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PubMed1984

Comparison of insulated and uninsulated needles for locating peripheral nerves with a peripheral nerve stimulator.

This study was designed to compare the use of insulated and uninsulated needles with a peripheral nerve stimulator for locating a peripheral nerve in an anesthetized cat. The needles were mounted on a one-dimensional manipulator and both the saphenous and sciatic nerves were located. The tip of the insulated needle was consistently placed on the sciatic nerve. The tip of the uninsulated needle was placed 0.1-0.9 cm past the sciatic nerve. Injecting saline to assess the position of the tip of the needle relative to the sciatic nerve did not detect the needle being past the nerve. With the saphenous nerve preparation, both the needle and nerve were visible through the tissue. Using an insulated needle, the minimum current required to stimulate the nerve occurred when the tip of the needle touched the saphenous nerve. Using an uninsulated needle, the minimum current occurred when the tip was 0.1-0.8 cm past the nerve. The conclusion is that insulated needles more precisely locate the peripheral nerve than uninsulated needles.

Animals↗
PubMed1990

Role of the blood-nerve barrier in experimental nerve edema.

Nerve edema is a common response to the nerve injury seen in many peripheral neuropathies and is an important component of Wallerian degeneration. However, independent pathologic effects of nerve edema that aggravate or induce nerve injury extend the role of edema beyond that of an epiphenomenon of injury. New insights into the mechanism and impact of nerve edema come largely from animal models. In the following review, we discuss the cause and consequences of nerve edema with particular reference to endoneurial fluid pressure and its relevance to the nerve microenvironment. Experimental models of nerve edema include conditions with increased vascular permeability such as lead poisoning, experimental allergic neuritis, and murine globoid leukodystrophy. Increased perineurial permeability induced by local anesthetics and neurolytic drugs can also induce nerve edema sufficient to increase endoneurial fluid pressure. Both perineurial and vascular permeability are increased after damage induced by crush, freeze, or laser injury. One of the most important forms of nerve edema is induced by external compression; the significance of this change is that edema has local compressive effects that persist after the external pressure has been relaxed. Nerve edema and increased endoneurial fluid pressure also occur in conditions in which vascular permeability appears to be unchanged such as experimental diabetic neuropathy and in hexachlorophene intoxication. In both of these conditions, reduced nerve blood flow has been demonstrated in rats and is viewed as a consequence of increased endoneurial fluid pressure. Whatever its mechanism, endoneurial edema has important structural and functional consequences for nerve fibers. A clear understanding of the underlying pathology of the nerve microenvironment may provide useful insights into treatment of clinical neuropathies.

Animals↗
PubMed2004

Long-term regeneration of the rat sciatic nerve through a biodegradable poly(DL-lactide-epsilon-caprolactone) nerve guide: tissue reactions with focus on collagen III/IV reformation.

Long-term studies on nerve-guide regeneration are scarce. Therefore, in rats, long-term (16 months) sciatic nerve regeneration through poly(DL-lactide-epsilon-caprolactone) [poly(DLLA-epsilon-CL)] nerve guides was studied and compared with the nonoperated control side. Poly(DLLA-epsilon-CL) degradation and possible long-term foreign body reaction against poly(DLLA-epsilon-CL) nerve guides, as well as the distribution of both collagen type III and IV were studied. In vivo poly(DLLA-epsilon-CL) studies have been performed before but not for such long time points; also, a detailed analysis of collagen III/IV has not been presented before. The results demonstrate that biodegradable poly(DLLA-epsilon-CL) nerve guides yield good nerve regeneration and collagen III/IV deposition relative to the anatomy of the control side. Regenerated nerve showed almost similar collagen type III/IV distribution patterns as compared with the nonoperated control side, although the delineation of matrix was clearer in the control side. The relative amount of collagen III and IV immunostaining in nerve cross-sections did not, however, differ between the control nerve tissue and the operated side after 16 months. After 16 months of implantation, however, some very small fragments of biomaterial could still be found on the edge of the epineurium of the regenerated nerve, indicating remnants of a secondary foreign body reaction. The biomaterial fragments and foreign body reaction did not influence the nerve regeneration process after 16 months. Biodegradable poly(DLLA-epsilon-CL) nerve guides are useful for long-term bridging of short peripheral nerve gaps.

