Search PubMed⌕ Search

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.

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

At least 55 records · Page 3Linked to original sources
PubMed2006

A comparison of commissure excursion following gracilis muscle transplantation for facial paralysis using a cross-face nerve graft versus the motor nerve to the masseter nerve.

BACKGROUND: The microneurovascular transfer of a free muscle transplant is the procedure of choice for facial animation in a child with facial paralysis. One of the critical factors of this procedure is the selection of a motor nerve to innervate the transplanted muscle. METHODS: From 1989 to 1999, 166 free segmental gracilis muscle transfers were performed in 121 children for facial animation. The cross-face nerve graft was used in 70 procedures (cross-face nerve graft group) to innervate the muscle by branches of the seventh nerve for the normal side. The ipsilateral masseteric nerve was used in 94 procedures (50 patients, masseter group) and the ipsilateral accessory nerve was used in two procedures (one patient). To compare the operative procedures between the first two groups, all charts were reviewed. The extent of oral commissure movement was determined by measurements taken from the tragion to the oral commissure, both at rest and with full smile. In the cross-face nerve graft group (n = 20), the extents were measured on both the normal side and the reconstructed side; in the masseter group (n = 16), they were measured on the left and right sides. RESULTS: No significant difference was found between the two groups (p < 0.05) for the mean age at the time of muscle transplantation, for the total operation time for muscle transplantation, and for the length of the muscle used or for the fraction of circumference of the segment of gracilis muscle used. Although the operative variables were similar between two groups, the muscle excursion differed. Excursion in the cross-face nerve graft group was less than that on the right (p = 0.0006) or left (p = 0.0000) in the masseter group. It was also less than on the normal side (p = 0.0000) of the cross-face nerve graft group. Also, there was no significant difference between the left and right sides within the masseter group (p < 0.05). Furthermore, the extent of oral commissure movement in the masseter group was similar to that of the normal side in the cross-face nerve graft group (p = 0.35, p = 0.61). CONCLUSION: These results indicate that segmental gracilis muscle transplantation using the motor nerve to the masseter nerve for facial animation in children is a very reproducible operation and provides a commissure excursion in the range of normal.

Body Weights and Measures↗
PubMed2006

Formation and distribution of the sural nerve based on nerve fascicle and nerve fiber analyses.

The formation and distribution of the sural nerve are presented on the basis of an investigation of 31 legs of Japanese cadavers using nerve fascicle and fiber analyses. Nerve fibers constituting the medial sural cutaneous nerve were designated as 'T', whereas those constituting the peroneal communicating branch were designated as 'F'. In 74.2% of cases (23/31), the T and F fibers joined each other in the leg, whereas in 9.7% of cases (3/31) they descended separately. In 16.1% of cases (5/31), the sural nerve was formed of only the T fibers. The sural nerve gave off lateral calcaneal branches and medial and lateral branches at the ankle. The lateral calcaneal branches always contained T fibers. The medial branches consisted of only T fibers, whereas most of the lateral branches consisted of only F fibers (71.0%; 22/31). In addition to the T and F fibers, P fibers, which derived from the superficial and deep peroneal nerves, formed the dorsal digital nerves. The P fibers were entirely supplied to the medial four and one-half toes. However, they were gradually replaced by the T and F fibers in the lateral direction. The 10th proper dorsal digital nerve consisted of T fibers only (38.7%; 12/31), of F fibers only (19.4%; 6/31) or of both T and F fibers (38.7%; 12/31). These findings suggest that the T fibers are essential nerve components for the skin and deep structures of the ankle and heel rather than the skin of the lateral side of the fifth toe. The designation of the medial sural cutaneous nerve should be avoided and only the T fibers are appropriate components for naming as the sural nerve.

Aged↗
PubMed1991

Changes in nerve fiber numbers distal to a nerve repair in the rat sciatic nerve model.

Changes in nerve fiber numbers distal to a nerve repair in the sciatic nerve of 48 rats were evaluated over a 1- to 24-month period. The results of the morphometric evaluation in the sciatic nerve distal to the nerve repair demonstrated an increase in nerve fiber counts as early as 1 month following the nerve repair. The number of nerve fibers in the distal nerve was greatest at 3 months and did not return to normal levels until 24 months. The results of this study will influence the timing of experimental studies in which nerve fiber counts are critical for evaluation, and provides a better understanding of the clinical events occurring following nerve repair.

Animals↗
PubMed1998

Axonal elongation through acellular nerve segments of the cat tibial nerve: importance of the near-nerve environment.

