Intraoperative neuromonitoring versus visual nerve identification for prevention of recurrent laryngeal nerve injury in adults undergoing thyroid surgery

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects of intraoperative neuromonitoring (IONM) versus visual nerve identification for prevention of recurrent laryngeal nerve injury in adults undergoing thyroid surgery

Identification alone versus intraoperative neuromonitoring of the recurrent laryngeal nerve during thyroid surgery: experience of 2034 consecutive patients

Background: The aim of this study was to evaluate the ability of intraoperative neuromonitoring in reducing the postoperative recurrent laryngeal nerve palsy rate by a comparison between patients submitted to thyroidectomy with intraoperative neuromonitoring and with routine identification alone. Methods: Between June 2007 and December 2012, 2034 consecutive patients underwent thyroidectomy by a single surgical team. We compared patients who have had neuromonitoring and patients who have undergone surgery with nerve visualization alone. Patients in which neuromonitoring was not utilized (Group A) were 993, patients in which was utilized (group B) were 1041. Results: In group A 28 recurrent laryngeal nerve injuries were observed (2.82%), 21 (2.11%) transient and 7 (0.7%) permanent. In group B 23 recurrent laryngeal nerve injuries were observed (2.21%), in 17 cases (1.63%) transient and in 6 (0.58%) permanent. Differences were not statistically significative. Conclusions: Visual nerve identification remains the gold standard of recurrent laryngeal nerve management in thyroid surgery. Neuromonitoring helps to identify the nerve, in particular in difficult cases, but it did not decrease nerve injuries compared with visualization alone. Future studies are warranted to evaluate the benefit of intraoperative neuromonitoring in thyroidectomy, especially in conditions in which the recurrent nerve is at high risk of injury. Keywords: Neuromonitoring, Recurrent laryngeal nerve, Thyroidectom

Simulation of intrafascicular and extraneural nerve stimulation

A model of nerve stimulation for control of muscle contraction and ensuing isometrical muscle force has been developed and implemented in a simulation algorithm. A description of nerve fiber excitation was obtained using probability distributions of a number of excitation parameters. The volume conduction model of the stimulated nerve incorporates both inhomogeneities and anisotropy within the nerve. The nerve geometry was assumed to be cylindrically symmetric. The model of the nerve fiber excitation mechanism was based on that of D.R. McNeal (1976), using the Frankenhaeuser-Huxley equations. Simulations showed that the diameter dependence of nerve fiber recruitment is influenced by the electrode geometr

Nerve commitment in Hydra. II. Localization of commitment in S phase

The kinetics of nerve differentiation were investigated during head regeneration in Hydra. In particular the cell cycle parameters of stem cells undergoing nerve commitment were determined. Head regeneration induces extensive nerve commitment localized at the regenerating tip (G. Venugopal and C. David, 1981, Develop. Biol.83, 353–360). The appearance of committed nerve precursors is followed 12 hr later by the appearance of newly differentiated nerves. Under these conditions the time from the end of S phase to nerve differentiation is about 9 hr and the time from the beginning of S phase to nerve differentiation is about 18 hr. Thus nerve commitment occurs in mid- to late S phase of the stem cell precursor

Multipotent vascular stem cells contribute to neurovascular regeneration of peripheral nerve.

BackgroundNeurovascular unit restoration is crucial for nerve regeneration, especially in critical gaps of injured peripheral nerve. Multipotent vascular stem cells (MVSCs) harvested from an adult blood vessel are involved in vascular remodeling; however, the therapeutic benefit for nerve regeneration is not clear.MethodsMVSCs were isolated from rats expressing green fluorescence protein (GFP), expanded, mixed with Matrigel matrix, and loaded into the nerve conduits. A nerve autograft or a nerve conduit (with acellular matrigel or MVSCs in matrigel) was used to bridge a transected sciatic nerve (10-mm critical gap) in rats. The functional motor recovery and cell fate in the regenerated nerve were investigated to understand the therapeutic benefit.ResultsMVSCs expressed markers such as Sox 17 and Sox10 and could differentiate into neural cells in vitro. One month following MVSC transplantation, the compound muscle action potential (CMAP) significantly increased as compared to the acellular group. MVSCs facilitated the recruitment of Schwann cell to regenerated axons. The transplanted cells, traced by GFP, differentiated into perineurial cells around the bundles of regenerated myelinated axons. In addition, MVSCs enhanced tight junction formation as a part of the blood-nerve barrier (BNB). Furthermore, MVSCs differentiated into perivascular cells and enhanced microvessel formation within regenerated neurovascular bundles.ConclusionsIn rats with peripheral nerve injuries, the transplantation of MVSCs into the nerve conduits improved the recovery of neuromuscular function; MVSCs differentiated into perineural cells and perivascular cells and enhanced the formation of tight junctions in perineural BNB. This study demonstrates the in vivo therapeutic benefit of adult MVSCs for peripheral nerve regeneration and provides insight into the role of MVSCs in BNB regeneration

Spatial pattern of nerve differentiation in Hydra is due to a pattern of nerve commitment

The pattern of nerve differentiation along the body column of Hydra was investigated. Nerve precursors in late S phase were labeled with [3H]thymidine and their distribution compared with that of newly differentiated nerves. The two distributions were found to be the same. Based on independent evidence that nerve commitment occurs in mid-to late S phase (G. Venugopal and C. David, 1981, Develop. Biol.83, 361–365) it was concluded that the pattern of nerve differentiation along the body column of Hydra is due to differences in nerve commitment in different body regions. Furthermore, the level of nerve commitment in head and foot tissue is sufficiently high to deplete stem cells in these regions as is observed