Effect of flipped venous catheter combined with spinal cord electrical stimulation on functional recovery in patients with sciatic nerve injury

OBJECTIVE

This study aimed to explore the effect of flipped venous catheters combined with spinal cord electrical stimulation on functional recovery in patients with sciatic nerve injury.

PATIENTS AND METHODS

160 patients with hip dislocation and sciatic nerve injury were divided into conventional release and flipped catheter + electrical stimulation groups according to the treatment methods (n=80). Motor nerve conduction velocity (MCV) and lower limb motor function were compared. Serum neurotrophic factors brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were compared. The frequency of complications and quality of life were also compared.

RESULTS

The MCV levels of the common peroneal nerve and tibial nerve in the flipped catheter + electrical stimulation group were greater than the conventional lysis group (p<0.05). After treatment, the lower extremity motor score (LMEs) in the flipped catheter + electrical stimulation group was greater than the conventional lysis group (p<0.05). The serum levels of BDNF and NGF in the flip catheter + electrical stimulation group were higher than the conventional lysis group (p<0.05). The complication rate in the flipped catheter + electrical stimulation group was lower than in the conventional release group (6.25% vs. 16.25%, p<0.05). The quality-of-life score in the flip catheter + electrical stimulation group was greater than the conventional lysis group (p<0.05).

CONCLUSIONS

The flipped venous catheter combined with spinal cord electrical stimulation can improve nerve conduction velocity, lower limb motor function, serum BDNF and NGF levels, reduce complications, and help improve the quality of life of sufferers with sciatic nerve injury. Chictr.org.cn ID: ChiCTR2400080984.

TsMS combined with EA promotes functional recovery and axonal regeneration via mediating the miR-539-5p/Sema3A/PlexinA1 signalling axis in sciatic nerve-injured rats

Enhancing axonal regeneration is one of the most important processes in treating nerve injuries. Both magnetic and electrical stimulation have the effect of promoting nerve axon regeneration. But few study has investigated the effects of trans-spinal magnetic stimulation (TsMS) combined with electroacupuncture (EA) on nerve regeneration in rats with sciatic nerve injury. In this study, we compared the improvement of neurological function in rats with sciatic nerve crush injuries after 4 weeks of different interventions (EA, TsMS, or TsMS combined with EA). We further explored the morphological and molecular biological alterations following sciatic nerve injury by HE, Masson, RT-PCR, western blotting, immunofluorescence staining and small RNA transcriptome sequencing. The results showed that TsMS combined with EA treatment significantly promoted axonal regeneration, increased the survival rate of neurons, and suppressed denervation atrophy of the gastrocnemius muscle. Subsequent experiments suggested that the combination treatment may play an active role by mediating the miR-539-5p/Sema3A/PlexinA1 signaling axis.

Evaluation of combined effects of brief electrical stimulation and Schwann-like cells on sciatic nerve injury model

Severe nerve injuries can be treated with electrical stimulation and stem cell therapies, but little is known about the potential benefits of combining these two treatments. In an effort to investigate this combination, we conducted a study to evaluate the effectiveness of electrical stimulation and Schwann-like cell transplantation in female Wistar albino rats. Our study consisted of five groups of rats: a sham group, an injury group, an electrical stimulation group, a Schwann-like cell group, and a combination group. The experimental groups received electrical stimulation, Schwann-like cell transplantation, or both. The animals sciatic function index was evaluated during a 6-week recovery period, and nerve conduction velocity, wet muscle mass, and nerve tissues were also analyzed. The results of the study showed that all experimental groups had a faster functional recovery compared to the injury group, although the difference between groups was not statistically significant. Both the combination group and the Schwann-like cell transplantation group had a higher nerve conduction velocity compared to the other experimental groups. However, there was no significant difference between the combination and Schwann-like cell transplantation groups. Nonetheless, histological analysis showed a better axonal reorganization in the combination group. The study provides preliminary evidence of the potential benefits of combining electrical stimulation and Schwann-like cell transplantation in treating severe nerve injuries. However, further studies with larger sample sizes are needed to confirm these findings and optimize the treatment parameters.

Amphiphysin-IgG autoimmune sciatic neuropathy and facial neuropathy related to primary central nervous system lymphoma: A case report

We reported a 61-year-old man presented with 10-month progressing left sciatic neuropathy and 10-day right facial neuropathy. Serum amphiphysin-IgG was positive. 18F-FDG PET/CT of the whole body showed no signs of malignancy. Treatment with plasma exchange and oral prednisone relieved the symptoms. Nine months later, right hemiparesis and seizure of right limbs developed. 18F-FDG and 18F-PBR06 (18 kDa translocator protein, TSPO) radioligand PET/MRI of the whole body revealed intense uptake in the intracranial lesions. Intracranial lymphoma was diagnosed by stereotactic needle brain biopsy. Mononeuropathies could be paraneoplastic syndromes. TSPO shows high uptake in intracranial lymphoma on 18F-PBR06 PET images.

Toll-Like Receptor 9-Mediated Neuronal Innate Immune Reaction Is Associated with Initiating a Pro-Regenerative State in Neurons of the Dorsal Root Ganglia Non-Associated with Sciatic Nerve Lesion

One of the changes brought about by Wallerian degeneration distal to nerve injury is disintegration of axonal mitochondria and consequent leakage of mitochondrial DNA (mtDNA)—the natural ligand for the toll-like receptor 9 (TLR9). RT-PCR and immunohistochemical or Western blot analyses were used to detect TLR9 mRNA and protein respectively in the lumbar (L4-L5) and cervical (C7-C8) dorsal root ganglia (DRG) ipsilateral and contralateral to a sterile unilateral sciatic nerve compression or transection. The unilateral sciatic nerve lesions led to bilateral increases in levels of both TLR9 mRNA and protein not only in the lumbar but also in the remote cervical DRG compared with naive or sham-operated controls. This upregulation of TLR9 was linked to activation of the Nuclear Factor kappa B (NFκB) and nuclear translocation of the Signal Transducer and Activator of Transcription 3 (STAT3), implying innate neuronal immune reaction and a pro-regenerative state in uninjured primary sensory neurons of the cervical DRG. The relationship of TLR9 to the induction of a pro-regenerative state in the cervical DRG neurons was confirmed by the shorter lengths of regenerated axons distal to ulnar nerve crush following a previous sciatic nerve lesion and intrathecal chloroquine injection compared with control rats. The results suggest that a systemic innate immune reaction not only triggers the regenerative state of axotomized DRG neurons but also induces a pro-regenerative state further along the neural axis after unilateral nerve injury.

Fourteen (14) months follow up of traumatic sciatic neuritis due to intramuscular injection: a case report

The injury caused due to the intramuscular (IM) mode of drug administration are still affecting population in rural area more than urban area. The IM injection given in any quadrant except the upper outer quadrant of buttock most commonly damages the sciatic nerve because of its course and extent in the injection prone site. The iatrogenic sciatic nerve injury because of IM injection in dorsogluteal site is a matter of concern all over the world covering the undeveloped, developing and developed countries. The iatrogenic sciatic neuritis causes severe neurological or motor deficits leading to the medico-legal consequences. An 8-year-old male child, post dorsogluteal IM injection for mild fever and cold, presented left lower limb weakness and pain in left gluteal region. The patient underwent the medical and physiotherapeutic management for 14 months. The medical management included the initial dose of steroids and ox carbamazepine along with methylcobalamine and folic acid. The physiotherapeutic intervention concentrated on the functional independency of child. The patient attended complete physiological and functional recovery by the end of 14th month concluding that sometimes waiting for lesion to resolve is better than intervention. The iatrogenic sciatic neuritis is a complication that needs attention for prevention following intramuscular drug administration technique.

