Current surgical strategies for the treatment of laryngeal paralysis are limited by the muscle atrophy associated with denervation. Moreover, attempts at reinnervation have not affected significant change in surgical outcome. To address this clinical problem, we have developed a rat laryngeal paralysis model to study novel gene transfer strategies. A muscle specific non-viral vector containing the a-actin promoter and hIGF-I gene formulated with polyvinyl polymers injected into denervated adult rat thyroarytenoid muscle has been shown to produce significant increase in muscle fiber diameter, significant decrease in motor endplate length and significant increase in percentage of endplates with nerve contact. Applied to laryngeal paralysis, hIGF-I gene therapy provides opportunity for augmentation of surgical treatment modalities by prevention or reversal of muscle atrophy, enhanced nerve sprouting and reinnervation. If proven effective, gene therapy may be applied clinically to fine-tune current surgical procedures or even eliminate the need for surgical intervention.
The Clarion, Med-E 1 Combi 40 and Nucleus 22 or 24 Cochlear Implant Systems programmed with the Continuous Interleaved Sampler (CIS), Simultaneous Analog Strategy (SAS), or SPEAK speech coding strategies on the average enable postlinguistical-ly deaf adults to understand 70-80% of words in open-set sentences by sound alone. Congenitally deaf children who were implanted between 2 and 5 years of age, received intensive spoken language training over a period of years, and use the most recent speech coding strategies, on the average are able to understand 30-40% of one-syllable, open-set words by sound alone. Several key studies indicate that the earlier a deaf child is implanted, the less language delay there is, the more intelligible their own speech is, and the earlier they are ready to be mainstreamed in normal hearing schools. Adults and children must have appropriately fitted speech processor programs (that are changed as soon as hearing changes) to achieve these levels of success. Because cochlear implants do not provide normal hearing, habilitation for children and rehabilitation for adults are essential. Preoperative evaluation, implantation, and postoperative care can only be effectively provided by close collaboration of a multidisciplinary team.