Peripheral nerve regeneration is considered to be influenced by structural, cellular and humoral factors in the distal nerve stump. Axonal elongation was, however, not affected by the presence of a 20 mm acellular nerve segment (ANS) distal to a crush lesion in a cat tibial nerve which was shielded from the environment by a silicone cuff [K. Fugleholm, H. Schmalbruch, C. Krarup, Early peripheral nerve regeneration after crushing, sectioning, and freeze studied by implanted electrodes in the cat, J. Neurosci., 14 (1994) 2659-2673]. In the present study axons were challenged to regenerate through crush lesions combined with 30-, 40-, 50-, 60- and 70-mm ANSs. For 30- and 40-mm ANSs, the nerves were shielded by impermeable silicone cuffs containing electrodes for electrophysiological evaluation of axonal elongation. All nerves were examined histologically by light microscopy 9 weeks after the lesion. The elongation through the shielded 30-mm ANS was slower than through a shielded nerve segment with viable cells. In the isolated 40-mm ANS, incomplete Wallerian degeneration and lack of blood vessels were observed, and axonal elongation was severely impaired. Regeneration across 40-70 mm non-shielded ANSs was intact and there was no relation between the number of regenerated fibers and the length of the ANS. There was no reduction in the number of blood vessels in the non-isolated ANSs. The results suggest that regeneration through an isolated acellular nerve segment exceeding 30 mm depends on cellular and humoral support from the near-nerve environment. Thus, the near-nerve environment is crucial for regeneration through long ANSs, and the importance of humoral, cellular and vascular support is discussed.

Action Potentials↗
PubMedDate not supplied

[Possibility of nerve lesions related to peripheral nerve blocks. A study of the human sciatic nerve using different needles].

UNLABELLED: When a needle tip comes too close to a nerve axon, the mechanical effect over the nerve membrane produces paresthesia. We examined the hypothetical mechanical damage of short bevel and long bevel needles over sciatic nerve bundles under scanning electron microscopy. METHODS: We obtained samples of sciatic nerve from three patients of 68, 74 and 76 years old. These samples were fixed, dehydrated and coated with gold microfilm for their observation under scanning electron microscopy. Ten short bevel needles and ten long bevel needles were studied under the same microscopic technique. We interpolated microscopic images from sciatic nerve samples and different needle bevels at various angles to study the mechanical damage of these needles to nerve axons. RESULTS: Sciatic nerve bundles were found 0.1 to 0.2 mm deep in the samples; information was given about the bevel length and angle of needles. The damage is perceptible under scanning electron microscopy, when the needle bevel is introduced 0.3-0.4 mm deep into the nerve bundle; here, the needle tip cuts through the perineurum, piercing the nerve bundle. At a depth of 1 mm, the lesion caused by short bevel needles is greater than that caused by long bevel needles. The type of epineural lesions caused by short bevel needles is also different from the ones caused by long bevel needles. CONCLUSIONS: Lesions that affect superficially the epineurum can cause paresthesia by compression of nerve fascicles without damaging the axons. If the perineurm is damaged, the lession will also affect the blood-nerve barrier, leading probably to posterior sequels.

Aged↗
PubMed1999

Nerve growth factor and proprotein convertases furin and PC7 in transected sciatic nerves and in nerve segments cultured in conditioned media: their presence in Schwann cells, macrophages, and smooth muscle cells.

Synthesis of proteins such as nerve growth factor (NGF) is induced after nerve lesion. The NGF precursor (pro-NGF) requires a posttranslational processing by proprotein convertases to become active. In this report, we re-examine the localization of NGF protein and mRNA in injured nerve and show that the candidate pro-NGF convertases furin and PC 7 colocalize with NGF in non-neuronal cells in nerve. By Northern blot analysis, 1.5-kb and 1.3-kb NGF mRNAs were shown to be increased in distal and immediately proximal nerve segments on days 1, 4, and 14 after lesion; by Western blot analysis, NGF proteins of high molecular weight were detected after injury. In vivo, two phases of NGF immunopositivity were observed, in macrophages and perivascular cells shortly after lesion and in endoneurial cells on day 1 and 4. To identify the cells containing NGF, nerve segments were incubated in serum-containing medium with or without conditioning by white blood cells isolated from the circulation. Both hybridization and immunoreactivity signals for NGF were elevated after incubation of nerve segments for 4 hours in conditioned media, so that cells with NGF immunoreactivity could be identified by antibodies to specific cell markers. In these nerve fragments, Schwann cells, perivascular smooth muscle cells, and macrophages contained NGF immunoreactivity. The concentration of furin and PC7 mRNA also increased in lesioned nerves. By immunocytochemical investigation of nerve explants, furin and PC7 were detected in endoneurial cells, macrophages and perivascular cells and were colocalized with NGF. These in vitro and in vivo findings suggest that both furin and PC7 are associated with NGF in several cell types of the sciatic nerve and, hence, may be implicated in intracellular processing of pro-NGF.