Effectiveness of electrical stimulation on nerve regeneration after crush injury: Comparison between invasive and non-invasive stimulation

Several studies have investigated the use of invasive and non-invasive stimulation methods to enhance nerve regeneration, and varying degrees of effectiveness have been reported. However, due to the use of different parameters in these studies, a fair comparison between the effectiveness of invasive and non-invasive stimulation methods is not possible. The present study compared the effectiveness of invasive and non-invasive stimulation using similar parameters. Eighteen Sprague Dawley rats were classified into three groups: the iES group stimulated with fully implantable device, the tES group stimulated with transcutaneous electrical nerve stimulation (TENS), and the injury group (no stimulation). The iES and tES groups received stimulation for 6 weeks starting immediately after the injury. Motor function was evaluated using the sciatic functional index (SFI) every week. The SFI values increased over time in all groups; faster and superior functional recovery was observed in the iES group than in the tES group. Histological evaluation of the nerve sections and gastrocnemius muscle sections were performed every other week. The axon diameter and muscle fiber area in the iES group were larger, and the g-ratio in the iES group was closer to 0.6 than those in the tES group. To assess the cause of the difference in efficiency, a 3D rat anatomical model was used to simulate the induced electric fields in each group. A significantly higher concentration and intensity around the sciatic nerve was observed in the iES group than in the tES group. Vector field distribution showed that the field was orthogonal to the sciatic nerve spread in the tES group, whereas it was parallel in the iES group; this suggested that the tES group was less effective in nerve stimulation. The results indicated that even though rats in the TENS group showed better recovery than those in the injury group, it cannot replace direct stimulation yet because rats stimulated with the invasive method showed faster recovery and superior outcomes. This was likely attributable to the greater concentration and parallel distribution of electric field with respect to target nerve.

GABAergic cell transplants in the anterior cingulate cortex reduce neuropathic pain aversiveness

Dysfunction of inhibitory circuits in the rostral anterior cingulate cortex underlies the affective (aversive), but not the sensory-discriminative features (hypersensitivity) of the pain experience. To restore inhibitory controls, we transplanted inhibitory interneuron progenitor cells into the rostral anterior cingulate cortex in a chemotherapy-induced neuropathic pain model. The transplants integrated, exerted a GABA-A mediated inhibition of host pyramidal cells and blocked gabapentin preference (i.e. relieved ongoing pain) in a conditioned place preference paradigm. Surprisingly, pain aversiveness persisted when the transplants populated both the rostral and posterior anterior cingulate cortex. We conclude that selective and long lasting inhibition of the rostral anterior cingulate cortex, in the mouse, has a profound pain relieving effect against nerve injury-induced neuropathic pain. However, the interplay between the rostral and posterior anterior cingulate cortices must be considered when examining circuits that influence ongoing pain and pain aversiveness.

Canine Adipose-Derived Mesenchymal Stromal Cells Enhance Neuroregeneration in a Rat Model of Sciatic Nerve Crush Injury

Crush injuries in peripheral nerves are frequent and induce long-term disability with motor and sensory deficits. Due to axonal and myelin sheath disruptions, strategies for optimized axonal regeneration are needed. Multipotent mesenchymal stromal cells (MSC) are promising because of their anti-inflammatory properties and secretion of neurotrophins. The present study investigated the effect of canine adipose tissue MSC (Ad-MSC) transplantation in an experimental sciatic nerve crush injury. Wistar rats were divided into three groups: sham ( n = 8); Crush+PBS ( n = 8); Crush+MSC ( n = 8). Measurements of sciatic nerve functional index (SFI), muscle mass, and electromyography (EMG) were performed. Canine Ad-MSC showed mesodermal characteristics (CD34-, CD45-, CD44+, CD90+ and CD105+) and multipotentiality due to chondrogenic, adipogenic, and osteogenic differentiation. SFI during weeks 3 and 4 was significantly higher in the Crush+MSC group ( p < 0.001). During week 4, the EMG latency in the Crush+MSC groups had better near normality ( p < 0.05). The EMG amplitude showed results close to normality during week 4 in the Crush+MSC group ( p < 0.04). There were no statistical differences in muscle weight between the groups ( p > 0.05), but there was a tendency toward weight gain in the Crush+MSC groups. Better motor functional recovery after crush and perineural canine Ad-MSC transplantation was observed during week 2. This was maintained till week 4. In conclusion, the canine Ad-MSC transplantation showed early pro-regenerative effects between 2-4 weeks in the rat model of sciatic nerve crush injury.

Effects of Lumbar Acupuncture Stimulation on Blood Flow to the Sciatic Nerve Trunk - An Exploratory Study

Introduction

Acupuncture may have a role in the treatment of intermittent claudication of the cauda equina due to lumbar spinal canal stenosis. The aim of this study was to explore the possible physiological mechanisms.

Methods

In a laboratory experiment, manual acupuncture was performed at a point adjacent to the sixth lumbar vertebra of 13 animals and its effect on sciatic nerve blood flow was measured using a laser Doppler flowmetry. Simultaneously, changes in blood pressure and cardiac rate were observed. Each animal was stimulated four to eight times, making a total of 58 experiments.

Results

Acupuncture stimulation did not produce consistent changes in sciatic nerve blood flow, with increased and decreased blood flow as well as no change in blood flow observed. Among the 58 individual experiments, sciatic nerve blood flow was increased in 33, reduced in 12, and unchanged in 13. Approximately half of the stimulations showed a correlation between blood flow and blood pressure change.

Conclusion

Our results indicate that lumbar acupuncture stimulation can have an influence on sciatic nerve blood flow. The effect is dependent not only on blood pressure but also other factors, for example vasodilator and vasoconstrictor nerve activity. This mechanism may contribute to a clinical effect on intermittent claudication of the cauda equina.

Mesenchymal stem cells therapy enhances the efficacy of pregabalin and prevents its motor impairment in paclitaxel-induced neuropathy in rats: Role of Notch1 receptor and JAK/STAT signaling pathway

Peripheral neuropathy is a common adverse effect observed during the use of paclitaxel (PTX) as chemotherapy. The present investigation was directed to estimate the modulatory effect of bone marrow derived mesenchymal stem cells (BM-MSCs) on pregabalin (PGB) treatment in PTX-induced peripheral neuropathy. Neuropathic pain was induced in rats by injecting PTX (2 mg/kg, i.p) 4 times every other day. Rats were then treated with PGB (30 mg/kg/day, p.o.) for 21 days with or without a single intravenous administration of BM-MSCs. At the end of experiment, behavioral and motor abnormalities were assessed. Animals were then sacrificed for measurement of total antioxidant capacity (TAC), nerve growth factor (NGF), nuclear factor kappa B p65 (NF-κB p65), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and active caspase-3 in the sciatic nerve. Moreover, protein expressions of Notch1 receptor, phosphorylated Janus kinase 2 (p-JAK2), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), and phosphorylated p38 mitogen-activated protein kinase (p-p38-MAPK) were estimated. Finally, histological examinations were performed to assess severity of sciatic nerve damage and for estimation of BM-MSCs homing. Combined PGB/BM-MSCs therapy provided an additional improvement toward reducing PTX-induced oxidative stress, neuro-inflammation, and apoptotic markers. Interestingly, BM-MSCs therapy effectively prevented motor impairment observed by PGB treatment. Combined therapy also induced a significant increase in cell homing and prevented PTX-induced sciatic nerve damage in histological examination. The present study highlights a significant role for BM-MSCs in enhancing treatment potential of PGB and reducing its motor side effects when used as therapy in the management of peripheral neuropathy.

Sciatic neuropathy caused by a pressure ulcer: A case report

RATIONALE

Sciatic neuropathy has various causes; however, cases in which a pressure ulcer led to sciatic neuropathy have not been reported to date.

PATIENT CONCERNS

A 33-year-old woman with no pre-existing mobility problems visited our department with the chief complaint of an extensive pressure ulcer and necrosis in her right buttock. She had a medical history of being bedridden for 2 days while in a coma due to a drug overdose 2 months previously. Physical examination revealed loss of sensation and foot drop in the right foot.

DIAGNOSIS

Physical examination, magnetic resonance imaging, and nerve conduction studies were conducted; the patient was diagnosed with a common peroneal branch injury of the right sciatic nerve.

INTERVENTIONS

The necrotic tissue was debrided and sciatic nerve decompression was performed, followed by frequent dressing changes. In addition, psychiatric treatment and physical therapy were performed simultaneously.

OUTCOMES

The pressure ulcer decreased in size and healed to some extent with granulation tissue. However, gait disorders, accompanied by symptoms of sciatic neuropathy, continued. The patient was transferred to the department of gastroenterology for the treatment of toxic hepatitis, which occurred during her inpatient treatment.

LESSONS

Physicians should be aware that sciatic neuropathy may occur during the treatment of patients with a pressure ulcer who exhibit no symptoms of paraplegia or quadriplegia. To prevent neuropathy, aggressive treatment of the pressure ulcer is necessary.

Epineural adipose-derived stem cell injection in a sciatic rodent model

BACKGROUND

The aim was to evaluate the regenerative effect of epineural injection of rat ASCs (rASCs) in three different settings of acute and chronic compression in a rat sciatic nerve model.

