Insights into the pathophysiology and response of persistent spinal pain syndrome type 2 to spinal cord stimulation: a human genome-wide association study.

BACKGROUND: Spinal cord stimulation (SCS) provides pain relief for some patients with persistent spinal pain syndrome type 2 (PSPS 2), but the precise mechanisms of action and prognostic factors for a favorable pain response remain obscure. This in vivo human genome-wide association study provides some pathophysiological clues. METHODS: We performed a high-density oligonucleotide microarray analysis of serum obtained from both PSPS 2 cases and pain-free controls who had undergone lower back spinal surgery at the study site. Using multivariate discriminant analysis, we tried to identify different expressions between mRNA transcripts from PSPS 2 patients relative to controls, SCS responders to non-responders, or SCS responders to themselves before starting SCS. Gene ontology enrichment analysis was used to identify the biological processes that best discriminate between the groups of clinical interest. RESULTS: Thirty PSPS 2 patients, of whom 23 responded to SCS, were evaluated together with 15 pain-free controls. We identified 11 significantly downregulated genes in serum of PSPS 2 patients compared with pain-free controls and two significantly downregulated genes once the SCS response became apparent. All were suggestive of enhanced inflammation, tissue repair mechanisms and proliferative responses among the former. We could not identify any gene differentiating patients who responded to SCS from those who did not respond. CONCLUSIONS: This study points out various biological processes that may underlie PSPS 2 pain and SCS therapeutic effects, including the modulation of neuroimmune response, inflammation and restorative processes.

The Neurostimulation Appropriateness Consensus Committee (NACC)®: Recommendations for the Mitigation of Complications of Neurostimulation.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise and international representation to establish evidence-based guidance on the mitigation of neuromodulation complications. This Neurostimulation Appropriateness Consensus Committee (NACC)® project intends to update evidence-based guidance and offer expert opinion that will improve efficacy and safety. MATERIALS AND METHODS: Authors were chosen on the basis of their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when NACC last published guidelines) to October 2023. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence was scant. RESULTS: The NACC examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The NACC recommends best practices regarding the mitigation of complications associated with neurostimulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be used as a guide to assist decision-making when clinically appropriate.

The Polyanalgesic Consensus Conference (PACC)®: Intrathecal Drug Delivery Guidance on Safety and Therapy Optimization When Treating Chronic Noncancer Pain.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians and scientists based on expertise with international representation to establish evidence-based guidance on intrathecal drug delivery in treating chronic pain. This Polyanalgesic Consensus Conference (PACC)® project, created more than two decades ago, intends to provide evidence-based guidance for important safety and efficacy issues surrounding intrathecal drug delivery and its impact on the practice of neuromodulation. MATERIALS AND METHODS: Authors were chosen on the basis of their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when PACC® last published guidelines) to the present. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence is scant. RESULTS: The PACC® examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The PACC® recommends best practices regarding intrathecal drug delivery to improve safety and efficacy. The evidence- and consensus-based recommendations should be used as a guide to assist decision-making when clinically appropriate.

Una rara complicación de la anestesia epidural y subaracnoidea. Tumores epidermoideos espinales / A rare complication of epidural and subarachnoid anesthesia iatrogenic spinal epidermoid tumors

Los tumores epidermoideos espinales son tumores muy poco frecuentes, que pueden tener un origen congénito o iatrogénico. Los tumores de origen iatrogénico pueden formarse a partir de la implantación de fragmentos de piel dentro del espacio epidural o subaracnoideo, que posteriormente crecen. El arrastre de células epidérmicas se puede producir por un "efecto de biopsia" durante las punciones lumbares, por una inadecuada adaptación del mandril dentro de la aguja. El tiempo de latencia hasta la aparición de los primeros síntomas neurológicos puede estar entre los 2 y 10 años. Se localizan, principalmente, en la columna lumbar. Los signos y los síntomas varían según la situación, el sitio y la dimensión del tumor. Las manifestaciones clínicas tienen relación con su efecto compresivo y aparecen cuando este tumor adquiere un tamaño de 1,5 a 3 cm. y comienza a ejercer presión sobre las raíces nerviosas de la cola de caballo. El diagnóstico presuntivo se establece por el antecedente de alguna punción lumbar practicada en años anteriores, en un paciente que presenta la clínica antes mencionada, sumado al informe radiológico del hallazgo de una imagen con diferente densidad dentro del canal medular, de localización extramedular y próxima a la zona de la punción lumbar. El pronóstico es bueno por su benignidad anatomopatológica y el tratamiento es quirúrgico.

Spinal epidermoid tumors are very rare and their origin may be either congenital or iatrogenic. Iatrogenic tumors may originate from the implant of skin fragments within the epidural or subarachnoid space and later grow. The dragging of epidermic cells may occur from a "biopsy effect" during lumbar punctures due to an inadequate placement of the mandrel inside the needle. The time of latency until the appearance of the first neurological symptoms may be between 2 to 10 years. They are mainly located in the lumbar spine. Signs and symptoms vary according to the situation, site and size of the tumor. Clinical manifestations are related to their compression effect and appear when the tumor reaches a size of 1.5 to 3 cm and begins to exert pressure on the nerve roots of the horsetail. Presumptive diagnosis is based on the history of a lumbar puncture of some years back in a patient with the above-mentioned background of compressive symptoms added to the radiological report of an image with a different density within the medullar canal, located extra-medularly and near the area of the lumbar puncture. Treatment is surgical and it has a good prognosis due to it being anatomo-pathologically benign.

Os tumores epidermóides espinhais sao raros. Podem ser congenitos ou iatrogenicos. Os iatrogenicos originam-se da implantação de fragmentos de pele dentro do espaço epidural ou subaracnóideo que posteriormente cresce. O arrasto de células epidérmicas pode ocorrer por "efeito de biópsia" durante punções lombares com agulhas com mandril inadaptados. O tempo de latencia até o aparecimento dos primeiros sintomas neurológicos varia entre 2 e 10 anos. Os tumores se localizam, principalmente, na coluna lombar. Os sinais e sintomas variam conforme a situação, o sítio e a dimensao do tumor. As manifestaçoes clínicas associam-se a seu efeito compressivo e aparecem quando o tamanho do tumor atinge 1,5 a 3 cm e começa a comprimir as raízes nervosas da cauda eqüina. O diagnóstico presuntivo é estabelecido pelo antecedente de alguma punção lombar praticada em anos anteriores, em um paciente que apresenta o quadro clínico antes mencionado, além de um relatório radiológico do achado de uma imagem com diferente densidade dentro do canal medular, de localização extramedular e próxima da região da punção lombar. Por sua benignidade anatomopatológica, o prognóstico é bom, e o tratamento é cirúrgico.