Neuromodulation最新文献

Objectives: This review aimed to compile the literature on synaptic plasticity induced by electrical nerve stimulation (ENS) in nociceptive and somatosensory circuits within the central nervous system, with a particular focus on its effects on both the brain and spinal cord. Understanding the mechanisms underlying synaptic changes, enhances our comprehension of how ENS contributes to both pain relief and the development of experimental pain models.

Materials and methods: We conducted a systematic search of PubMed, Scopus, PEDro, SciELO, and Cochrane databases, adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, and evaluated the quality of evidence using SYRCLE's risk of bias tool. The inclusion criteria were application of ENS to peripheral nerves, reporting of a detailed methodology, providing direct physiological measurements of synaptic activity (eg, field potentials or intracellular recordings), and publication in English or Spanish. From 8094 results, 85 studies met the inclusion criteria.

Results: ENS was found to induce synaptic potentiation in 70 studies, depression in 7, and both effects in 8. These outcomes were determined by specific stimulation parameters and individual characteristics, with distinct molecular mechanisms involved in each case. Notably, most research focused on long-term potentiation in nociceptive pathways to create experimental pain models, with most studies conducted in the spinal cord. Few studies explored the link between ENS-induced synaptic plasticity and its analgesic effects or the role of plasticity in supraspinal brain regions, suggesting promising areas for future research.

Conclusions: ENS-induced synaptic plasticity presents a valuable opportunity for both pain management and the development of experimental pain models. Further research is needed to explore the connections between plasticity, analgesia, and higher brain regions.

Objectives: The present systematic review aimed to assess the outcome of sacral neuromodulation (SNM) in adult patients with chronic constipation.

Materials and methods: A systematic review of randomized controlled trials (RCTs) that assessed the efficacy of SNM in chronic constipation was conducted and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guideline. PubMed, Scopus, and Web of Science were screened from their inception through March 2024. The primary outcome was improvement in constipation and quality of life (QoL), and the secondary outcome was adverse events after treatment. The risk of bias and certainty of evidence were assessed by the risk of bias 2 tool and Grading of Recommendations Assessment, Development, and Evaluation approach.

Results: Five RCTs incorporating 187 patients (93.6% female) with a median age of 42.5 years were included; 154 patients underwent SNM whereas 86 patients were crossed over to sham stimulation, and 33 received conservative treatment, amounting to a control group of 119 patients. The odds of relief of constipation after SNM were similar to those in the control group in the random-effect model (odds ratio [OR]: 1.92, 95% CI: 0.68-5.42, p = 0.217). The median percentage of reduction in the Cleveland Clinic Florida/Wexner Constipation Score was 27.9% in the SNM group vs 18.4% in the control group. No significant differences were observed in QoL. Both groups had similar odds of adverse events (OR: 2.22, 95% CI: 0.19-25.53, p = 0.521).

Conclusion: Although a relatively safe treatment, SNM was not associated with any tangible improvements in either constipation or QoL.

Background: CrossFit integrates diverse functional movements to optimize overall fitness, with muscle strength training being a core component. Ultrasound-guided percutaneous neuromodulation (US-guided PNM) has emerged as a potential adjunct to enhance muscle strength gains; however, its efficacy in the upper limb in healthy individuals remains unexplored.

Objective: This study evaluated the efficacy of two US-guided PNM protocols (three sessions and one session) targeting the axillary and suprascapular nerves in improving shoulder muscle strength in healthy CrossFit athletes.

Materials and methods: A pilot, randomized, controlled, single-blind clinical trial was conducted with 39 healthy CrossFit athletes randomly allocated to one of three groups: control (G1, no intervention), one session of US-guided PNM (G2), or three sessions of US-guided PNM (G3). Shoulder muscle strength was assessed using a hand-held dynamometer to measure external and internal rotation muscle strength at various shoulder positions before each treatment session (days 1, 7, and 14) and one week after the last session (day 21). Moreover, the one-repetition maximum (1RM) shoulder press exercise was evaluated on day 1 and day 21.

Results: No statistically significant differences were observed among groups for any outcome. However, the within-group analysis indicated statistically significant improvements over time in the treated limbs of intervention groups (G2 and G3), whereas no statistically significant changes were observed in the control (G1) or the untreated limbs of G2 and G3. The improvements were more consistent for shoulder strength measured in the neutral position than at 90° abduction.