Animals↗
PubMed2005

Nerve regeneration across a 2-cm gap in the rat median nerve using a resorbable nerve conduit filled with Schwann cells.

OBJECT: In a rat model, nerve regeneration was evaluated across a 2-cm defect in the median nerve by using a resorbable artificial nerve conduit. The aim of this study was to develop an artificial, biocompatible nerve guide to induce regeneration in the peripheral nervous system. METHODS: The authors compared a nerve conduit of trimethylenecarbonate-co-epsilon-caprolactone (TMC/CL) filled with autologous Schwann cells with both an empty hollow conduit and an autologous nerve graft. Animals that did not undergo surgery served as the control group. Nerve regeneration was evaluated with the grasping test, histological analysis of the nerve, muscle weight analysis (flexor digitorum superficialis muscle), and electrophysiological examination. After an observation period of 9 months, regeneration occurred only in animals that had received an autologous graft or a Schwann cell containing nerve conduit. No signs of regeneration were found in animals supplied with the empty conduit. CONCLUSIONS: Results of this study reveal the important role of Schwann cells in the regeneration process across a 2-cm defect in the rat median nerve. Furthermore, Schwann cell-filled nerve conduits induced functional recovery, as demonstrated in the grasping test, that was comparable with that of the autologous graft 9 months after implantation.

Absorbable Implants↗
PubMed2004

Comparative experimental study on treatment outcome of nerve transfer, using selective C7 nerve root vs. phrenic nerve.

The treatment outcome of nerve transfer using the C7 nerve root or phrenic nerve was compared in a rat experiment. One hundred and twenty SD rats were divided into two groups, one undergoing phrenic nerve transfer to the musculocutaneous nerve, and the other partial ipsilateral C7 (anteriolateral fascicles of the anterior division) to the musculocutaneous nerve. Neurotization outcomes of the two groups were evaluated by comparing the electrophysiologic, histologic, and myophysiologic changes of the biceps muscle. No significant differences were found between parameters from the phrenic nerve transfer group and those from the ipsilateral C7 nerve transfer group. This indicates that the treatment outcome of selective ipsilateral C7 transfer is comparable to that of phrenic nerve transfer. It is the surgery of choice in treating brachial plexus upper-trunk avulsion accompanied by phrenic nerve injury.

Animals↗
PubMed2004

Interposed autologous nerve segment stimulates nerve regeneration in peripheral nerve allografts in a rat model.

The ability of autologous nerve segments interposed between allografts, to increase the total nerve-gap distance, was studied. Sciatic nerve allografts were carried out in a rat model. A 15-mm nerve gap was repaired with a 25-mm nerve graft (interposed group: allo-auto-allograft; control group: allo-allo-allograft). Cyclosporin was given for 12 weeks. Nerve regeneration was evaluated using the weight of the anterior tibial muscle and histologic, morphometric and immunohistochemical analyses at 12, 13, 14, 15, 16, 20, and 24 weeks. Nerve regeneration in the interposed group was statistically significantly better than that in the control group. The authors concluded that a nerve allograft with interposed autograft may enhance nerve regeneration in this model, because of the migration of host-derived Schwann cells into the graft from not only the proximal and distal host nerve stumps, but also the interposed autograft.

Animals↗
PubMed1999

Functional assessment of sciatic nerve reconstruction: biodegradable poly (DLLA-epsilon-CL) nerve guides versus autologous nerve grafts.

The aim of this study was to compare functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with modified denatured muscle tissue (MDMT), or an autologous nerve graft. We evaluated nerve recovery using walking track analysis (measurement of the sciatic function index [SFI]) and electrostimulation tests. Functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with MDMT was faster when compared with nerve reconstruction using an autologous nerve graft. We conclude that in case of a short nerve gap in the rat, reconstruction can best be carried out using a p(DLLA-epsilon-CL) biodegradable nerve guide filled with MDMT.

Absorbable Implants↗
PubMed2003

Carbon dioxide laser-assisted nerve repair: effect of solder and suture material on nerve regeneration in rat sciatic nerve.

