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Brain Research Bulletin Jun 2024Intraoperative remifentanil administration has been linked to increased postoperative pain sensitivity. Recent studies have identified the involvement of euchromatic...
Euchromatin histone-lysine N-methyltransferase 2 regulates the expression of potassium-sodium-activated channel subfamily T member 1 in primary sensory neurons and contributes to remifentanil-induced pain sensitivity.
Intraoperative remifentanil administration has been linked to increased postoperative pain sensitivity. Recent studies have identified the involvement of euchromatic histone-lysine N-methyltransferase 2 (Ehmt2/G9a) in neuropathic pain associated with the transcriptional silencing of many potassium ion channel genes. This study investigates whether G9a regulates the potassium sodium-activated channel subfamily T member 1 (Slo2.2) in remifentanil-induced post-incisional hyperalgesia (RIH) in rodents. We performed remifentanil infusion (1 μg·kg-1·min-1 for 60 min) followed by plantar incision to induce RIH in rodents. Our results showed that RIH was accompanied by increased G9a and H3K9me2 production and decreased Slo2.2 expression 48 h postoperatively. Deletion of G9a rescued Slo2.2 expression in DRG and reduced RIH intensity. Slo2.2 overexpression also reversed this hyperalgesia phenotype. G9a overexpression decreased Slo2.2-mediated leak current and increased excitability in the small-diameter DRG neurons and laminal II small-diameter neurons in the spinal dorsal horn, which was implicated in peripheral and central sensitization. These results suggest that G9a contributes to the development of RIH by epigenetically silencing Slo2.2 in DRG neurons, leading to decreased central sensitization in the spinal cord. The findings may have implications for the development of novel therapeutic targets for the treatment of postoperative pain.
Topics: Animals; Histone-Lysine N-Methyltransferase; Male; Remifentanil; Hyperalgesia; Sensory Receptor Cells; Potassium Channels, Sodium-Activated; Mice; Analgesics, Opioid; Ganglia, Spinal; Neuralgia; Pain, Postoperative; Rats; Pain Threshold; Rats, Sprague-Dawley; Mice, Inbred C57BL; Nerve Tissue Proteins
PubMed: 38670469
DOI: 10.1016/j.brainresbull.2024.110966 -
International Journal of Exercise... 2024The main objective was to ascertain the acute responses in autonomic nervous activity and peripheral sensation induced by moderate-intensity treadmill exercise performed...
OBJECTIVE
The main objective was to ascertain the acute responses in autonomic nervous activity and peripheral sensation induced by moderate-intensity treadmill exercise performed under different ambient temperatures.
METHODS
Twelve young healthy subjects underwent three sessions of moderate-intensity treadmill exercise (warming, 5 min and running, 25 min), on different days under 10°C, 20°C and 30°C room temperatures. Pre- and post-intervention, heart rate variability (HRV) and plantar vibrotactile perception threshold (VPT) were measured. Additionally, rate of perceived exertion (RPE) was recorded after intervention.
RESULTS
In comparison with the corresponding baseline values, after intervention, low frequency power (LF) and LF/high frequency power (HF) of HRV increased significantly and HF decreased significantly under the condition of 10°C only ( < .005). Following intervention, VPT increased significantly at the hallux for 31.5 Hz test frequency under 30°C and at the heel for 31.5 Hz test frequency under 10°C (both < .05). In contrast, VPT decreased significantly at the hallux for 125 Hz test frequency under 10°C ( < .005). Exposure under the temperature of 20°C did not result in any significant change in VPT. After intervention, RPE under 30°C showed significantly higher values than those under 20°C ( < .01) and 10°C ( < .005) conditions with no difference between the latter two conditions.
CONCLUSIONS
Treadmill exercise under 20°C ambient temperature did not exert any negative impacts on autonomic and peripheral nerve function and resulted in a perceived exertion of moderate intensity among the study participants. Therefore, an ambient temperature around 20°C might be recommended for the mentioned purpose.
PubMed: 38665327
DOI: No ID Found -
Medicine Apr 2024It is essential to understand the considerable variations in bifurcation patterns of the tibial nerve (TN) and its peripheral nerves at the level of the tarsal tunnel to...
