-
World Neurosurgery Jun 2024This systematic review aims to determine the effectiveness of Dorsal Root Ganglion Stimulation (DRGS) in chronic pain management. (Review)
Review
OBJECTIVE
This systematic review aims to determine the effectiveness of Dorsal Root Ganglion Stimulation (DRGS) in chronic pain management.
MATERIALS AND METHODS
In 2023, a comprehensive systematic review was undertaken utilizing various electronic databases, employing MeSH terms and free search terms tailored to the study's aims. This review included primary research such as cohorts, case-control studies, and clinical trials, all focusing on the efficacy of DRGS in treating various chronic pain conditions. Non-human or animal studies were omitted from the selection process. A review of study quality was conducted, followed by meticulous analysis of the findings to synthesize the evidence. This review represents the most current research, with updates extending to 2024. A total of 400 articles were reviewed. 29 articles were included in our review after meticulous screening.
RESULTS
Twenty-nine articles published in the last five years meeting selection criteria were identified, encompassing patients with various diagnoses warranting the use of DRGS beyond CRPS. Additionally, the analysis includes different outcome measurement tools, emphasizing improvements in pain management, functionality, and quality of life. Finally, common complications such as surgical site infection and issues with electrodes are highlighted.
CONCLUSIONS
This systematic review affirms the effectiveness of DRGS therapy in managing diverse chronic pain conditions, highlighting improvements in quality of life, functionality, and mood states, making it a viable alternative for patients unresponsive to traditional treatments.
PubMed: 38945208
DOI: 10.1016/j.wneu.2024.06.138 -
Journal of the Mechanical Behavior of... Jun 2024Micro finite-element (μFE) simulations serve as a crucial research tool to assist laboratory experiments in the biomechanical assessment of screw anchorage in bone....
Micro finite-element (μFE) simulations serve as a crucial research tool to assist laboratory experiments in the biomechanical assessment of screw anchorage in bone. However, accurately modelling the interface between bone and screw threads at the microscale poses a significant challenge. Currently, the gold-standard approach involves employing computationally intensive physical contact models to simulate this interface. This study compared nonlinear μFE predictions of deformations, whole-construct stiffness, maximum force and damage patterns of three different computationally efficient simplified interface approaches to the general contact interface in Abaqus Explicit, which was defined as gold-standard and reference model. The μCT images (resolution: 32.8 μm) of two human radii with varying bone volume fractions were utilized and a screw was virtually inserted up to 50% and 100% of the volar-dorsal cortex distance. Materially nonlinear μFE models were generated and loaded in tension, compression and shear. In a first step, the common simplification of using a fully-bonded interface was compared to the general contact interface, revealing overestimations of whole-construct stiffness (19% on average) and maximum force (26% on average), along with inaccurate damage pattern replications. To enhance predictions, two additional simplified interface models were compared: tensionally strained element deletion (TED) and a novel modification of TED (TED-M). TED deletes interface elements strained in tension based on a linear-elastic simulation before the actual simulation. TED-M extends the remaining contact interface of TED by incorporating neighboring elements to the contact area. Both TED and TED-M reduced the errors in whole-construct stiffness and maximum force and improved the replication of the damage distributions in comparison to the fully-bonded approach. TED was better in predicting whole-construct stiffness (average error of 1%), while TED-M showed lowest errors in maximum force (1% on average). In conclusion, both TED and TED-M offer computationally efficient alternatives to physical contact modelling, although the fully-bonded interface may deliver sufficiently accurate predictions for many applications.
PubMed: 38945119
DOI: 10.1016/j.jmbbm.2024.106634 -
Journal of Electromyography and... Jun 2024This study aimed to develop an insertion technique for intramuscular EMG recording of the oblique head of adductor hallucis (AddH) and first dorsal interosseous (FDI)...
This study aimed to develop an insertion technique for intramuscular EMG recording of the oblique head of adductor hallucis (AddH) and first dorsal interosseous (FDI) muscles in humans via the dorsum of the foot, and report feasibility of intramuscular EMG data acquisition during walking in shoes. In eight individuals without musculoskeletal pain or injury (5 males; 32 ± 8 years), intramuscular electrodes were inserted into AddH (oblique head) and FDI through the right foot's dorsum (between metatarsals I-II) with ultrasound guidance. The ultrasound transducer was positioned on the plantar surface. Intramuscular EMG was also recorded from abductor hallucis, tibialis posterior, flexor digitorum longus and peroneus longus. Participants performed six overground walking trials wearing modified shoes, and rated pain associated with the intramuscular electrodes during walking (numerical rating scale, 0-10). High-quality EMG recordings were obtained from intrinsic and extrinsic foot muscles. Analyses of power spectral densities indicated that movement artefacts commonly observed during gait were removed by filtering. Pain associated with AddH/FDI electrodes during walking was low (median[IQR] 1[2]; range 0-4) and similar to other sites. Findings demonstrate that intramuscular EMG recording from AddH (oblique head) and FDI using this insertion technique is feasible and associated with minimal pain when walking in shoes.
