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PubMed2005

Prognostic factors for the surgical management of peripheral nerve lesions.

Although the evaluation and treatment of patients with peripheral nerve injuries has evolved and improved over the years, there are still some arguments on the methods and results of surgery. We reviewed retrospectively the clinical, electrophysiological and surgical characteristics of peripheral nerve lesions for 1,636 nerves in 1,565 patients who had been managed in our department in a 10-year period. The most common cause of injuries was gunshot wound in 56.3% of all patients, followed by sharp lacerations (20.6%), fractures (10.6%) and tractions (5.1%). Among 1,636 cases of nerve injuries, the most frequently wounded nerve was median nerve (32.3%), followed by ulnar (24.1%), radial (12.1%), sciatic (10.7%) and peroneal nerves (7.7%), and brachial plexus (7.7%). Simple decompression was the most preferred technique for nerve repair in 27.8%. The electrophysiological improvement was observed in 66.8%, as assessed by electromyography. Clinical improvement was found in 58.4%, as judged by muscle strength grading. If the nerve is compressed or contused, but remains intact, the improvement is satisfactory after surgery. The type of injury, its time of occurrence, initial deficit, and degree of recovery expected are important issues in establishing the treatment plan, which may range from skilled observation to extensive surgical intervention.

Adolescent↗
PubMed1976

Peripheral nerve abnormalities related to galactose administration in rats.

Electrophysiological, biochemical, and morphometric observations were made on the peripheral nerves of rats after galactose feeding. Motor nerve conduction velocity was found to be reduced. This was associated with an accumulation of galactitol in the peripheral nerves and a diminution in their myoinositol content. An increased water content and fascicular area, taken in conjunction with a probable increase in the area of the endoneurial spaces, indicated overhydration of the peripheral nerves. Morphometric observations on the myelinated fibre population in the tibial nerve showed no loss of fibres and although both the maximal and the average diameter of the myelinated fibres was slightly less than in age-matched controls, this was insufficient to explain the reduction in conduction velocity. Segmental demyelination was not detected and the relationship between myelin thickness and axon circumference was not altered. Electron microscope observations revealed no ultrastructural changes in the myelinated fibres and, in particular, no abnormalities at the nodes of Ranvier or indication of abnormal hydration of the Schwann cells. The relevance of these findings to the peripheral nerve changes in human and experimental diabetes is discussed.

Animals↗
PubMed1976

Protein metabolism in transected peripheral nerves of the crayfish.

The significance of the protein metabolism in crayfish peripheral nerve was studied in relation the ability of crayfish motor axons to survive for over 200 days following axotomy. In contrast to frog peripheral nerves, the crayfish nerves appear to more closely resemble ganglia in their profiles of synthesis expressed on sodium dodecyl sulfate (SDS) gels, and have higher incorporation rates of [3H]leucine into protein than ganglia. Since anisomycin inhibits over 95% of protein synthesis in crayfish peripheral nerve, it was concluded that this local protein synthesis was dependent upon a eukaryotic ribosomal mechanism. Radioautography of isolated nerves reveals newly synthesized proteins in glial sheaths, and also within the axoplasm of large motor fibers. Based upon the data available at present, a hypothesis that the glia surrounding the axons are responsible for the local protein synthesis, and that some of these newly synthesized proteins are transported into the axon, is presented. Transection of crayfish peripheral nerves proximal to the neuron cell bodies produced a more than two-fold increase in [3H]leucine incorporation, but no significant changes in labeling profiles of the proteins on SDS gels. The data suggest that while an active local protein synthesis may be necessary for the maintenance of several crayfish motor axons, it is not a sufficient condition.

Animals↗
PubMed2001

Functional evaluation of peripheral nerve regeneration in the rat: walking track analysis.

The experimental model of choice for many peripheral nerve investigators is the rat. Walking track analysis is a useful tool in the evaluation of functional peripheral nerve recovery in the rat. This quantitative method of analyzing hind limbs performance by examining footprints, known as the sciatic function index (SFI), has been widely used to quantify functional recovery from sciatic nerve injury in a number of different injury models, although some limitations of the SFI has been questioned by several authors. This article is designed to offer the peripheral nerve investigator a noninvasive method to evaluate quantitatively the integrated motor recovery in experimental studies.