Animals↗
PubMed2002

Superficial or deep implantation of motor nerve after denervation: an experimental study--superficial or deep implantation of motor nerve.

Neurorraphy, conventional nerve grafting technique, and artificial nerve conduits are not enough for repair in severe injuries of peripheral nerves, especially when there is separation of motor nerve from muscle tissue. In these nerve injuries, reinnervation is indicated for neurotization. The distal end of a peripheral nerve is divided into fascicles and implanted into the aneural zone of target muscle tissue. It is not known how deeply fascicles should be implanted into muscle tissue. A comparative study of superficial and deep implantation of separated motor nerve into muscle tissue is presented in the gastrocnemius muscle of rabbits. In this experimental study, 30 white New Zealand rabbits were used and divided into 3 groups of 10 rabbits each. In the first group (controls, group I), only surgical exposure of the gastrocnemius muscle and motor nerve (tibial nerve) was done without any injury to nerves. In the superficial implantation group (group II), tibial nerves were separated and divided into their own fascicles. These fascicles were implanted superficially into the lateral head of gastrocnemius muscle-aneural zone. In the deep implantation group (group III), the tibial nerves were separated and divided into their own fascicles. These fascicles were implanted around the center of the muscle mass, into the lateral head of the gastrocnemius muscle-aneural zone. Six months later, histopathological changes and functional recovery of the gastrocnemius muscle were investigated. Both experimental groups had less muscular weight than in the control group. It was found that functional recovery was achieved in both experimental groups, and was better in the superficial implantation group than the deep implantation group. EMG recordings revealed that polyphasic and late potentials were frequently seen in both experimental groups. Degeneration and regeneration of myofibrils were observed in both experimental groups. New motor end-plates were formed in a scattered manner in both experimental groups. However, they were more dense in the superficial implantation group than the deep implantation group. It was concluded that superficial implantation has a more powerful contractile capacity than that of deep implantation. We believe that this might arise from the high activity of glycolytic enzymes in peripheral muscle fibers of gastrocnemius muscle, decrease in insufficient intramuscular guidance apparatus, and intramuscular microneuroma formation at the insufficient neuromuscular junction since the motor nerve had less route to muscle fibers.

Animals↗
PubMed2005

Peroneal nerve lesion after sural nerve graft harvest: an unusual complication--case report.

After harvesting of the sural nerve, the patient developed a partial palsy of the common peroneal nerve due to a lesion of the peroneal nerve and a neuroma of the sural nerve stump. Motor function recovered after performing neurolysis of the common peroneal nerve and mobilization of the neuroma. The sural nerve, in this case originating from the common peroneal nerve, was harvested using a nerve stripper and four small skin incisions. Direct lesion by the forced use of the nerve-stripping instrument followed by the formation of a neuroma close to the peroneal nerve are the suspected reasons for motor dysfunction. Although many authors report using a nerve stripper as a safe, less invasive method to gain nerve material for transplantation, we recommend lengthening the skin incision so as to be aware of anatomical variations and to refrain from pulling the nerve distally to avoid the described complications.

Adult↗
PubMed1990

Sensory nerve conduction velocities in the cutaneous afferents of the ulnar and peroneal nerves of the dog: tissue temperature-dependent reference ranges.

Sensory nerve conduction velocities in the cutaneous afferents of the ulnar and peroneal nerves of the neurologically normal adult dog were determined by stimulation at stimulus intensities of 15, 20 and 25 V through subcutaneously placed electrodes and by the averaged evoked response technique. Stimulus intensities of 15 V for the ulnar nerve and 20 V for the peroneal nerve were adequate to measure the sensory nerve conduction velocities of these nerves. A linear relationship was seen between sensory nerve conduction velocity (y in m/s) and tissue temperature (x in degree C) and the regression equations were expressed as follows: y = 1.6x + 12.3 at a stimulus intensity of 15 V for the ulnar nerve and y = 2.0x - 10.6 at 20 V for the peroneal nerve, respectively. The 95% confidence limits of the regressions of the sensory nerve conduction velocities against tissue temperature, obtained at a stimulus intensity of 15 V for the ulnar nerve or at a stimulus intensity of 20 V for the peroneal nerve, were proposed for a tissue temperature-dependent reference range to enable the clinician to evaluate graphically the sensory nerve conduction velocity in a diseased dog.

