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Children (Basel, Switzerland) Jun 2024Pediatric regional anesthesia has been driven by the gradual rise in the adoption of opioid-sparing strategies and the growing concern over the possible adverse effects... (Review)
Review
BACKGROUND
Pediatric regional anesthesia has been driven by the gradual rise in the adoption of opioid-sparing strategies and the growing concern over the possible adverse effects of general anesthetics on neurodevelopment. Nonetheless, performing regional anesthesia studies in a pediatric population is challenging and accounts for the scarce evidence. This study aimed to review the scientific foundation of studies in cadavers to assess regional anesthesia techniques in children.
METHODS
We searched the following databases MEDLINE, EMBASE, and Web of Science. We included anatomical cadaver studies assessing peripheral nerve blocks in children. The core data collected from studies were included in tables and comprised block type, block evaluation, results, and conclusion.
RESULTS
The search identified 2409 studies, of which, 16 were anatomical studies on the pediatric population. The techniques evaluated were the erector spinae plane block, ilioinguinal/iliohypogastric nerve block, sciatic nerve block, maxillary nerve block, paravertebral block, femoral nerve block, radial nerve block, greater occipital nerve block, infraclavicular brachial plexus block, and infraorbital nerve block.
CONCLUSION
Regional anesthesia techniques are commonly performed in children, but the lack of anatomical studies may result in reservations regarding the dispersion and absorption of local anesthetics. Further anatomical research on pediatric regional anesthesia may guide the practice.
PubMed: 38929312
DOI: 10.3390/children11060733 -
Brain Sciences Jun 2024Neuropathic pain arises from injuries to the nervous system in diseases such as diabetes, infections, toxicity, and traumas. The underlying mechanism of neuropathic pain... (Review)
Review
Neuropathic pain arises from injuries to the nervous system in diseases such as diabetes, infections, toxicity, and traumas. The underlying mechanism of neuropathic pain involves peripheral and central pathological modifications. Peripheral mechanisms entail nerve damage, leading to neuronal hypersensitivity and ectopic action potentials. Central sensitization involves a neuropathological process with increased responsiveness of the nociceptive neurons in the central nervous system (CNS) to their normal or subthreshold input due to persistent stimuli, leading to sustained electrical discharge, synaptic plasticity, and aberrant processing in the CNS. Current treatments, both pharmacological and non-pharmacological, aim to alleviate symptoms but often face challenges due to the complexity of neuropathic pain. Neuromodulation is emerging as an important therapeutic approach for the treatment of neuropathic pain in patients unresponsive to common therapies, by promoting the normalization of neuronal and/or glial activity and by targeting cerebral cortical regions, spinal cord, dorsal root ganglia, and nerve endings. Having a better understanding of the efficacy, adverse events and applicability of neuromodulation through pre-clinical studies is of great importance. Unveiling the mechanisms and characteristics of neuromodulation to manage neuropathic pain is essential to understand how to use it. In the present article, we review the current understanding supporting dorsal root ganglia and spinal cord neuromodulation as a therapeutic approach for neuropathic pain.
PubMed: 38928589
DOI: 10.3390/brainsci14060589 -
Brain Sciences May 2024Conservative therapy is currently the elective treatment for peripheric facial palsy according to scientific literature. The success of conservative therapy is due to... (Review)
Review
BACKGROUND
Conservative therapy is currently the elective treatment for peripheric facial palsy according to scientific literature. The success of conservative therapy is due to physiotherapy and the application of its methods. The aim of this systematic review was to assess mirror therapy, a physiotherapeutic method.
OBJECTIVES
The aim of the following systematic review is to evaluate the effectiveness of using mirror therapy in patients with peripheral paralysis of the seventh cranial nerve.
METHODS
This systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The screening of literature was carried out on Cochrane, PEDro, PubMed/Medline, Scopus and Web of Science databases up until August 2022. All studies were randomized controlled trials (RCTs) and 5 articles met the inclusion criteria and were included in this study. The risk of bias was evaluated with PEDro and Jadad scales.
DISCUSSION
In the present study, we reviewed 5 RCTs that compared mirror therapy with other physiotherapy treatments or placebo to reduce pain, depression and improve range of motion in patients with peripheric facial nerve palsy.
