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Neural Regeneration Research Jun 2024Successful polyethylene glycol fusion (PEG-fusion) of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to: (1) rapidly restore...
Successful polyethylene glycol fusion (PEG-fusion) of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to: (1) rapidly restore electrophysiological continuity; (2) prevent distal Wallerian Degeneration and maintain their myelin sheaths; (3) promote primarily motor, voluntary behavioral recoveries as assessed by the Sciatic Functional Index; and, (4) rapidly produce correct and incorrect connections in many possible combinations that produce rapid and extensive recovery of functional peripheral nervous system/central nervous system connections and reflex (e.g., toe twitch) or voluntary behaviors. The preceding companion paper describes sensory terminal field reorganization following PEG-fusion repair of sciatic nerve transections or ablations; however, sensory behavioral recovery has not been explicitly explored following PEG-fusion repair. In the current study, we confirmed the success of PEG-fusion surgeries according to criteria (1-3) above and more extensively investigated whether PEG-fusion enhanced mechanical nociceptive recovery following sciatic transection in male and female outbred Sprague-Dawley and inbred Lewis rats. Mechanical nociceptive responses were assessed by measuring withdrawal thresholds using von Frey filaments on the dorsal and midplantar regions of the hindpaws. Dorsal von Frey filament test was a more reliable method than plantar von Frey filament test to assess mechanical nociceptive sensitivity following sciatic nerve transections. Baseline withdrawal thresholds of the sciatic-mediated lateral dorsal region differed significantly across strain but not sex. Withdrawal thresholds did not change significantly from baseline in chronic Unoperated and Sham-operated rats. Following sciatic transection, all rats exhibited severe hyposensitivity to stimuli at the lateral dorsal region of the hindpaw ipsilateral to the injury. However, PEG-fused rats exhibited significantly earlier return to baseline withdrawal thresholds than Negative Control rats. Furthermore, PEG-fused rats with significantly improved Sciatic Functional Index scores at or after 4 weeks postoperatively exhibited yet-earlier von Frey filament recovery compared with those without Sciatic Functional Index recovery, suggesting a correlation between successful pPEG-fusion and both motor-dominant and sensory-dominant behavioral recoveries. This correlation was independent of the sex or strain of the rat. Furthermore, our data showed that the acceleration of von Frey filament sensory recovery to baseline was solely due to the PEG-fused sciatic nerve and not saphenous nerve collateral outgrowths. No chronic hypersensitivity developed in any rat up to 12 weeks. All these data suggest that PEG-fusion repair of transection peripheral nerve injuries could have important clinical benefits.
PubMed: 38934383
DOI: 10.4103/NRR.NRR-D-23-01846 -
Medicina (Kaunas, Lithuania) May 2024A ganglion cyst is a benign mass consisting of high-viscosity mucinous fluid. It can originate from the sheath of a tendon, peripheral nerve, or joint capsule....
A ganglion cyst is a benign mass consisting of high-viscosity mucinous fluid. It can originate from the sheath of a tendon, peripheral nerve, or joint capsule. Compressive neuropathy caused by a ganglion cyst is rarely reported, with the majority of documented cases involving peroneal nerve palsy. To date, cases demonstrating both peroneal and tibial nerve palsies resulting from a ganglion cyst forming on a branch of the sciatic nerve have not been reported. In this paper, we present the case of a 74-year-old man visiting an outpatient clinic complaining of left-sided foot drop and sensory loss in the lower extremity, a lack of strength in his left leg, and a decrease in sensation in the leg for the past month without any history of trauma. Ankle dorsiflexion and great toe extension strength on the left side were Grade I. Ankle plantar flexion and great toe flexion were Grade II. We suspected peroneal and tibial nerve palsy and performed a screening ultrasound, which is inexpensive and rapid. In the operative field, several cysts were discovered, originating at the site where the sciatic nerve splits into peroneal and tibial nerves. After successful surgical decompression and a series of rehabilitation procedures, the patient's neurological symptoms improved. There was no recurrence.
Topics: Humans; Aged; Male; Ganglion Cysts; Peroneal Neuropathies; Peroneal Nerve; Tibial Nerve; Paralysis
PubMed: 38929493
DOI: 10.3390/medicina60060876 -
The Indian Journal of Radiology &... Jul 2024Macrodystrophia lipomatosa (MDL) is a rare congenital, nonhereditary anomaly characterized by overgrowth of all the mesenchymal elements, predominantly the fibroadipose...
