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PubMed1995

Wrist denervation. Anatomical considerations.

In 1966, Wilhelm published a technique of denervation of the wrist joint based on his own anatomical studies of 1958. Other authors have published their experience in wrist denervations with similar results, but there are some discrepancies in descriptions of the innervation of the wrist. We have studied the innervation of the wrist by dissection under magnification on 20 cadaver limbs and by histological examination of five human foetal wrists. Based in our anatomical findings, we have demonstrated that Wilhelm's technique does not achieve total denervation of the wrist.

Cadaver↗
PubMed1996

Tennis elbow: treatment of resistant cases by denervation.

Anatomical and clinical research has shown that the entire lateral epicondylar region is innervated only by radial nerve branches. Based on these investigations we have developed a surgical procedure for complete denervation which is indicated only in resistant cases of tennis elbow. Only one nerve pathway calls for careful exposure, otherwise denervation is accomplished blindly by disinsertion of certain muscles. The result of this procedure also depends on simultaneous indirect decompression of the posterior interosseous nerve. Excellent or good results were obtained in 90% on average. Results of denervation did not improve by additional direct radial nerve release.

Adult↗
PubMed2002

Management of chronic testalgia by microsurgical testicular denervation.

OBJECTIVES: Chronic testicular pain (CTP) is defined as uni- or bilateral, intermittent or continuous testicular discomfort of at least 3 months duration that interferes with the patient's daily activities and prompts him to seek medical advice is a rather common urological manifestation of chronic pain syndrome. Diagnosis and treatment of CTP has been a difficult and often unrewarding clinical situation. Success rates of conservative and surgical measures including epididymectomy and orchiectomy rarely exceed 55-73% and 10-40%, respectively. We report our experience on microsurgical testicular denervation as therapeutic option in CTP. PATIENTS AND METHODS: Following an extensive preoperative work-up (urine/semen cultures, transrectal ultrasound, testicular sonography, pain and orthopedic consultation) not revealing any pathologic abnormalities and a positive response to spermatic cord block, 35 patients underwent microsurgical testicular denervation. In brief, spermatic cord was dissected, vas deferens, cremasteric muscle and testicular vessels were separated. After identification of the testicular artery by application of vasodilatating agents using magnifying loops or the operating microscope, all structures besides the testicular artery, vas deferens and 1-2 lymphatic vessels were coagulated and transsected using bipolar diathermy. RESULTS: After a mean follow-up of 31.5 months 34/35 (96%) patients are completely pain-free; no intra- or postoperative complications were encountered. No case of testicular atrophy or hydrocele formation was observed during postoperative follow-up. CONCLUSIONS: Microsurgical testicular denervation results in reliable and reproducible excellent therapeutic success rates of 96% and should be integrated in the management of CTP at an early stage. High success rates require adequate and meticulous diagnostic work-up of the patients by spermatic cord block using saline as placebo and different local anaesthetics as an initial therapeutic armentarium predicting postoperative outcome.

Adult↗
PubMed2001

Enhanced excitatory synaptic transmission in spiny neurons of rat striatum after unilateral dopamine denervation.

The synaptic transmission and intrinsic membrane properties of spiny neurons in rat neostriatum were studied after unilateral dopamine depletion using in vivo intracellular recording and staining techniques. Two to four weeks after dopamine denervation, the spontaneous firing rate of spiny neurons increased and the spontaneous membrane potential fluctuation stayed at a more depolarized state for longer periods of time. The amplitude of cortically evoked initial excitatory postsynaptic potentials increased and a late excitatory postsynaptic potential that was occasionally found in control neurons was elicited from 23% of spiny neurons after dopamine denervation. No significant changes in intrinsic membrane properties of spiny neurons were observed after dopamine denervation. These results suggest that dopamine inhibits excitatory synaptic transmission of spiny neurons in naïve animals.

Animals↗
PubMed2001

Denervation causes changes in electrophysiological properties in rat phrenic motoneurons.

