SEARCH · Search PubMed

Results for “NERVES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

PubMed1990

A study of nerve regeneration across synthetic (Maxon) and biologic (collagen) nerve conduits for nerve gaps up to 5 cm in the primate.

In a primate model, nerve regeneration was evaluated across 2- and 5-cm nerve gaps using a synthetic nerve conduit (glycolide trimethylene carbonate, Maxon) and a biologic conduit (collagen). Two types of conduits from glycolide trimethylene carbonate (Maxon) were evaluated. The first was fashioned into a tube from a single flat piece of Maxon mesh. The second was prefabricated in a crimped form. The other material evaluated was a biologic collagen tube. At 14 months, excellent regeneration was noted across the 2-cm nerve gap through both the collagen and Maxon conduits. At 5 cm, the regeneration, as determined by morphometric analysis, was significantly better across the Maxon prefabricated, crimped conduit, although regeneration at this longer gap in all experimental groups was significantly less than across the shorter nerve gap. At the longer gap, there was no statistical difference between the groups by electrophysiologic assessment.

Animals↗

PubMed1992

[Nerve growth factor receptor (NGFR)-like immunoreactivity in the perineurial cells of the adult rat peripheral nerves: normal appearance and response to nerve section].

The expression of the nerve growth factor receptor (NGFR)-like immunoreactivity in the perineurial cells of normal rat sensory and sympathetic nerves and after surgical severance was analyzed using a specific anti-rat NGFR monoclonal antibody (192-IgG). The perineurial cells as well as axonal endings showed NGFR-like immunoreactivity in the terminal region of normal nerves and the immunoreactivity in the terminal perineurial cells was enhanced after nerve severance. In the nerve trunk region, no cellular elements exhibited NGFR-like immunoreactivity in normal rats, but immunoreactivity was induced in the innermost perineurial cells and all Schwann cells in portions distal to the severance. These findings suggest that the perineurial cells function to provide NGF for intact and regenerating axons by binding NGF to NGFR on the perineurial cell surface.

Animals↗

PubMed1994

Blood flow in the sciatic nerve is regulated by vasoconstrictive and vasodilative nerve fibers originating from the ventral and dorsal roots of the spinal nerves.

Anesthetized rats were subjected to repetitive electrical stimulation of either the ventral or dorsal root of the spinal nerves between the 11th thoracic and 2nd sacral spinal segments. The response of nerve blood flow (NBF) in the sciatic nerve was examined using laser Doppler flowmetry. For all nerve fibers stimulation was for a 10-30-s period at a supramaximal intensity. (1) Stimulation of the T11-L1 ventral roots produced an increase in mean arterial pressure (MAP) and a biphasic NBF response was comprised of an initial increase and a subsequent decrease. The initial increase was a passive vasodilation due to the increase in MAP, while the following decrease in NBF resulted from active vasoconstriction of the vasa nervorum due to the activation of sympathetic nerves innervating the sciatic vasa nervorum. (2) Stimulation of the ventral root of the L6 segment produced an increase in NBF, even though MAP decreased. This increase in NBF was apparently mediated by activation of parasympathetic cholinergic vasodilators, because the response was abolished by i.v. injection of atropine, a muscarinic cholinergic receptor antagonist. (3) Stimulation of the dorsal roots between the L3 and S1 segments produced an increase in NBF, independent of changes in MAP. This increase in NBF appeared to be mediated by activation of a calcitonin gene-related peptide (CGRP) containing afferent fibers innervating the vasa nervorum, because the response was abolished by topical application of hCGRP (8-37), a CGRP receptor antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1981

Partial anastomosis between the lingual and mandibular nerves for restoration of sensibility in the mental nerve area after injury to the mandibular nerve. Case report.

A 35-year-old woman had to be operated on because of a displaced wisdom tooth combined with a follicular cyst in the right mandible. During the excision, the mandibular nerve was disrupted, and a piece about 1 cm in length was removed together with the whole specimen. Not being planned beforehand, and because of the lack of an operating microscope, the nerve repair in terms of a graft and fascicular suture was impossible. A partial anastomosis between the distal mandibular nerve stump and the lateral third of the lingual nerve recreated normal sensibility in the mental nerve area without leaving behind a sensibility defect in the tongue.

Adult↗

PubMed1977

Nerve conduction velocity of small components in human sensory nerves. Studies in normal and diseased nerves.

Slow conducted components of sensory nerve action potentials were investigated in median and in sural nerves of controls and in patients with peripheral nerve diseases. In the normal group the slow components showed no relation to age which is in contrast to the maximum velocity. In both the median nerve and sural nerve of about 20% of the patients with neuropathy exclusively a decrease of the conduction velocity of slow components was found, the other investigated parameters were normal. Possible causes are an alternation of the myelin sheath or changes in the properties of the nodal gap membrane.

