Motion-specific laryngeal reinnervation using muscle-nerve-muscle neurotization

There is no current treatment method that can reliably restore physiologic movement to a paralyzed vocal fold. The purposes of this study were to test the hypotheses that 1) muscle-nerve-muscle (M-N-M) neurotization can be in duced in feline laryngeal muscles and 2) M-N-M neurotization can restore mo vement to a paralyzed vocal fold. Muscle-nerve-muscle neurotization can be defined as the reinnervation of a denervated muscle via axons that are indu ced to sprout from nerves within an innervated muscle and that then travers e a nerve graft interposed between it and the target denervated muscle. A p aralyzed laryngeal muscle could be reinnervated by axons from its contralat eral paired muscle, thus achieving motion-specific reinnervation. Eighteen adult cats were divided into sham, hemilaryngeal-denervated, and M-N-M-rein nervated thyroarytenoid muscle groups. Five of the 6 reinnervated animals h ad histologic evidence of axons in the nerve graft, 4 of the 6 had evoked e lectromyographic evidence of crossed reinnervation, and I of the. 6 had a r eturn of appropriately phased adduction. This technique has great potential and should be further investigated.