It is essential to understand the considerable variations in bifurcation patterns of the tibial nerve (TN) and its peripheral nerves at the level of the tarsal tunnel to prevent iatrogenic nerve injury during surgical nerve release or nerve block. A total of 16 ankles of 8 human cadavers were dissected to investigate the branching patterns of the TN, using 2 imaginary lines passing through the tip of the medial malleolus (MM) as reference lines. Bifurcation patterns and detailed information on the relative locations of the medial plantar, lateral plantar, medial calcaneal, and inferior calcaneal nerves to the reference lines were recorded. The most common bifurcation pattern was Type 1 in 12 ankles (75%), followed by Type 2 in 2 ankles (13%). One medial calcaneal nerve (MCN) was seen in 11 (69%) specimens and 2 MCN branches were seen in 5 (31%) specimen. 88% of the MCN branches bifurcated from the TN, whereas 6% originated from both TN and lateral plantar nerve (LPN). At the level of the tip of the MM, 2 of 7 parameters showed statistically significant difference between both sexes (P < .05). There was a statistically significant difference between left and right ankles in 2 of 7 measurements (P < .05). Further morphometric analysis of the width, distance, and angle between the TN branches and the tip of MM showed a highly variable nature of the location of the peripheral nerve branches.
Topics: Female; Male; Humans; Ankle; Ankle Joint; Tibial Nerve; Tibia; Leg
PubMed: 38608103
DOI: 10.1097/MD.0000000000037745 -
Frontiers in Neuroscience 2024Plantar cutaneous augmentation is a promising approach in balance rehabilitation by enhancing motion-dependent sensory feedback. The effect of plantar cutaneous...
INTRODUCTION
Plantar cutaneous augmentation is a promising approach in balance rehabilitation by enhancing motion-dependent sensory feedback. The effect of plantar cutaneous augmentation on balance has been mainly investigated in its passive form (e.g., textured insole) or on lower-limb amputees. In this study, we tested the effect of plantar cutaneous augmentation on balance in its active form (i.e., electrical stimulation) for individuals with intact limbs.
METHODS
Ten healthy subjects participated in the study and were instructed to maintain their balance as long as possible on the balance board, with or without electrotactile feedback evoked on the medial side of the heel, synched with the lateral board sway. Electrotactile feedback was given in two different modes: 1) Discrete-mode E-stim as the stimulation on/off by a predefined threshold of lateral board sway and 2) Proportional-mode E-stim as the stimulation frequency proportional to the amount of lateral board sway. All subjects were distracted from the balancing task by the n-back counting task, to test subjects' balancing capability with minimal cognitive involvement.
RESULTS
Proportional-mode E-stim, along with the n-back counting task, increased the balance time from 1.86 ± 0.03 s to 1.98 ± 0.04 s ( = 0.010). However, discrete-mode E-stim did not change the balance time ( = 0.669). Proportional-mode E-stim also increased the time duration per each swayed state ( = 0.035) while discrete-mode E-stim did not ( = 0.053).
DISCUSSION
These results suggest that proportional-mode E-stim is more effective than discrete-mode E-stim on improving standing balance. It is perhaps because the proportional electrotactile feedback better mimics the natural tactile sensation of foot pressure than its discrete counterpart.
PubMed: 38562307
DOI: 10.3389/fnins.2024.1249783 -
Journal of Orthopaedic Case Reports Mar 2024Numerous reflexive responses have been documented as alterations to the Babinski sign within upper motor neuron lesions. However, scant attention has been given to...
INTRODUCTION
Numerous reflexive responses have been documented as alterations to the Babinski sign within upper motor neuron lesions. However, scant attention has been given to reflexes beyond these, which exhibit independence from the extensor plantar response. These reflexes predominantly form polysynaptic arcs, with nociceptive stimuli acting as afferents.