Action Potentials↗

PubMed1987

Nerve fibre counts for an intercostal nerve to cauda equina nerve root anastomosis.

Mean nerve root diameters of thoracal, lumbal and sacral roots have been determined and the corresponding cross section areas calculated. The myelinated axons of these roots have been counted and the axon densities calculated. The myelinated axons of 3 lower intercostal nerves have also been counted. One intercostal nerve has with about 9,000 myelinated fibres enough axons for the regeneration of the ventral (3,000) and dorsal (16,000) myelinated fibres of the sacral roots 3 and 4 together. One intercostal has enough nerve fibres to reconstruct urinary bladder and bowel function on one side. The importance of performing a nerve anastomosis which considers functional aspects has been emphasized.

Aged↗

PubMed1987

Modification of median nerve somatic evoked potentials by prior median nerve, peroneal nerve, and auditory stimulation.

In a recovery function design, changes were measured in the somatic evoked potential (SEP) to right median nerve (RMN) shocks preceded by stimulation of: the same nerve (RMN-RMN); the left median nerve having primary input to the homologous sensory area in the contralateral hemisphere (LMN-RMN); the right peroneal nerve having primary input to a different region of the same hemisphere (RPN-RMN); and the auditory nerve with primary input to a different sensory modality (AUD-RMN). Eight inter-stimulus intervals ranged from zero (simultaneous) to 2.5 sec. It was assumed that the degree of interaction between evoked potentials would be related to the degree to which common neural structures are activated or modulated in response to the stimuli. Results were: (a) the primary somatosensory response N20-P30 was little influenced by other somatic or auditory stimulation, interaction occurring predominantly in the RMN-RMN condition; (b) with increasing latency, components showed increasing interaction across modalities; (c) preceding homolateral stimulation (RPN-RMN) showed no greater interaction than preceding contralateral stimulation (LMN-RMN); (d) N55-P100 differed from the primary somatosensory response N20-P30 by showing greater interaction with other somatic stimuli; and (e) N140-P190 showed similarly shaped recovery functions across stimulus pairs but significant differences in magnitude of interaction. These results show that components with similar wave form and topographical characteristics can have different neurophysiological properties.

Acoustic Stimulation↗

PubMed1994

Neural conduction velocity of the human auditory nerve: bipolar recordings from the exposed intracranial portion of the eighth nerve during vestibular nerve section.

We measured the conduction velocity of the intracranial portion of the auditory nerve in 3 patients undergoing vestibular nerve section to treat Ménière's disease. The conduction velocity varied from patient to patient, with an average value of 15.1 m/sec. The latency of peak III of the brain-stem auditory evoked potentials (BAEPs) increased by an average of 0.5 msec as a result of exposure of the eighth nerve, and if that increase is assumed to affect the entire length of the auditory nerve (2.6 cm) evenly, then the corrected estimate of conduction velocity would be 22.0 m/sec. Estimates of conduction velocity based on the interpeak latencies of peaks I and II of the BAEP, assuming that peak II is generated by the mid-portion of the intracranial segment of the auditory nerve, yielded similar values of conduction velocities (about 20 m/sec).

Electroencephalography↗

PubMed1983

[Indications and methods of treatment of injuries of the peripheral nerves. Comparative clinical results of the management of the median nerve and ulnar nerve using the epineural, perineural fascicular suture and transplantation].

In the last five years we have treated 95 lesions of the peripheral nerves. There were 24 lacerations of median and 25 of ulnar nerve. The results of treatment of median and ulnar nerve with epineural, perineural fascicular suture and transplant have been compared. The authors have tested the localisation of touch, two-point discrimination, recognition of small items, basic positions of the hand, precise action of the hand, and the motor power according to the Seddon's scale. The results were divided in excellent (2PD: 3-5 mm, power 5), very good (2PD: 6-9 mm. power 4), good (2 PD: 10-12 mm. power 4), fair (2PD: over 12 mm. power 3) and poor. The good results are groups excellent, very good and good. There were 44% good results using perineural fascicular suture of median nerve and 50% of ulnar nerve. The other methods have given poor results.

Humans↗

PubMed1999

En bloc resection of an intracavernous oculomotor nerve schwannoma and grafting of the oculomotor nerve with sural nerve. Case report and review of the literature.

A case in which a left oculomotor nerve schwannoma treated by en bloc resection of the lesion and grafting of the oculomotor nerve with sural nerve is presented. Recovery of nerve function was partial, but useful and cosmetically good. The last follow-up examination performed 2 years after surgery revealed recovery of function in the elevator muscle of the upper eyelid, together with slight vertical movement of the eye.