METHODS

Acute compression (60 s) with a vessel clamp over a distance of 1 mm (group 1) or 10 mm (group 2), as well as chronic compression with a permanent remaining, nonabsorbable polymeric clip over a distance of 1 mm (group 3) was performed. Depending on the group, either 5 × 106 rASCs or the same volume (25 μl) of culture medium (CM) was injected with a 30G needle in the epineurium at the time of compression. Outcome measures were functional gait evaluations, imaging analysis, histomorphometric analyses, and muscle weight.

RESULTS

The rats in group 2 had a better function than those with group 1 at one and especially at 2 weeks. After 4 weeks however, almost all rats were close to a normal function. There was a similar Muscle Weight Ratio (MWR) after 2 weeks in all groups, whereas after 4 weeks, the MWR in group 3 was lower compared with group 1 and 2. Histomorphometric analysis showed a better myelination in group 1 & 2 compared to group 3 after 4 weeks. ASCs have a beneficial effect on myelin thickness (G-Ratio).

CONCLUSIONS

We successfully evaluated the regenerative effect of epineural injection of rASCs in three different settings of acute and chronic compression. However, there were no significant differences in outcomes between the ASC-treated groups and control groups.

Heparanase attenuates axon degeneration following sciatic nerve transection

Axon degeneration underlies many nervous system diseases; therefore understanding the regulatory signalling pathways is fundamental to identifying potential therapeutics. Previously, we demonstrated heparan sulphates (HS) as a potentially new target for promoting CNS repair. HS modulate cell signalling by both acting as cofactors in the formation of ligand-receptor complexes and in sequestering ligands in the extracellular matrix. The enzyme heparanase (Hpse) negatively regulates these processes by cleaving HS and releasing the attached proteins, thereby attenuating their ligand-receptor interaction. To explore a comparative role for HS in PNS axon injury/repair we data mined published microarrays from distal sciatic nerve injury. We identified Hpse as a previously unexplored candidate, being up-regulated following injury. We confirmed these results and demonstrated inhibition of Hpse led to an acceleration of axonal degeneration, accompanied by an increase in β-catenin. Inhibition of β-catenin and the addition of Heparinase I both attenuated axonal degeneration. Furthermore the inhibition of Hpse positively regulates transcription of genes associated with peripheral neuropathies and Schwann cell de-differentiation. Thus, we propose Hpse participates in the regulation of the Schwann cell injury response and axo-glia support, in part via the regulation of Schwann cell de-differentiation and is a potential therapeutic that warrants further investigation.

Crush injury to motor nerves in the G93A transgenic mouse model of amyotrophic lateral sclerosis promotes muscle reinnervation and survival of functionally intact nerve-muscle contacts

Selective survival of small motor nerve fibers and their neuromuscular contacts in the SOD1^G93A transgenic mouse model of amyotrophic lateral sclerosis (ALS) suggests that smaller regenerated nerve fibers are more able to sustain reformed nerve-muscle connections as functionally intact motor units (MUs). The sciatic nerve was crushed unilaterally in SOD1^G93A transgenic mice at 40 days of age and contractile forces of reinnervated muscles and their MUs were recorded at 90 days in order to determine the capacities of the nerves to regenerate and to form and retain functional neuromuscular connections. Reduced MU numbers in fast-twitch tibialis anterior, extensor digitorum longus and medial gastrocnemius muscles and the lesser reductions in slow-twitch soleus muscle of SOD1^G93A transgenic mice were reversed in reinnervated muscles: there were more reinnervated MUs and their contractile forces and the muscle forces and weights increased. In line with the contrasting ability of only small not large nerve fibers to sprout to form enlarged MUs in the SOD1^G93A transgenic mouse, the smaller regenerating nerve fibers formed enlarged MUs that were better able to survive. Because nerve fibers with and without muscle contacts were severed by the sciatic nerve crush injury, the conditioning lesion is untenable as the explanation for improved maintenance of reinnervated neuromuscular junctions. Elevated neurotrophic factor expression in axotomized motoneurons and/or denervated Schwann cells and the synapse withdrawal from axotomized motoneurons are other factors that, in addition to reduced size of nerve fibers reinnervating muscles, may account for increased survival and size of reinnervated MUs in ALS.

The Effects of Two Different Exercise Programs on the Ultrastructural Features of the Sciatic Nerve and Soleus Muscle After Sciatic Crush

Peripheral nerve injuries constitute a significant medical problem and the recovery is critically dependent on post-injury treatment. In this study, following sciatic nerve crush, we investigated the effects of a 4-week endurance training program (ET) and balance and coordination training program (BCT) on the ultrastructural features of the sciatic nerve and soleus muscle. The animals were randomly divided into Sham, non-trained (NT), ET, and BCT groups each of which included three animals. Ultra-thin cross and longitudinal sections (70-85 nm) were digitized and analyzed comparatively. The electron micrographic analysis of the sciatic nerve showed similar organelles features in the injury groups (myelin debris and swelling mitochondria). Nonetheless, the ET group presented better ultrastructural features as demonstrated by the greater predominance of rounded fibers and more defined organization in the myelinated axon bundles. In the soleus muscle's analyses, the injured groups demonstrated similar organelles' features (nucleus contained highly heterochromatic nuclei and smaller mitochondria). However, ET and BCT groups showed apparently enlarged myofibril cross-sectional areas and less collagen around muscle fibers, although, the ET group displayed reduced intermyofibrillar spaces and more closely aligned myofilaments when compared with the BCT group. Based on electron micrographic analysis, our findings suggest the presence of ultrastructural differences between the Sham, NT, and the trained groups. Therefore, exercise type seems to be responsible for producing some different positive features in the trained groups, while ET seems to have a more pronounced influence on the ultrastructural features of the sciatic nerve and the soleus muscle after a crush injury. Anat Rec, 300:1654-1661, 2017. © 2017 Wiley Periodicals, Inc.

[Effect of Electroacupuncture Stimulation of Different Tissues at "Huantiao" (GB 30) Acupoint on Expression of Phosphorylated JNK and c-jun in Spinal Cord of Rats with Sciatic Nerve Injury]

OBJECTIVE

To observe the effects of electroacupuncture (EA) stimulation of different tissues (nerve stem, muscular layer) at "Huantiao" (GB 30) acupoint on expression of hosphorylated c-jun N-terminal kinase (p-JNK) and c-jun (p-c-jun) proteins in the lumbar spinal cord in rats with sciatic nerve injury, so as to explore its mechanism underlying improvement of peripheral neuropathic damage.

METHODS

Forty-eight SD rats were randomly divided into normal, model (the left sciatic nerve severed), GB 30 deep needling (the acupuncture needle tip was inserted to the sciatic nerve trunk to elicit an instantaneous jerk of the hind limb) and GB 30 shallow needling (the needle tip was inserted to the muscle layer to evoke a local muscular contraction) groups (n = 12 rats in each group). EA stimuli were delivered at 2 Hz/100 Hz, 1 mA, 20 min in duration per treatment for 10 consecutive days. Histopathological changes were observed by Hematoxylin-eosin (HE) staining and immunohistochemical assay was carried out to examine the pathological change of spinal segments (L4-L5) and the expression of p-JNK and p-c-jun proteins, respectively.

RESULTS

For rats with the sciatic nerve severed, the spinal neurons became swelling, degeneration or even apoptosis. Acupuncture intervention reduced the number of apoptosic neurons and improved the pathological change, which was relatively better in the.deep needling group than in the shallow needling group. Likewise, the elevated spinal p-JNK and p-c-jun expression levels of the model group were significantly reduced by EA intervention (deep needling vs shallow needling, P < 0.01.

CONCLUSION

Acupuncture can improve the spinal pathological changes in rats with sciatic nerve injury, which is probably achieved by decreasing the p-JNK and p-c-jun expression and inhibiting the JNK signaling pathway, and thereby, reducing the apoptosis of the spinal neurons. Deep needling results in greater benefits than shallow needling.

Improved neurological outcome by intramuscular injection of human amniotic fluid derived stem cells in a muscle denervation model

Purpose

The skeletal muscle develops various degrees of atrophy and metabolic dysfunction following nerve injury. Neurotrophic factors are essential for muscle regeneration. Human amniotic fluid derived stem cells (AFS) have the potential to secrete various neurotrophic factors necessary for nerve regeneration. In the present study, we assess the outcome of neurological function by intramuscular injection of AFS in a muscle denervation and nerve anastomosis model.

Materials and Methods

Seventy two Sprague-Dawley rats weighing 200–250 gm were enrolled in this study. Muscle denervation model was conducted by transverse resection of a sciatic nerve with the proximal end sutured into the gluteal muscle. The nerve anastomosis model was performed by transverse resection of the sciatic nerve followed by four stitches reconnection. These animals were allocated to three groups: control, electrical muscle stimulation, and AFS groups.