CASE REPORT
The reflex was serendipitously discovered in an 18-year-old female patient who presented with spastic paraplegia with bowel and bladder involvement, as a consequence of an aneurysmal bone cyst of the D3 (dorsal) vertebrae, and the same was named after the authors as "Yadav-Kunal reflex" which can be defined as: "In individuals with spastic paraparesis, forcibly plantarflexing the toes will result in sudden jerky flexion of the knee and hip on the same side." This novel reflex was further investigated and validated in two additional patients with spastic paraplegia: one, a 45-year-old female with D9-D10 Pott's spine and bowel and bladder involvement, and the other, a 65-year-old male with D10-D11 compressive myelopathy and bowel and bladder involvement. This reflex was meticulously tracked until the abatement of spasticity following surgical intervention. Notably, its manifestation was evident in individuals experiencing spastic paraparesis, dissipating concomitantly with the resolution of spasticity - a direct clinical correlation. Conversely, the reflex was conspicuously absent in cases of flaccid paraplegia.
CONCLUSION
Spasticity, characterized by an increase in muscle tone on swift stretching movements, is a manifestation of a stretch reflex disorder. This condition is primarily induced by lesions affecting upper motor neurons. The activation of muscle spindles in toe dorsiflexors (primarily governed by the L5 nerve) occurs during forceful elongation caused by plantarflexion.
PubMed: 38560301
DOI: 10.13107/jocr.2024.v14.i03.4326 -
Medicina (Kaunas, Lithuania) Feb 2024Refractory peripheral neuropathy can occur as a side effect in 60-70% of patients receiving Paclitaxel (PTX). Yokukansan (YKS) is a Japanese herbal medicine reported to...
Refractory peripheral neuropathy can occur as a side effect in 60-70% of patients receiving Paclitaxel (PTX). Yokukansan (YKS) is a Japanese herbal medicine reported to have analgesic properties for entrapment nerve injuries. Therefore, we investigated the anti-allodynic effect of Yokukansan on Paclitaxel-induced neuropathic pain. All experiments used 6-week-old male Sprague Dawley rats. Mechanical allodynia was evaluated using a dynamic plantar aesthesiometer. A mobile touch-stimulator unit applied progressively increasing force to the mid-plantar region of the hind paw in a vertical direction until the animal withdrew its paw. This was carried out before the Paclitaxel administration and during the first, second, third, and fourth weeks. Using a rat model of PTX-induced neuropathic pain (PTX rat), we injected PTX (intraperitoneally, 2 mg/kg) five times every 2 days. Using the dynamic plantar test, we evaluated the anti-allodynic effect of YKS (orally administered, 1 g/kg). YKS administration on a daily basis significantly enhanced the withdrawal threshold in PTX rats and reduced the expression level of activated microglia immunostaining with Iba1, a specific marker for microglia. The intrathecal administration of WAY-100635 (5-hydroxytryptamine [5-HT] receptor antagonist) and Ketanserin (5-HT receptor antagonist) inhibited the protective effects of YKS. YKS exhibited an anti-allodynic effect in a rodent model of PTX-induced neuropathic pain by reducing the sensitivity to pain stimuli. These results suggest that Yokukansan may activate 5-HT receptors in the spinal cord, mediating Paclitaxel-induced neuropathic pain.
Topics: Humans; Rats; Male; Animals; Hyperalgesia; Serotonin; Paclitaxel; Rats, Sprague-Dawley; Neuralgia; Disease Models, Animal; Drugs, Chinese Herbal
PubMed: 38541085
DOI: 10.3390/medicina60030359 -
Journal of Orthopaedic Surgery and... Mar 2024Isolated gastrocnemius contracture has been associated with more than 30 lower limb disorders, including plantar heel pain/plantar fasciitis, Achilles tendinosis,...
BACKGROUND
Isolated gastrocnemius contracture has been associated with more than 30 lower limb disorders, including plantar heel pain/plantar fasciitis, Achilles tendinosis, equinus foot, adult flatfoot, and metatarsalgia. Although many techniques are available for gastrocnemius recession, potential anesthetic, cosmetic, and wound-related complications can lead to patient dissatisfaction. Open and endoscopic recession techniques usually require epidural or general anesthesia, exsanguination of the lower extremities and stitches and can damage the sural nerve, which is not under the complete control of the surgeon at all stages of the procedure. The purpose of this study is to evaluate the clinical results of a surgical technique for gastrocnemius lengthening with a needle, as previously described in cadaver specimens.