Macrodystrophia lipomatosa (MDL) is a rare congenital, nonhereditary anomaly characterized by overgrowth of all the mesenchymal elements, predominantly the fibroadipose tissue in a sclerotomal distribution commonly involving the median nerve territory in the upper extremity and plantar nerve territory in the lower extremity. It can be either static or progressive, with the former being the more common. MDL is usually present since birth and the affected digit/region increases in length and girth, and growth ceases after puberty. We discuss a rare case of ulnar nerve territory involvement that progressed to grow even after puberty.
PubMed: 38912255
DOI: 10.1055/s-0043-1777745 -
American Journal of Veterinary Research Jun 2024The objective of this study was to optimize an MRI-based diffusion tensor imaging (DTI) protocol for imaging the plantar nerves at the level of the tarsus in normal...
OBJECTIVE
The objective of this study was to optimize an MRI-based diffusion tensor imaging (DTI) protocol for imaging the plantar nerves at the level of the tarsus in normal equine limbs.
SAMPLE
12 pelvic cadaver limbs from horses without evidence of proximal suspensory pathology were imaged with a 3T MRI system.
METHODS
For diffusion-weighted imaging, b values of 600, 800, and 1,000 s/mm2 were tested. Data were processed with DSI Studio. Cross-sectional areas of the medial and lateral plantar nerve along the plantar tarsus were recorded. The length and number of fiber tracts, signal-to-noise ratio, and DTI variables were recorded.
RESULTS
At the level of interest, the mean cross-sectional areas of the plantar nerves ranged from 5.03 to 7.42 mm2. The DTI maps consistently generated tracts in the region of the lateral and medial plantar nerves with DTI values in the range of values reported for peripheral nerves in humans. Our findings demonstrate that DTI of the medial and lateral plantar nerves can be performed successfully and used to generate quantitative parameters including fractional anisotropy and mean, axial, and radial diffusivity.
CLINICAL RELEVANCE
Quantitative data generated with this imaging technique can be used to noninvasively characterize the microstructural integrity of neural tissue with possible applications in the evaluation of pathologic changes to the plantar tarsal and metatarsal nerves of horses with proximal suspensory desmopathy.
PubMed: 38889743
DOI: 10.2460/ajvr.24.03.0092 -
Cureus May 2024An autoimmune polyradiculoneuropathy, Guillain-Barré syndrome (GBS) is an acute, rapidly progressive, and fulminant one. Rapidly developing motor weakness along with...
An autoimmune polyradiculoneuropathy, Guillain-Barré syndrome (GBS) is an acute, rapidly progressive, and fulminant one. Rapidly developing motor weakness along with absent reflexes, with or without sensory impairment, is the hallmark of GBS. GBS is never a hereditary entity; it is always acquired by the individual. Here, we present an interesting case of GBS in a 37-year-old male patient presenting with lower limb weakness for one day which had progressed to upper limb weakness in a day. There was a history of fever and loose stools four days back. On examination, vitals were within normal limits including single breath count. Central nervous system (CNS) examination revealed as follows: bicep jerk, tricep jerk, and supinator jerk were National Institute of Neurological Disorders and Stroke (NINDS) scale grade 2 in bilateral upper limbs. Knee jerk was NINDS scale grade 3 in bilateral lower limbs, which was unusual considering that GBS presents with areflexia or reduced reflexes. Ankle jerk was absent in bilateral lower limbs. Plantars were mute bilaterally. Nerve conduction study was suggestive of axonal and demyelinating motor neuropathy involving all four limbs. The patient was planned for intravenous immunoglobulin at a dose of 2 g/kg/day for five days but developed an allergic reaction to the first dose; hence, the therapy was discontinued, and the option of plasmapheresis was given to which the patient refused. This is a report of a case of GBS with hyperreflexia which is an uncommon entity in the Indian subcontinent.
PubMed: 38883035
DOI: 10.7759/cureus.60494 -
NMC Case Report Journal 2024The flexor digitorum accessorius longus muscle (ALM) can be overlooked as the eliciting factor in patients with tarsal tunnel syndrome (TTS), an entrapment neuropathy of...
