ABSTRACT
BACKGROUND:Studies have shown that the application of electrical stimulation of peripheral nerve fibers can recover partial muscle functions due to the loss of central nervous control. OBJECTIVE:To verify the feasibility of selective nerve excitatory effectively used the symmetric biphasic pulses under the bipolar electrodes stimulation of 1 mm. METHODS:Eight adult Wistar rats were selected to expose the sciatic nerves after anesthesia and then the electrodes were placed on the sciatic nerves careful y to establish the model of selective nerve stimulation. Experimental electrode was homemade Cuff bipolar electrode, and the electrode stimulators were Grass S88 stimulator and AWG2005 arbitrary waveform signal generator. The two-way dual-electrode stimulation was used. The distance between two electrodes was 1 mm, and the stimulation waveform was symmetric biphasic pulse with the width of 0.2 ms. The output pulse amplitude, pulse width and delay could be adjusted. The stimulation intensity was adjusted, and the law of nerve excitability was detected under two-way dual-electrode stimulation, in order to achieve selective nerve excitability, and the feasibility of two-way dual-electrode stimulation to achieve selective nerve excitatory was verified with“col ision”method. RESULTS AND CONCLUSION:The change of nerve action potential was amplified by P511 amplifier and then linked into oscil oscope for displaying, and dual-electrode stimulation waveform was the symmetric biphasic pulse with the width of 0.2 ms. With the increasing of stimulus amplitude, we achieved the selective nerve excitatory. The results indicate the selective nerve excitatory can be achieved with the closed (1 mm) dual-electrode symmetric pulse, and the feasibility and effectiveness of this method can be verified with“col ision”principle.
ABSTRACT
BACKGROUND: Therapeutic methods for of peripheral facial nerve injury include surgery, physical therapy and drug treatment, but the treatment effect is not ideal in some certain cases. OBJECTIVE: To study the effect of autologous platelet rich plasma on repair of facial nerve injury. METHODS: The bilateral destroyed buccal nerve branches of the 10 white rabbits were put in silica gel nerve regeneration chamber, one side injected with platelet rich plasma as experimental group, the other side injected with normal saline as control group. The general observation, neuroelectrophysiology detection, histological observation, image analysis and evaluation of facial nerve regeneration recovery were performed at 8 weeks after surgery. RESULTS AND CONCLUSION: The action potential latency of the orbicularis oris at the experimental side was significantly lower than that at the control side, and the action potential amplitude (M wave) of compound nerve muscle of the experimental side was significantly higher than that of the control side (P < 0.01). Compared with the control side, the regenerative nerves of the experimental side were more mature with more regenerative axons, and the differentiation of myelin sheath was more mature and the thickness of myelin sheath was wel -distributed. Meanwhile, the diameters of axons were closed to the normal diameter, and the nerve axons were more intensive and arranged more regularly, the outer membrane of nerve fiber was thicker and the col agen fiber and elastic fiber layer were increased when compared with the control group. The number of regenerative axons of the control side was less, and the axons were distributed irregularly and poorly developed, and a large number of fibrous connective tissues were observed. The vacuolar degeneration at the control side was more than the experimental side. The regenerated nerve in the experimental side was better than the control side in the diameter of myelinated axon, area, myelin sheath thickness and axon count, and there were significant differences between two groups (P < 0.01). It indicates that platelet rich plasma has a promoting effect in the repair and regeneration of facial nerve.