Animals ; Macaca mulatta ; Nerve Regeneration ; Peripheral Nerve Injuries ; physiopathology ; Peripheral Nerves ; physiology ; Rats

Diseases and injuries to the nervous system can lead to a devastating chronic pain condition called neuropathic pain. We review changes that occur in the peripheral nervous system that may play a role in this disease. Common animal models for neuropathic pain involve an injury to one or more peripheral nerves. Following such an injury, the nerve fibers that have been injured exhibit many abnormal properties including the development of spontaneous neural activity as well as a change in the expression of certain genes in their cell body. Recent data indicate that adjacent, uninjured nerve fibers also exhibit significant changes. These changes are thought to be driven by injury-induced alterations in the milieu surrounding the uninjured nerve and nerve terminals. Thus, alteration in neural signaling in both injured and uninjured neurons play a role in the development of neuropathic pain after peripheral nerve injury.
Animals ; Disease Models, Animal ; Nerve Fibers ; pathology ; Neuralgia ; physiopathology ; Neurons, Afferent ; cytology ; Peripheral Nerve Injuries ; physiopathology

Assessment of peripheral nerve injury is a common task in forensic practice. As an objective assistance of inspection, electrophysiological examination is significant in the evaluation of peripheral nerve function after injury. There are currently several methods of electrophysiological examination, including I-T curve, EMG, NCV and SEP. Because electrophysiological examination can assess the injury and regeneration of peripheral nerve injury at different times, it is valuable to estimate prognosis of peripheral nerve injury in forensic medicine. Besides the electrophysiological examination, evaluation of the peripheral nerve injury needs to combine other clinical manifestations to provide an accurate appraisal.
Electrodiagnosis/methods* ; Electromyography/methods* ; Forensic Medicine ; Humans ; Neural Conduction/physiology* ; Peripheral Nerve Injuries ; Peripheral Nerves/physiopathology*

Neural stem cells (NSCs) and Schwann cells (SCs) both play an important role in the recovery and regeneration of peripheral nerve injury, which makes them become the focus in the field of nerve injury research. SCs provide a suitable microenvironment for the recovery and regeneration of injured peripheral nerve through secreting various cytokines and other related factors, and they can significantly promote the differentiation of NSCs into neurons. Recently with the development of microsurgical technique, using nerve conduits along with NSCs and SCs to bridge nerve stumps so as to repair peripheral nerve injury has now attracted increasing research interest. In this article, we focus on the effects and mechanisms of NSCs and SCs on peripheral nerve injury and regeneration process, and describe the future trend and potential clinical application of the technology combining both two cells and nerve conduits to repair peripheral nerve injury.
Animals ; Cells, Cultured ; Humans ; Nerve Regeneration ; Neural Stem Cells ; Peripheral Nerve Injuries ; physiopathology ; surgery ; Schwann Cells

Traumatic injury or inflammatory irritation of the peripheral nervous system often leads to persistent pathophysiological pain states. It has been well-documented that, after peripheral nerve injury or inflammation, functional and anatomical alterations sweep over the entire peripheral nervous system including the peripheral nerve endings, the injured or inflamed afferent fibers, the dorsal root ganglion (DRG), and the central afferent terminals in the spinal cord. Among all the changes, ectopic discharge or spontaneous activity of primary sensory neurons is of great clinical interest, as such discharges doubtless contribute to the development of pathological pain states such as neuropathic pain. Two key sources of abnormal spontaneous activity have been identified following peripheral nerve injury: the injured afferent fibers (neuroma) leading to the DRG, and the DRG somata. The purpose of this review is to provide a global account of the abnormal spontaneous activity in various animal models of pain. Particular attention is focused on the consequence of peripheral nerve injury and localized inflammation. Further, mechanisms involved in the generation of spontaneous activity are also reviewed; evidence of spontaneous activity in contributing to abnormal sympathetic sprouting in the axotomized DRG and to the initiation of neuropathic pain based on new findings from our research group are discussed. An improved understanding of the causes of spontaneous activity and the origins of neuropathic pain should facilitate the development of novel strategies for effective treatment of pathological pain.
Animals ; Axotomy ; Ganglia, Spinal ; cytology ; Humans ; Neuralgia ; physiopathology ; Neurons, Afferent ; cytology ; Peripheral Nerve Injuries ; physiopathology ; Spinal Cord ; cytology

Bone marrow mesenchymal stem cells (BMSCs) possess the potential of self-duplication, multi-directional differentiation, and also the ability to differentiate (in the direction of ectoderm) into neuron and neuroglial cells in vitro as well as to promote the reparation of sciatic nerve injury in vivo, especially for the reparation of the long-segment nerve. Progress in repair of sciatic nerve injury by BMSCs has been reviewed in this article.
Bone Marrow Cells ; cytology ; physiology ; Humans ; Mesenchymal Stromal Cells ; cytology ; physiology ; Nerve Regeneration ; physiology ; Peripheral Nerve Injuries ; physiopathology ; therapy ; Sciatic Nerve ; injuries ; physiology ; Stem Cell Transplantation ; methods

BACKGROUNDPeripheral nerve injury causes a high rate of disability and a huge economic burden, and is currently one of the serious health problems in the world. The use of nerve grafts plays a vital role in repairing nerve defects. Acellular nerve grafts have been widely used in many experimental models as a peripheral nerve substitute. The purpose of this study was to test the biomechanical properties of acellular nerve grafts.

