intraspinal drug delivery systems is particularly distressing. An attempt was made to determine the extent of this problem in both reported and in heretofore unreported cases.

Is pulsed radiofrequency a neuromodulation technique

In this issue of Neuromodulation, J. Van Zundert et al. have published an article titled, Percutane-ous pulsed radiofrequency treatment of the cervi-cal dorsal root ganglion in the treatment of chronic cervical pain syndromes: A clinical audit (1). The question that our readers might ask is this: Is pulsed radiofrequency neuromodulation? It is the opinion of these authors that it is. The exact definition of neuromodulation is hard to find in the literature. Neuromodulation is considered a normal property of the nervous system that regulates or modifies electrical impulses flowing through neural tissues by enhancing, inhibiting , extending, or shortening them. Interventional neuromodulation is considered nondestructive and reversible therapy and includes the use of implanted or nonimplanted electrical stimulation systems, electrically stimulating peripheral nerves, dorsal root ganglia, the spinal cord, or the brain, and chemical neuromodulation, the infusion of chemical agents directly to the central nervous system. Considering that the accepted definition of therapeutic neuromodulation only includes either electrical stimulation of the nervous system or chemical modulation of the nervous system, could we consider the new technique of pulsed radiofrequency of cranial nerves, dorsal root gan-glia and peripheral nerves as neuromodulation? Neuromodulation of nociceptive information takes place in spinal synapses through presynaptic and postsynaptic inhibition. The gate control theory described by Patrick Wall and Ronald Melzack in 1965 postulates that reception and activation of small fiber, nociceptive, afferent information, at the spinal, gray-matter level, is inhibited by activation of large, A-beta afferent fibers, preventing the release of substance P presynaptically (2). Descending inhibitory control is also another example of neuromodulation. There exists a series of descending pathways starting in upper neural centers and terminating in the spinal cord. These upper neural centers, including the nucleus raphe magnus, the paragigantosuperior reticulum, the peri-aquadectal gray, and the substantia nigra can all be activated by direct spinal electrical stimulation or intrathecal chemical neuromodulation, inhibiting the sensation of pain along the descending pathways. As previously stated, therapeutic electrical stimulation of the nervous system includes peripheral stimulation of the nervous system (transcutaneuous nerve stimulation (TENS) (3), and peripheral nerve stimulation (PNS) (4)), spinal cord stimulation (5), and stimulation of deep brain structures and motor cortex (6). Spinal cord stimulation (SCS) acts upon any structure or tract of the spinal cord if the electrical

Dual Spinal Cord Stimulation for Complex Pain: Preliminary Study

Objectives  To retrospectively analyze by indices of success, patients with chronic complex pain, including, axial low back pain, receiving dual spinal cord stimulation (SCS) systems.

Continuous Morphine Infusion: A Retrospective Study of Efficacy, Safety, and Demographic Variables

Objectives.  This study aims to assess the efficacy of intrathecal infusion in different types of pain. A number of different variables were assessed to analyze their effect on therapy and to determine in which patients intrathecal infusion is more effective.

Spinal Cord Stimulation: A 20-Year Retrospective Analysis in 260 Patients

Introduction. Spinal cord stimulation (SCS) is used clinically by many pain physicians and neurosurgeons alike without regard to their own outcome data. Methods. We reviewed our 20‐year experience retrospectively of patients receiving SCS implants and analyzed our data by pain type and group. Results. We present 260 patients, 140 men and 120 women. The most frequent type of pain in our series was neuropathic pain in 44.25% and the most frequent diagnosis was peripheral vascular disease (PVD) with 98 cases. The second was failed back surgery syndrome (FBSS) with 65 cases and the third was complex regional pain syndrome type I (CRPS I), with 40 cases. In CRPS group, the mean visual analog scale (VAS) of this group was 77.89 ± 13.38. In total, 5% had no pain relief, 40% had poor pain relief, 47.5% had good pain relief, and 7.5% had excellent pain relief. In FBSS group, the mean VAS was 79.62 ± 11.69 mm. A total of 13.80% had no pain relief at all, 35.39% had poor pain relief, 50.76% had good pain relief, and there were no patients in this group who had complete pain relief. A total of 98 patients, 78 men and 20 women, were diagnosed with PVD. The mean VAS of this group was 69.75 ± 14.36 mm. A total of 11.22% had poor pain relief, 87.75% had good pain relief. One patient had complete pain relief and all patients in this group perceived at least some improvement in their symptoms. The rate of complications was close to 28% in our overall sample. Conclusions. In conclusion, we demonstrated the utility over time of this type of treatment is comparable with other series of efficacy of SCS. The analgesic efficacy was close to 65% in the overall group. The therapy was not free of complications. The preponderance of our patients was patients with the diagnosis of PVD and our results in this group of patients were excellent. These excellent results of more than 90% improvement suggest to us that SCS be considered as a first‐line approach to the clinical management of patients with pain and ulcer of PVD.