METHODS AND RESULTS
We performed a prospective study of ultrasound-guided gastrocnemius tendon lengthening in level II using a needle in 24 cases (19 patients) of gastrocnemius contracture. The study population comprised 12 males and 7 females. Mean age was 41 years (18-64). All but 5 recessions were bilateral and occurred simultaneously. The indication for the procedure was gastrocnemius contracture; although the patients also presented other conditions such as non-insertional Achilles tendinopathy in 6 patients (2 were bilateral), insertional Achilles calcifying enthesitis in 4 (1 was bilateral), metatarsalgia in 4, flexible flat foot in 1 and plantar fasciitis in 5 (2 were bilateral). The inclusion criteria were the failure of a previous conservative protocol, that the Silfverskiöld test was positive, and that the pathology suffered by the patient was within the indications for surgical lengthening of the patients and were described in the scientific literature. The exclusion criteria were that the inclusion criteria were not met, and patients with surgical risk ASA 3 or more and children. In these patients, although possible, it is preferable to perform the procedure in the operating room with monitoring, as well as in children since they could be agitated during the procedure at the office. We used the beveled tip of an Abbocath needle as a surgical scalpel. All patients underwent recession of the gastrocnemius tendon, as in an incomplete Strayer release. We evaluated pre- and postoperative dorsiflexion, outcomes, and procedural pain (based on a visual analog scale and the American Orthopedic Foot and Ankle Society scores), as well as potential complications. No damage was done to the sural bundle.
RESULTS
Ankle dorsiflexion increased on average by 17.89°. The average postoperative visual analog score for pain before surgery was 5.78, 5.53 in the first week, 1.89 at 1 month, and 0.26 at 3 months, decreasing to 0.11 at 9 months. The mean postoperative American Orthopedic Foot and Ankle Society Ankle-Hindfoot score the average was 50.52 before surgery, 43.42 at 1 week, 72.37 at 1 month, 87.37 at 3 months, and 90.79 at 9 months.
CONCLUSION
Ultrasound-guided needle lengthening of the gastrocnemius tendon is a novel, safe, and effective technique that enables the surgeon to check all the structures clearly, thus minimizing the risk of neurovascular damage. The results are encouraging, and the advantages of this approach include absence of a wound and no need for stitches. Recovery is fast and relatively painless. A specific advantage of ultrasound-guided needle lengthening of the gastrocnemius tendon is the fact that it can be performed in a specialist's office, with a very basic instrument set and local anesthesia, thus reducing expenses.
Topics: Adult; Male; Female; Child; Humans; Achilles Tendon; Prospective Studies; Fasciitis, Plantar; Tendinopathy; Muscle, Skeletal; Contracture; Ultrasonography, Interventional; Metatarsalgia
PubMed: 38532430
DOI: 10.1186/s13018-024-04685-0 -
Noro Psikiyatri Arsivi 2024Rosai-Dorfman disease (RDD) is a benign histiocytosis with unknown etiology. It generally occurs in cervical lymph nodes. Isolated central nervous system (CNS) RDD is...
Rosai-Dorfman disease (RDD) is a benign histiocytosis with unknown etiology. It generally occurs in cervical lymph nodes. Isolated central nervous system (CNS) RDD is very rare in the literature. We reported a case of no systemic involvement Rosai-Dorfmann which is rarely seen and shows CNS involvement by mimicking meningioma. A 32-year-old man presented with diplopia and a headache he has been experiencing for the past two years. His neurological examination showed left facial paresthesia, consistent with trigeminal nerve trace. Tendon reflexes were increased at the right side and the right plantar reflex was extensor. Brain magnetic resonance imaging demonstrated irregularly shaped, tumor-like lesions in the bilateral cerebellopontin area that were compressing pons. Rosai-Dorfman disease can be differentiated from IgG4 related disease (IgG4-RD) by its characteristic features such as plasma cell density and emperipolesis seen in its histopathology. Rosai-Dorfman disease can be confused with other diseases radiologically and histopathologically, especially the IgG4-RD, so be careful about differential diagnosis.