PubMed: 38945047
DOI: 10.1016/j.jelekin.2024.102914 -
Schizophrenia Research Jun 2024The striatum is thought to play a critical role in the pathophysiology and antipsychotic treatment of schizophrenia. Previous studies have revealed abnormal functional...
BACKGROUND
The striatum is thought to play a critical role in the pathophysiology and antipsychotic treatment of schizophrenia. Previous studies have revealed abnormal functional connectivity (FC) of the striatum in early-onset schizophrenia (EOS) patients. However, no prior studies have examined post-treatment changes of striatal FC in EOS patients.
METHODS
We recruited 49 first-episode drug-naïve EOS patients to have resting-state functional magnetic resonance imaging scans at baseline and after 8 weeks of treatment with antipsychotics, along with baseline scanning of 34 healthy controls (HCs) for comparison purposes. We examined the FC values between each seed in striatal subregion and the rest of the brain. The Positive and Negative Syndrome Scale (PANSS) was applied to measure psychiatric symptoms in patients.
RESULTS
Compared with HCs at baseline, EOS patients exhibited weaker FC of striatal subregions with several brain regions of the salience network and default mode network. Meanwhile, FC between the dorsal caudal putamen (DCP) and left supplementary motor area, as well as between the DCP and right postcentral gyrus, was negatively correlated with PANSS negative scores. Furthermore, after 8 weeks of treatment, EOS patients showed decreased FC between subregions of the putamen and the triangular part of inferior frontal gyrus, middle frontal gyrus, supramarginal gyrus and inferior parietal lobule.
CONCLUSIONS
Decreased striatal FC is evident, even in the early stages of schizophrenia, and enhance our understanding of the neurodevelopmental abnormalities in schizophrenia. The findings also demonstrate that reduced striatal FC occurs after antipsychotic therapy, indicating that antipsychotic effects need to be accounted for when considering striatal FC abnormalities in schizophrenia.
PubMed: 38944974
DOI: 10.1016/j.schres.2024.06.016 -
Cell Reports Jun 2024Exposure to stressors has profound effects on sleep that have been linked to serotonin (5-HT) neurons of the dorsal raphe nucleus (DR). However, the DR also comprises...
Exposure to stressors has profound effects on sleep that have been linked to serotonin (5-HT) neurons of the dorsal raphe nucleus (DR). However, the DR also comprises glutamatergic neurons expressing vesicular glutamate transporter type 3 (DR), leading us to examine their role. Cell-type-specific tracing revealed that DR neurons project to brain areas regulating arousal and stress. We found that chemogenetic activation of DR neurons mimics stress-induced sleep perturbations. Furthermore, deleting VGLUT3 in the DR attenuated stress-induced sleep perturbations, especially after social defeat stress. In the DR, VGLUT3 is found in subsets of 5-HT and non-5-HT neurons. We observed that both populations are activated by acute stress, including those projecting to the ventral tegmental area. However, deleting VGLUT3 in 5-HT neurons minimally affected sleep regulation. These findings suggest that VGLUT3 expression in the DR drives stress-induced sleep perturbations, possibly involving non-5-HT DR neurons.
PubMed: 38944834
DOI: 10.1016/j.celrep.2024.114411 -
Journal of Pediatric Urology Jun 2024The bladder exstrophy-epispadias complex includes some of the most challenging conditions treated by pediatric urologists. They are associated with the need for multiple...
Redo surgery to improve urinary function, sexual function and cosmesis in male patients with exstrophy-epispadias complex complications. Technical principles and pearls based on case scenarios.