Animals↗
PubMed1976

Microdissection of peripheral nerve: collagen and lipid distribution with morphological correlation.

Peripheral nerve is a complex tissue composed of endoneurial fascicles surrounded by perineurium and epineurium. We separated endoneurium from peri- and epineurium in human sural nerves by "endoneurial plucking", a method of microdissection. Endoneurial contents (axons, myelin sheaths, Schwann cells, vessels, and interstitial collagen) were cleanly separated in high yield from enveloping connective tissue, by both microscopic and biochemical criteria. Most of the nerve sulfatide and unesterified sterol was found in the endoneurial fraction while most of the collagen was in the peri-epineurial fraction. This microdissection method should prove useful in biochemical investigations of peripheral nerve.

Adult↗
PubMed1998

Heterogeneity of macrophage and T cell subpopulations in peripheral nerves from HIV infected individuals: A preliminary study.

GOAL: To determine the heterogeneity of surface marker expression of macrophages in peripheral nerve of patients who died with AIDS. BACKGROUND: Peripheral neuropathy occurs in 20%-40% of AIDS patients. There is evidence that activated macrophages may be involved in the neural damage associated with HIV-1 infection. We studied the expression of macrophage surface markers CD14, CD11c, CD68, and HLA-DR and also T cell surface markers CD3, CD4, and CD8 in peripheral nerves of AIDS patients. METHODS: Three levels of peripheral nerves (sciatic, tibial, or sural) were examined from a limited number of subjects consisting of 4 HIV-seropositive and 5 HIV-seronegative individuals. Standard immunohistochemical technique utilized alkaline phosphatase conjugate and fuchsin substrate. RESULTS: Surface antigen expression was significantly (p < .0025 increased in HIV-positive tissues compared with HIV-negative controls for CD14 and CD4 in sciatic nerves, CD68 and CD4 in tibial nerves, and CD68 in sural nerves. There were trends for increased expression of HLA-DR, CD3, and CD8 in sciatic nerves, CD11c and CD14 in tibial nerves, and CD14, HLA-DR, and CD4 in sural nerves in HIV-positive tissues compared with HIV-negative controls. CONCLUSION: During the course of AIDS there may be an involvement of all three levels of peripheral nerves suggesting that HIV-related neuropathy is a multifocal process.

Antigens, CD↗
PubMed2001

Intrathoracic malignant peripheral nerve sheath tumor in von Recklinghausen's disease.

Malignant peripheral nerve sheath tumor (MPNST) is defined as any malignant tumor arising from or differentiating toward the cells of the peripheral nerve sheath. MPNST accounts for about 5-10% of all soft tissue tumors and is often associated with neurofibromatosis type I (NF-1, von Recklinghausen's disease). It is one of the malignant tumors associated with von Recklinghausen's disease. Its common site is the lower and upper extremities, trunk, head and neck. But intrathoracic manifestations are very rare. We report a case of a 40 year-old man with multiple neurofibromatosis who was presented with an intrathoracic malignant peripheral nerve sheath tumor.

Adult↗
PubMed1991

Techniques of peripheral nerve repair.

At present, the principles of microsurgical reconstruction of the peripheral nerve incorporate a clear understanding of the pathophysiology of the peripheral nerve, accurate preoperative assessment of the lesion, aggressive early treatment to avoid irreversible atrophy of the end organ, use of nontraumatic microtechniques for optimal alignment of individual fascicular bundles, introduction of a minimum amount of foreign material at the suture line, resection of the scar-producing epineurium, total avoidance of tension at the suture line, and placement of the nerve repair in a well-vascularized soft tissue bed. If tension is eliminated, a minimal amount of suture material is required to repair the nerve ends, because the bundles are maintained in anatomical alignment by a fibrin clot. We have reviewed the various nerve repair methods, stressing that with strict attention to microsurgical technique, the surgeon can hope to maximize reinnervation. Although the importance of all aspects of careful surgical technique cannot be overemphasized, we believe that it is unlikely that improved clinical results will come from further refinements in microsurgical techniques. We are not limited by a working knowledge and understanding of the details of the neurobiology and the neurochemistry of nerve regeneration.

Humans↗
PubMed1998

In vitro nerve repair--in vivo. The reconstruction of peripheral nerves by entubulation with biodegradeable glass tubes--a preliminary report.