Results

NT-3 (Neurotrophin 3), BDNF (Brain derived neurotrophic factor), CNTF (Ciliary neurotrophic factor), and GDNF (Glia cell line derived neurotrophic factor) were highly expressed in AFS cells and supernatant of culture medium. Intra-muscular injection of AFS exerted significant expression of several neurotrophic factors over the distal end of nerve and denervated muscle. AFS caused high expression of Bcl-2 in denervated muscle with a reciprocal decrease of Bad and Bax. AFS preserved the muscle morphology with high expression of desmin and acetylcholine receptors. Up to two months, AFS produced significant improvement in electrophysiological study and neurological functions such as SFI (sciatic nerve function index) and Catwalk gait analysis. There was also significant preservation of the number of anterior horn cells and increased nerve myelination as well as muscle morphology.

Conclusion

Intramuscular injection of AFS can protect muscle apoptosis and likely does so through the secretion of various neurotrophic factors. This protection furthermore improves the nerve regeneration in a long term nerve anastomosis model.

Nerve guidance conduits from aligned nanofibers: improvement of nerve regeneration through longitudinal nanogrooves on a fiber surface

A novel fibrous conduit consisting of well-aligned nanofibers with longitudinal nanogrooves on the fiber surface was prepared by electrospinning and was subjected to an in vivo nerve regeneration study on rats using a sciatic nerve injury model. For comparison, a fibrous conduit having a similar fiber alignment structure without surface groove and an autograft were also conducted in the same test. The electrophysiological, walking track, gastrocnemius muscle, triple-immunofluorescence, and immunohistological analyses indicated that grooved fibers effectively improved sciatic nerve regeneration. This is mainly attributed to the highly ordered secondary structure formed by surface grooves and an increase in the specific surface area. Fibrous conduits made of longitudinally aligned nanofibers with longitudinal nanogrooves on the fiber surface may offer a new nerve guidance conduit for peripheral nerve repair and regeneration.

Effects of extracorporeal shock wave therapy on functional recovery and neurotrophin-3 expression in the spinal cord after crushed sciatic nerve injury in rats

The study described here investigated the effects of extracorporeal shock wave therapy (ESWT) on functional recovery and neurotrophin-3 expression in the spinal cord after sciatic nerve injury in rats. Forty-five 8-wk-old rats were used and randomly divided into three groups: An experimental group, a control group and a sham group. The experimental group received ESWT after the nerve-crushing damage. The sciatic functional index and Dartfish Software were used to determine the effect of sciatic nerve damage on functional changes. A 1-cm length of spinal cord encompassing the L4-6 level was removed for Western blot analysis. The sciatic functional index significantly changed in both the ESWT and control groups after impairment. In the time course evaluation of the ankle angle in the toe off, the ESWT group had statistically significant increases from day 21 onward. There was a significant difference in neurotrophin-3 expression between the groups on days 1, 7 and 14 after impairment. Early application of ESWT increased the expression of neurotrophin-3 and neurotrophin-3 mRNA, and daily therapy facilitated the activity of macrophages and Schwann cells, which affect the survival and regeneration of neurons.

[AN EXPERIMENTAL STUDY ON REPAIR OF SCIATIC NERVE INJURY BY Schwann-LIKE CELLS DERIVED FROM UMBILICAL CORD BLOOD MESENCHYMAL STEM CELLS]

OBJECTIVE

To evaluate the effect of using Schwann-like cells derived from human umbilical cord blood mesenchymal stem cells (hUCBMSCs) as the seed cells to repair large sciatic nerve defect in rats so as to provide the experimental evidence for clinical application of hUCBMSCs.

METHODS

Fourty-five male Sprague Dawley (SD) rats in SPF grade, weighing 200-250 g, were selected. The hUCBMSCs were harvested and cultured from umbilical cord blood using lymphocyte separating and high molecular weight hydroxyethyl starch, and then was identified. The hUCBMSCs of 3rd generation were induced to Schwann-like cells, and then was identified by chemical derivatization combined with cytokine. The acellular nerve basal membrane conduit was prepared as scaffold material by the sciatic nerve of SD rats through repeated freezing, thawing, and washing. The tissue engineered nerve was prepared after 7 days of culturing Schwann-like cells (1 x 10(7) cells/mL) on the acellular nerve basal membrane conduit using the multi-point injection. The 15 mm sciatic nerve defect model was established in 30 male SD rats, which were randomly divided into 3 groups (10 rats each group). Defect was repaired with tissue engineered nerve in group A, with acellular nerve basal membrane conduit in group B, and with autologous sciatic nerve in group C. The nerve repair was evaluated through general observation, sciatic function index (SFI), nerve electrophysiology, weight of gastrocnemius muscle, and Masson staining after operation.

RESULTS

The hUCBMSCs showed higher expression of surface markers of mesenchymal stem cells, and Schwann-like cells showed positive expression of glia cell specific markers such as S100b, glial fibrillary acidic protein, and P75. At 8 weeks after operation, the acellular nerve basal membrane conduit had no necrosis and liquefaction, with mild adhesion, soft texture, and good continuity at nerve anastomosis site in group A; group B had similar appearance to group A; adhesion of group C was milder than that of groups A and B, with smooth anastomotic stoma and no enlargement, and the color was similar to that of normal nerve. SFI were gradually decreased, group C was significantly greater than groups A and B, group A was significantly greater than group B (P < 0.05). The compound action potential could be detected in anastomotic site of 3 groups, group C was significantly greater than groups A and B, and group A was significantly greater than group B in amplitude and conduction velocity (P < 0.05). Atrophy was observed in the gastrocnemius of 3 groups; wet weight's recovery rate of the gastrocnemius of group C was significantly greater than that of groups A and B, and group A was significantly greater than group B (P < 0.05). Masson staining showed that large nerve fibers regeneration was found in group A, which had dense and neat arrangement with similar fiber diameter. The density and diameter of medullated fibers, thickness of myelinated axon, and axon diameter of group C were significantly greater than those of groups A and B, and group A was significantly greater than group B (P < 0.05).

CONCLUSION

Tissue engineered nerves from hUCBMSCs-derived Schwann-like cells can effectively repair large defects of the sciatic nerve. hUCBMSCs-derived Schwann-like cells can be used as a source of seed cells in nerve tissue engineering.

Therapeutic ultrasound suppresses neuropathic pain and upregulation of substance P and neurokinin-1 receptor in rats after peripheral nerve injury

We studied the mechanisms and impact of therapeutic ultrasound (TU) for pain caused by nerve injury. TU began on post-operative day 5 (POD5) and then continued daily for the next 22 d. Sensitivity to thermal and mechanical stimuli and levels of neurokinin-1 receptor, substance P, tumor necrosis factor-α and interleukin-6 in the sciatic nerve were examined. On POD7, chronic constriction injury rats undergoing TU at an intensity of 1 W/cm(2), but not 0.25 or 0.5 W/cm(2), had increases in both the mechanical withdrawal threshold and the thermal withdrawal latency compared with the chronic constriction injury group. Moreover, chronic constriction injury rats exhibited upregulation of neurokinin-1 receptor, substance P, tumor necrosis factor-α and interleukin-6 in the sciatic nerve on PODs 14 and 28, whereas TU inhibited their increased expression. We suggest that the efficacy of TU is dependent on its ability to limit the upregulation of neurokinin-1 receptor, substance P, tumor necrosis factor-α and interleukin-6 around the injured sciatic nerve.

[Effect of embryonic anlage allografts of the rat spinal cord on growth of regenerating fibers of the recipient nerve]

A comparative study of the effect of tissue and suspension allografts of an embryonic spinal cord on regeneration of nerve fibers of impaired (by application of a ligature) sciatic nerve in rats was conducted. It was demonstrated that unlike tissue grafts that reach a large volume 21 and 60 days after transplantation, suspension grafts do not inhibit the growth of axons of the recipient to the periphery. It was established that introduction of a suspension of dissociated cells of the spinal cord embryonic anlages (but not fragments of these anlages) into the impaired sciatic nerve in rats results in an increase in the amount of myelinated regenerating nerve fibers of the recipient 60 days after the operation.

[Expression of connective tissue growth factor in sciatic nerve after chronic compression injury and effect of rhodiola sachalinensis on its expression]

OBJECTIVE

To investigate the expression of connective tissue growth factor (CTGF) in the chronic sciatic nerve compression injury and to explore the effect of rhodiola sachalinensis on the expression of CTGF.