In order to further improve and explore the role of lasers for nerve reconstruction, this study was designed to investigate regeneration of sharply transected peripheral nerves repaired with a CO(2) milliwatt laser in combination with three different suture materials and a bovine albumin protein solder as an adjunct to the welding process. Unilateral sciatic nerve repair was performed in 44 rats. In the laser group, nerves were gently apposed, and two stay sutures (10-0 nylon, 10-0 polyglycolic acid, or 25 microm stainless steel) were placed epi/perineurially. Thereafter, the repair site was fused at 100 mW with pulses of 1.0 s. In the subgroup of laser-assisted nerve repair (LANR), albumen was used as a soldering agent to further reinforce the repair site. The control group consisted of nerves repaired by conventional microsurgical suture repair (CMSR), using 4-6 10-0 nylon sutures. Evaluation was performed at 1 and 6 weeks after surgery, and included qualitative and semiquantitative light microscopy. LANR performed with a protein solder results in a good early peripheral nerve regeneration, with an optimal alignment of nerve fibers and minimal connective tissue proliferation at the repair site. All three suture materials produced a foreign body reaction; the least severe was with polyglycolic acid sutures. CMSR resulted in more pronounced foreign-body granulomas at the repair site, with more connective-tissue proliferation and axonal misalignment. Furthermore, axonal regeneration in the distal nerve segment was better in the laser groups. Based on these results, CO(2) laser-assisted nerve repair with soldering in combination with absorbable sutures has the potential of allowing healing to occur with the least foreign-body reaction at the repair site. Further experiments using this combination are in progress.

Albumins↗
PubMed2001

Sensory nerve function and auto-mutilation after reconstruction of various gap lengths with nerve guides and autologous nerve grafts.

The aim of this study was to evaluate sensory nerve recovery and auto-mutilation after reconstruction of various lengths of nerve gaps in the sciatic nerve of the rat, using different techniques. Group 4, in which the longest nerve gap (15 mm) was reconstructed with a thin-walled p(DL-lactide-gamma-caprolactone) nerve guide filled with modified denatured muscle tissue, showed the best results in the electro-stimulation tests and signs of severe auto-mutilation were not observed. Even in the control group, in which a 10 mm nerve gap was left open, in two of the five rats improvement of the sensory nerve function was observed, which was caused by re-innervation of the sciatic nerve and not by expansion of the neighboring saphenous nerve. It is hypothesized that a better quality of nerve reconstruction/guidance channel/support results in faster regeneration and hence re-innervation, thereby, preventing auto-mutilation. A thin red glabrous skin, anhydrosis (dryness of the skin), short nails and edema were interpreted as signs of autonomic dysfunction.

Animals↗
PubMed2002

Distal anterior interosseous nerve transfer to the deep motor branch of the ulnar nerve for reconstruction of high ulnar nerve injuries.

Proximal ulnar nerve injuries can result in loss of intrinsic muscle function of the hand, and distal nerve transfers provide nerve coaptation close to the target muscle. This retrospective chart review evaluated patient outcome following a distal nerve transfer of the anterior interosseous nerve (AIN) to the deep motor branch of the ulnar nerve. There were eight patient charts reviewed, three women, and five men. The mean patient age was 38 years (standard deviation: 22 years). The mean time from injury to surgery was 3 months (standard deviation: 3 months), and mean postoperative follow-up time was 18 months (standard deviation: 11 months). All patients had reinnervation of the ulnar nerve intrinsic hand muscles with improved postoperative lateral pinch and grip strength. One patient had a secondary tendon transfer. No functional deficit in performing tasks in pronation was reported. The distal nerve transfer of the AIN to the deep motor branch of the ulnar nerve provides good reinnervation of the ulnar-nerve-innervated intrinsic muscles of the hand.

Adult↗
PubMed2004

New one-stage nerve pedicle grafting technique using the great auricular nerve for reconstruction of facial nerve defects.

A new one-stage nerve pedicle grafting technique, employing a vascularized great auricular nerve graft, was used to repair a facial nerve defect. The facial nerve of a 39-year-old woman with facial schwannoma was resected, and an island vascularized great auricular nerve graft from the ipsilateral side was transferred to bridge a 4 cm long defect of the buccal branch. Postoperatively, rapid nerve sprouting through the vascularized nerve graft and excellent facial reanimation were obtained within 6 months after surgery. This method in one-stage using a vascularized nerve graft is technically easy, requires a short operating time, has minimal donor-site morbidity, and leads to successful nerve regeneration postoperatively.

Adult↗
PubMed1976

Intraneural tissue reactions induced by internal neurolysis. An experimental study on the blood-nerve barrier, connective tissues and nerve fibres of rabbit tibial nerve.