Action Potentials↗
PubMed1998

Facial nerve parasympathetic preganglionic afferents to the accessory otic ganglia by way of the chorda tympani nerve in the cat.

The distribution of accessory otic ganglia and connections between the ganglia and the chorda tympani nerve were investigated in the cat in order to determine the parasympathetic preganglionic facial nerve afferents to the otic ganglia using whole mount acetylthiocholinesterase (WATChE) histochemistry. The otic ganglia consist of a single main prominent ganglion and many small accessory ganglia lying on a plexus around the origins of the branches of the mandibular nerve and near the junction of the chorda tympani nerve and lingual nerve. In cell analysis of Nissl-stained preparations, the neurons composing the accessory otic ganglia were morphologically similar to the main otic ganglion neurons. Connecting branches from the chorda tympani nerve to the peripherally located accessory otic ganglia were found and they were not stained by WATChE histochemistry. WATChE-positive connecting branches from the ganglia to the inferior alveolar, lingual, and mylohyoid nerves were also found in the same preparations. The WATChE histochemistry on various autonomic nervous tissues revealed that autonomic postganglionic nerve fibers are selectively stained darkly and that preganglionic fibers remain unstained. Therefore, it is considered that the WATChE-negative connections from the chorda tympani nerve consist chiefly of autonomic preganglionic fibers, whereas the WATChE-positive connections to the branches of the mandibular nerve are mainly postganglionic fibers. This suggests that some of the facial nerve parasympathetic preganglionic fibers in the chorda tympani nerve are mediated in the accessory otic ganglia and then join the branches of the mandibular nerve to supply the target mandibular tissues.

Acetylcholinesterase↗
PubMed1991

Order-disorder phenomena in myelinated nerve sheaths. III. The structure of myelin in rat optic nerves over the course of myelinogenesis.

An X-ray scattering study was performed on optic nerves dissected from rats aged from ten days to one year. The spectra were analysed using the procedure described in the previous papers of this series. Each experiment yields the values of a variety of parameters: the average D and the variance sigma D of the repeat distance, the average number mean value of N of motifs per crystallite, the fraction alpha loose of myelin that does not belong to the compact sheaths, the sets [idiff(h/D)] and [imotif(k/2D)] that suffice to define, respectively, the spurious scattering and the continuous intensity curve of the elementary membrane pair. A surprising result is that, in the native optic, as previously found in the swollen sciatic nerves, the stacking disorder affects the external space, whereas in native sciatic nerves the disorder affects the cytoplasmic space. An analysis of the evolution of the structure parameters as a function of the age of the animal and a comparison with the results previously obtained with rat sciatic nerves led to the following conclusions: the structure of the elementary membrane pair is constant throughout myelinogenesis; mean value of N is much smaller in optic than in sciatic nerves; mean value of N and the degree of myelination increase with age in the two types of nerve; D is smaller in optic than in sciatic nerves; in optic nerves, D decreases slightly with age, but in sciatic nerves it increases; sigma D is strongly age-dependent in optic nerves, but almost age-independent in sciatic nerves. In contrast to sciatic, the structure of optic nerve myelin was found to be almost insensitive to hypertonic solutions. Finally, a pair of electron density profiles was selected, quite similar to those selected previously in sciatic nerves, one corresponding to Caspar & Kirschner's the other to Worthington & McIntosh's proposals, neither of which can be ruled out according to the criteria used in this work.

Aging↗
PubMed1993

Peptide-immunoreactive neurons and nerve fibres in lumbosacral sympathetic ganglia: selective elimination of a pathway-specific expression of immunoreactivities following sciatic nerve resection in kittens.

