Decreased incidence of scoliosis in hearing-impaired children. Implications for a neurologic basis for idiopathic scoliosis.

Abstract

A retrospective survey of the incidence of positive scoliosis screenings in schools for the hearing impaired was performed. The incidence rate of scoliosis in a population with a high incidence of vestibular dysfunction was compared with the national normative incidence rate. The comparison was done to investigate the contribution of the vestibular system to scoliosis. Several reports have emphasized a possible neural etiology to idiopathic scoliosis. Based on the experimental hypothesis that an altered 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 that hearing-impaired children have a high incidence of vestibular dysfunction, it was hypothesized that their screening incidence would change if the vestibular system contributed to idiopathic scoliosis. Surveys were sent to 100 schools for the hearing impaired asking for their most recent scoliosis screening data. Of the 40 surveys returned, 28 schools for the hearing impaired conducted routine scoliosis 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 significantly less than national incidence rate of 4%-10%. The results suggested that hearing-impaired students may be a population that is protected from idiopathic scoliosis by a neural dysfunction. These data strongly suggest that idiopathic scoliosis has a neural etiology.