小児人工内耳への対応

Abstract

In the United States, Australia and in Europe, the number of children who receive cochlear implants is increasing dramatically, but it is still rather small in Japan. However, before any rapid increase of pediatric cochlear implantation in our country, the following two factors should be considered; 1. growth of the temporal bone in Japanese children (for better surgical results); 2. intellectual development (to plan appropriate rehabilitation). From the anatomical point of view, the child should be more than 5 years old at the time of the surgery. CT scans of Japanese children reveal slower development of the temporal bone than in Euro-American children. Also, to facilitate rehabilitation after surgery, more than 4 years of age is recommended so as to obtain consistent responses to verbal stimulation. In the United States, no objective evidence has been obtained to support an earlier age for implantation in respect to better hearing acquisition. In conclusion, 4 years of age appears to be the lower limit for cochlear implantation in Japanese children.