PubMed: 38496223
DOI: 10.29399/npa.28323 -
Brain Communications 2024Experimental autoimmune neuritis is a common animal model for acute human immune-mediated polyneuropathies. Although already established in 1955, a number of...
Experimental autoimmune neuritis is a common animal model for acute human immune-mediated polyneuropathies. Although already established in 1955, a number of pathophysiological mechanisms remain unknown. In this study, we extensively characterize experimental autoimmune neuritis progression in Lewis rats, including new insights into the integrity of small nerve fibres, neuropathic pain and macrophage activation. Acute experimental autoimmune neuritis was induced with P2 peptide and consequently investigated using the gait analysis system CatWalk XT, electrophysiological and histopathological analyses, quantitative polymerase chain reaction (PCR), dorsal root ganglia outgrowth studies, as well as the von Frey hair and Hargreaves tests. For the longitudinal setup, rats were sacrificed at Day (d) 10 (onset), d15 (peak), d26 (recovery) and d29 (late recovery). We confirmed the classical T-cell and macrophage-driven inflammation and the primarily demyelinating nature of the experimental autoimmune neuritis. The dual role of macrophages in experimental autoimmune neuritis is implicated by the high number of remaining macrophages throughout disease progression. Furthermore, different subpopulations of macrophages based on (, and expressions were identified. In addition, modulation of the sensory system in experimental autoimmune neuritis was detected. An outgrowth of small fibres in the plantar skin at the onset and peak of the experimental autoimmune neuritis was evident parallel to the development of acute hyperalgesia mediated through transient receptor potential vanilloid 1 modulation. Our data depict experimental autoimmune neuritis as a primary demyelinating disease with implicated axonal damage, a small unmyelinated fibre impairment throughout the disease progression course, and underline the pivotal role of macrophages in the effector and during the recovery stage.
PubMed: 38482371
DOI: 10.1093/braincomms/fcae059 -
The Journal of Neuroscience : the... Apr 2024Following peripheral nerve injury, denervated tissues can be reinnervated via regeneration of injured neurons or collateral sprouting of neighboring uninjured afferents...
Following peripheral nerve injury, denervated tissues can be reinnervated via regeneration of injured neurons or collateral sprouting of neighboring uninjured afferents into denervated territory. While there has been substantial focus on mechanisms underlying regeneration, collateral sprouting has received less attention. Here, we used immunohistochemistry and genetic neuronal labeling to define the subtype specificity of sprouting-mediated reinnervation of plantar hindpaw skin in the mouse spared nerve injury (SNI) model, in which productive regeneration cannot occur. Following initial loss of cutaneous afferents in the tibial nerve territory, we observed progressive centripetal reinnervation by multiple subtypes of neighboring uninjured fibers into denervated glabrous and hairy plantar skin of male mice. In addition to dermal reinnervation, CGRP-expressing peptidergic fibers slowly but continuously repopulated denervated epidermis, Interestingly, GFRα2-expressing nonpeptidergic fibers exhibited a transient burst of epidermal reinnervation, followed by a trend towards regression. Presumptive sympathetic nerve fibers also sprouted into denervated territory, as did a population of myelinated TrkC lineage fibers, though the latter did so inefficiently. Conversely, rapidly adapting Aβ fiber and C fiber low threshold mechanoreceptor (LTMR) subtypes failed to exhibit convincing sprouting up to 8 weeks after nerve injury in males or females. Optogenetics and behavioral assays in male mice further demonstrated the functionality of collaterally sprouted fibers in hairy plantar skin with restoration of punctate mechanosensation without hypersensitivity. Our findings advance understanding of differential collateral sprouting among sensory neuron subpopulations and may guide strategies to promote the progression of sensory recovery or limit maladaptive sensory phenomena after peripheral nerve injury.
Topics: Female; Mice; Male; Animals; Peripheral Nerve Injuries; Nerve Regeneration; Skin; Neurogenesis; Neurons, Afferent
PubMed: 38471780
DOI: 10.1523/JNEUROSCI.1494-23.2024