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At least 1,009 records · Page 56Linked to original sources
PubMed2006

Quantitation of and landmarks for the muscular branches of the ulnar nerve to the forearm for application in peripheral nerve neurotization procedures.

OBJECT: In neurotization procedures, donor nerves--either whole or in part-with relatively pure motor function can be carefully chosen to provide the optimal nearby motor input with as little donor site morbidity as possible. In this context, the ulnar nerve branches to the forearm muscles are relatively dispensable; however, quantitation of and landmarks for these branches are lacking in the literature. METHODS: The ulnar branches to the flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP) muscles in 20 upper extremities obtained in adult cadaveric specimens were dissected and quantified. In the forearm, a mean of four nerve branches led to the FCU and FDP muscles. A mean of 3.4 branches led to the FCU muscle; of these, one to three were medial branches and zero to two were lateral. Medial branches to the FCU muscle originated a mean of 2.7 cm inferior to the medial epicondyle. Lateral branches to the FCU muscle originated at a mean of 3.3 cm inferior to the medial epicondyle. The mean length of the medial branches was 3.2 cm, whereas the mean length of the lateral branches was 3.3 cm. All nerves had a single trunk for the FDP muscle, and in all specimens this branch was located deep to the main ulnar nerve trunk, originating from the ulnar nerve a mean of 2.7 cm inferior to the medial epicondyle. These branches had a mean length of 5.6 cm. The mean diameter of all medial and lateral branches to the FCU muscle was 1 mm, and the mean diameter of the branch to the FDP muscle was 2.1 mm. All branches to both the FCU and FDP muscles arose from the ulnar nerve, over its first approximately 5 cm from the level of the medial epicondyle. Additionally, all branches could be easily lengthened by gentle proximal dissection from the main ulnar nerve. CONCLUSIONS: Ulnar branches to the forearm can be easily localized and used for neurotization procedures. The branch to the FDP muscle had the greatest diameter and longest length, easily reaching the median nerve and posterior interosseous nerve via a transinterosseous membrane tunneling procedure. Furthermore, this branch could be teased away from the main ulnar nerve trunk and made to reach the distal branches of the musculocutaneous nerve in the arm.

Aged↗
PubMed1987

The distribution of serum albumin in rat peripheral nerve.

To clarify the nature of the blood-nerve barrier (BNB) in excluding serum proteins from peripheral nerve endoneurium, we studied the ultrastructural distribution of albumin in peripheral nerve using light and electron microscopic immunocytochemistry. We found that serum albumin is commonly found within the endoneurium, but that it is not normally found intraaxonally. After subperineurial injection of labeled albumin, the albumin redistributed within intrafascicular clefts towards the perivascular spaces and the perineurium. These results suggest that, contrary to previous evidence, axons are exposed to serum proteins in normal nerves, and implies that they may be subject to interaction with abnormal proteins or altered serum proteins without any disruption of the BNB.

Animals↗
PubMed1993

[Ganglia of peripheral nerves].

The authors present two different types of ganglion affecting the peripheral nerves: extraneural and intraneural ganglion. Compression of peripheral nerves by articular ganglions is well known. The surgical management involves the complete removal of the lesion with preservation of most nerve fascicles. Intraneural ganglion is an uncommon lesion which affects the nerve diffusely. The nerve fascicles are usually intimately involved between the cysts, making complete removal of all cysts impossible. There is no agreement about the best surgical management to be applied in these cases. Two possibilities are available: opening of the epineural sheath lengthwise and pressing out the lesion; or resection of the affected part of the nerve and performing a nerve reconstruction. While in case of extraneural ganglion the postoperative clinical evolution is very favourable, only long follow up studies will reveal in case of intraneural ganglion the best surgical approach.

Adolescent↗
PubMed2006

Generalized peripheral nerve failure during thoracic spine surgery: a case report.