The distributions of peptide-immunoreactive nerve fibres and cell bodies in lumbosacral paravertebral sympathetic ganglia of young cats were analysed with antibodies to calcitonin gene-related peptide, enkephalin, neurotensin, somatostatin, substance P, galanin, neuropeptide Y and vasoactive intestinal polypeptide. Fairly dense networks of nerve fibres showing enkephalin-, neurotensin-, somatostatin- or substance P-like immunoreactivity were observed in the ganglia. Double-staining experiments revealed that enkephalin- and somatostatin-immunoreactive nerve fibres preferentially surrounded calcitonin gene-related peptide- and/or vasoactive intestinal polypeptide-immunoreactive cell bodies. Neurotensin- and substance P-immunoreactive nerve fibres were mainly associated with neurons showing neuropeptide Y and/or galanin-like immunoreactivity. Occasional nerves containing calcitonin gene-related peptide-, galanin-, neuropeptide Y- or vasoactive intestinal polypeptide-like immunoreactivity were observed. These fibres did not seem to have any direct regional distribution within the ganglia. In kittens surviving for three months after early postnatal sciatic nerve resection, no calcitonin gene-related peptide-immunoreactive cell bodies could be detected in ganglia ipsilateral to the operation. In contrast, vasoactive intestinal polypeptide-like immunoreactivity, which partly co-exists with calcitonin gene-related peptide, was observed to the same extent as in control ganglia. Furthermore, almost all of the somatostatin-immunoreactive varicose nerve fibres had disappeared, whereas a fairly dense network of calcitonin gene-related peptide-immunoreactive nerve fibres could be observed. This change was paralleled by an increased content of nerve fibres that were immunoreactive to antibodies against the growth-associated protein GAP-43 (also known as B-50). The present findings suggest that experimental perturbations where postganglionic neurons are separated from their target areas by axotomy, not only induce differential changes in neurotransmitter expression in the principal ganglion cells, but also in preganglionic sympathetic neurons projecting to the ganglia. One possible explanation for the occurrence of an axotomy-induced network of calcitonin gene-related peptide-immunoreactive nerve fibres, is that extrinsic sensory nerve fibres grow into the ganglia after the sciatic nerve lesion. Thus, these findings seem to suggest one additional possibility with regard to the question of a possible interaction between sympathetic and sensory neurons after peripheral nerve injury.

Animals↗
PubMedDate not supplied

The musculocutaneous nerve: ultrasound appearance for peripheral nerve block.

BACKGROUND AND OBJECTIVES: To gain complete anesthesia of the forearm, block of the musculocutaneous nerve is necessary. Variations in its course and position make localization of the musculocutaneous nerve problematic. The aim of the study is to describe the ultrasound appearance of the musculocutaneous nerve in the axilla and to suggest potential areas to target neural block. METHODS: We scanned the axillary regions of 19 volunteers and assessed the size and shape of 34 musculocutaneous nerves at entry into, exit from, and in the center of the coracobrachialis muscle. Furthermore, we measured the depth of the musculocutaneous nerve under the skin surface and its distance from the axillary artery at those 3 measurement points. RESULTS: As it travels through the coracobrachialis muscle, the musculocutaneous nerve changes in shape from oval to flat-oval to triangular. During this course, the musculocutaneous nerve also separates from the axillary artery and becomes more lateral while changing its depth from the surface. The musculocutaneous nerve increases its transverse area along this nerve path. In 2 subjects, the musculocutaneous nerve could not be visualized unilaterally within the course of the coracobrachialis muscle. CONCLUSIONS: Knowledge of its ultrasound appearance facilitates localization and successful block of the musculocutaneous nerve. Because the distance between the musculocutaneous nerve and brachial plexus varies, different locations of musculocutaneous nerve puncture during ultrasound-guided regional anesthesia can be chosen.

Axillary Artery↗
PubMed2000

Proximal and distal motor nerve conduction in obturator and femoral nerves.

