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International Journal of Molecular... Dec 2021Central and peripheral nerve injuries can lead to permanent paralysis and organ dysfunction. In recent years, many cell and exosome implantation techniques have been... (Review)
Review
Central and peripheral nerve injuries can lead to permanent paralysis and organ dysfunction. In recent years, many cell and exosome implantation techniques have been developed in an attempt to restore function after nerve injury with promising but generally unsatisfactory clinical results. Clinical outcome may be enhanced by bio-scaffolds specifically fabricated to provide the appropriate three-dimensional (3D) conduit, growth-permissive substrate, and trophic factor support required for cell survival and regeneration. In rodents, these scaffolds have been shown to promote axonal regrowth and restore limb motor function following experimental spinal cord or sciatic nerve injury. Combining the appropriate cell/exosome and scaffold type may thus achieve tissue repair and regeneration with safety and efficacy sufficient for routine clinical application. In this review, we describe the efficacies of bio-scaffolds composed of various natural polysaccharides (alginate, chitin, chitosan, and hyaluronic acid), protein polymers (gelatin, collagen, silk fibroin, fibrin, and keratin), and self-assembling peptides for repair of nerve injury. In addition, we review the capacities of these constructs for supporting in vitro cell-adhesion, mechano-transduction, proliferation, and differentiation as well as the in vivo properties critical for a successful clinical outcome, including controlled degradation and re-absorption. Finally, we describe recent advances in 3D bio-printing for nerve regeneration.
Topics: Animals; Axons; Exosomes; Humans; Peripheral Nerve Injuries; Printing, Three-Dimensional; Sciatic Nerve; Tissue Scaffolds
PubMed: 34948144
DOI: 10.3390/ijms222413347 -
The Journal of International Medical... Aug 2014Nerve injury is a common complication following intramuscular injection and the sciatic nerve is the most frequently affected nerve, especially in children, the elderly... (Review)
Review
Nerve injury is a common complication following intramuscular injection and the sciatic nerve is the most frequently affected nerve, especially in children, the elderly and underweight patients. The neurological presentation may range from minor transient pain to severe sensory disturbance and motor loss with poor recovery. Management of nerve injection injury includes drug treatment of pain, physiotherapy, use of assistive devices and surgical exploration. Early recognition of nerve injection injury and appropriate management are crucial in order to reduce neurological deficit and to maximize recovery. Sciatic nerve injection injury is a preventable event. Total avoidance of intramuscular injection is recommended if other administration routes can be used. If the injection has to be administered into the gluteal muscle, the ventrogluteal region (gluteal triangle) has a more favourable safety profile than the dorsogluteal region (the upper outer quadrant of the buttock).
Topics: Buttocks; Humans; Injections, Intramuscular; Pain; Sciatic Nerve; Sciatic Neuropathy
PubMed: 24920643
DOI: 10.1177/0300060514531924 -
Journal of Materials Science. Materials... Jan 2022There has been an increased number of studies of nerve transection injuries with the sciatic nerve gap-injury model in the rabbit in the past 2 years. We wanted to...
There has been an increased number of studies of nerve transection injuries with the sciatic nerve gap-injury model in the rabbit in the past 2 years. We wanted to define in greater detail what is needed to test artificial nerve guides in a sciatic nerve gap-injury model in the rabbit. We hope that this will help investigators to fully exploit the robust translational potential of the rabbit sciatic nerve gap-injury model in its capacity to test devices whose diameter and length are in the range of those commonly applied in hand and wrist surgery (diameter ranging between 2 and 4 mm; length up to 30 mm). We suggest that the rabbit model should replace the less translational rat model in nerve regeneration research. The rabbit sciatic model, however, requires an effective strategy to prevent and control self-mutilation of the foot in the postoperative period, and to prevent pressure ulcers.
Topics: Animals; Disease Models, Animal; Male; Nerve Regeneration; Rabbits; Sciatic Nerve
PubMed: 35061121
DOI: 10.1007/s10856-022-06642-x -
Journal of Ultrasound Mar 2022The sciatic nerve innervates the hamstring muscles. Occasionally, the sciatic nerve is injured along with a hamstring muscle. Detailed biomechanical and sensory...
PURPOSE
The sciatic nerve innervates the hamstring muscles. Occasionally, the sciatic nerve is injured along with a hamstring muscle. Detailed biomechanical and sensory thresholds of these structures are not well-characterized. Therefore, we designed a prospective study that explored high-resolution ultrasound (US) at multiple sites to evaluate properties of the sciatic nerve, including cross-sectional area (CSA) and shear-wave elastography (SWE). We also assessed SWE of each hamstring muscle at multiple sites. Mechanical algometry was obtained from the sciatic nerve and hamstring muscles to assess multi-site pressure pain threshold (PPT).
METHODS
Seventy-nine asymptomatic sciatic nerves and 147 hamstring muscles (25 males, 24 females) aged 18-50 years were evaluated. One chiropractic radiologist with 4.5 years of US experience performed the evaluations. Sciatic nerves were sampled along the posterior thigh at four sites obtaining CSA, SWE, and algometry. All three hamstring muscles were sampled at two sites utilizing SWE and algometry. Descriptive statistics, two-way ANOVA, and rater reliability were assessed for data analysis with p ≤ 0.05.