OBJECTIVE: Intra-operative systemic changes impairing peripheral nerve function are not commonly detected with electrophysiology. This case presentation illustrates how somatosensory evoked potential (SSEP) monitoring can detect global changes in peripheral nerve excitability during spine surgery. METHODS: A posterior thoracic spine fixation was performed on a young male with multiple traumatic injuries. Bilateral tibial nerve SSEPs were intraoperatively recorded, along with the right median nerve SSEP for control. RESULTS: A rapid, progressive loss of tibial and median nerve potentials (followed by cortical SSEP loss) occurred 90 min after anaesthetic induction. Oxygenation and fluid volume were adequate throughout the case, despite mean airway resistance being elevated (33 cmH(2)0) and blood pressure being low (80/45 mmHg). Corresponding to the decrease in peripheral nerve responses was a drop in end-tidal CO(2) partial pressure (PaCO(2)) from 37 to 25 mmHg. Approximately, 100 min later, the peripheral and cortically generated SSEPs recovered in 2 of 3 limbs monitored. On emergence from anesthesia it was clear that the patient had bitten and kinked the endotracheal tube thus increasing the airway resistance. Ventilation difficulties were magnified with the patient's prone position. Post-operatively there were no sensorimotor deficits. CONCLUSIONS: Somatosensory evoked potential monitoring during spine surgery can detect uncommon generalized nerve conduction block, and further alert surgical teams to a systemic impairment. This was discovered to result from a compromised endotracheal tube. This can apply in various monitoring situations, as the changes affecting the SSEPs were not related to surgical manipulation.

Adult↗
PubMed2001

Health-related quality of life in type 1 diabetic patients and influence of peripheral nerve involvement.

We examined the relationships between diabetic peripheral nerve involvement and patients' own perception of quality of life in a multidimensional study based on outcome research recommendations. The study enrolled 50 consecutive outpatients with type 1 diabetes mellitus (23 men, 27 women; mean age, 40.1 years). The patients were evaluated with validated clinical tests (e. g. Semmes-Weinstein, vibration perception threshold, muscle strength), neurophysiological tests (sural, peroneal and ulnar nerves) and patient-oriented (SF-36 and NASS) questionnaires. Patient-oriented physical scores were significantly related with: (1) neurophysiological findings of the lower limbs; (2) conventional measurements of sensitivity. Conversely, patient-oriented mental scores were not related with these findings. The patient-oriented questionnaires provided an important perspective of the severity of the disease, often closely related with the biological parameters. They offered new interpretations to conventional biological measurements. In particular, the peripheral nerve picture was strictly related to the physical aspects of the patients' quality of life, and not with the mental aspects.

Adult↗
PubMed1980

A method of HRP bathing of transected peripheral nerves using a rubber bag.--Its technique and advantage.

The horseradish peroxidase (HRP) bathing method of transected peripheral nerves using a small rubber bag is described and its advantage for labeling neurons is evaluated. In order to apply the HRP to the peripheral nerves, a small rubber bag of appropriate size for the nerves to be bathed was made and was filled with a solution of 20% HRP. The proximal stump of the transected nerve was then inserted into the rubber bag. Nerve cell bodies, retrogradely labeled by this method, were observed to be intense. HRP diffusion to the surrounding tissues was considered negligible at the bathing region. The method presented in this paper is useful adjacent to methods previously reported for HRP application to the peripheral nerves. To illustrate this method, the results of the HRP bathing of either the chorda tympani or the intermediofacial nerve in cats were described.

Animals↗
PubMed2002

Identification of the regulatory region of the peripheral myelin protein 22 (PMP22) gene that directs temporal and spatial expression in development and regeneration of peripheral nerves.

Minor changes in PMP22 gene dosage have profound effects on the development and maintenance of peripheral nerves. This is evident from the genetic disease mechanisms in Charcot-Marie-Tooth disease type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsies (HNPP) as well as transgenic animals with altered PMP22 gene dosage. Thus, regulation of PMP22 is a crucial aspect in understanding the function of this protein in health and disease. In this study, we have generated transgenic mice containing 10 kb of the 5'-flanking region of the PMP22 gene, including the two previously identified alternative promoters, fused to a lacZ reporter gene. We show that this part of the PMP22 gene contains the necessary information to mirror the endogenous expression pattern in peripheral nerves during development and regeneration and in mouse models of demyelination due to genetic lesions. Transgene expression is strongly regulated during myelination, demyelination, and remyelination in Schwann cells, demonstrating the crucial influence of neuron-Schwann cell interactions in the regulation of PMP22. In addition, the region of the PMP22 gene present on this transgene confers also neuronal expression in sensory and motor neurons. These results provide the crucial basis for further dissection of the elements that direct the temporal and spatial regulation of the PMP22 gene and to elucidate the molecular basis of the master program regulating peripheral nerve myelination.