OBJECTIVE: To study the proximal and distal motor conduction properties of obturator and femoral nerves. DESIGN: For evaluation of distal motor conduction properties, obturator and femoral nerves were stimulated at the inguinal ligament, and M responses were recorded with needle electrodes from gracilis and rectus femoris muscles. Upper lumbar roots were stimulated with needle electrodes inserted between L1-L2 vertebral laminae. PARTICIPANTS: Sixteen healthy adults, eight of each gender, age 22 to 52 years (mean 37.5). MAIN OUTCOME MEASURES: Description of a method for assessing motor conduction along the obturator nerve and evaluating proximal motor conduction measurements obtained with stimulation of obturator and femoral nerves. RESULTS: Distal motor conduction latencies were 3.9 +/- 0.7 msec for gracilis and 4.6 +/- 0.5msec for rectus femoris after stimulation of obturator and femoral nerves, respectively. Proximal conduction times from lumbar vertebral level were 10.4 +/- 0.3msec for the obturator nerve and 10.8 +/- 0.4msec for the femoral nerve. Conduction velocities of proximal segments of both nerves were similar, 62m/sec for the obturator nerve and 65m/sec for the femoral nerve. Submaximal stimulation of both nerves evoked H-reflex responses from their associated muscles. CONCLUSIONS: Motor conduction properties of the obturator nerve can be assessed by the method described, particularly to differentiate between peripheral, plexus, or radicular lesions that involve the obturator nerve.

Adult↗
PubMed2006

Secondary digital nerve repair in the foot with resorbable p(DLLA-epsilon-CL) nerve conduits.

Nerve guides are increasingly being used in peripheral nerve repair. In the last decade, much preclinical research has been undertaken into a resorbable nerve guide composed of p(DLLA-epsilon-CL). This report describes the results of secondary digital nerve reconstruction in the foot in a patient with post-traumatic neuromas of the common plantar digital nerves II-III and III-IV. The neuromas were resected and reconstruction of the nerves was carried out with resorbable Neurolac nerve guides. The Pressure Specified Sensory Device was used to measure the static (s) and moving (m) 1- and 2-point discrimination (PD). Fourteen months after nerve repair, the m1-PD returned in all digital nerves. The s1-PD returned only on the lateral side of the second toe. The m2-PD and s2-PD did not return in any of the toes originally innervated by the reconstructed nerves. According to the British Classification System, the sensory nerve recovery was poor. However, there were no complaints of painful neuromas after this procedure. In conclusion, this report shows no beneficial effects of Neurolac nerve guides in terms of return of sensibility after repair of common plantar digital nerves. Painful neuromas, however, could be well-treated.

Absorbable Implants↗
PubMed1996

Influence of partial nerve injury in the rat on efferent function of sympathetic and antidromically acting sensory nerve fibers.

OBJECTIVE: To investigate how partial injury of a large peripheral nerve affects efferent (vasomotor) function of sympathetic and antidromically acting sensory nerve fibers. DESIGN: Randomized animal study. MATERIALS AND METHODS: We assessed, by laser Doppler flowmetry, skin blood flow (SBF) in the hindpaw of male Lewis rats before partial injury of the ipsilateral sciatic nerve (through loose ligation) as well as at an early stage (day 4) and at a later stage (day 21) after this procedure. This procedure has been reported to induce signs and symptoms like those observed in patients with causalgia. At the two time points after nerve injury, SBF was assessed before and after (chemical) blockade of sensory and nonsensory (sympathetic) sciatic nerve fibers. Furthermore, at day 21 we measured the density of sympathetic nerve fibers in footpad arteries. MEASUREMENTS AND MAIN RESULTS: At day 4, compared with preligation values, we observed an increase in SBF that was reduced by blockade of sensory nerve fibers. Subsequent blockade of nonsensory nerve fibers further reduced SBF. At day 21, SBF was decreased compared with preligation values. Blockade of sensory nerve fibers further reduced SBF, and subsequent blockade of nonsensory nerve fibers did so as well. The density of sympathetic nerve fibers was lower on the ligated side than on the nonligated side. CONCLUSIONS: Partial injury of the rat sciatic nerve causes an ipsilateral increase in SBF at an early stage, which is followed by a decrease at a later stage. At both stages, antidromically acting sensory and orthodromically acting nonsensory (sympathetic) nerve fibers are involved in the vasodilator response. At a later stage, however, neurogenic vasodilator mechanisms are overruled by a nonneurogenic vasoconstrictor mechanism. The latter may consist of supersensitivity of skin microvessels to catecholamines consequent to reduced neurogenic disposition of catecholamines.

Animals↗
PubMed2004

Effects of external beam radiation in the rat tibial nerve after crush, transection and repair, or nerve isograft paradigms.