Biodegradeable "controlled release" inorganic polymer glass tubes can be manufactured to fit the dimensions of any nerve and their rate of solubility can be adjusted to encompass the time taken for nerve regeneration. They have been used in a number of biological applications. The facial nerve was repaired in a group of five sheep by entubulation with biodegradeable glass tubes. The sheep were assessed 10 months after repair and compared with a similar sized group of normal sheep. It was found that while there was a reduction in the peak velocity of conduction in the repaired nerves and in the range of conduction velocities, the minimum conduction velocity was within normal limits. There was a diminution in all of the measured variables of nerve morphometry but in no case did this reach statistical significance. These findings are consistent with the view that regeneration of the nerves had taken place to a degree at least as effective as that seen in nerves of a similar size repaired by conventional means.

Animals↗
PubMed2000

Peripheral nerve injuries associated with anaesthesia.

Peripheral nerve injuries can occur at any time during the peri-operative period. The long-term disability that results may have serious consequences for a patient. The incidence of peri-operative nerve injuries can be reduced by anaesthetists being aware of their causes and pathophysiology. This review article aims to explain the incidence, pathophysiology and medicolegal implications of peri-operative nerve injury and provides suggestions as to how they may best be avoided.

Anesthesia↗
PubMed1996

Peripheral nerve pathology in rats with streptozotocin-induced insulinoma.

Peripheral nerve structure was systematically examined in rats with insulinoma induced by streptozotocin (STZ). Normal Wistar rats, aged 3 months (n = 10), were treated with intravenous injections of STZ (20 mg/kg) and housed in plastic cages with free access to water and chow until 24 months of age. Three rats with insulinoma survived and were examined pathologically. Age-matched normal Wistar rats (n = 6) were used for comparison. The insulinoma-bearing rats showed a marked increase in body weight and decrease in blood glucose. In a teased nerve fiber study of the sciatic nerve, the percentage of abnormal fibers undergoing axonal degeneration and de- and remyelination in age-matched normal control rats was 3.9 +/- 2.5% (means +/- SD), whereas in the three insulinoma-bearing rats 49%, 50%, and 24%, respectively, of the fibers showed such changes. Regenerating fibers were also numerous in each insulinoma-bearing rat (36%, 42% and 27%, respectively). Morphometric analysis revealed smaller mean myelinated fiber and axonal areas in all the nerves examined (sciatic, tibial and sural) in insulinoma-bearing rats as compared to those in age-matched normal rats. Fiber area frequency histograms showed a decrease in large myelinated fibers and an increase in small regenerated fibers in insulinoma-bearing rats. Ultrastructurally, endoneurial microvessels exhibited a narrowed vascular lumen with swollen endothelial cells and vacuolar degeneration of pericytes, suggesting an involvement of vascular changes in the neuropathic development. The present study demonstrated marked structural changes in both motor and sensory peripheral nerves of rats bearing experimentally induced insulinoma. We consider that axonal degeneration, regeneration and demyelination constitute the main pathology in the peripheral nerves of insulinoma-bearing rats, although no particular difference in severity of the lesions between sensory and motor and between proximal and distal nerves was apparent.

Animals↗
PubMed2002

Intrathecal administration of nerve growth factor delays GAP 43 expression and early phase regeneration of adult rat peripheral nerve.

Whether nerve growth factor (NGF) promotes peripheral nerve regeneration in vivo, in particular in adults, is controversial. We therefore examined the effect of exogenous NGF on nerve regeneration and the expression of GAP 43 (growth-associated protein 43) in adult rats. NGF was infused intrathecally via an osmotic mini-pump, while control rats received artificial cerebrospinal fluid. Two days after the infusion was initiated, the right sciatic nerves were transected or crushed, and the animals allowed to survive for 3 to 11 days. The right DRG, the right proximal stump of the transected sciatic nerve, and the posterior horn of the spinal cord were examined by Western blotting, immunohistochemistry, and electron microscopy. GAP 43 immunoreactivity in the NGF-treated animals was significantly lower than in the aCSF-treated controls. Electron microscopy showed that the number of myelinated and unmyelinated axons decreased significantly in the NGF-treated rats as compared with the controls. These findings are indicative that exogenous NGF delayed GAP 43 induction and the early phase of peripheral nerve regeneration and supports the hypothesis that the loss of NGF supply from peripheral targets via retrograde transport caused by axotomy serves as a signal for DRG neurons to invoke regenerative responses. NGF administered intrathecally may delay the neurons' perception of the reduction of the endogenous NGF, causing a delay in conversion of DRG neurons from the normal physiological condition to regrowth state.

