SUPERIOR LARYNGEAL NERVE EVOKED-POTENTIALS - AN EXPERIMENTAL-STUDY INTHE RABBIT

An experimental model is described for recording laryngeal evoked pote ntials at the brainstem level through electrical stimulation of the su perior laryngeal nerve. Rabbits were divided into two groups according to age: Group 1 consisted of 20 adults (over 6 months old), while gro up 2 was comprised of 1-month-old rabbits. Under general anesthesia, t he superior laryngeal nerve was electrically stimulated and the corres ponding evoked potentials were recorded by needle electrodes placed cl ose to the dorsal and ventral aspects of the brain stem. Clear age rel ated differences were observed for latency, amplitude, and morphology of the potentials. This fact suggests postnatal maturation of the nerv e structures, both peripheral. and central. Sectioning the superior la ryngeal nerve abolished all responses. Adduction of both vocal cords w as observed in conjunction with the use of stimulation.