METHODS

Forty-five adult male Sprague Dawley rats were randomly divided into groups A, B, and C: In group A (sham-operated group), only the sciatic nerve was exposed; in group B (compression group), sciatic nerve entrapment operation was performed on the right hind leg according to Mackinnon method to establish the chronic sciatic nerve compression model; and in group C (compression and rhodiola sachalinensis group), the sciatic nerve entrapment operation was performed on the right hind leg and rhodiola sachalinensis (2 g/mL) was given by gavage at a dose of 0.5 mL/100 g for 2 weeks. The nerve function index (SFI) was observed and neural electrophysiology was performed; histology, transmission electron microscope, real-time fluorescent quantitative PCR, and Western blot were performed to observe the morphological changes of the compressed nerve tissue and to determine the mRNA and protein levels of CTGF, collagen type I, and collagen type III at 2, 6, and 10 weeks after operation.

RESULTS

At 6 and 10 weeks after operation, SFI of groups A and C were significantly better than that of group B (P < 0.05), but there was no significant difference between groups A and C (P > 0.05). The nerve function test showed that the nerve motor conduction velocity (MCV) and the amplitude of compound muscle action potential (CMAP) of group B were significantly lower than those of groups A and C, and distal motor latency (DML) was significantly prolonged in group B (P < 0.05), but there was no significant difference between groups A and C (P > 0.05). Histology and transmission electron microscope observations showed that myelinated nerve fibers degenerated and collagen fiber hyperplasia after sciatic nerve chronic injury in group B, and rhodiola sachalinensis could promote the repair of nerve fibers in group C. At 2 weeks postoperatively, the number of myelinated nerve fibers in groups B and C were significantly less than that of group A (P < 0.05), and the myelin sheath thickness of groups B and C were significantly larger than that of group A (P < 0.05). At 6 and 10 weeks postoperatively, the number of myelinated nerve fibers in groups B and C were significantly more than that of group A (P < 0.05); the myelin sheath thickness of group B was significantly less than that of groups A and C (P < 0.05). The effective area of nerve fiber had no significant difference among groups at each time point (P > 0.05). Real-time fluorescent quantitative PCR and Western blot results showed that the mRNA and protein expressions of CTGF, collagen type I, and collagen type III in group B were significantly higher than those in groups A and C at each time point (P < 0.05), but there was no significant difference between groups A and C (P > 0.05).

CONCLUSION

Sciatic nerve fibrosis can be caused by chronic nerve compression. The increased expression of CTGF suggests that CTGF plays an important role in the process of neural injury and fibrosis. Rhodiola sachalinensis can significantly reduce the level of CTGF and plays an important role in nerve functional recovery.

[Effect of deep electroacupuncture stimulation of "Huantiao" (GB 30) on changes of function and nerve growth factor expression of the injured sciatic nerve in rats]

OBJECTIVE; To observe the effect of deep electroacupuncture (EA) stimulation of "Huantiao"(GB 30) on the functional and pathological changes and nerve growth factor (NGF) expression of the damaged sciatic nerve in rats, so as to study its mechanisms underlying reliving sciatica.

METHODS

Forty-eight SD rats were randomly divided into normal, model, deep EA and shallow EA groups (n = 12 in each group). The sciatic nerve injury model was established by mechanical clamp of the sciatic nerve stem. For deep and shallow EA, the acupuncture needles were inserted into GB 30 about 16 mm and 7 mm, respectively. The EA treatment was given 20 min, once daily for 14 days. The evoked potentials of the injured sciatic nerve stem responding to electrical stimulation were recorded by using a biophysiological experimental system for calculating the motor conduction velocity. Pathological changes of the sciatic nerve were displayed by H. E. stain. The expression of NGF and Fos proteins was detected by immunohistochemistry.

RESULTS

In comparison with the normal group, the conduction velocity and the amplitude of the evoked potentials of the sciatic nerve were significantly decreased in the model group (P < 0.05). Following EA, both conduction velocity and amplitude of the evoked potentials in the deep EA group, and the conduction velocity in the shallow EA group were considerably increased (P < 0.05). The therapeutic effects were significantly better in the deep EA group than that in the shallow EA group (P < 0.05). No significant differences were found between the shallow EA and model groups in the amplitude of evoked potentials (P > 0.05), and no significant changes of latencies of the evoked potentials inthe four groups (P > 0.05). In the model group, the disorganized nerve fibers axons, myelin and Schwann cells of the damaged sciatic nerve were found, which became milder in the EA groups particularly in the deep EA group. In regard to the NGF and Fos immunoactivity of the injured sciatic nerve, the expression levels of both NGF and Fos proteins were obviously higher in the model group than in the normal group (P < 0.05). After EA stimulation, NGF expression was further significantly up-regulated in both deep and shallow EA groups (P < 0.05), and Fos protein expression was notably down-regulated in the deep and shallow EA groups (P < 0.05). The expression of NGF was significantly higher and Fos protein was obviously lower in the deep EA group than in the shallow EA group (P < 0.05).

CONCLUSION

Deep EA stimulation of GB 30 can improve the pathological changes and function of the injured sciatic nerve in the rat, which is closely associated with its effects in up-regulating NGF expression and down-regulating Fos expression. The deep EA is relatively better in the therapeutic effect. These facts may be one of the mechanisms of EA in relieving sciatica in clinic practice.

[The comparative pattern of neuromidin and magnetic stimulation influence on neuroplasticity in experimental traumatic neuropathy]

OBJECTIVE

Traumatic neuropathies are among the most actual problems in neurology due to the severe neurological deficit in most cases and poor prognosis of recovery. We evaluated the effect of ipidacrin (cholinesterase inhibitor) and magnetic stimulation on neuroplastic axonal changes after experimental neurotmesis of rat's sciatic nerve.

MATERIAL AND METHODS

Animals (20 rats) were stratified into 3 groups. There was no treatment in the control group; in the second -group experimental animals underwent 3-5 min daily rhythmic magnetic stimulation (0,8-1T, 3 Hz) The third group of animals received intramuscular 0,035 mg of ipidacrin daily within 1 month.

RESULTS AND CONCLUSIONS

Based on the received data on the restoration of myelin, axons, myelin nodes structure and lemmocyte ultrastructure), we have concluded that both magnetic stimulation and ipidacrin can trigger restorative and compensative processes in traumatic neuropathies.

[Application of direct long-standing electrostimulation in consequences of the sciatic nerve injury]

The results of surgical treatment of 57 patients, suffering consequences of the sciatic nerve injury, using the system for long-lasting electrostimulation "Naysi 3M", were presented. The domestically manufactured system is individual and gives possibility to conduct the direct electrostimulation procedures in the home conditions, several times a day, for a long time. Positive results, consisting of the various degree enhancement of the lower extremities movements volume and strength, the sensitivity restoration and the pain severity reduction or disappearance, were achieved in 46 (81%) patients. In inefficacy of conservative treatment and presence of indications for the operation in patients with sciatic nerve injury the long-lasting electrostimulation secures restoration of the lower extremities lost functions, the pain syndrome and the vegetative-trophic disorders regress.

Poly (dextrogyr-levogyr) lactide acid-triiodothyronine scaffold for peripheral nerve regeneration

OBJECTIVES

To evaluate the poly(dextrogyr-levogyr) lactide acid-triiodothyronine (PDLLA-T3) seeded with Schwann cells conduit for repairing sciatic nerve defect.

MATERIALS & METHODS

The rats were divided into three groups: autologous nerve transplantation (Group A), PDLLA-T3 + Schwann cells (Group B) and PDLLA + Schwann cells (Group C).

RESULTS

Myelin sheath thickness was significantly greater in Group A compared with Group B and Group C. The regenerated nerves had nearly normal structure in Group A, and in Groups B and C nerve tissues filled in the anastomotic site and angiogenesis was noted. The mean number of myelinated nerve fibers and neurons in Group B was greater than in Group C.

CONCLUSIONS

PDLLA-T3 is superior to PDLLA alone for repairing nerve defects.

c-Jun reprograms Schwann cells of injured nerves to generate a repair cell essential for regeneration

The radical response of peripheral nerves to injury (Wallerian degeneration) is the cornerstone of nerve repair. We show that activation of the transcription factor c-Jun in Schwann cells is a global regulator of Wallerian degeneration. c-Jun governs major aspects of the injury response, determines the expression of trophic factors, adhesion molecules, the formation of regeneration tracks and myelin clearance and controls the distinctive regenerative potential of peripheral nerves. A key function of c-Jun is the activation of a repair program in Schwann cells and the creation of a cell specialized to support regeneration. We show that absence of c-Jun results in the formation of a dysfunctional repair cell, striking failure of functional recovery, and neuronal death. We conclude that a single glial transcription factor is essential for restoration of damaged nerves, acting to control the transdifferentiation of myelin and Remak Schwann cells to dedicated repair cells in damaged tissue.