Animals↗
PubMed2004

Regeneration of peripheral nerve gaps with a polyglycolic acid-collagen tube.

OBJECTIVE: The aim of this study was to report by means of objective methods on the effectiveness of a nerve reconstruction procedure using a bioresorbable tube in two patients. Our previous successes in regenerating canine peripheral nerves across long distances (80-mm gaps) using a bioabsorbable tube have led us to investigate the value of such a tube for the treatment of human patients with chronic nerve injuries. METHODS: The device was made from a cylindrically woven polyglycolic acid tube filled with a collagen sponge. It was designed to be resorbed after nerve regeneration. Peripheral sensory nerve defects in two patients with neuroma and pain were reconstructed using this tube. Patient 1 (a 62-year-old man) had a 20-mm defect of the proper digital nerve, and Patient 2 (a 56-year-old woman) had a 65-mm defect of the superficial peroneal nerve. RESULTS: After surgery, both patients recovered from the unpleasant sensations and intolerable pain. In Patient 1, functional recovery was objectively identified at 2 months, and conduction velocity of the nerve recovered to 49.1 m/s. In Patient 2, conduction velocity of the nerve was determined to be 16.9 m/s at 5 months. Current perception threshold testing indicated that sensory nerve function had been recovered by 65 days after surgery. CONCLUSION: This work represents the first precise clinical evaluation, performed under objective evaluation criteria, of sensory recovery achieved using a nerve tube, suggesting that the use of a polyglycolic acid-collagen tube has the potential to become a viable alternative to conventional autografting for the repair of peripheral nerve defects.

Action Potentials↗
PubMed1980

Peripheral nerve conduction in Fabry disease.

Peripheral nerve conduction was studied in 34 members, aged 3 to 54 years, from three separate kindreds with Fabry disease. Nerve conduction velocity was prolonged in one-third (11 of 34) of the study group. Of the 9 control family members with normal plasma alpha-galactosidase levels, 8 had normal velocity. A 6-year-old girl with normal plasma and leukocyte alpha-galactosidase levels and absent corneal deposits had slightly lower than normal nerve conduction velocity. One of the 3 obligate female carriers and 1 of 10 suspected carriers of Fabry disease had prolonged conduction velocity but normal distal latency. On the other hand, 8 of 12 males affected with Fabry disease demonstrated slow nerve conduction velocity while 4 of the 8 had prolonged distal latency. Frequently, only one of the two nerves studied showed abnormalities. These abnormalities were not related to patient age. Interfamilial variations in the abnormalities were present.

Adolescent↗
PubMed2006

Effects of antineoplastic agents on the peripheral nerves under a surgical tissue expansion procedure: an experimental study.

BACKGROUND: Elongation of peripheral nerve by the use of a tissue expander is helpful to repair nerve defects. This study was designed to investigate the effects of some antineoplastic agents on the peripheral nerves under a surgical tissue expansion procedure. MATERIALS AND METHODS: Twenty-five Wistar rats were used in this study. Following the exposition of the sciatic nerve and placement of two 10/0-nylon sutures in the epineurium 20 mm apart, a tissue expander was then placed under it. Inflation of the expander was immediately accomplished by the separate percutaneous injections of 6, 6, and 8 ml for every 3 min under general anesthesia. The expander was fully deflated at the end of each 3 min The distance between two sutures was measured 1 h later to measure the rate of elongation. Rats were randomly divided into five groups (according to the administered drugs), each consisting of five rats (10 sciatic nerves). Normal saline (1 ml) in the control group (group I), cyclophosphamide (15 mg/kg) in the group II, cisplatinum (3 microg/kg) in the group III, mitomycin-C (0.5 mg/kg) in the group IV and 5-fluorouracil (10 mg/kg) in the group V were injected intravenously. Intravenous injections of drugs were performed via the tail vein 30 min before expansion, 48 and 96 h after removal of expander. The incision was reopened on the third and seventh postoperative days, and five sciatic nerves of each group were exposed and then the pinching test was performed to measure regeneration distance. Electroneurographic changes were recorded. The expanded portion of the sciatic nerve between two sutures was harvested for histological evaluation. RESULTS: There is no significant difference between the elongation rates of all groups (P < 0.05). Histologic evaluation showed that inflammatory changes, vacuolization, intraneural edema, demyelination, axonal changes in the control group, the cisplatinum group, and the mitomycin-C group. These changes were significantly decreased in the cyclophosphamide group and the 5-fluorouracil group. In the cyclophosphamide group and the 5-fluorouracil group, the amplitude of compound action potential (CAP) values were significantly higher and the latency was significantly shorter (P > 0.05). CONCLUSION: We believed that cyclophosphamide and 5-fluorouracil may be helpful in tissue expansion of peripheral nerves, by decreasing the effects of the ischemia-reperfusion injury on the expanded peripheral nerves.