The flexor digitorum accessorius longus muscle (ALM) can be overlooked as the eliciting factor in patients with tarsal tunnel syndrome (TTS), an entrapment neuropathy of the posterior tibial nerve that elicits sole numbness and pain. Most elicitations are idiopathic, however, mass lesions within the tarsal tunnel can be also implicated. We report an 80-year-old woman whose flexor digitorum ALM led to the onset of bilateral TTS. She had suffered numbness in both soles for 3 years. Magnetic resonance imaging (MRI) of the bilateral tarsal tunnel showed that the posterior tibial nerve was compressed by the arteriovenous complex and in contact with the flexor digitorum ALM. We diagnosed bilateral TTS based on her symptoms and imaging findings, and performed bilateral decompression surgery of the posterior tibial nerve under local anesthesia. The artery on both sides was dislocated for nerve decompression. Because the posterior tibial nerve on the right side was strongly compressed in ankle plantar flexion we excised a portion of the tendon compressing the nerve. Postoperatively her symptoms gradually improved and she reported surgical satisfaction 6 months after the operation. In patients with flexor digitorum ALM-related TTS, the effect of dynamic factors on MRI findings and on surgical treatment decisions must be considered. Intraoperatively, not only the flexor digitorum ALM, but also other potential etiologic factors eliciting TTS must be kept in mind.
PubMed: 38863580
DOI: 10.2176/jns-nmc.2023-0136 -
Surgical Neurology International 2024Gunshot wounds (GSWs) can result in various peripheral nerve injuries (PNIs), ranging from direct nerve transection to neuropraxia caused by the ballistic shockwave...
BACKGROUND
Gunshot wounds (GSWs) can result in various peripheral nerve injuries (PNIs), ranging from direct nerve transection to neuropraxia caused by the ballistic shockwave mechanism. PNIs from GSWs can be treated with either early or delayed intervention, with the literature supporting both approaches and sparking a debate between early and delayed intervention for PNIs from GSWs. Here, we present a case that underwent delayed exploration of the right common peroneal nerve after GSW and a literature review comparing early versus delayed intervention for PNIs from GSWs.
CASE DESCRIPTION
A 29-year-old male underwent right common peroneal nerve exploration 2 months after he sustained a GSW to the right lower extremity at the level of the fibular head tracking to the lateral malleolus. Initially, after the injury, he was offered supportive care. On evaluation, 1 month later, he reported a right-sided foot drop and paresthesias in the right lower extremity. A partial-thickness injury of the right peroneal nerve was seen on ultrasound, and a bullet fragment in the distal right lower extremity was revealed on computed tomography. The surgical intervention consisted of the right common peroneal nerve decompression proximally to distally and removal of the bullet fragment. Postoperatively, the patient did well with improvements in his right ankle dorsiflexion and plantar flexion seen at his 1.5-month follow-up visit.
CONCLUSION
Many factors must be considered when treating PNIs from GSWs. For each case, clinical judgment, injury mechanism, and risk-benefit analysis must be evaluated to determine each patient's optimal treatment strategy.
PubMed: 38840615
DOI: 10.25259/SNI_197_2024 -
Scientific Reports Jun 2024Lumbar sympathetic ganglion neurolysis (LSGN) has been used for long-term pain relief in patients with complex regional pain syndrome (CRPS). However, the actual effect... (Observational Study)
Observational Study
Lumbar sympathetic ganglion neurolysis (LSGN) has been used for long-term pain relief in patients with complex regional pain syndrome (CRPS). However, the actual effect duration of LSGN has not been accurately measured. This prospective observational study measured the effect duration of LSGN in CRPS patients and investigated the relationship between temperature change and pain relief. After performing LSGN, the skin temperatures of both the maximum pain site and the plantar area in the affected and unaffected limbs were measured by infrared thermography, and pain intensity was assessed before and at 2 weeks, 1 month, and 3 months. The median time to return to baseline temperature was calculated using survival analysis. The skin temperature increased significantly at all-time points relative to baseline in both regions (maximum pain site: 1.4 °C ± 1.0 °C, plantar region: 1.28 °C ± 0.8 °C, all P < 0.001). The median time to return to baseline temperature was 12 weeks (95% confidence interval [CI] 7.7-16.3) at the maximum pain site and 12 weeks (95% CI 9.4-14.6) at the plantar area. Pain intensity decreased significantly relative to baseline, at all-time points after LSGN. In conclusion, the median duration of the LSGN is estimated to be 12 weeks.
Topics: Humans; Complex Regional Pain Syndromes; Female; Male; Middle Aged; Prospective Studies; Skin Temperature; Adult; Ganglia, Sympathetic; Pain Measurement; Thermography; Autonomic Nerve Block; Treatment Outcome; Aged; Time Factors; Lumbosacral Region
PubMed: 38830944
DOI: 10.1038/s41598-024-63732-2 -
Journal of Ethnopharmacology May 2024Piper methysticum G. Forst (Piperaceae) is traditionally consumed in Polynesian culture. The roots are used to produce an entheogenic drink and traditional medicine with...