Morphological Studies on Crushed Sciatic Nerve of Rabbits with Electroacupuncture or Diclofenac Sodium Treatment

Sciatic nerves of 15 rabbits were crushed by Halsted straight mosquito hemostat with 8-11 Newton force for 60 seconds on a point 5 mm above the knee joint, and then the rabbits were equally divided into three groups. The acupuncture group was treated by electroacupuncture on Huan Tiao and Wei Zhong points (25 minutes/day) for 7 days. The medicine group was treated with intramuscular administration of dicofenac sodium (15 mg) daily for 7 days. The control group was not treated. After treatment, the distal parts of crushed nerve were examined under light microscope, the densities of normal myelinated fibers in 0.126 mm2were counted, and the diameters of 20 normal myelinated fibers were measured for each animal. The results showed that the mean densities were 176.2 ± 5.953 in the acupuncture group, 118.2 ± 10.878 in the medicine group and 101.4 ± 8.548 in the control group. The mean values were significantly different between the acupuncture and medicine groups ( p < 0.01) and highly significant difference between the acupuncture and control groups ( p < 0.001); but there was no significant difference between the medicine and control groups ( p > 0.05). There are more small myelinated fibers (0–9 μm) in the acupuncture group than in the medicine and control groups ( p = 0.0028). The results revealed and confirmed that acupuncture promotes nerve regeneration; diclofenac sodium did not show such an effect. The present study demonstrates the positive effect of acupuncture on regeneration of a crushed sciatic nerve in the rabbits. And acupuncture is a better treatment for regeneration of crushed nerve than diclofenac sodium.

[Comparative experimental study on treatment of rat's injured sciatic nerve with electroacupuncture and Buyang Huanwu Decoction]

OBJECTIVE

To study the effect of the electroacupuncture and Buyang Huanwu Decoction (BYHWD) on the regeneration of the rat's injured sciatic nerve.

METHODS

Rat's sciatic nerve injury model was made by operation. The rats were treated with electroacupuncture or BYHWD and their nerve electro-physiological indices and histological changes tested by HRP were observed.

RESULTS

It was demonstrated that the recovery ratios of nerve conduction velocity and muscle evoked action potential of the group treated with electroacupuncture and the group treated with BYHWD were higher than those of the group treated with western medicine or the group without treatment. The differences were significant. The labeling cells in anterior horn of spinal marrow and spinal ganglion of the group treated with electroacupuncture and the group treated with BYHWD were more abundant than those of the group treated with western medicine or the group without treatment. The differences were significant. The effect of electroacupuncture was better than that of the BYHWD.

CONCLUSION

It suggests that both electroacupuncture therapy and BYHWD can promote the recovery of the function in early stage of injured nerve, and they are effective methods for promoting the regeneration of injured peripheral nerve.

[Morphometric evaluation of the effectiveness of post-traumatic peripheral nerve regeneration after a single and repeated courses of electrostimulation]

Sciatic nerve (SN) transection and microsurgical suture were performed in 41 dogs to assess the effect of electrostimulation (ES) on peripheral nerve regeneration. 23 dogs served as a control group, ES of the spinal cord and SN was made with alternating current of 50-Hz frequency in 18 dogs: in 13 dogs one course of 18 sessions was performed within the period of 1-2.5 months after surgery (ESL1), in 5 dogs two courses were performed: the first one--in a similar time interval, the second one--within 6-7.5 months after surgery (ES2). The mean diameter of myelinated fibers (MF) after 2.5, 4, 6, and 12 postoperational months for ES1 was significantly greater than the control values, mainly due to the increase of axonal diameter. After 12 months, the tendency towards the restoration of MF diameter bimodal distribution was marked in ES2, and, to a lesser degree, in ES1. Thus, it was found that ES effectively activates the regeneration and differentiation of MF, but leads to their relative hypomyelination.

Effects of combining electrical stimulation with BDNF gene transfer on the regeneration of crushed rat sciatic nerve

BACKGROUND AND AIMS

Various techniques have been investigated to enhance peripheral nerve regeneration including the application of low-intensity electrical stimulation (ES) and the administration of growth factors, especially brain-derived neurotrophic factor (BDNF). The purpose of this study was to investigate the effects of combining short-term (ES) and recombinant adenoviral vector-mediated BDNF (BDNF-Ad) transfer, in comparison to each sole modality, on peripheral nerve regeneration in a rat model with crush-injured sciatic nerve.

METHODS

Sixty male Sprague-Dawley rats (250-300 g) were equally distributed into four groups; the control group, the ES group, the BDNF-Ad group, and the combination group (n = 15 each). A standard crush injury was introduced to the sciatic nerve. The control group received no treatment after injury, the ES group received 30 minutes of low-intensity ES, the BDNF-Ad group received an injection of recombinant BDNF-Ad (concentration = 10(11) pfu/μl, 3 μl/rat) after injury, and the combination group received both ES and BDNF-Ad. The rats were followed-up for 3 weeks.

RESULTS

At the end of the follow-up period, the sciatic function index (ES =-39, BDNF-Ad =-38) and number of the retrogradely labeled sensory neurons were significantly increased in the ES group and the BDNF-Ad group (ES = 326, BDNF-Ad = 264), but not in the combined treatment group, compared to the control group (SFI = -53, retrogradely labeled neurons = 229). Axonal counts were highest in the ES group (7,208 axons), axonal densities in the BDNF group (10,598 axons/mm(2)), and the myelin thickness was greater in both groups as compared to the control group. The combined treatment group showed no signs of superior recovery compared to the other groups.

CONCLUSIONS

Both the ES and the BDNF-Ad treatments were effective techniques enhancing the sciatic nerve regeneration following a crush injury in rats. Nevertheless, the combined treatment with ES and BDNF-Ad produces neither a synergistic effect nor an improvement in this injury model.

[Experimental study on regeneration of sciatic nerve injury with physical therapy]

OBJECTIVE

Peripheral nerve injury is a common clinical disease, to study the effects of the physical therapy on the regeneration of the injured sciatic nerve, and provide a reference for clinical treatment.

METHODS

Sixty-four female adult Wistar rats (weighing 252-365 g) were chosen and randomly divided into 4 groups (n = 16): group A, group B, group C, and group D. The experimental model of sciatic nerve defect was established by crushing the right sciatic nerve in groups B, C, and D; group A served as the control group without crushing. At 2 days after injury, no treatment was given in group B, electrical stimulation in group C, and combined physical therapies (decimeter and infrared ray) in group D. At 0, 7, 14, and 30 days after treatment, the sciatic nerve function index (SFI) and the motor nerve conduction velocity (MNCV) were measured, and morphological and transmission electron microscopy (TEM) examinations were done; at 30 days after treatment, the morphological evaluation analysis of axons was performed.

RESULTS

At 0 and 7 days after treatment, the SFI values of groups B, C, and D were significantly higher than that of group A (P < 0.05); at 14 and 30 days after treatment, the SFI value of group D decreased significantly, no significant difference was observed between group D and group A (P > 0.05) at 30 days; whereas the SFI values of groups B and C decreased, showing significant difference when compared with the value of group A (P < 0.05). At 0, 7, and 14 days after treatment, the MNCV values of groups B, C, and D were significantly lower than that of group A (P < 0.05), and there were significantly differences between group B and groups C, D (P < 0.05); at 14 days, the MNCV value of group D was significantly higher than that of group C (P < 0.05); and at 30 days, the MNCV values of groups B and C were significantly lower than that of group A (P < 0.05), but there was no significant difference between group D and group A (P > 0.05). At 0 and 7 days, only collagen and lipid were observed by TEM; at 14 and 30 days, many Schwann cells and perineurial cells in regeneration axon were observed in groups B, C, and D, especially in group D. Automated image analysis of axons showed that there was no significant difference in the number of myelinated nerve fibers, axon diameter, and myelin sheath thickness between group D and group A (P > 0.05), and the number of myelinated nerve fibers and axon diameter of group D were significantly higher than those of groups B and C (P < 0.05).

CONCLUSION

Physical therapy can improve the regeneration of the injured sciatic nerve of rats.