INTRODUCTION: In head and neck surgery, radiation therapy is often administered to an injured nerve. Previous studies have examined the effects of either preoperative or postoperative radiation on nerve regeneration in rodents. In these studies, histomorphometric analysis was performed up to 8 month postoperatively. Given the exceptional neuroregenerative capacity of rodents, significant differences in nerve regeneration may go undetected if nerves are evaluated at such distant postoperative time points. This study is designed with a more appropriate model and investigates the effects of radiation after three common nerve injury paradigms. METHODS: Sixty-four Lewis rates were randomized to 8 groups corresponding to uninjured, tibial nerve crush, transection and repair, or reconstruction with isografts. Half of the animals in each of these paradigms (n = 8 per group) were treated with 10 Gy of external beam radiation to the site of nerve injury at 7 days postoperatively. On postoperative day 28, functional recovery and histomorphometric assessment was performed. RESULTS: For a given paradigm of nerve injury, no significant differences in nerve fiber number, neural density, neural debris, or fiber width were noted between the control and radiated groups, and radiation did not affect functional recovery. CONCLUSION: Radiation had no discernible effect on nerve regeneration or functional recovery in the rodent nerve injury models studied. All assessments were made at time points suitable for detecting differences in nerve regeneration between groups. These findings suggest that administration of radiation to fields containing injured peripheral nerve is unlikely to adversely affect functional outcomes.

Animals↗
PubMed1995

Chronic nerve root compression. Pathophysiologic mechanism of nerve root dysfunction.

STUDY DESIGN: The pathophysiologic changes of the spinal nerve root caused by chronic compression were assessed in the lumbar spine of the adult dog. METHODS: The seventh lumbar nerve root was banded with a Silastic tube 5 mm long and a 3 mm internal diameter, which is slightly larger than the diameter of the nerve root. Histologic and electrophysiologic studies as well as assessment of the blood-nerve barrier function in the nerve root were conducted at 24 hours through 12 months. RESULTS: The earliest findings were thickening of the dura mater and arachnoid membrane around the affected nerve root corresponding to the alteration of the blood-nerve barrier in the nerve root after 1 month. After 3 months, large myelinated fibers decreased in number and small newly formed fibers increased in the periphery of the fascicle. At 6 months, endoneurial fibrosis and Wallerian degeneration of nerve fibers became obvious. Compound action potentials and sensory nerve conduction velocity decreased by 3 and 12 months, respectively. Decrease in amplitude of the compressed action potential was identical to the period of decrease in large myelinated fibers, and nerve conduction velocity did not decrease as long as some large myelinated fiber remained until 12 months after tubing. CONCLUSION: Intraradicular edema caused by alteration of the blood-nerve barrier is the most important factor in the nerve root dysfunction due to chronic compression.

Animals↗
PubMed2004

Transfer of fascicles from the ulnar nerve to the nerve to the biceps in the treatment of upper brachial plexus palsy.

BACKGROUND: The transfer of one or more ulnar nerve fascicles to the nerve to the biceps can restore elbow flexion in patients with upper brachial plexus palsy. The purposes of the present retrospective study were to evaluate the results of this procedure, to measure the delay in reinnervation of the biceps muscle, and to define the indications for a secondary Steindler flexorplasty. METHODS: Thirty-two patients with an upper nerve-root brachial plexus injury were reviewed at an average of thirty-one months after the nerve fascicle transfer. The average age of the patients was twenty-eight years. The average time between the injury and the operation was nine months. Patients were evaluated with regard to reinnervation of the biceps, ulnar nerve function, elbow flexion strength, and grip strength. RESULTS: The average time required for reinnervation of the biceps after nerve fascicle transfer was five months. No motor or sensory deficits related to the ulnar nerve were noted clinically. The average grip strength at the time of the last follow-up was 25 kg (an improvement of 9 kg compared with the preoperative value). After the nerve transfer, twenty-four patients achieved grade-3 elbow flexion strength or better according to the grading system of the Medical Research Council. A Steindler flexorplasty was performed as a secondary procedure in ten patients with persistent grade-3 flexor strength or worse. In eight of these cases, elbow flexion strength improved after nerve transfer and flexorplasty. Overall, thirty of the thirty-two patients achieved a good result (grade-4 strength) or a fair result (grade-3 strength). CONCLUSIONS: We recommend this procedure for brachial plexus injuries involving the C5-C6 or C5-C6-C7 nerve roots. This procedure spares the C5 nerve root and other nerves for grafting or transfer elsewhere. A secondary Steindler flexorplasty is indicated for patients who have persistent grade-3 elbow flexion strength or worse for at least twelve months after nerve fascicle transfer.