Cavernous Sinus↗

PubMed1995

4-Methylcatechol, an inducer of nerve growth factor synthesis, enhances peripheral nerve regeneration across nerve gaps.

The effect on peripheral nerve regeneration of 4-methylcatechol (MC), which is a potent inducer of nerve growth factor (NGF) synthesis in vitro and in vivo, was examined in a sciatic nerve-lesioned animal model. The sciatic nerve of adult male Wistar rats was transected and both of the cut ends were then inserted into sterile silicone tubes that were subsequently attached to an intervening silicone chamber. After surgery, the rats were injected i.p. every day for 2 weeks with MC. Two weeks after surgery, the density of nonmyelinated axons within the chamber was significantly increased in the MC-treated group compared with that in the control group. Five weeks after surgery, both the number and the diameter of myelinated axons within the chamber of the MC-treated group were significantly larger than those of the control group. When the chamber was filled with anti-NGF antibody solution, most of the MC effect was blocked. These results suggest that MC stimulates de novo synthesis of NGF (and/or NGF-related molecules), which results in the enhancement of sprouting and maturation of peripheral axons.

Animals↗

PubMed2000

Fast blue and diamidino yellow as retrograde tracers in peripheral nerves: efficacy of combined nerve injection and capsule application to transected nerves in the adult rat.

Capsule application of Diamidino Yellow (DY) to the cut end of the sciatic nerve immediately followed by capsule application of Fast Blue (FB) resulted in approximately 95% double-labelled dorsal root ganglion neurones (DRGn) and motoneurones (Mn). Nerve injection of DY followed either immediately or 2 months later by capsule application of FB resulted in approximately 90% double-labelled DRGn and Mn, indicating that DY and FB label similar populations of DRGn and Mn, and that insignificant DY fading occurred during this period. Inversing the order of application, however, i.e. nerve injection of FB followed immediately by capsule application of DY, resulted in double labelling in only approximately 10% of the DRGn and Mn. These percentages increased to 70% of the DRGn and 60% of the Mn when the FB injection was followed 1 or 2 months after by the DY application, indicating that DY uptake is blocked by recent administration of FB. The results indicate that DY and FB might be useful for sequential labelling before and after nerve injury as a tool to investigate the accuracy of sensory and motor regeneration.

Amidines↗

PubMed1989

Maturation of peripheral nerves in preterm infants: proprioceptive and motor nerve conductions of tibial nerve.

Premature birth induces a profound change in the environmental factors affecting nerve maturation. The proprioceptive sensory and motor nerve conduction velocities (NCV) of the posterior tibial nerve, which reflect peripheral nerve maturation, have been measured in 3 groups of newborns. Two groups of premature (PT) babies, studied when they reached the expected date of birth (group I, gestational age (GA) at birth, 28-31 weeks, n = 8; group II, GA at birth, 32-35 weeks, n = 6) were compared to 9 normal full-term (FT) newborns. As previously shown, the motor NCV of PT babies at a post-conceptional age close to term is similar to that of FT newborns: group I, 22.70 +/- 2.95 m/s (mean +/- SD); group II, 25.90 +/- 4.61 m/s; FT, 25.48 +/- 4.09 m/s. The proprioceptive sensory NCV was significantly lower in group I (21.59 +/- 4.39 m/s) than in group II (31.89 +/- 4.15 m/s) and FT newborns (32.22 +/- 6.56 m/s) (p less than 0.01). Such a delay in maturation could be responsible for the subtle clinical dysfunctions often observed in PT babies.

Gestational Age↗

PubMed1989

Effects of nerve compression or ischaemia on conduction properties of myelinated and non-myelinated nerve fibres. An experimental study in the rabbit common peroneal nerve.

Compound action potentials of both myelinated (A) and non-myelinated (C) fibres in the common peroneal nerve of rabbits were studied during and after acute, graded compression of the nerve at 200 or 400 mmHg applied for 2 h or during ischaemia created by nitrogen inhalation or aortic occlusion. Compression of the nerve at 200 mmHg blocked the AI component (large myelinated fibres) after about 23 min, while compression at 400 mmHg shortened this time to 11 min. The A2 component (thinner myelinated fibres) had a lower conduction velocity and a higher resistance to compression. There was just a slight decrease in conduction velocity of the non-myelinated fibres when the nerves were compressed at 200 mmHg for 2 h. However, compression at 400 mmHg for 2 h induced a marked deterioration of amplitude and conduction velocity of the C-fibres. There was an incomplete restitution of function of A- and C-fibres during 2 h of recovery. The thinner myelinated fibres were more susceptible to deprivation of oxygen than the thicker ones, while non-myelinated fibres differed in response according to method of ischaemia induction. It is concluded that non-myelinated fibres are very resistant to compression and a very high pressure (greater than 400 mmHg) is needed to affect these fibres.