METHODSThirty-four fresh sciatic nerves were obtained from 17 adult male Wistar rats (age of 3 months) and randomly assigned to 3 groups: normal control group, nerve segments underwent no treatment and were put in phosphate buffered saline (pH 7.4) and stored at 4°C until further use; physical method group, nerve segments were frozen at -196°C and then thawed at 37°C; and chemical method group, nerve segments were chemically extracted with the detergents Triton X-200, sulfobetaine-10 (SB-10) and sulfobetaine-16 (SB-16). After the acellularization process was completed, the structural changes of in the sciatic nerves in each group were observed by hematoxylin-eosin staining and field emission scanning electron microscopy, then biomechanical properties were tested using a mechanical apparatus (Endura TEC ELF 3200, Bose, Boston, USA).

RESULTSHematoxylin-eosin staining and field emission scanning electron microscopy demonstrated that the effects of acellularization, demyelination, and integrity of nerve fiber tube of the chemical method were better than that of the physical method. Biomechanical testing showed that peripheral nerve grafts treated with the chemical method resulted in some decreased biomechanical properties (ultimate load, ultimate stress, ultimate strain, and mechanical work to fracture) compared with normal control nerves, but the differences were not statistically significant (P > 0.05).

CONCLUSIONNerve treated with the chemical method may be more appropriate for use in implantation than nerve treated with the physical method.

Animals ; Biomechanical Phenomena ; Male ; Microscopy, Electron, Scanning ; Peripheral Nerve Injuries ; therapy ; Peripheral Nerves ; physiology ; ultrastructure ; Rats ; Rats, Wistar ; Sciatic Nerve ; physiopathology ; ultrastructure ; Tissue Engineering

OBJECTIVETo search for the best program for treatment of peripheral nerve incomplete injury.

METHODSNinety cases were randomly divided into a treatment group, a control group I and a control group II, 30 cases in each group. The treatment group were treated with electroacupuncture at Jianyu (LI 15), Hegu (LI 4), Quchi (LI 11), etc. plus functional training, and the control group I with electroacupuncture and the control group H with functional training. After treatment for 3 months, basic function, practical function, EMG, nerve conduction velocity were compared among the 3 groups.

RESULTSThe good rate of basic function of 50.0%, the curemarkedly effective rate of practical function of 50.0% and the total effective rate of neurophysiology of 64.3% in the treatment group were better than 20.7%, 17.2%, 41.4% in the control group I (P < 0.05) and 23.3%, 20.0% and 36.O7% in the control group II (P 0.05).

CONCLUSIONElectroacupuncture combined with functional training can accelerate nervous repair, promote functional recovery of the denervated muscles, so as to shorten the restoring time of nerve-muscle and increase life quality of the patient.

Adult ; Electroacupuncture ; methods ; Female ; Humans ; Male ; Medicine, Chinese Traditional ; Peripheral Nerve Injuries ; Peripheral Nerves ; physiopathology ; Physical Therapy Modalities ; Upper Extremity ; innervation

OBJECTIVE: To analyze and compare different methods for assessment of the limbs joints function and to discuss the rationality of the methods. METHODS: Eight hundred and six cases were collected from the Fujian Minzhong Forensic Appraisal Center from 2007 to 2010. These cases included injuries of large limbs joints with or without peripheral nerve injury. The loss of joint function was calculated according to the simple joint mobility method or the table method introduced in the book "Forensic Clinical Judicial Authentication Practice". The results of disability evaluation with different methods were analyzed and compared between different joints and injury patterns. RESULTS: In 642 cases of simple joint injuries without peripheral nerve injury, the results of disability evaluation based on simple joint mobility were the same as that based on the table. In 118 cases of joint injuries with peripheral nerve injury, all of them could be classified as disability, 33 cases (28.00%) had higher degree based on the table method than based on the simple joint mobility method. While 21 cases (17.80%) did not be evaluated as disabled based on the simple joint mobility method. CONCLUSION The evaluation for loss of limb function would be easier, more scientific and reasonable by the direct table method than the simple joint mobility method.
Accidents, Traffic ; Adult ; Arm Injuries/physiopathology* ; Disability Evaluation ; Extremities ; Female ; Forensic Medicine/methods* ; Humans ; Joints/physiopathology* ; Leg Injuries/physiopathology* ; Male ; Peripheral Nerve Injuries/physiopathology* ; Range of Motion, Articular/physiology* ; Trauma Severity Indices

OBJECTIVE: To explore the application value of needle electromyography (EMG) and nerve conduction study (NCS) in the forensic appraisal; to provide scientific basis for establishing normative and unified assessment methods of the peripheral nerve study in forensic medicine. METHODS: One hundred and sixty-four samples with injured peripheral nerve (injury group) and 138 samples with normal peripheral nerve (control group) were collected and tested with methods of EMG and NCS respectively. The relevance rate of two methods were compared and statistical analysis was performed. RESULTS: In the injury group, there was no statistical difference on the relevance rate between the application of EMG and that of NCS (P > 0.05). In the control group, there was no statistical difference on the negative rate between the two methods (P > 0.05). The false negative rate of the injury group and the false positive rate of the control group were both 0% when using the two methods together. CONCLUSION When the injured peripheral nerve in forensic appraisal is in doubt, application of both EMG and NCS could disclose truth from falsehood. The accuracy and credibility of identification results could be enhanced.
Action Potentials ; Adolescent ; Adult ; Case-Control Studies ; Electromyography/methods* ; Female ; Forensic Medicine/methods* ; Humans ; Lower Extremity/injuries* ; Male ; Middle Aged ; Muscle, Skeletal/physiopathology* ; Needles ; Neural Conduction/physiology* ; Peripheral Nerve Injuries/physiopathology* ; Trauma Severity Indices ; Upper Extremity/injuries* ; Young Adult