CONCLUSIONS
Further studies are needed to determine the effectiveness of this type of treatment, but nevertheless the data obtained are very encouraging.
PubMed: 38928530
DOI: 10.3390/brainsci14060530 -
International Journal of Molecular... Jun 2024The influence of accelerated electrons on neuronal structures is scarcely explored compared to gamma and X-rays. This study aims to investigate the effects of...
The influence of accelerated electrons on neuronal structures is scarcely explored compared to gamma and X-rays. This study aims to investigate the effects of accelerated electron radiation on some pivotal neurotransmitter circuits (cholinergic and serotonergic) of rats' myenteric plexus. Male Wistar rats were irradiated with an electron beam (9 MeV, 5 Gy) generated by a multimodality linear accelerator. The contractile activity of isolated smooth muscle samples from the gastric corpus was measured. Furthermore, an electrical stimulation (200 μs, 20 Hz, 50 s, 60 V) was performed on the samples and an assessment of the cholinergic and serotonergic circuits was made. Five days after irradiation, the recorded mechanical responses were biphasic-contraction/relaxation in controls and contraction/contraction in irradiated samples. The nature of the contractile phase of control samples was cholinergic with serotonin involvement. The relaxation phase involved ACh-induced nitric oxide release from gastric neurons. There was a significant increase in serotonergic involvement during the first and second contractile phases of the irradiated samples, along with a diminished role of acetylcholine in the first phase. This study demonstrates an increased involvement of serotonergic neurotransmitter circuits in the gastric myenteric plexus caused by radiation with accelerated electrons.
Topics: Animals; Myenteric Plexus; Male; Rats; Rats, Wistar; Stomach; Electrons; Muscle, Smooth; Serotonin; Muscle Contraction; Acetylcholine; Nitric Oxide
PubMed: 38928511
DOI: 10.3390/ijms25126807 -
International Journal of Molecular... Jun 2024Gap injuries to the peripheral nervous system result in pain and loss of function, without any particularly effective therapeutic options. Within this context,... (Review)
Review
Gap injuries to the peripheral nervous system result in pain and loss of function, without any particularly effective therapeutic options. Within this context, mesenchymal stem cell (MSC)-derived exosomes have emerged as a potential therapeutic option. Thus, the focus of this study was to review currently available data on MSC-derived exosome-mounted scaffolds in peripheral nerve regeneration in order to identify the most promising scaffolds and exosome sources currently in the field of peripheral nerve regeneration. We conducted a systematic review following PRISMA 2020 guidelines. Exosome origins varied (adipose-derived MSCs, bone marrow MSCs, gingival MSC, induced pluripotent stem cells and a purified exosome product) similarly to the materials (Matrigel, alginate and silicone, acellular nerve graft [ANG], chitosan, chitin, hydrogel and fibrin glue). The compound muscle action potential (CMAP), sciatic functional index (SFI), gastrocnemius wet weight and histological analyses were used as main outcome measures. Overall, exosome-mounted scaffolds showed better regeneration than scaffolds alone. Functionally, both exosome-enriched chitin and ANG showed a significant improvement over time in the sciatica functional index, CMAP and wet weight. The best histological outcomes were found in the exosome-enriched ANG scaffold with a high increase in the axonal diameter and muscle cross-section area. Further studies are needed to confirm the efficacy of exosome-mounted scaffolds in peripheral nerve regeneration.
Topics: Exosomes; Nerve Regeneration; Mesenchymal Stem Cells; Humans; Animals; Tissue Scaffolds; Peripheral Nerve Injuries; Mesenchymal Stem Cell Transplantation
PubMed: 38928194
DOI: 10.3390/ijms25126489 -
International Journal of Molecular... Jun 2024The use of acellular nerve allografts (ANAs) to reconstruct long nerve gaps (>3 cm) is associated with limited axon regeneration. To understand why ANA length might...
Limited Nerve Regeneration across Acellular Nerve Allografts (ANAs) Coincides with Changes in Blood Vessel Morphology and the Development of a Pro-Inflammatory Microenvironment.
