Neuroprosthesis in the Treatment of RLN

A neuroprosthesis is an electrical stimulator that generates a signal whose amplitude (mA), frequency (Hz), pulse duration (micro sec), and pulse characteristic (phase) can be controlled. Early investigation in laryngeal neuroprosthesis proves that reanimation of the arytenoid cartilage and vocal fold was possible in dogs (Sanders et al., 1991, Zealar et al., 1994). More recently, positive results were reported in humans in a small clinical study (Zealar et al., 2003). The aim of our project is twofold: 1) test the hypothesis that restoration of abduction can be obtained through electrical stimulation of the recurrent laryngeal nerve or the cricoarytenoid dorsalis muscle (CAD) in horses, 2) determine stimulation-response curves for electrical stimulation under each condition in horses.
The focus of our investigation is the motor limb of neuroprosthesis. For a fully physiological laryngeal reanimation we would need to explore the sensory limb or trigger of the contraction. Ex-vivo experiments have indicated that maximal opening of the rima glottitis is obtained with stimulation of the medial and lateral compartments of the CAD; Stimulation of the lateral compartment produced more lateral displacement of the arytenoid cartilage, while stimulation of the medial compartment produced more dorsal movement of the arytenoid cartilage (Cheetham et al., 2008). […]