Animals↗
PubMedDate not supplied

Ischemic rest pain of the lower extremities. Treatment with peripheral nerve crush.

The authors report the results obtained from peripheral nerve crushing in the treatment of ischemic rest pain and/or trophic lesions of toes and feet. They studied retrospectively 102 patients who were submitted to peripheral nerve crushing at the "Hospital das Clínicas da Universidade de São Paulo" during a sixteen-year period, from March 1971 to April 1987. These patients had no other choice, either clinical or surgical. The results were evaluated under three aspects: elimination of pain, evolution of trophic lesions and postoperative complications. The follow-up period varied from 1 month to 6 years (mean of 18 months). The results showed immediate elimination of pain in 94% of the patients. The remaining 6% were reoperated on within 24 to 48 hours, due to technical failure in identifying some of the nerves during the first operation. Regarding the trophic lesions, in 71% of the patients the results were good and the remaining underwent amputation at leg or thigh. The worst results were obtained in patients with necrotic lesions (p < 0.05). Three patients presented surgical wound dehiscence. The authors conclude that peripheral nerve crushing constitutes a valid alternative for a select group of patients with uncontrollable ischemic rest pain in the feet.

Adult↗
PubMed2000

Peripheral nerve injury from intravenous cannulation: a case report.

The following is a case report of a patient who had an intravenous (i.v.) catheter inserted into her cephalic vein and thereafter sustained an injury to the superficial branch of the radial nerve. When an i.v. catheter penetrates a nerve, it can cause temporary or permanent damage. After sustaining an injury, a nerve will regenerate in an attempt to reconnect with the fibers it once innervated. Recovery from nerve damage may take only weeks or a year or more. Some patients, however, may sustain lifelong damage depending on the severity of the needle stick to the nerve. To avoid injury to peripheral nerves when inserting i.v. catheters, a few recommendations should be followed. First, if inserting an i.v. catheter in the cephalic vein, be conscious of the proximity of the superficial peripheral nerves. Second, if a paresthesia is elicited when inserting an i.v. catheter, withdraw the catheter immediately. Third, if a patient complains of paresthesias or numbness near the i.v. site, remove the i.v. catheter immediately. Fourth, limit the amount of probing after inserting the catheter into the skin. Finally, if nerve damage is suspected from a peripheral i.v. cannulation, consult a hand specialist promptly.

Catheterization, Peripheral↗
PubMed2006

Successful storage of peripheral nerves using University of Wisconsin solution with polyphenol.

We have previously reported that green tea polyphenol can preserve peripheral nerve segments for up to 1 month. In this study, we investigated the effect on peripheral nerve preservation of adding polyphenol to the conventional University of Wisconsin solution (UW solution), which has been widely used for organ storage. Twenty millimeter-long sciatic nerve segments, harvested from Lewis rats, were immersed in UW solution containing polyphenol (1 mg/mL) for 1 week and then in UW solution alone at 4 degrees C for 3 additional weeks before transplantation into recipient Lewis rats. Neural cell viability of the preserved nerve segments was confirmed by vital staining (calcein-AM/ethidium homodimer), electron microscopy, and genomic studies. Morphologically, nerve regeneration was similar to that of fresh isografts and superior to that of grafts stored with UW solution alone. Moreover, the electrophysiological results were equal to those of fresh isografts. Polyphenol has the potential to be used for peripheral nerve storage and could be useful for routine peripheral nerve banking.

Actins↗