Animals↗

PubMed1981

A comparative scanning electron-microscopical study of endoneurial collagen around normal mouse nerve fibres, nerve fibres following crush injury and nerve fibres of the dystonic mouse mutant (dt/dt).

The endoneurial collagen sheath around teased nerve fibres following crush injury was studied by scanning electron microscopy and compared with uninjured sciatic nerve fibres and with fibres from the dystonic mutant mouse. Following crush injury the endoneurial collagen became more abundant than seen in untreated nerve fibres and formed large, seperate and longitudinally oriented bundles. However, by four weeks post injury the sheath regained a normal external appearance. Mutant nerve fibres were also associated with more than the usual amount of collagen, but the sheaths were more disorganised, with a marked disorientation and irregular aggregation of collagen, and these abnormalities were not confined to obviously degenerating or demyelinated regions of the fibres. The dystonic abnormalities of the endoneurial sheath may be important in the mechanism of the neuropathy.

Animals↗

PubMed2004

Nerve injury about the shoulder in athletes, part 2: long thoracic nerve, spinal accessory nerve, burners/stingers, thoracic outlet syndrome.

Nerve injuries about the shoulder in athletes are being recognized with increasing frequency. Prompt and correct diagnosis of these injuries is important to treat the patient and to understand the potential complications and natural history, so as to counsel our athletes appropriately. This 2-part article is a review and an overview of the current state of knowledge regarding some of the more common nerve injuries seen about the shoulder in athletes, including long thoracic nerve, spinal accessory nerve, burners and stingers, and thoracic outlet syndrome. Each of these clinical entities will be discussed independently, reviewing the anatomy, mechanism of injury, patient presentation (history and examination), the role of additional diagnostic studies, differential diagnosis, and management.

Accessory Nerve Injuries↗

PubMed1982

[Effect of oxythiamine on rat peripheral nerve. --Morphological changes in sciatic nerve and plantar nerve of thiamine deficiency-- (author's transl)].

Morphological changes in rat sciatic nerve (SN) and plantar nerve (PN) induced by a thiamine deficient diet (TDD) and administration of oxythiamine (OT: 4 mg/100 g X 6 days) were observed, and thiamine (T) levels in rat nerve were simultaneously determined. Body weight gain ratio in rats which received OT fed a TDD (OTD group) was much reduced, and anorexia and ataxia were recognized in this group. Rats fed a regular diet, whose weights were restricted to be the same as those in the OTD group (EWC group), showed the symptoms of starvation. T levels of the SN and PN in the OT group, OTD group, and rats fed a TDD (TDD group) were reduced, but in the EWC group, T levels were the same as those in the control group (C group). There were myelin folds and myelin oboids in the EWC group, and these were recognized before axonal degeneration. In the TDD group, an increase in the number of mitochondria (Mit) was seen in the myelinated axon (MAx). In the TDD group, an increase in the number of mitochondria (Mit) was seen in the myelinated axon (MAx). In the OT and OTD groups, axonal degeneration (increase in the number of Mit, appearance of degenerated Mit, axonal shrinkage, and disappearance of neurofilament and neurotubule) was observed in the MAx. Degeneration of the MAx caused by TDD and OT was more severe in the PN than in the SN. Since these changes progressed from the peripheral nerve to the centripetal one, these changes in OTD group might be dying-back polyneuropathy.

Animals↗

PubMed1993

Time course of degeneration and regeneration of myelinated nerve fibres following chronic loose ligatures of the rat sciatic nerve: can nerve lesions be linked to the abnormal pain-related behaviours?

This study of a mononeuropathy of 1-15 weeks (W) duration was induced in rats by setting 4 loose ligatures around the common sciatic nerve. This chronic lesion, in which the continuity of the nerve was maintained, has been introduced as a model for experimental pain. Quantitative analyses of teased nerve fibres and a morphometric analysis of semi-thin transverse sections, were performed and completed by electron microscopic examination. Morphological changes were observed mainly distal, but also proximal, to the ligatures, indicating significant axonopathy with simultaneous degeneration and regeneration. The lesions were analysed in parallel with the time course of the pain-related behaviours. Both were at their maximum 2 weeks after ligature with progressive recovery beginning between W3 and W4. However, the largest fibres had not totally recovered by W15, contrasting with the disappearance of abnormal nociceptive reactions between W8 and W10. Although the damage to unmyelinated fibres is of importance, the abnormal pain-related behaviours seen in these rats appeared to be closely linked to the presence of both degenerative and regenerative changes in the A delta-range fibres, which did not necessarily correspond to initial A delta fibres.

Animals↗