Surgical treatment of peripheral nerve lesions associated with intraneural fibrosis is sometimes extended to include internal neurolysis. This procedure is performed in order to release the individual nerve fascicles from interfascicular scar tissue which is believed to constrict nerve fibres and thereby interfere with their function and regenerative capacity. However, an internal neurolysis per se implies a significant trauma to the nerve and may induce microvascular damage and formation of new intraneural scar tissue. Considering this, such a procedure appears justified only when the preoperative intraneural fibrosis is more severe than the scarring which might be induced by the surgical procedure as such. In order to evaluate the tissue reactions following internal neurolysis an experimental investigation was carried out: internal neurolysis was performed on normal rabbit tibial nerve. After varying postoperative periods up to 6 months specimens of nerves were analysed. Reactive changes of connective tissue and myelin sheath lesions, indicating nerve fibre damage, were investigated in histological sections studied by light microscopy. Barrier function of perineurial membrane and endoneurial vessels was investigated by fluorescent microscopic tracing of locally applied or intravenously injected albumin labelled with Evans' blue. The results indicate that an experimental internal neurolysis per se may induce fibrosis in all layers of the nerve and may cause some nerve fibre damage. However, the barrier function of the perineurium and the endoneurial vessels seems to be generally well preserved. The findings are discussed in relation to indications for internal neurolysis.

Animals↗
PubMed1995

[Nerve sutures and nerve grafts for repairing a gap in peripheral nerve injury: an experimental study].

An experimental study was performed using the canine sciatic nerve in order to compare the efficacies of a vascularized trunk graft (VTG), a free trunk graft (FTG), a vascularized cable graft (VCG), a free cable graft (FCG) and a two stage procedure (TSP) for the repair of a peripheral nerve defect. Both a 4 cm, and a 5 cm nerve defect was repaired using each method, and also a 6 cm defect, using VCG and FCG. After 24 weeks, the intraneural blood flow (IBF) was measured in the 4 cm defect group, and the recovery of nerve regeneration and muscle reinnervation were evaluated by motor nerve conduction velocity, wet muscle weight, and histological examinations of the nerve and the muscles. VTG and VCG both demonstrated superior IBF. The IBF after TSP was less than after VTG and VCG but greater than after FTG and FCG. In the 4 cm defect group, VTG showed the most favorable recovery in both the axonal regeneration and muscle reinnervation and was followed by VCG. Although the recovery after FTG, FCG and TSP appeared to be worse than after VTG and VCG, there was no significant difference. In the 5 cm defect group, VTG showed the most favorable recovery followed by VCG and FCG. For axonal regeneration, FTG was significantly worse than VTG, VCG and FCG. TSP was worst within the 5 cm defect group for muscular reinnervation, although it showed somewhat better axonal regeneration than FTG. In the 6 cm defect group, no significant difference was found between VCG and FCG for the axonal regeneration. Clinically, TSP is used for repairing a short nerve defect just beyond the critical distance that cannot be overcome by a primary end-to-end suture. Nerve grafting, other than FTG, appeared to be the most reliable method of bridging a long nerve defect, and FCG might be the most practical method.

Animals↗
PubMed1997

Transfer of a branch of the anterior interosseus nerve to the motor branch of the median nerve and ulnar nerve.

OBJECTIVE: To explore the applied microsurgical anatomy of the intrinsic hand muscles and related nerves after nerve injuries in the wrist region and to report the results of new technique for the restoration of motor functions of the injured nerves. METHODS: Seven fresh forearm amputation specimens were employed for studying the anatomical and microsurgical characteristics of the relevant tissues. Transfer of the pronator quadratus branch of the anterior interosseous nerve (PBAN) to the recurrent branch of the median nerve (RBMN) and the deep branch of the ulnar nerve (DBUN) to restore the functions of the intrinsic hand muscles was performed on 20 patients from April 1979 to January 1994. Fourteen patients were followed up for 3-9 years with an average of 5 years and 8 months. RESULTS: The RBMN, DBUN and PBAN had approximately the same lengths of diameter and similar amounts of fascicles and nerve fibers so that after nerve transfer, the possibilities of misdirected connections were greatly reduced. In the latest follow-up, normal muscle strength was regained in 3 patients, grade VI strength in 6, grade III strength in 3 and grade II strength in 2. CONCLUSION: This new technique is able to restore the intrinsic hand muscular functions after median or ulnar nerve injuries in the wrist region or distal forearm.

Adolescent↗