Animals↗
PubMed1986

Peripheral nerve injection injury: an experimental pilot study of treatment modalities.

The accidental injection of various drugs into peripheral nerves has serious medical complications and medicolegal implications. The most neurotoxic substances of II agents tested in a previous study were penicillin G, diazepam, and chlorpromazine. The appropriate management of such an injury has not been well-established. In an attempt to define the proper treatment in accidental peripheral nerve injection, an experimental study was carried out, in which 70 sciatic nerves of rats were injected intrafascicularly with penicillin G and treated by neurolysis, neurolysis and Celestone irrigation (betamethasone, a synthetic glucocorticoid), and neurolysis and saline irrigation. The degree of damage was evaluated histologically after two weeks. Statistical analysis of the results showed that neurolysis performed at 24 hours after the injury lessened the damage to the peripheral nerve. No additional improvement was found when, in addition to neurolysis, the nerves were irrigated with Celestone or saline solutions.

Animals↗
PubMed2000

Antibodies to glutamic acid decarboxylase and peripheral nerve function in type 1 diabetes.

Autoimmune mechanisms have been implicated in the pathophysiology of diabetic neuropathy. We studied the association between glutamic acid decarboxylase (GAD65) and islet cell (IA-2) autoantibodies as well as autoantibodies to the autonomic nervous system and peripheral nerve function in recent onset type 1 diabetes. Thirty-seven patients (27 females and 10 males) enrolled 2-22 months after diagnosis. Humoral factors, glycemic control, and peripheral nerve function were measured annually for 3 yr. Patients with high GAD65Ab had worse glycemic control and higher insulin requirements. Patients with high GAD65Ab had slower motor nerve conduction velocities in the median, ulnar, and peroneal nerves (P < 0.025 for each nerve). The mean motor nerve conduction velocity Z scores at the time of the third evaluation was 0.341 +/- 0.25 for the low GAD65Ab patients and -0.600 +/- 0.25 for the high GAD65Ab patients (P < 0.01). Similar differences between the low and high GAD65Ab groups were observed for F wave latencies, thermal threshold detection, and cardiovascular autonomic function. The composite peripheral nerve function Z scores in the low GAD65Ab patients were 0.62 +/- 11, 0.71 +/- 0.19, and 0.21 +/- 0.14 at the first, second, and third evaluations, significantly different from those in the high GAD65Ab patients in whom they were -0.35 +/- 0.15, -0.46 +/- 0.18, and -0.42 +/- 0.16 (P < 0.001). In summary, GAD65Ab in patients with recent onset type 1 diabetes are associated with worse glycemic control and slightly worse peripheral nerve function. Although the latter remained within normal limits and none of the patients had clinical neuropathy, the GAD65Ab-related differences in composite peripheral nerve function were highly significant (P < 0.001) and could not be attributed to GAD65Ab-related differences in glycemic control.

Adolescent↗
PubMed2003

Inhibition of the proliferation of a malignant peripheral nerve sheath tumor cell line by gamma interferon gene transfection.

A solitary malignant peripheral nerve sheath tumor was resected, and a tumor cell line was obtained using an explant culture. The morphology of this cell line was quite similar to those of cell lines of dermal neurofibromas of neurofibromatosis 1, except for the fact that the malignant peripheral nerve sheath tumor cell line could be cultured for more than two months. When the tumor cell line was transfected with human gamma interferon gene, the growth rate was remarkably abolished, as previously observed in neurofibroma cell lines transfected with the gamma interferon gene. This new finding suggests the potential for treating either solitary or neurofibroma-related, inoperable, malignant peripheral nerve sheath tumors by local gamma interferon gene transfection in vivo.