Thirty-nine male adult rats were divided into a control group and a denervation group that had been subjected to phrenicotomy 4 weeks earlier. Electrophysiological membrane properties (input resistance and rheobase) of phrenic motoneurons were measured from intracellular recordings made with glass microelectrodes. Under anesthetized and artificially ventilated conditions, the recorded motoneurons were divided into recruited (spike discharge) and non-recruited (depolarization only) types. There was a significant inverse relationship between the rheobase and input resistance in the control rats, but not in the denervated rats. In the control rats, the mean value of rheobase in the non-recruited motoneurons was significantly higher than that in the recruited motoneurons. In denervated rats, however, the mean value of rheobase in the recruited motoneurons was identical to that in the non-recruited motoneurons. The results indicated that phrenicotomy induced a de-differentiation of electrophysiological properties of the phrenic motoneurons, and that these changes might be restricted to the motoneurons innervating fast-twitch, low fatigue resistance muscle fibers.

Animals↗
PubMed1997

Neurotrophin-3 mRNA expression in rat intrafusal muscle fibres after denervation and reinnervation.

We have studied the regulation of the expression of neurotrophin-3 (NT-3) mRNA in neonatal and adult rat muscle spindles after denervation and after denervation followed by reinnervation. Denervation of the intrafusal fibres did not result in an upregulation of the NT-3 mRNA expression but decreased this expression below the detection limit of the in situ hybridization method. Reinnervation of intrafusal fibres restored the NT-3 mRNA expression. The results suggest that the expression of NT-3 mRNA in postnatal muscle spindles is controlled by neuronal factors. The intrafusal fibre derived NT-3 may act as an instructive, feedback messenger for innervating neurons and may play a role in stabilizing and maintaining functional neuromuscular connections.

Animals↗
PubMed1998

Optical imaging of the spontaneous neuronal activities in the male rat major pelvic ganglion following denervation of the pelvic nerve.

Measurement of groups of neuronal activities following pelvic nerve transection to the major pelvic ganglion (MPG) of the rat was performed using voltage-sensitive dye (RH795) and an optical recording system. In control MPG, averaged neuron diameters were 32.0 +/- 0.6 x 22.6 +/- 0.4 microm. Application of KCl (10-50 mM) to the ganglia exhibited excitation which increased in a dose-dependent fashion. Fluctuating membrane potentials were not observed in control ganglion neurons. After the denervation of pelvic nerve chronically (2-6 weeks), the spontaneous neuronal activities were recorded in 91% of the experiments (n = 32). The activity was occurring somewhat periodically (2-15 s). Averaged neuron diameters were 41.3 +/- 1.3 x 24.7 +/- 0.9 microm in denervated MPG which is significantly larger than control. Since average neuron size increased 4 weeks after the denervation, the new excitatory activities could have influenced the change of the neuron size. The new activities might produce contraction of target organs in the pelvic viscera.

Animals↗
PubMed1997

Denervation-induced supersensitivity to forskolin and pinacidil is not related to changes in the adenylate cyclase transduction pathway in the rabbit femoral artery.

1. The present study investigates whether chemical sympathectomy compromises the relaxation of the rabbit femoral artery precontracted with serotonin. The vasodilating agents promoted cyclic adenosine monophosphate (cAMP) accumulation or opening of the potassium channels. The effect of denervation on the adenylyl cyclase transduction pathway was also studied. 2. 6-Hydroxydopamine treatment did not impair the relaxation to adenosine, 8-bromoadenosine-cAMP (a membrane-permeable analog of cAMP) and 3-isobutyl-1-methylxanthine (a cAMP phosphodiesterase inhibitor). Moreover, denervation enhanced the relaxation to forskolin (a direct Gs-type protein activator) and pinacidil (a potassium channel opener). 3. Denervation modified neither adenosine diphosphate ribosylation of Gs- and Gi-proteins nor adenylyl cyclase activity.

1-Methyl-3-isobutylxanthine↗
PubMed1999

Changes in the regional and compartmental distribution of FosB- and JunB-like immunoreactivity induced in the dopamine-denervated rat striatum by acute or chronic L-dopa treatment.