RESULTS
A significant decrease in sciatic CSA from proximal to distal was correlated with increasing BMI (p < 0.001). Intra-rater and inter-rater reliability for CSA was moderate and poor, respectively. Elastographic values significantly increased from proximal to distal with significant differences in gender and BMI (p = 0.002). Sciatic PPT significantly decreased between sites 1 and 2, 1 and 3, and 1 and 4. Significant correlation between gender and PPT was noted as well as BMI (p < 0.001). Hamstring muscle elastographic values significantly differed between biceps femoris and semitendinosus (p < 0.001) and biceps femoris and semimembranosus (p < 0.001). All three hamstring muscles demonstrated increased PPT in males compared to females (p < 0.001). In addition, PPT of the biceps femoris correlated with BMI (p = 0.02).
CONCLUSION
High-resolution US provided useful metrics of sciatic nerve size and biomechanical properties. PPT for the normal sciatic nerve and hamstring muscles was obtained for future clinical application.
Topics: Adolescent; Adult; Female; Hamstring Muscles; Humans; Male; Middle Aged; Prospective Studies; Reproducibility of Results; Sciatic Nerve; Sensory Thresholds; Young Adult
PubMed: 33515412
DOI: 10.1007/s40477-020-00552-w -
Frontiers in Endocrinology 2023Diabetic sensorimotor polyneuropathy (DSPN) is one of the most prevalent and poorly understood diabetic microvascular complications. Recent studies have found that...
Sciatic nerve fractional anisotropy and neurofilament light chain protein are related to sensorimotor deficit of the upper and lower limbs in patients with type 2 diabetes.
BACKGROUND
Diabetic sensorimotor polyneuropathy (DSPN) is one of the most prevalent and poorly understood diabetic microvascular complications. Recent studies have found that fractional anisotropy (FA), a marker for microstructural nerve integrity, is a sensitive parameter for the structural and functional nerve damage in DSPN. The aim of this study was to investigate the significance of proximal sciatic nerve's FA on different distal nerve fiber deficits of the upper and lower limbs and its correlation with the neuroaxonal biomarker, neurofilament light chain protein (NfL).
MATERIALS AND METHODS
Sixty-nine patients with type 2 diabetes (T2DM) and 30 healthy controls underwent detailed clinical and electrophysiological assessments, complete quantitative sensory testing (QST), and diffusion-weighted magnetic resonance neurography of the sciatic nerve. NfL was measured in the serum of healthy controls and patients with T2DM. Multivariate models were used to adjust for confounders of microvascular damage.
RESULTS
Patients with DSPN showed a 17% lower sciatic microstructural integrity compared to healthy controls (<0.001). FA correlated with tibial and peroneal motor nerve conduction velocity (NCV) (r=0.6; <0.001 and r=0.6; <0.001) and sural sensory NCV (r=0.50; <0.001). Participants with reduced sciatic nerve´s FA showed a loss of function of mechanical and thermal sensation of upper (r=0.3; p<0.01 and r=0.3; <0.01) and lower (r=0.5; <0.001 and r=0.3; =<0.01) limbs and reduced functional performance of upper limbs (Purdue Pegboard Test for dominant hand; r=0.4; <0.001). Increased levels of NfL and urinary albumin-creatinine ratio (ACR) were associated with loss of sciatic nerve´s FA (r=-0.5; <0.001 and r= -0.3, = 0.001). Of note, there was no correlation between sciatic FA and neuropathic symptoms or pain.
CONCLUSION
This is the first study showing that microstructural nerve integrity is associated with damage of different nerve fiber types and a neuroaxonal biomarker in DSPN. Furthermore, these findings show that proximal nerve damage is related to distal nerve function even before clinical symptoms occur. The microstructure of the proximal sciatic nerve and is also associated with functional nerve fiber deficits of the upper and lower limbs, suggesting that diabetic neuropathy involves structural changes of peripheral nerves of upper limbs too.
Topics: Humans; Diabetes Mellitus, Type 2; Anisotropy; Intermediate Filaments; Sciatic Nerve; Diabetic Neuropathies; Lower Extremity; Biomarkers
PubMed: 37008917
DOI: 10.3389/fendo.2023.1046690 -
Radiology. Imaging Cancer Jun 2022
Topics: Diagnosis, Differential; Histiocytosis, Sinus; Humans; Sciatic Nerve
PubMed: 35748761
DOI: 10.1148/rycan.220046 -
Journal of Neuroscience Methods Mar 2015In the pre-clinical view, the study of peripheral nerve repair and regeneration still needs to be carried out in animal models due to the structural complexity of this... (Review)
Review
In the pre-clinical view, the study of peripheral nerve repair and regeneration still needs to be carried out in animal models due to the structural complexity of this organ which can be only partly simulated in vitro. The far most used experimental model is based on the injury of the sciatic nerve, the largest nerve trunk in mammals. In this paper, the potential application of the sciatic nerve injury model in pre-clinical research is critically reviewed. This paper is aimed at helping researchers in properly employing this in vivo model for the study of nerve repair and regeneration as well as interpreting the results in a clinical translation perspective.