Aged↗
PubMed1980

The distal sensory nerve action potential as a diagnostic tool for the differentiation of lesions in dorsal roots and peripheral nerves.

On the basis of the conception that, in preganglionic lesions, peripheral sensory nerve fibers should remain intact, the question arises whether evaluation of distal sensory nerve action potentials can be helpful in differentiating between cervical dorsal root and peripheral nerve lesions. Amplitudes of sensory nerve action potentials (SNAP) and corresponding distal sensory conduction velocities (SCV) of the median and ulnar nerves were measured in 194 patients with distal sensory impairment and in 20 control subjects. In dorsal root lesions attributable to degenerative changes of cervical spines and/or discs, SNAP and SCV were within the normal range. In peripheral nerve lesions, located in the brachial plexus, or at the elbow or wrist, diminished SNAP amplitudes and/or slowing of SCV were found. It is concluded that in patients with sensory deficit in the hands recordings of SNAP make a differentiation between lesions of dorsal roots and peripheral nerves possible.

Action Potentials↗
PubMed2003

The peripheral nerve complications of human immunodeficiency virus (HIV) infection.

Peripheral nerve complications occurring in patients with human immunodeficiency virus (HIV) infection are frequent and challenging. This review discusses these various complications according to the degree of advancement of HIV disease. Particular emphasis is placed upon emerging causes of neuropathy found in the context of HIV disease, such as infection with hepatitis C and human T-lymphotropic virus type I, as well as neuropathies related to antiretroviral medications.

Animals↗
PubMed1997

Angiogenesis at the site of neuroma formation in transected peripheral nerve.

Investiture of new microvessels within an injured peripheral nerve trunk may determine the success that the local environment has in promoting axonal sprouting and regeneration. We therefore examined microvessel investment of 24 h-14 d proximal nerve stump preparations in rat sciatic nerves. The stumps, later destined to form neuromas, were created by sciatic nerve transection with resection of distal branches to prevent distal reinnervation. Microvessels were studied in the proximal stump in semithin whole mount sections of nerve and by analysis of India ink perfused microvessel profiles. Quantitative image analysis was made of the luminal profiles of vessels perfused with India ink from unfixed sections of the stumps, contralateral uninjured nerves and sham-exposed but uninjured nerves. Evidence of angiogenesis was observed in stumps 7 d after transection, indicated by a rise in the total numbers of perfused microvessels and in the numbers of 2-6 microns diameter perfused microvessels. There was a shift in the histogram of the percentage of perfused microvessels towards the 2-4 microns range and a reduction in the mean microvessel luminal area in the stumps. By 14 d, new microvessels were larger, indicated by an increase in total luminal area. New microvessels were prominent in the epineurial connective tissue or between layers of perineurial cells of former fascicles. Microvessels probably share a battery of trophic signals with other proliferating cellular elements in the milieu of the injured peripheral nerve trunk.

Analysis of Variance↗
PubMed1979

A spin label study of myelin fluidity with normal and pathological peripheral nerves.

The myelin fluidity in peripheral nerves from normal subjects and patients with neuropathy has been studied. Nerve biopsies were made in subjects without neuropathy and in patients with Guillain-Barré, alcoholic or diabetic polyneuropathies and heredodegenerative diseases. The fluidity was studied using a stearic acid spin label with a nitroxide radical at C12 (12-doxylstearic acid) which was introduced by exchange between spin label-charged BSA and nerve myelin. Spectra was obtained with a VARIAN E 109 ESR spectrometer, at temperatures from 5 to 45 degrees C. The ultrastructure of biopsied nerves was also studied. The electron spin resonance (ESR) spectra were all typical of a partially immobilized nitroxide with a distance between outer hyperfine lines (2T//) of about 50 G, at room temperature. The curve 2T// against temperature shows two critical temperatures: 10 and 30 degrees C for all nerves. No correlation could be established between ultrastructure and fluidity of nerves. However, the myelin of nerves from diabetic patients showed a significant increase in viscosity. This physicochemical modification may represent an initial alteration of the myelin sheath, and demands further investigation. No modification of the myelin fluidity was observed in any of the other nerves studied.

