DECREASED INCIDENCE OF SCOLIOSIS IN HEARING-IMPAIRED CHILDREN - IMPLICATIONS FOR A NEUROLOGIC BASIS FOR IDIOPATHIC SCOLIOSIS

Study Design. A retrospective survey of the incidence of positive scol iosis screenings in schools for the hearing impaired was performed. Ob jectives. The incidence rate of scoliosis in a population with a high incidence of vestibular dysfunction was compared with the national nor mative incidence rate. The comparison was done to investigate the cont ribution of the vestibular system to scoliosis. Summary of Background Data. Several reports have emphasized a possible neural etiology to id iopathic scoliosis. Based on the experimental hypothesis that an alter ed vestibular processing is critical for the production of scoliosis, 100 schools for the hearing impaired were surveyed to determine their incidence of positive screenings for scoliosis. Because it is known th at hearing-impaired children have a high incidence of vestibular dysfu nction, it was hypothesized that their screening incidence would chang e if the vestibular system contributed to idiopathic scoliosis. Method s. Surveys were sent to 100 schools for the hearing impaired asking fo r their most recent scoliosis screening data. Results. Of the 40 surve ys returned, 28 schools for the hearing impaired conducted routine sco liosis screenings, of which 17 had demographics representative of the national norms. Of the 3127 students screened at these 17 schools, 1.2 % of the students screened positive for scoliosis. This is significant ly less than national incidence rate of 4%-10%. Conclusion. The result s suggested that hearing-impaired students may be a population that is protected from idiopathic scoliosis by a neural dysfunction. These da ta strongly suggest that idiopathic scoliosis has a neural etiology.