Topics: Animals; Disease Models, Animal; Nerve Regeneration; Sciatic Nerve; Sciatic Neuropathy
PubMed: 25629799
DOI: 10.1016/j.jneumeth.2015.01.021 -
Anatomical Record (Hoboken, N.J. : 2007) Oct 2018Sutureless nerve repair has been regarded as a promising technique for nerve repair as the suture materials often results in neuroma formation and scar tissue that... (Comparative Study)
Comparative Study
Sutureless nerve repair has been regarded as a promising technique for nerve repair as the suture materials often results in neuroma formation and scar tissue that impede nerve regeneration. The aim of this study was to analyze the mechanical stability and morphological outcome of sutureless repair using fibrin glue conduit and an alternative approach of modified suture placement. Using rat sciatic nerve, we tested the following experimental conditions: conventional suture repair; single suture combined with fibrin glue repair, and fibrin conduit reinforced with modified suture or fibrin glue. Nerve detachment anatomical measures such as axon density, myelin, and fiber caliber were analyzed for evaluation of nerve regeneration. Muscle atrophy were evaluated by muscle wet weight and H&E staining. All animals in sutureless repair group exhibited complete detachment or elongation by two or four weeks after repair. No detachment was found in any other groups. Animals treated with fibrin conduit reinforced with modified suture showed better axonal regeneration with good alignment. There were no significant differences in axon caliber among the groups. Muscle atrophy was found in all groups and there was no significant difference in muscle wet-weight among the groups. In summary, sutureless nerve repair with fibrin glue was mechanically unstable for resistance of mechanical stretches, fibrin glue conduit with modified suture placement is mechanically stable and resulted in better morphological outcome. Anat Rec, 301:1690-1696, 2018. © 2018 Wiley Periodicals, Inc.
Topics: Animals; Axons; Female; Fibrin Tissue Adhesive; Muscle, Skeletal; Muscular Atrophy; Nerve Regeneration; Peripheral Nerve Injuries; Rats, Sprague-Dawley; Sciatic Nerve; Sciatic Neuropathy; Suture Techniques; Tissue Adhesives
PubMed: 30353694
DOI: 10.1002/ar.23921 -
Journal of Plastic, Reconstructive &... Mar 2020The specific patterns of revascularization of allograft nerves after the addition of vascularization remain unknown. The aim of this study was to determine the...
INTRODUCTION
The specific patterns of revascularization of allograft nerves after the addition of vascularization remain unknown. The aim of this study was to determine the revascularization patterns of optimized processed allografts (OPA) after surgically induced angiogenesis to the wound bed in a rat sciatic nerve model.
MATERIALS AND METHODS
In 51 Lewis rats, sciatic nerve gaps were repaired with (i) autografts, (ii) OPA and (iii) OPA wrapped in a pedicled superficial inferior epigastric artery fascia flap (SIEF) to provide vascularization to the wound bed. At 2, 12, and 16 weeks, the vascular volume and vascular surface area in nerve samples were measured using micro CT and photography. Cross-sectional images were obtained and the number of vessels was quantified in the proximal, mid, and distal sections of the nerve samples.
RESULTS
At 2 weeks, the vascular volume of SIEF nerves was comparable to control (P = 0.1). The vascular surface area in SIEF nerves was superior to other groups (P<0.05). At 12 weeks, vascularity in SIEF nerves was significantly higher than allografts (P<0.05) and superior compared to all other groups (P<0.0001) at 16 weeks. SIEF nerves had a significantly increased number of vessels compared to allografts alone in the proximal (P<0.05) and mid-section of the graft (P<0.05).
CONCLUSIONS
Addition of surgical angiogenesis to the wound bed greatly improves revascularization. It was demonstrated that revascularization occurs primarily from proximal to distal (proximal inosculation) and not from both ends as previously believed and confirms the theory of centripetal revascularization.
Topics: Allografts; Animals; Disease Models, Animal; Graft Survival; Male; Rats; Rats, Inbred Lew; Sciatic Nerve; Surgical Flaps
PubMed: 31928962
DOI: 10.1016/j.bjps.2019.11.048 -
The Kurume Medical Journal Mar 2022The sciatic nerve typically follows its course through the greater sciatic foramen, below the piriformis muscle, and down the posterior aspect of the thigh, but many...
The sciatic nerve typically follows its course through the greater sciatic foramen, below the piriformis muscle, and down the posterior aspect of the thigh, but many anatomical variations exist. Herein, we report an unusual relationship between the sciatic nerve and piriformis muscle in which the split common fibular nerve went through the piriformis and had a variant communication with the tibial nerve. To our knowledge, this anatomical variation has not been previously reported. Such variants are important to fully understand pathologies involving the sciatic nerve.
Topics: Humans; Muscle, Skeletal; Peroneal Nerve; Sciatic Nerve; Tibial Nerve
PubMed: 35095018
DOI: 10.2739/kurumemedj.MS671006