This study was carried out in order to examine the effects of acute or chronic L-DOPA treatment on striatally expressed FosB- and JunB-like proteins in a rat model of Parkinson's disease. Rats with a unilateral, near-total 6-hydroxydopamine lesion of the ascending mesostriatal projection received either an acute challenge or a one-week treatment with 10 mg/kg/day methyl L-DOPA (combined with 15 mg/mg benserazide), and were killed at either 3 h or two days post-injection. Both acute and chronic L-DOPA treatment caused a pronounced, persistent increase in the number of FosB-like immunoreactive cells in the dopamine-denervated striata (five- and seven-fold increase, respectively, above the levels found in lesioned but non-drug-treated controls), but the two treatment groups differed markedly with respect to both the average amount of staining per cell, which was two-fold larger in the chronic L-DOPA cases, and the anatomical distribution of the labeled cells. After an acute injection of L-DOPA, FosB-positive cells were distributed rather uniformly across all striatal subregions, whereas chronic L-DOPA treatment induced discrete clusters of strongly FosB-like immunoreactive cells within medial and central striatal subregions, as well as in a large, yet sharply defined portion of the lateral caudate-putamen. Strongly labeled cell clusters that appeared in the medial and central caudate-putamen were preferentially located within calbindin-poor, mu-opioid receptor-rich striosomes, whereas the lateral area displaying FosB activation encompassed both striosomal and matrix domains. In both the medial and the lateral striatum a near-total overlap was found between strongly FosB-like immunoreactive cell groups and areas showing pronounced dynorphin expression. NADPH-diaphorase-positive striatal interneurons did not express FosB-like immunoreactivity after a 6-hydroxydopamine lesion alone, a negligible proportion of them did after an acute L-DOPA challenge, but about 8% of these interneurons were FosB positive following chronic L-DOPA treatment. Like FosB, JunB was induced in the DA-denervated striatum by both acute and chronic L-DOPA treatment, and exhibited similar distribution patterns. However, JunB did not exhibit prolonged expression kinetics, and was somewhat down-regulated in the chronically compared with the acutely L-DOPA-treated rats. The present results show that L-DOPA administration produces a long-lasting increase in the levels of FosB-, but not JunB-like immunoreactivity in the dopamine-denervated striatum. More importantly, these data show that striatal induction of FosB- and JunB-like proteins by chronic L-DOPA treatment exhibits both regional and compartmental specificity.

Animals↗
PubMed1977

Denervation of the wrist joint.

A collective review was made of the results of denervation of the wrist joint for painful restrictiorn of motion done in 313 patients and follow-up studies on 195 (average 4.1 years, ranging from 9 months to 14 years). Complete denervation was done in only 30, partial denervation in the others being done after testing with local anesthetic blocks. Sixty-nine of the patients retained a moble wrist without pain or with slight pain with heavy work. No evidence of Charcot-like joints was seen. Poorest results followed when the operation was done for sequelae of intra-articular fracture of the radius, fracture dislocations, unstable ligamentous support, joint surface destruction, or for those required to do heavy manual labor. Arthrodesis was done secondarily in nine patients.

Arthrodesis↗
PubMed1998

The effect of denervated muscle and Schwann cells on axon collateral sprouting.

The effects of denervated muscle and Schwann cells on collateral sprouting from peripheral nerve were studied in the peroneal and tibial nerves of 48 Sprague-Dawley rats. Three groups were prepared. In group MSW (muscle-Schwann cell-window), the peroneal nerves were transected 3 mm below the sciatic bifurcation. The proximal stumps were sealed in a blocked tube to prevent regeneration and the distal stumps were implanted into denervated muscle cells that were wrapped around the ipsilateral tibial nerve, which had a window of perineurium resected. Schwann cells from the ipsilateral sural nerve were implanted into the muscle. Group MS (muscle-Schwann cell) was similar to group MSW, except that the tibial nerve perineurium was kept intact. In group MW (muscle-window), the muscle was prepared without Schwann cells and the tibial nerve perineurium was windowed. S-100 immunostain was used to identify the Schwann cells surviving 1 week after transplantation. After 16 weeks of regeneration, horseradish peroxidase tracer was used to label motor neurons and sensory neurons reinnervating the peroneal nerve. Myelinated axons of the reinnervated peroneal nerves were quantified with the Bioquant OS/2 computer system (R&M Biometrics, Nashville, TN). A mean of 169 motor neurons in group MSW, 64 in group MW, and 26 in group MS reinnervated the peroneal nerve. In the dorsal root ganglion, the mean number of labeled sensory neurons was 1,283 in group MSW, 947 in group MS, and 615 in group MW. The mean number of myelinated axons in the reinnervated peroneal nerve was 1,659 in group MSW, 359 in group MS, and 348 in group MW. Reinnervated anterolateral compartment muscles in group MSW were significantly heavier than those in group MS or MW. This study demonstrates that the transplantation of denervated muscle and Schwann cells promotes motor and sensory nerve collateral sprouting through a perineurial window.