Adolescent↗
PubMed2004

[The results of nerve repair in combined nerve-tendon injuries of the forearm].

BACKGROUND: We evaluated the clinical and functional results of nerve repair in patients with combined tendon-nerve injuries of the forearm. METHODS: The study included 68 patients (58 males, 10 females; mean age 33.5 years; range 5 to 48 years) with combined tendon-nerve injuries of the forearm. A total of 96 nerves were repaired. Patients with nerve defects were excluded. Both median and ulnar nerves were injured in 17 patients; median and ulnar nerve injuries were detected in 17 patients and 34 patients, respectively. The mean time to operation was four hours (range 20 min to 24 h). Primary nerve repair was performed in 60 patients, and secondary repair was performed in eight patients. The interfascicular technique was employed in 18 patients, and epiperineural suture in 50 patients. Rehabilitation included early motion using the Washington regimen. A modified MRC (Medical Research Council) motor and sensory classification system was used for postoperative evaluation. The mean follow-up was at least two years. RESULTS: The modified MRC results were as follows: of 17 patients with median nerve injuries, 10 had excellent, seven had good results. Of 34 patients with ulnar nerve injuries, the results were excellent in nine, very good in 10, good in 10, and fair in five patients. Of those with median and ulnar nerve injuries, four, seven, and six patients had excellent, very good, and good results, respectively. Overall, 61 patients (89.7%) had satisfactory results. A significant correlation was found between age and the MRC results (p=0.016). CONCLUSION: Primary nerve repair followed by early motion results in substantial rates of excellent and satisfactory results in patients with combined nerve-tendon injuries.

Adolescent↗
PubMed1995

Regeneration of nitric oxide synthase-containing nerves after cavernous nerve neurotomy in the rat.

In patients who recover erectile function after radical prostatectomy (with preservation of at least 1 neurovascular bundle), a recovery time of 6 to 18 months is not uncommon. As this is also the usual time required for regeneration of spinal nerves, we believe that regeneration of cavernous nerves, partially damaged inadvertently, may be responsible. In a rat model, we examined the long-term effect of unilateral and bilateral cavernous nerve transection on the nonadrenergic/noncholinergic (NANC) nervous system and erectile function. In 31 rats, nitric oxide synthase (NOS), the enzyme that catalyzes nitric oxide production, was identified in penile nerve fibers from a mid-shaft segment with nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining and antibody to neuronal NOS. Animals were divided into three groups: 5 rats underwent pelvic exploration without transection of cavernous nerves (sham group); 13 rats underwent unilateral neurotomy of a 5-mm. segment of the cavernous nerve; and 13 rats underwent bilateral neurotomy. After bilateral ablation, the NOS-positive nerve fibers were significantly decreased at 3 weeks and remained so at 6 months; no erectile response could be elicited by pelvic nerve stimulation. After unilateral ablation, the NOS-positive nerve fibers were similarly decreased on the side of the neurotomy at 3 weeks, but by 6 months the number had increased significantly and approximated the level on the contralateral side. Furthermore, electrostimulation of the intact side induced a greater intracavernous pressure response at 6 months than at 3 weeks (N.B. the rat has an incomplete septum). Fibers positive for NOS were also identified in the dorsal nerve. The staining pattern diminished as rapidly and significantly on the side of neurotomy as in tissue from the corpus cavernosum. However, regeneration was not seen. To our knowledge, this is the first demonstration of regeneration of NOS-containing nerves after cavernous nerve neurotomy. Our findings support the reports by others that unilateral nerve-sparing is sufficient to preserve erectile function.

Amino Acid Oxidoreductases↗