ETHNOPHARMACOLOGICAL RELEVANCE
Piper methysticum G. Forst (Piperaceae) is traditionally consumed in Polynesian culture. The roots are used to produce an entheogenic drink and traditional medicine with sedative and anxiolytic properties. There is also evidence that it functions as a pain reliever. Kavalactones, its main active ingredients, exhibit psychoactive effects on the central nervous system. However, the active ingredients and pharmacological mechanisms underlying the analgesic effect of kavalactones are unclear.
AIM OF THE STUDY
This study investigated the effects of kavain and yangonin on nociception, inflammatory hyperalgesia, and neuropathic mechanical allodynia at the spinal level.
MATERIALS AND METHODS
Male Sprague-Dawley rats were administered kavain and yangonin (27.14 and 19.36 nmol/rat) via intrathecal injection. Tail-flick tests were performed to evaluate the anti-nociceptive properties. The efficacy of kavain and yangonin on inflammatory hyperalgesia was examined using a plantar test in rats with carrageenan-induced paw inflammation. The von Frey test was used to assess mechanical allodynia induced by partial sciatic nerve ligation.
RESULTS
Intrathecal injection of yangonin demonstrated a relatively potent anti-nociceptive effect and attenuated carrageenan-induced hyperalgesia. These effects were completely reversed by the co-administration of PF 514273, a cannabinoid 1 (CB) receptor antagonist. However, yangonin did not affect mechanical allodynia at the spinal level. Kavain, another abundant kavalactone, did not affect nociception, hyperalgesia, or mechanical allodynia at the spinal level.
CONCLUSIONS
Overall, our study demonstrated that yangonin exerts anti-nociception and anti-inflammatory hyperalgesia effects via CB receptors at the spinal level. We identified a single kavalactone, yangonin, extracted from kava as a promising treatment for pain.
PubMed: 38823663
DOI: 10.1016/j.jep.2024.118394 -
Cancers May 2024Bone cancer and its related chronic pain are huge clinical problems since the available drugs are often ineffective or cannot be used long term due to a broad range of...
Osteosarcoma-Induced Pain Is Mediated by Glial Cell Activation in the Spinal Dorsal Horn, but Not Capsaicin-Sensitive Nociceptive Neurons: A Complex Functional and Morphological Characterization in Mice.
Bone cancer and its related chronic pain are huge clinical problems since the available drugs are often ineffective or cannot be used long term due to a broad range of side effects. The mechanisms, mediators and targets need to be identified to determine potential novel therapies. Here, we characterize a mouse bone cancer model induced by intratibial injection of K7M2 osteosarcoma cells using an integrative approach and investigate the role of capsaicin-sensitive peptidergic sensory nerves. The mechanical pain threshold was assessed by dynamic plantar aesthesiometry, limb loading by dynamic weight bearing, spontaneous pain-related behaviors via observation, knee diameter with a digital caliper, and structural changes by micro-CT and glia cell activation by immunohistochemistry in BALB/c mice of both sexes. Capsaicin-sensitive peptidergic sensory neurons were defunctionalized by systemic pretreatment with a high dose of the transient receptor potential vanilloid 1 (TRPV1) agonist resiniferatoxin (RTX). During the 14- and 28-day experiments, weight bearing on the affected limb and the paw mechanonociceptive thresholds significantly decreased, demonstrating secondary mechanical hyperalgesia. Signs of spontaneous pain and osteoplastic bone remodeling were detected both in male and female mice without any sex differences. Microglia activation was shown by the increased ionized calcium-binding adapter molecule 1 (Iba1) immunopositivity on day 14 and astrocyte activation by the enhanced glial fibrillary acidic protein (GFAP)-positive cell density on day 28 in the ipsilateral spinal dorsal horn. Interestingly, defunctionalization of the capsaicin-sensitive afferents representing approximately 2/3 of the nociceptive fibers did not alter any functional parameters. Here, we provide the first complex functional and morphological characterization of the K7M2 mouse osteosarcoma model. Bone-cancer-related chronic pain and hyperalgesia are likely to be mediated by central sensitization involving neuroinflammation via glial cell activation in the spinal dorsal horn, but not the capsaicin-sensitive sensory neuronal system.
PubMed: 38791867
DOI: 10.3390/cancers16101788