The bladder exstrophy-epispadias complex includes some of the most challenging conditions treated by pediatric urologists. They are associated with the need for multiple intricate reconstructive procedures, aimed at restoring the anatomy and function of the bladder, urethra and external genitalia. These patients often endure multiple redo reconstructive procedures to improve urinary function, sexual function and cosmesis throughout the first two decades of life. In this article, we present the 30-year experience of a single surgeon performing redo surgery for males born with epispadias and bladder exstrophy. Through detailed documentation of 6 clinical cases, we highlight technical aspects that may contribute to a successful surgical reconstruction in these patients. The article is focused specifically on patients undergoing redo epispadias repair with or without concomitant continence procedures. We make the case for complete penile disassembly with external rotation of the corpora to correct recurrent dorsal curvature; this approach also allows the surgeon to have access to the proximal urethra and bladder neck after opening the intersymphiseal scar/band. This is useful when additional procedures on the bladder, such as bladder neck tailoring, are necessary. We also highlight the importance of avoiding reverse Byars' flaps when performing skin closure, due to the resulting midline scar. Besides being associated with a poor cosmetic outcome, it can also contribute to recurrent dorsal curvature. The authors advocate for rotational skin flaps to cover the penile shaft. Correction of dorsal curvature and improved cosmesis obtained with complete penile disassembly sometimes comes at the expense of the urethra being left as a hypospadias (figure). This will require further surgeries (usually a 2-stage buccal mucosa graft), much like the treatment of proximal hypospadias. Redo epispadias surgery in males remains a challenge. The systematic approach offered by the case scenarios may help guide surgeons dealing with this difficult condition. Patient with complications after repair of classic bladder exstrophy. A) Stone retrieved from posterior urethra after complete penile disassembly. B) After opening the inter-symphiseal scar, the bladder has been opened and the bladder neck tailored. C) Complete penile disassembly has been completed with corporal bodies and urethra individualized. D,E,F) Final appearance of the repair; abdominal wall was closed with anterior rectus sheath flaps, penile skin was closed with rotational flaps and urethra ended up as a hypospadias.
PubMed: 38944626
DOI: 10.1016/j.jpurol.2024.06.004 -
Developmental Biology Jun 2024During neural development, sculpting of early formed circuits by cell death and synaptic pruning is necessary to generate a functional and efficient nervous system. This...
During neural development, sculpting of early formed circuits by cell death and synaptic pruning is necessary to generate a functional and efficient nervous system. This allows for the establishment of rudimentary circuits which necessitate early organism survival to later undergo subsequent refinement. These changes facilitate additional specificity to stimuli which can lead to increased behavioral complexity. In multiple species, Rohon-Beard neurons (RBs) are the earliest mechanosensory neurons specified and are critical in establishing a rudimentary motor response circuit. Sensory input from RBs gradually becomes redundant as dorsal root ganglion (DRG) neurons develop and integrate into motor circuits. Previous studies demonstrate that RBs undergo a dramatic wave of cell death concurrent with development of the DRG. However, contrary to these studies, we show that neurogenin1 (ngn1) RBs do not undergo a widespread wave of programmed cell death during early zebrafish development and instead persist until at least 15 days post fertilization (dpf). Starting at 2 dpf, we also observed a dramatic medialization and shrinkage of ngn1 RB somas along with a gradual downregulation of ngn1 in RBs. This alters a fundamental premise of early zebrafish neural development and opens new avenues to explore mechanisms of RB function, persistence, and circuit refinement.
PubMed: 38944329
DOI: 10.1016/j.ydbio.2024.06.020 -
Acta Biomaterialia Jun 2024To probe its environment, the flying insect controllably flexes, twists, and maneuvers its antennae by coupling mechanical deformations with the sensory output. We...
To probe its environment, the flying insect controllably flexes, twists, and maneuvers its antennae by coupling mechanical deformations with the sensory output. We question how the materials properties of insect antennae could influence their performance. A comparative study was conducted on four hawkmoth species: Manduca sexta, Ceratomia catalpae, Manduca quinquemaculata, and Xylophanes tersa. The morphology of the antennae of three hawkmoths that hover while feeding and one putatively non-nectar-feeding hawkmoth (Ceratomia catalpa) do not fundamentally differ, and all the antennae are comb-like (i.e., pectinate), markedly in males but weakly in females. Applying different weights to the free end of extracted cantilevered antennae, we discovered anisotropy in flexural rigidity when the antenna is forced to bend dorsally versus ventrally. The flexural rigidity of male antennae was less than that of females. Compared with the hawkmoths that hover while feeding, Ceratomia catalpae has almost two orders of magnitude lower flexural rigidity. Tensile tests showed that the stiffness of male and female antennae is almost the same. Therefore, the differences in flexural rigidity are explained by the distinct shapes of the antennal pectination. Like bristles in a comb, the pectinations provide extra rigidity to the antenna. We discuss the biological implications of these discoveries in relation to the flight habits of hawkmoths. Flexural anisotropy of antennae is expected in other groups of insects, but the targeted outcome may differ. Our work offers promising new applications of shaped fibers as mechanical sensors. STATEMENT OF SIGNIFICANCE: Insect antennae are blood-filled, segmented fibers with muscles in the two basal segments. The long terminal segment is muscle-free but can be flexed. Our comparative analysis of mechanical properties of hawkmoth antennae revealed a new feature: antenna resistance to bending depends on the bending direction. Our discovery replaces the conventional textbook scenario considering hawkmoth antennae as rigid rods. We showed that the pectinate antennae of hawkmoths behave as a comb in which the bristles resist bending when they come together. This anisotropy of flexural resistance offers a new mode of environmental sensing that has never been explored. The principles we found apply to other insects with non-axisymmetric antennae. Our work offers new applications for shaped fibers that could be designed to sense the flows.