A treatment option for post-injection sciatic neuropathy: transsacral block with methylprednisolone

BACKGROUND

Accidental intraneural injection induced nerve injury is an iatrogenic tragedy and intramuscular injection (IM) is the most common injury mechanism affecting the sciatic nerve. The most frequent presentation of sciatic nerve injury includes radicular pain and paresthesia with almost immediate onset of variable motor and sensory deficit.

OBJECTIVES

Intraneural injection is a common injury mechanism of the sciatic nerve and generates neuropathic pain with inflammatory neuritis. Steroids inhibit the production of inflammatory mediators and reduce ectopic discharges on damaged neural membranes. The results of transsacral steroid injection on neuropathic pain in 5 patients with accidental sciatic nerve injury due to intraneural injection were presented in this report.

DESIGN

Report of 5 cases.

DESCRIPTION OF CASES

Five patients, 32, 34, 45, 54 and 70 years old respectively, complaining of severe neuropathic pain, paresthesia and progressive weakness of the lower extremity with difficulty in walking secondary to gluteal injection were admitted to the clinic. The symptoms were resistant to drug therapies. Electromyography disclosed axonal damage of the sciatic nerve. The initial examination of the patients revealed a Numeric Rating Scale (NRS) of 10, 10, 9, 9, and 10 respectively.

RESULTS

Diagnostic block was performed through the unilateral S1-S2-S3 sacral foramina with 22-G spinal needle by 5 mL 1% lidocaine into each foramen. NRS scores decreased to 1, 2, 2, 2 and 1, respectively. One week later, the patients were administered 80 mg methylprednisolone with 1% lidocaine in 15 mL solution shared equally in each foramen. The patients were checked one month after therapeutic block and a full recovery was achieved in all patients.

CONCLUSION

The neuropathic pain due to accidental intraneural injection of the sciatic nerve would be an acceptable indication for transsacral nerve block with corticosteroids in the treatment of sciatic neuropathic pain symptoms.

Upgraded nerve growth factor expression induced by low-intensity continuous-wave ultrasound accelerates regeneration of neurotometicly injured sciatic nerve in rats

Low-intensity ultrasound (LIU) can stimulate injured nerve regeneration but the mechanism is still unclear. We investigated the stimulating effect and its mechanism of continuous-wave LIU on neurotometic injury of sciatic nerve. The right sciatic nerves of 64 adult Wistar rats were first crushed and then exposed (32 rats) or sham-exposed (32 rats) to LIU at the crush site. The LIU had a spatial averaged and temporal averaged intensity of 0.25 W/cm(2) operated at 1.0 MHz for 1 min every other day. At various stages (the second, fourth, sixth and eighth weeks) after LIU exposure, the sciatic nerve function index (SFI), the sensory nerve conduction velocity (SNCV), the expression of nerve growth factor (NGF) and sample histology were studied. It was found that the density of nerve fibers with myelin sheath, SFI, SNCV and NGF expression of the treatment group were higher than that of control group (p < 0.05). It has been determined that LIU treatment can accelerate the regeneration and functional recovery of neurotometic injured sciatic nerve at earlier stages after injury, the upgraded expression of NGF induced by LIU may be the primary mechanism of the acceleration effects.

Thirty minutes of low intensity electrical stimulation promotes nerve regeneration after sciatic nerve crush injury in a rat model

We investigated whether electrical stimulation (ES) applied directly for 30 minutes after crushing injury to the sciatic nerves of rats could improve nerve regeneration. Two groups of animals were used in this study (n = 20 each): the ES group received 30 minutes of low intensity ES (20 Hz pulse rate, 2 uA amplitude) immediately after a standard crush injury, while the control group received no stimulation after injury. Both groups were followed up for three weeks. The sciatic function index (SFI) was calculated weekly. Mean conduction velocity (MCV) and peak voltage (PV) were calculated, and the sensory neurons in L4 and L5 dorsal root ganglia (DRG) were traced with Fluorogold in retrograde fashion and quantified at the end of the follow up period. Histomorphometric studies were also carried out in both groups. The ES group showed improved functional and sensory recovery compared to the control group three weeks after injury. SFI, MCV and the number of retrogradely labeled sensory neurons were significantly higher in the ES group. Additionally, axon counts, myelin thicknesses and G-ratio values were also higher in the ES group. Quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) showed an elevated expression of brain derived neurotrophic factor (BDNF) in DRG sensory neurons of the ES group five days post-injury. Here, we present the first evidence that the application of ES for 30 minutes immediately following crush injury is effective to promote nerve regeneration in a rat sciatic nerve model.

Optimizing the diameter of holes for flexible regeneration microelectrode

In this study, we suggest a new guideline for regeneration microelectrode to be implanted between the severed stumps of peripheral nerves, the microelectrode designed particularly for connecting the signal line of an artificial hand directly to the nerve system. The nerve regeneration microelectrode is an interface device expected to realize a BMI (brain-machine interface).

Hyperbaric oxygen treatment decreases pain in two nerve injury models

Hyperbaric oxygen (HBO) treatment has been used clinically to treat a variety of ailments, including severe burns and carbon monoxide poisoning, and in research settings has produced promising results when used to treat animal models of inflammatory pain. However, studies examining neuropathic pain or nerve injury models have been limited to physiological assessments and not whether the pain condition improves. The purpose of this study was to evaluate the effect of HBO on two common models of neuropathic pain, L5 ligation and chronic constriction injury (CCI) of the sciatic nerve. Following surgical manipulations, animals demonstrating mechanical hyperalgesia were randomly assigned to either HBO treatment or control for 90min treatment sessions, after which mechanical sensitivity was assessed at 15min and 6h post. Daily HBO sessions, with assessments 15min post-treatment, continued for two weeks, followed by 5 days of assessment only. The results indicated that both models demonstrated significant improvement in response to treatment over the course of the two-week period, with CCI animals recovering more quickly and maintaining this recovery throughout the post-treatment period. Hyperbaric oxygen treatment appears to be successful in relieving neuropathic pain for an extended period of time, and future research should be aimed at investigating the precise mechanisms underlying this positive effect.

[Effect of adenovirus expressing NGF on sciatic nerve injury in rats]

OBJECTIVE

To construct adenovirus expressing NGF (Ad-NGF) and to investigate its promotive effect on the reparation and regeneration of sciatic nerve injury in rats.

METHODS

NGF gene sequence was cloned into shuttle plasmid pCA13 of adenovirus type 5. After packed in HEK-293 cells, the recombinant adenoviruses-Ad-NGF underwent sequence identification. Thirty-two male SD rats weighing 180-200 g were randomly divided into 4 groups (n = 8 rats per group). Sciatic nerve injury model was established by disconnecting and direct suturing the right sciatic nerve in the rat. The right gastrocnemius muscle of group A and C received Ad-NGF injection and adenovirus vector without NGF gene sequence injection, respectively, and 1 x 10(8) PFU/per time was given every other day for three times. Group B and D received NGF injection (200 U/d) and normal saline (100 microL/d), respectively, for 3 weeks. The effect of various treatments on injured sciatic nerve was evaluated by performing sciatic nerve function index and nerve electrophysiology detections 31 days after operation. Meanwhile, the sciatic nerve in the anastomosis and at the site 1 cm distal to the anastomosis were obtained, and underwent RT-PCR and Western blot analysis for detecting NGF mRNA and protein expression level in the injured sciatic nerve in the rats. Histology, immunohistochemistry, and transmission electron microscope observations were conducted.

RESULTS

Ad-NGF carrying NGF gene sequence was constructed successfully and confirmed by sequence analysis. The sciatic nerve function index, nerve conduction velocity, evoked potential amplitude, and latent period of group A was better than those of other groups (P < 0.05), and there were no significant differences among group B, C, and D (P > 0.05). RT-PCR and Western blot detection: the expression levels of NGF mRNA and protein in group A were greater than those of group B, C, and D (P < 0.05), and no significant differences were noted among group B, C, and D (P > 0.05). Histology and immunohistochemistry observation showed that the regeneration of the sciatic nerve in group A was obvious superior to that of other groups. Transmission electron microscopy observation suggested there was significant difference between group A and groups B, C, and D in terms of axonal diameter of sciatic nerve cross-section, myelin sheath thickness and nerve fiber number (P < 0.05), and there were no significant differences among group B, C, and D (P > 0.05).

CONCLUSION

Ad-NGF can effectively promote the repair of sciatic nerve injury in rats, and is a new method for obtaining large amounts of NGF in the area of injured peripheral nerve.