Conclusions: Although US-guided PNM did not yield significantly greater improvements than did the control group, both one and three sessions targeting the axillary and suprascapular nerves enhanced rotational shoulder muscle strength in treated limbs and 1RM shoulder press performance. These findings should be interpreted with caution, and further investigation is warranted, particularly in populations with lower baseline strength and in exploring varied application parameters to optimize efficacy.

Clinical trial registration: The Clinicaltrials.gov registration number for the study is NCT06529770.

Objectives: The proposed mechanisms of spinal cord stimulation (SCS) follow the polarization of dorsal column axons; however, the development of subparesthesia SCS has encouraged the consideration of different targets. Given their relative proximity to the stimulation electrodes and their role in pain processing (eg, synaptic processing and gate control theory), spinal cord dorsal horn interneurons may be attractive stimulation targets.

Materials and methods: We developed a computational modeling pipeline termed "quasiuniform-mirror assumption" and applied it to predict polarization of dorsal horn interneuron cell types (islet type, central type, stellate/radial, vertical-like) to SCS. The quasiuniform-mirror assumption allows the prediction of the peak and directional axes of dendrite polarization for each cell type and location in the dorsal horn, in addition to the impact of the stimulation pulse width and electrode configuration.

Results: For long pulses, the peak polarization per milliampere of SCS with a spaced bipolar configuration was islet type 3.5mV, central type 1.3mV, stellate/radial 1.4mV, and vertical-like 1.6mV. For stellate/radial, the peak dendrite polarization was dorsal-ventral, and for islet-type, the peak dendrite polarization was in the rostral-caudal axis. For islet type and central type cells, peak dendrite polarization was between stimulation electrodes, whereas for stellate/radial and vertical-like cells, peak dendrite polarization was under the stimulation electrodes. The impact of the pulse width depends on the membrane time constants. Assuming a 1-millisecond time constant, for a 1-millisecond or 100-μs pulse width, the peak dendrite polarization decreases (from direct current values) by approximately 33% and approximately 88%, respectively. Increasing the interelectrode distance beyond approximately 3 cm did not significantly increase the peak polarization but expanded the region of interneuron polarization.

Conclusions: Predicted maximum polarization of islet-cells in the superficial dorsal horn at locations between electrodes is 4.6mV for 2 mA, 1-millisecond pulse SCS. A polarization of a few millivolts is sufficient to modulate synaptic processing through subthreshold mechanisms. Our simulations provide support for SCS approaches optimized to modulate the dendrites of dorsal horn neurons.

Of background data: The use of peripheral nerve stimulation (PNS) devices within pain and spine-related care has increased significantly in recent years. The United States Food and Drug Administration (FDA)-approved indications for PNS have expanded rapidly with technologic advances and randomized controlled trials demonstrating its efficacy. Analysis of real-world data regarding the complications associated with PNS can help inform clinical decision-making and patient counseling as the use of this neuromodulation therapy continues to evolve.

Objectives: This study aimed to categorize adverse events (AEs) described in medical device reports (MDRs) within the FDA Manufacturer and User Facility Device Experience (MAUDE) data base related to the use of PNS for pain and spinal indications.

Materials and methods: A comprehensive search within the MAUDE data base was conducted to identify AEs related to FDA-approved PNS devices reported between January 1, 2023 and December 31, 2023, specifically to capture AEs related to current PNS technology in clinical use. AEs were manually categorized according to event descriptions.

Results: We identified 594 unique MDRs associated with the five PNS devices currently approved by the FDA for use in the spine. While most MDRs (77.1%) did not specify lead location, spinal lead placements were implicated in 9.1% of cases, and appendicular lead placement accounted for 13.8%. Infection (22.7%), migration (14.7%), and skin erosion (9.4%) were the most common AEs reported. Most entries were categorized as device-related (40.1%) or procedural AEs (32.7%), and the remainder as patient complaints (17.3%), serious AEs (1.0%), and "other" complications (6.1%). Most complications were managed with explantations (43.8%) rather than revisions (29.5%).

Discussion/conclusion: New technologies and their applications must be regularly evaluated for safety and effectiveness. Our analysis of the MAUDE data base revealed that infection, lead migration, and skin erosion were the most commonly reported AEs associated with the use of PNS technology during 2023. Most AEs were deemed to be device- or procedure-related.