The optimal distance between two electrode tips during recording of compound nerve action potentials in the rat median nerve

The distance between the two electrode tips can greatly influence the parameters used for record- ing compound nerve action potentials. To investigate the optimal parameters for these recordings in the rat median nerve, we dissociated the nerve using different methods and compound nerve action potentials were orthodromically or antidromically recorded with different electrode spac- ings. Compound nerve action potentials could be consistently recorded using a method in which the middle part of the median nerve was intact, with both ends dissociated from the surrounding fascia and a ground wire inserted into the muscle close to the intact part. When the distance be- tween two stimulating electrode tips was increased, the threshold and supramaximal stimulating intensity of compound nerve action potentials were gradually decreased, but the amplitude was not changed significantly. When the distance between two recording electrode tips was increased, the amplitude was gradually increased, but the threshold and supramaximal stimulating intensity exhibited no significant change. Different distances between recording and stimulating sites did not produce significant effects on the aforementioned parameters. A distance of 5 mm between recording and stimulating electrodes and a distance of 10 mm between recording and stimulating sites were found to be optimal for compound nerve action potential recording in the rat median nerve. In addition, the orthodromic compound action potential, with a biphasic waveform that was more stable and displayed less interference （however also required a higher threshold and higher supramaximal stimulus）, was found to be superior to the antidromic compound action potential.

Olfactory ensheathing cells promote nerve regeneration and functional recovery after facial nerve defects

Olfactory ensheathing cells from the olfactory bulb and olfactory mucosa have been tbund to increase axonal sprouting and pathfinding and promote the recovery of vibrissae motor performance in facial nerve transection injured rats. However, it is not yet clear whether olfactory ensheathing cells promote the reparation of facial nerve defects in rats. In this study, a collagen sponge and silicone tube neural conduit was implanted into the 6-mm defect of the buccal branch of the facial nerve in adult rats. Olfactory ensheathing cells isolated from the olfactory bulb of newborn Sprague-Dawley rats were injected into the neural conduits connecting the ends of tile broken nerves, the morphology and function of the regenerated nerves were compared between the rats implanted with olfactory ensheathing cells with the rats injected with saline. Facial paralysis was assessed. Nerve electrography was used to measure facial nerve-induced action potentials. Visual inspection, anatomical microscopy and hematoxylin-eosin staining were used to assess the histomorphology around the trans planted neural conduit and the morphology of the regenerated nerve. Using fluorogold retrograde tracing, toluidine blue staining and lead uranyl acetate staining, we also measured the number of neurons in the anterior exterior lateral f：acial nerve motor nucleus, the number of myelinated nerve fibers, and nerve fiber diameter and myelin sheath thickness, respectively. After surgery, olfactory ensheathing cells de- creased facial paralysis and the latency of the facial nerve-induced action potentials. There were no differences in the general morphology of the regenerating nerves between the rats implanted with olfactory ensheathing cells and the rats injected with saline. Between-group results showed that olfactory ensheathing cell treatment increased the number of regenerated neurons, improved nerve fiber morphology, and increased the number of myelinated nerve fibers, nerve fiber diameter, and myelin sheath thickness. In conclusion, implantation of olfactory ensheathing cells can promote regeneration and functional recovery after facial nerve damage in rats.

Berrettini Anastomosis Iatrogenic Injury Relating to Carpel Tunnel Syndrome Case Study

Some diseases require medical mitigation following the diagnosis, and sometimes the situation means that the patient has to undertake strong medication. However, this medicine is designed pharmacodynamically to interact with other organs before they reach the intended organ. Some mitigation imposes challenges on the involved organ. While the main organ will be healed, some drugs’ footprints will be left out to other organs. These are called iatrogenic injuries. In the case of anastomosis, it requires the alteration of surgical methods or the origin of iatrogenic injury in the arm;thus, the knowledge of anastomosis is very important to the field of medical practice. In addition, carpal tunnel release becomes vital in curing carpal tunnel syndrome. The paper focuses on a case of a 42-year-old woman found to have a complication to her middle finger. This case becomes important for studying Berrettini anastomosis iatrogenic injury, which relates to carpal tunnel syndrome. The Berrettini branch is a complication that facilitates communication between the superficial ulnar and median nerve. The analysis also provides the electro-diagnostic evidence of Berrettini anastomosis on how it can give a position three-finger and thus contribute to a force explanation of the median neuropraxia. Lastly, the paper provides information on the implication of the Berrettini branch for surgical use. The implication of pictures in the digital era can be used to analyze the varied connection and length between the median nerve and ulnar section. It’s easy to locate the position of high risk of iatrogenic injury in the palm due to the consistent location of Berrettini communication branches. The precaution is that operations have to be conducted moderately for a clear vision as the carefully mitigated practice ensures protection from the destruction and injury of the surrounding structures.