[Positional damage of the sciatic nerve during neurosurgical intervention into the posterior cranial fossa in the sitting position]

The paper describes a rare case of severe, but reversible bilateral damage to the sciatic nerve (compression neuropathy) in a patient with Blumenbach's clivus meningioma developing during 12-hour operation removing the tumor in the patient's sitting position on the operating table. The etiology and prevention of this complication are discussed.

Acute flaccid paralysis: a five-year review of cases managed by physiotherapy at the University College Hospital, Ibadan

A 5-year (1999-2004) review of acute flaccid paralysis (AFP) cases managed at the physiotherapy clinic of the University College Hospital, Ibadan Nigeria was carried out. Collection of data involved retrieving the records of all patients seen at the physiotherapy clinic during the study period, from which the paediatric cases were sorted out. The treatment records cards of patients with acute flaccid paralysis were identified and reviewed. Information on age, gender, immunization history, and specific physician diagnosis and discharge practice were collated. A total of 757 paediatric cases reviewed out of which 132 (17.4 %) were AFP case, with mean age of 44.31+ 33.03 months and a 1.2:1.0 male: female ratio. Sciatic nerve palsy accounted for majority (72.0 %) of the AFP; only 43.2 % of the patients had completed immunization before the onset; majority of the cases (78.8 %) were referred to physiotherapy within 6 months of onset and the discharge pattern revealed that only 9.8 % of the patients were formally discharged. With injection palsy accounting for majority of the AFP cases, the need for caution in administration of intramuscular injections at the buttocks of children with febrile illnesses is suggested. Importance of adequate documentation of clinical information by clinicians is also emphasised.

A three year review of sciatic nerve injection palsy in the Physiotherapy Department of a Nigerian Specialist Hospital

Sciatic Nerve palsy associated with intramuscular injection is a major cause of disability among children under 6-years-old in the developing Countries. A retrospective study was conducted with an objective to review cases of all patients with Injection induced sciatic nerve palsy managed at the Physiotherapy Department, State Specialist Hospital, Akure Ondo State over a period of 3 years (January 2004 and December 2006). The case notes of these patients were reviewed and the details of the patients' sex, age and presentations were obtained. Records of 160 patients presenting with Sciatic Nerve Injection Palsy were studied. Males accounted for 60% while 40% were females. They were aged from 3 months to 70 years with paediatric cases accounting for 90% of cases. All of the patients had intramuscular injections following febrile illness. Muscle paralysis with foot drop accounted for 41% cases while 59% had varying degrees of muscle paresis, without foot drop, and 4% had equinovarus deformity as a complication of the paralytic foot drop. Sciatic Nerve Injection Palsy especially in children is a common referral to the Physiotherapy Clinic. There is therefore need for caution in the administration of gluteal intramuscular injections particularly in children.

Immediate electrical stimulation enhances regeneration and reinnervation and modulates spinal plastic changes after sciatic nerve injury and repair

We have studied whether electrical stimulation immediately after nerve injury may enhance axonal regeneration and modulate plastic changes at the spinal cord level underlying the appearance of hyperreflexia. Two groups of adult rats were subjected to sciatic nerve section followed by suture repair. One group (ES) received electrical stimulation (3 V, 0.1 ms at 20 Hz) for 1 h after injury. A second group served as control (C). Nerve conduction, H reflex, motor evoked potentials, and algesimetry tests were performed at 1, 3, 5, 7 and 9 weeks after surgery, to assess muscle reinnervation and changes in excitability of spinal cord circuitry. The electrophysiological results showed higher levels of reinnervation, and histological results a significantly higher number of regenerated myelinated fibers in the distal tibial nerve in group ES in comparison with group C. The monosynaptic H reflex was facilitated in the injured limb, to a higher degree in group C than in group ES. The amplitudes of motor evoked potentials were similar in both groups, although the MEP/M ratio was increased in group C compared to group ES, indicating mild central motor hyperexcitability. Immunohistochemical labeling of sensory afferents in the spinal cord dorsal horn showed prevention of the reduction in expression of substance P at one month postlesion in group ES. In conclusion, brief electrical stimulation applied after sciatic nerve injury promotes axonal regeneration over a long distance and reduces facilitation of spinal motor responses.

Infiltrations, blocs et neurolyses en pathologie ostéo-articulaire

Computed Tomography fluoroscopy for blocks and neurolysis provides a minimally-invasive, accurate and rapid alternative to surgery. Spinal and peri-spinal ultrasound-guided procedures, excluding peripheral procedures, will be discussed as well. The imaging-guided procedures discussed are performed using small needles. These percutaneous procedures must be performed with maximum patient comfort and cause as little complications as possible. These procedures should be performed by an experienced radiologist after discussion with the treating clinician.

Clinical and Histopathologic Study of the Use of Gangliosides for Nerve Regeneration in Rats After Axonotmesis

PURPOSE

This study involved a clinical and histopathologic evaluation of the use of gangliosides in nerve regeneration, using an experimental model with higher vertebrates.

MATERIALS AND METHODS

Forty Sprague Dawley rats had their right sciatic nerve crushed for 1 minute in a hemostatic tweezer. The animals were divided into experimental and control groups. The animals in the experimental group received an intramuscular injection of gangliosides in the left thigh for 25 days, whereas those in the control group received infiltrations of distilled water. A clinical evaluation of gait was made 24 hours and then 45 days after the surgical intervention, and a histopathologic evaluation of the sciatic nerves was performed after 45 days.

RESULTS

There were no signs that the use of gangliosides significantly altered the animals' gait after 45 days. The animals in the experimental group had a greater frequency and intensity of inflammatory response than seen in the control group.

CONCLUSION

The systemic use of gangliosides produced no improvement in gait and led to a more frequent and intense inflammatory response at the site of injury.

[Study on therapy of experimental autoimmune neuritis by bone marrow stromal cells]

AIM

To investigate the therapeutic effect of bone marrow stromal cells (BMSCs) transplantation on experimental autoimmune neuritis (EAN) and study the possible mechanism.

METHODS

EAN model was established by immunizing Lewis rats with P(0)180-199 peptide and complete Freund's adjuvant (CFA). In the therapy group, BMSCs (2x10(6) cells/rat) were marked with fluorochrome PKH26 and injected into the rats' caudal vein 10 d after immunization. The therapeutic effect of BMSC transplantation on EAN rats was investigated by clinical assessment, immunohistochemical staining, and ELISA, respectively.

RESULTS

The injected BMSCs could migrate to the demyelinated nerve tissues, and the demyelination and inflammatory infiltration was relieved. The infiltration of CD4(+) and CD8(+) T cells and the sera level of IFN-gamma and TNF-alpha were decreased significantly (P<0.05), whereas IL-4 level in the supernatant of cultured lymphocytes was increased (P<0.05).

CONCLUSION

Certain therapeutic effect of BMSC transplantation on EAN was observed. BMSCs could reverse the disbalance of Th1/Th2 cells by regulating the cytokine expression and could inhibit the activation and proliferation of T cells.

Selective migration and engraftment of bone marrow mesenchymal stem cells in rat lumbar dorsal root ganglia after sciatic nerve constriction

Bone marrow mesenchymal stem cells (MSCs) preferentially migrate to the injured hemisphere when administered intravenously to rats with traumatic or ischemic brain injuries. In this study, we have investigated the localization of MSCs injected into the lumbar-4 dorsal root ganglion (L4-DRG) of rats with a sciatic nerve single ligature nerve constriction (SLNC). MSCs were isolated by their adherence to plastic, cultured until confluence and labelled with Hoechst. Animals with a unilateral injection of MSCs were subjected to an ipsilateral, bilateral or contralateral SLNC. After 9 days, they were perfused and the lumbar DRGs were dissected out, cut in a cryostat and observed with a fluorescence microscope. Large numbers of Hoechst-positive cells were observed in the injected L4-DRG, distributed around primary afferent neurons, resembling the anatomical localization of glial cells. In animals with an ipsilateral SLNC, some cells were detected in the ipsilateral L3, L5 or L6-DRGs but not in the contralateral ganglia. In animals with a bilateral lesion, MSCs migrated to both the ipsilateral and contralateral DRGs whereas in animals with a contralateral ligature, MSCs migrated to the contralateral DRGs. These results suggest that MSCs preferentially engraft in DRGs hosting primary sensory neurons affected by a lesion of their peripheral branches. Further studies should be carried out in order to elucidate the molecular mechanisms involved in this migration and homing, in order to evaluate the possible use of MSCs as a new therapeutic strategy for the treatment of peripheral nerve neuropathies.