The use of acellular nerve allografts (ANAs) to reconstruct long nerve gaps (>3 cm) is associated with limited axon regeneration. To understand why ANA length might limit regeneration, we focused on identifying differences in the regenerative and vascular microenvironment that develop within ANAs based on their length. A rat sciatic nerve gap model was repaired with either short (2 cm) or long (4 cm) ANAs, and histomorphometry was used to measure myelinated axon regeneration and blood vessel morphology at various timepoints (2-, 4- and 8-weeks). Both groups demonstrated robust axonal regeneration within the proximal graft region, which continued across the mid-distal graft of short ANAs as time progressed. By 8 weeks, long ANAs had limited regeneration across the ANA and into the distal nerve (98 vs. 7583 axons in short ANAs). Interestingly, blood vessels within the mid-distal graft of long ANAs underwent morphological changes characteristic of an inflammatory pathology by 8 weeks post surgery. Gene expression analysis revealed an increased expression of pro-inflammatory cytokines within the mid-distal graft region of long vs. short ANAs, which coincided with pathological changes in blood vessels. Our data show evidence of limited axonal regeneration and the development of a pro-inflammatory environment within long ANAs.
Topics: Animals; Nerve Regeneration; Rats; Sciatic Nerve; Allografts; Axons; Male; Blood Vessels; Inflammation; Cellular Microenvironment; Transplantation, Homologous; Cytokines; Rats, Sprague-Dawley
PubMed: 38928119
DOI: 10.3390/ijms25126413 -
Biomedicines Jun 2024Pain is a multifaceted, multisystem disorder that adversely affects neuro-psychological processes. This study compares the effectiveness of central stimulation...
Pain is a multifaceted, multisystem disorder that adversely affects neuro-psychological processes. This study compares the effectiveness of central stimulation (transcranial direct current stimulation-tDCS over F3/F4) and peripheral stimulation (transcutaneous electrical nerve stimulation-TENS over the median nerve) in pain inhibition during a cognitive task in healthy volunteers and to observe potential neuro-cognitive improvements. Eighty healthy participants underwent a comprehensive experimental protocol, including cognitive assessments, the Cold Pressor Test (CPT) for pain induction, and tDCS/TENS administration. EEG recordings were conducted pre- and post-intervention across all conditions. The protocol for this study was categorized into four groups: G1 (control), G2 (TENS), G3 (anodal-tDCS), and G4 (cathodal-tDCS). Paired -tests ( < 0.05) were conducted to compare Pre-Stage, Post-Stage, and neuromodulation conditions, with t-values providing insights into effect magnitudes. The result showed a reduction in pain intensity with TENS ( = 0.002, t-value = -5.34) and cathodal-tDCS ( = 0.023, t-value = -5.08) and increased pain tolerance with TENS ( = 0.009, t-value = 4.98) and cathodal-tDCS ( = 0.001, t-value = 5.78). Anodal-tDCS ( = 0.041, t-value = 4.86) improved cognitive performance. The EEG analysis revealed distinct neural oscillatory patterns across the groups. Specifically, G2 and G4 showed delta-power reductions, while G3 observed an increase. Moreover, G2 exhibited increased theta-power in the occipital region during CPT and Post-Stages. In the alpha-band, G2, G3, and G4 had reductions Post-Stage, while G1 and G3 increased. Additionally, beta-power increased in the frontal region for G2 and G3, contrasting with a reduction in G4. Furthermore, gamma-power globally increased during CPT1, with G1, G2, and G3 showing reductions Post-Stage, while G4 displayed a global decrease. The findings confirm the efficacy of TENS and tDCS as possible non-drug therapeutic alternatives for cognition with alleviation from pain.