Animals↗
PubMed2003

Effects of partial locus coeruleus denervation and chronic mild stress on behaviour and monoamine neurochemistry in the rat.

It has been proposed that lesions of the ascending noradrenergic projections render animals more vulnerable to stress. In this study, the effects of partial denervation of the locus coeruleus (LC) by DSP-4 (10 mg/kg) treatment, chronic mild stress (CMS) and their combination were examined. DSP-4 was administered to rats 1 week before the onset of CMS, which was applied for 5 weeks. In the forced swimming test, the immobility time was decreased by both DSP-4 and CMS. In the open field test, the number of defecations was increased after DSP-4 treatment plus CMS. Partial LC denervation decreased the levels of noradrenaline (NA) by 34%, increased NA turnover, and decreased the density of beta-adrenoceptors in the cerebral cortex. CMS decreased the binding affinity of beta-adrenoceptors, an effect not observed in the DSP-4 treated animals. In conclusion, 6 weeks after partial LC denervation NA turnover is increased in the cortex, and the effect of CMS on emotionality is enhanced.

Analysis of Variance↗
PubMed2003

The nifk gene is widely expressed in mouse tissues and is up-regulated in denervated hind limb muscle.

Denervation of skeletal muscle alters the expression of many genes, which may be important for establishing optimal conditions for reinnervation. Using the differential display technique we have attempted to discover neurally regulated genes in skeletal muscle. An mRNA that is up-regulated in denervated hind limb muscle was identified and cloned. The cDNA encodes an RNA-binding protein, which was discovered during the course of this work to be a nucleolar protein interacting with the fork-head associated domain of the proliferation marker protein Ki-67, and named NIFK. We show that the nifk gene is widely expressed in adult mouse tissues and that the expression is up-regulated in denervated hind limb muscle. No difference between expression in perisynaptic and extrasynaptic portions of muscle was observed. The widespread expression in adult tissues suggests that the NIFK protein has other functions in addition to its interaction with Ki-67, which is only expressed in proliferating cells.

3' Untranslated Regions↗
PubMed2002

[Trapeziometacarpal denervation. Description of surgical technique and preliminary results from a prospective series of 14 cases].

INTRODUCTION: The main goal of first carpometacarpal arthritis surgical treatment is to relieve pain. The main disadvantages of the usual techniques (trapeziectomy, implant arthroplasty) are loss of strength or presence of a prosthetic device. It is difficult to propose such extensive surgery at an early stage of the disease. Selective denervation of the first carpometacarpal joint seems to be an interesting choice. We propose a new technique of denervation based on our previous anatomical investigations. TECHNIQUE: Two incisions are needed to cut all the articular branches derive from the superficial branch of the radial nerve, the palmar cutaneous branch of the median nerve, the thenar branch of the median nerve and the lateral ante brachial cutaneous nerve. MATERIAL: Fourteen patients were prospectively included in our study with a mean follow-up of 5 months. RESULTS: Pain relief was very satisfying in 12 cases (mean decrease 84%). An increase in grip and key pinch strength was noted. Complications were uncommon, excepted temporary paresthésia in the radial nerve area. DISCUSSION: This technique seems to be promising and a good indication for patients with no disabling deformity, but only long-term results will confirm the place of denervation in the treatment of first carpometacarpal arthritis.

Adult↗
PubMed2001

Cardiac autonomic denervation and functional response to neurotoxins during acute experimental Chagas' disease in rats.