PubMed: 38944324
DOI: 10.1016/j.actbio.2024.06.036 -
The American Journal of the Medical... Jun 2024Non-small cell lung cancer (NSCLC) is a pernicious tumor with high incidence and mortality rates. The incidence rate of NSCLC increases with age and poses a serious...
BACKGROUND AND OBJECTIVE
Non-small cell lung cancer (NSCLC) is a pernicious tumor with high incidence and mortality rates. The incidence rate of NSCLC increases with age and poses a serious danger to human health. The aim of this study was to determine the mechanism by which (-)-epicatechin (EC) alleviates NSCLC.
METHODS
Twenty-four pairs of NSCLC tissues and cancer-adjacent tissues were collected, and A549 and H460 radiotherapy-resistant strains were generated by repeatedly irradiating A549 and H460 cells with dose-gradient X-rays. Radiotherapy-resistant H460 cells were successfully injected subcutaneously into the left dorsal side of nude mice at a dose of 1 × 10 to establish an NSCLC animal model. The levels of interrelated genes and proteins were detected by RT‒qPCR and Western blotting, and cell proliferation and apoptosis were evaluated by CCK‒8 assay, Transwell assay, flow cytometry, and TUNEL staining.
RESULTS
LOC107986454 was highly expressed in NSCLC patients, while miR-143-3p was expressed at low levels and was negatively correlated with LOC107986454. Functionally, EC promoted autophagy and apoptosis induced by radiotherapy, restrained cell proliferation and migration, and ultimately enhanced the radiosensitivity of NSCLC cells. A downstream mechanistic study showed that EC facilitated miR-143-3p expression by inhibiting LOC107986454 and then restraining the expression of EZH2, which ultimately facilitated autophagy and apoptosis in cancer cells, inhibited proliferation and migration, and enhanced the radiosensitivity of NSCLC cells.
CONCLUSION
EC can enhance the radiosensitivity of NSCLC cells by regulating the LOC107986454/miR-143-3p/EZH2 axis.
PubMed: 38944201
DOI: 10.1016/j.amjms.2024.06.027 -
NeuroImage Jun 2024Research indicates that hearing loss significantly contributes to tinnitus, but it alone does not fully explain its occurrence, as many people with hearing loss do not...
Research indicates that hearing loss significantly contributes to tinnitus, but it alone does not fully explain its occurrence, as many people with hearing loss do not experience tinnitus. To identify a secondary factor for tinnitus generation, we examined a unique dataset of individuals with intermittent chronic tinnitus, who experience fluctuating periods of tinnitus. EEGs of healthy controls were compared to EEGs of participants who reported perceiving tinnitus on certain days, but no tinnitus on other days.. The EEG data revealed that tinnitus onset is associated with increased theta activity in the pregenual anterior cingulate cortex and decreased theta functional connectivity between the pregenual anterior cingulate cortex and the auditory cortex. Additionally, there is increased alpha effective connectivity from the dorsal anterior cingulate cortex to the pregenual anterior cingulate cortex. When tinnitus is not perceived, differences from healthy controls include increased alpha activity in the pregenual anterior cingulate cortex and heightened alpha connectivity between the pregenual anterior cingulate cortex and auditory cortex. This suggests that tinnitus is triggered by a switch involving increased theta activity in the pregenual anterior cingulate cortex and decreased theta connectivity between the pregenual anterior cingulate cortex and auditory cortex, leading to increased theta-gamma cross-frequency coupling, which correlates with tinnitus loudness. Increased alpha activity in the dorsal anterior cingulate cortex correlates with distress. Conversely, increased alpha activity in the pregenual anterior cingulate cortex can transiently suppress the phantom sound by enhancing theta connectivity to the auditory cortex. This mechanism parallels chronic neuropathic pain and suggests potential treatments for tinnitus by promoting alpha activity in the pregenual anterior cingulate cortex and reducing alpha activity in the dorsal anterior cingulate cortex through pharmacological or neuromodulatory approaches.
PubMed: 38944171
DOI: 10.1016/j.neuroimage.2024.120713