PubMed: 38927476
DOI: 10.3390/biomedicines12061269 -
Biomedicines Jun 2024Nerve injury is a common condition that occurs as a result of trauma, iatrogenic injury, or long-lasting stimulation. Unlike the central nervous system (CNS), the... (Review)
Review
Nerve injury is a common condition that occurs as a result of trauma, iatrogenic injury, or long-lasting stimulation. Unlike the central nervous system (CNS), the peripheral nervous system (PNS) has a strong capacity for self-repair and regeneration. Peripheral nerve injury results in the degeneration of distal axons and myelin sheaths. Macrophages and Schwann cells (SCs) can phagocytose damaged cells. Wallerian degeneration (WD) makes the whole axon structure degenerate, creating a favorable regenerative environment for new axons. After nerve injury, macrophages, neutrophils and other cells are mobilized and recruited to the injury site to phagocytose necrotic cells and myelin debris. Pro-inflammatory and anti-inflammatory factors involved in the inflammatory response provide a favorable microenvironment for peripheral nerve regeneration and regulate the effects of inflammation on the body through relevant signaling pathways. Previously, inflammation was thought to be detrimental to the body, but further research has shown that appropriate inflammation promotes nerve regeneration, axon regeneration, and myelin formation. On the contrary, excessive inflammation can cause nerve tissue damage and pathological changes, and even lead to neurological diseases. Therefore, after nerve injury, various cells in the body interact with cytokines and chemokines to promote peripheral nerve repair and regeneration by inhibiting the negative effects of inflammation and harnessing the positive effects of inflammation in specific ways and at specific times. Understanding the interaction between neuroinflammation and nerve regeneration provides several therapeutic ideas to improve the inflammatory microenvironment and promote nerve regeneration.
PubMed: 38927464
DOI: 10.3390/biomedicines12061256 -
Biomedicines Jun 2024Despite the fact that the global COVID-19 pandemic has officially ended, we continue to feel its effects and discover new correlations between SARS-CoV-2 infection and... (Review)
Review
Despite the fact that the global COVID-19 pandemic has officially ended, we continue to feel its effects and discover new correlations between SARS-CoV-2 infection and changes in the organism that have occurred in patients. It has been shown that the disease can be associated with a variety of complications, including disorders of the nervous system such as a characteristic loss of smell and taste, as well as less commonly reported incidents such as cranial polyneuropathy or neuromuscular disorders. Nervous system diseases that are suspected to be related to COVID-19 include Guillain-Barré syndrome, which is frequently caused by viruses. During the course of the disease, autoimmunity destroys peripheral nerves, which despite its rare occurrence, can lead to serious consequences, such as symmetrical muscle weakness and deep reflexes, or even their complete abolition. Since the beginning of the pandemic, case reports suggesting a relationship between these two disease entities have been published, and in some countries, the increasing number of Guillain-Barré syndrome cases have also been reported. This suggests that previous contact with SARS-CoV-2 may have had an impact on their occurrence. This article is a review and summary of the literature that raises awareness of the neurological symptoms' prevalence, including Guillain-Barré syndrome, which may be impacted by the commonly occurring COVID-19 disease or vaccination against it. The aim of this review was to better understand the mechanisms of the virus's action on the nervous system, allowing for better detection and the prevention of its complications.
PubMed: 38927455
DOI: 10.3390/biomedicines12061248 -
Biology May 2024Auditory temporal processing is a vital component of auditory stream segregation, or the process in which complex sounds are separated and organized into perceptually...
Auditory temporal processing is a vital component of auditory stream segregation, or the process in which complex sounds are separated and organized into perceptually meaningful objects. Temporal processing can degrade prior to hearing loss, and is suggested to be a contributing factor to difficulties with speech-in-noise perception in normal-hearing listeners. The current study tested this hypothesis in middle-aged adults-an under-investigated cohort, despite being the age group where speech-in-noise difficulties are first reported. In 76 participants, three mechanisms of temporal processing were measured: peripheral auditory nerve function using electrocochleography, subcortical encoding of periodic speech cues (i.e., fundamental frequency; F0) using the frequency following response, and binaural sensitivity to temporal fine structure (TFS) using a dichotic frequency modulation detection task. Two measures of speech-in-noise perception were administered to explore how contributions of temporal processing may be mediated by different sensory demands present in the speech perception task. This study supported the hypothesis that temporal coding deficits contribute to speech-in-noise difficulties in middle-aged listeners. Poorer speech-in-noise perception was associated with weaker subcortical F0 encoding and binaural TFS sensitivity, but in different contexts, highlighting that diverse aspects of temporal processing are differentially utilized based on speech-in-noise task characteristics.
PubMed: 38927251
DOI: 10.3390/biology13060371