Severe cardiac autonomic denervation occurs in the acute Chagas' disease in rats. The present study aims at verifying whether this denervation was accompanied by impairment of heart function. Scorpionic (Tityus serrulatus) crude venom was used for neurotransmitter release in isolated hearts (Langendorff's preparation). In control hearts, the venom induced significant bradycardia followed by tachycardia. In infected animals, despite the severe (sympathetic) or moderate (parasympathetic) cardiac denervation, the venom provoked similar bradycardia but the tachycardia was higher. The hearts of infected animals beat at significantly lower rate. Atropine prevented this lower rate. Our results demonstrated sympathetic dysfunction during the acute phase of Trypanosoma cruzi infection in rats, the parasympathetic function being spared.

Acetylcholine↗
PubMed1986

Effect of denervation on primate laryngeal muscles: a morphologic and morphometric study.

Primate intrinsic laryngeal muscles studied consisted of Type I and Type II fibres. Type II fibres were larger than Type I fibres. The coefficient of variance of these muscles suggested that the fibre-size variation was similar in all of these muscles. Denervation resulted in shrinking of Type II fibres at two weeks in all the muscles, while at four weeks the thyroarytenoid showed an inflammatory reaction and far greater reduction in size than the other muscles. At eight weeks, however, all the muscles were fibrosed. We conclude that laryngeal muscles begin to show evidence of denervation at two weeks and are fibrosed in eight weeks. The thyroarytenoid muscle showed inflammatory degeneration, while the posterior cricoarytenoid and cricothyroid muscles showed classical changes of denervation. These findings should have clinical significance in the timing of reinnervation procedures.

Animals↗
PubMed2002

Extrinsic denervation causes a transient proabsorptive adrenergic hypersensitivity in the canine proximal colon.

Our aim was to determine if extrinsic denervation alters the absorptive response of the colon to proabsorptive and prosecretory stimuli. Ten dogs underwent enteric isolation of a 50-cm proximal colonic segment; five were also randomized to undergo extrinsic denervation (DEN). At 2 and 13 wk postoperatively, net absorptive fluxes (mean +/- SEM) of water and electrolytes were determined during basal conditions and during proabsorptive low-dose (0.3 microg/kg/min) or high-dose (3 microg/kg/min) norepinephrine or prosecretory VIP (500 pg/kg/min). The net absorptive flux of water under basal conditions was decreased in DEN versus neurally intact controls at two weeks (4.0 +/- 0.6 vs 6.6 +/- 0.7 microl/min/cm, P = 0.03) but did not differ at 13 weeks (5.0 +/- 1.0 vs 5.7 +/- 0.9, P > 0.05). Low- and high-dose norepinephrine increased water absorption in both groups at two weeks; the change in flux for high-dose norepinephrine was greater in DEN versus controls (4.1 +/- 1 vs 2.1 +/- 0.6 microl/min/cm, P = 0.04). Net absorptive fluxes of Na+ and Cl- followed these trends. VIP did not alter absorption of water or electrolytes. Extrinsic denervation of the proximal colon causes a decrease in net colonic absorption and a transient, proabsorptive adrenergic hypersensitivity in colonic absorption of water and electrolytes. VIP does not have a net secretory effect in the proximal canine colon.

Adrenergic alpha-Agonists↗
PubMed1979

Agonist-induced potentiation of acetylcholine sensitivity in denervated skeletal muscle.

The entire surface membrane of denervated skeletal muscle is sensitive to the neuromuscular transmitter, acetylcholine (ACh), whereas in innervated muscle only the junctional area is sensitive. It has been proposed that this difference is due to a 'trophic' effect exerted by ACh in innervated muscle to keep the extrajunctional regions of the surface membrane insensitive to its depolarising action. Several studies have demonstrated an agonist-induced potentiation of ACh sensitivity, followed by desensitisation, at the endplate region of normal muscles. The potentiation has been attributed to a cooperative action of ACh on the receptors. Desensitisation of the extrajunctional regions of denervated muscles by ACh has also been described. We now provide evidence that the transmitter itself potentiates the ACh contracture and depolarisation responses of the denervated muscles of the rat in vitro and that it produces this effect by increasing the number of available ACh receptors on the surface membrane.

Acetylcholine↗