Spinal Cord Stimulation in Peripheral Vascular Disease: A Retrospective Analysis of 95 Cases

Abstract: Spinal Cord Stimulation is one of the interventionist treatments used for treating diverse chronic pain syndromes.

Estándares de calidad asistencial y catálogo de procedimientos de las unidades de dolor crónico

Resumen Objetivos Desarrollar unos estandares de calidad asistencial y un catalogo de procedimientos para las unidades de dolor cronico. Material y metodos Un comite cientifico, formado por 6 expertos en el tratamiento del dolor cronico, selecciono despues de una revision sistematica de la bibliografia un conjunto de 130 criterios de calidad asistencial y 80 procedimientos. Posteriormente, siguiendo la metodologia Delphi, un panel formado por el propio comite cientifico y otros 12 expertos introdujo 4 criterios y 5 procedimientos adicionales, y valoro su grado de acuerdo sobre cada uno de los 134 criterios, y el grado de prioridad de los 85 procedimientos seleccionados. Resultados Se ha obtenido un grado elevado de consenso sobre la mayoria de los estandares de calidad propuestos. En particular, se han consensuado 31 estandares generales sobre instalaciones y equipamiento, 15 sobre recursos humanos y 13 sobre procesos. Se han desarrollado 40 estandares sobre consultas externas, que incluyen parametros estructurales, organizativos y de tiempo, como el numero de consultas necesario por cada 100.000 habitantes asignados (1,5 consultas), el numero maximo de horas de consulta diarias que debe tener un facultativo (5 horas), el numero maximo de dias de consulta semanales por facultativo (3 dias), el tiempo necesario para completar una primera consulta (50 min) y una sucesiva (20 min), y el tiempo maximo que debe permanecer un paciente en lista de espera en funcion de la enfermedad subyacente, entre otros. Tambien se han desarrollado 18 estandares de hospitalizacion y hospital de dia, que incluyen estandares como el numero de camas y sillones de readaptacion al medio necesarios en el hospital de dia por cada 100.000 habitantes (1 cama y 1 sillon), el numero maximo de pacientes hospitalizados que puede tener a su cargo un especialista en el tratamiento del dolor (4 si es la unidad del dolor la responsable del ingreso, 7 si son otros servicios los responsables, 8 si son pacientes del hospital de dia de la unidad), el tiempo necesario para realizar la primera consulta de un paciente hospitalizado (60 min si esta ingresado a cargo de la unidad del dolor y 45 min si son otros servicios los responsables del ingreso). El estudio tambien incluye 8 estandares sobre actividad cientifica y docente. Finalmente, se ha evaluado la prioridad de 85 procedimientos (18 del hospital de dia, 24 de las salas de bloqueo y 43 del quirofano) para que formen parte de la cartera de servicios de las unidades del dolor, y se han establecido unos estandares de tiempo para 76 de ellos. Conclusiones Con el debido rigor cientifico y tecnico, se han desarrollado unos estandares de calidad y un catalogo actualizado de procedimientos propios de las unidades del dolor cronico, que deben resultar utiles tanto para la actualizacion de la estructura y la organizacion de las unidades ya existentes, como para la planificacion y el desarrollo de futuras unidades. Esperamos contribuir con este trabajo a la mejora de la calidad asistencial de los pacientes con dolor cronico.

Intrathecal Non-Opioid Analgesics for the Control of Pain

Publisher Summary This chapter focuses on the use of intrathecal nonopioid analgesics for controlling pain. Spinal infusion of analgesics, through totally implantable systems, is one of the most widely used therapeutic options for patients with chronic pain who do not respond to other, less invasive therapies. Use of this therapy requires a medication that is safe, effective, stable, and compatible with other medications and an infusion system to improve analgesic efficacy. Approximately, 35% of patients treated with intrathecal morphine do not obtain acceptable analgesia and it is often necessary to combine intrathecal morphine with other nonopioid agents in order to reduce pain. The currently available nonopioid agents for intrathecal delivery include local anesthetics, clonidine, midazolam, and baclofen that are to be used only in very selected cases when there is no other way to treat the patients pain. Local anesthetics such as sodium (Na+) channel blocking agents, cause a reversible blockade of nerve impulse conduction by preventing the propagation of action potentials in the axons of autonomic, sensory, and motor nerve fibers. Blockade of Na+ channels may be augmented by blockade of potassium channels, calcium channels, and G-protein-coupled receptors. Clonidine, a selective α2-adrenergic agonist, is a lipophilic agent that has analgesic effects when used intrathecally and it is indicated for patients with chronic neuropathic pain. Pain relief with this therapy has been reported to be between 70 and 100%. Midazolam is a benzodiazepine that exerts its effect via the GABA receptor type A. When a bolus of midazolam is injected into the CSF, it produces analgesia of long duration, and probably has a synergistic effect with bupivacaine.