Adolescent↗
PubMed1993

Number, distribution, and morphology of retinal ganglion cells with axons regenerated into peripheral nerve graft in adult cats.

The optic nerve of adult cats was transected and an autologous peripheral nerve was transplanted to the stump. Two months later retinal ganglion cells (RGCs) that had regenerated their axons were retrogradely labeled with fluorescent dye injected into the graft. The more than 4000 labeled cells, which were 3.0-4.3% of total ganglion cell number in the intact retina, were distributed in a high-density area elongating horizontally, in a pattern similar to that observed in the intact retina. The dendritic morphology of RGCs with regenerated axons was examined after intracellular injections of HRP or Lucifer yellow in vitro. The morphology of alpha- and gamma-cells appeared comparable to normal, whereas the dendrites of some beta-cells seemed to degenerate. Some "unclassified" cells could not be identified as alpha-, beta-, or gamma-cells. The main dendrites of most unclassified cells were thin and less ramified than alpha- and beta-cells. Some unclassified cells had a vacant area in their dendritic fields, suggesting degenerative change in dendrites. The distal dendrites of some unclassified and gamma-cells had many fine processes that probably regrew during axonal regeneration. The proportion of alpha-, beta-, and other cells including gamma- and unclassified cells in the regenerating cell population was evaluated by examining all of the Lucifer yellow-injected cells in local patches. The average proportion of alpha-cells was 23.9%, about six times higher than in intact retinas. The average proportion of beta-cells was 50.3%, slightly higher than in intact retinas. The remaining cells (25.7%) could not be categorized as alpha or beta; this proportion is about half that found in intact retinas. These findings suggest that alpha-cells have the highest capacity to regenerate their axons into nerve grafts, rather than all types equally regenerating their axons.

Animals↗
PubMed2000

Comparative morphometric evaluation of peripheral nerves and muscle fibers in myotonic dystrophy.

We compared peripheral nerve fibers and muscle fibers in myotonic dystrophy (MD) using a computer-assisted device for morphometry. In the 17 cases with MD studied, the sural nerves of 14 cases (82%) showed various degrees of reduction of the myelin sheath area (MSA) per endoneurial area. Of these, 8 cases (47%) presented with a mild reduction of the MSA, 5 cases (29.4%) with moderate reduction, and one case (6%) with severe reduction. The number of myelinated nerve fibers was not significantly reduced in MD when compared with control nerves, due to clusters of small regenerated nerve fibers. The mean diameter of the muscle fibers in 6 of the 17 cases was less than 40 microm. Of these 6 severely affected cases, 5 revealed a considerable reduction of the MSA. Other cases, which appeared to be normal in respect to the diameter of muscle fibers, showed various degrees of reduction of the MSA. Thus, there is usually, but not always a morphometric correlation of the severity of changes between peripheral nerves and muscle. The severity of the peripheral neuropathy appears to depend largely on the patient's age, the stage of the disorder, and the time of progression. Electron microscopic examination of sural nerves showed significant, though non-specific pathological changes.

Adult↗
PubMed2000

Engineering strategies for peripheral nerve repair.

Tissue engineering in the peripheral nervous system unites efforts by physicians, engineers, and biologists to create either natural or synthetic tubular nerve guidance channels as alternatives to nerve autografts for the repair of peripheral nerve defects. Guidance channels help direct axons sprouting from the regenerating nerve end, provide a conduit for diffusion of neurotropic and neurotrophic factors secreted by the damaged nerve stumps, and minimize infiltration of fibrous tissue. In addition to efforts to control these physical characteristics of nerve guidance channels, researchers are optimizing the incorporation of biologic factors and engineering interactive biomaterial that can specifically stimulate the regeneration process. Current and future research will ultimately result in biologically active and interactive nerve guidance channels that can support and enhance peripheral nerve regeneration over longer, more clinically relevant defect lengths.

Animals↗