The effect of surgical exposure of nerves and muscles in neurophysiologic tests on rats

Abstract

The neurophysiologic study in the modality of electroneuromyography (ENMG) determined and quantified the components in the motor ambit. The main data supplied by the examination was from the motor and sensory nerve conduction studies and by electromyography. However, many factors can interfere with the nervous response to electrostimulation, such as: age, gender, temperature, humidity, and other things. The aim of this work was to verify the effect of surgical exposure of the sciatic, common fibular, tibial, and cranial tibial muscle nerves in a neurophysiologic test on rats. Twenty (20) Wistar male rats were utilized, with approximately 80 days of age, divided into two groups. In the normal group the exam was made without the surgical exposure of the fibular nerve. In the surgical group the common fibular nerve was exposed. With the experimental model utilized, it was concluded that the neurophysiologic test done on animals with nerves and muscles surgically exposed is viable, since the alteration in animal temperature did not interfere significantly with the values of the electrophysiological parameters observed. In addition, the exposure of nerves and muscles allows stimulation of an exact point on the target nerve.

Double muscle innervation using end-to-side neurorrhaphy in rats

“…After anesthesia, clipping and aseptic preparation, a wide incision was made in the right hind limb, to allow access to the sciatic, peroneal and tibial nerves and the cranial tibial muscle. 7 The frequency (1 pps), duration (100 µs) and intensity (5.1 millivolts) of the stimulus were fixed. The motor unit action potential was recorded using needle electrodes.…”

“…The functional properties of the muscle were evaluated by applying stimuli delivered through bipolar electrodes that had been specially developed for this purpose, in which the cathode and anode were separated by a gap of 2 mm. 7 The electrode for bipolar stimulation was placed directly on the sciatic nerve in G3, G4 and G5 to enable propagation of electrical impulses through the end-to-side neurorrhaphy. In G1, G2 and G3, the electrophysiological test was performed just before the animals were sacrificed.…”