Postural effects on nystagmus response during caloric labyrinthine stimulation in patients with adolescent idiopathic scoliosis. II. An electro-nystagmographic study.

An electro-nystagmographic study of postural effects on the nystagmus response has been performed in 40 patients with adolescent idiopathic scoliosis aged from 10 to 16 years. The control group comprised 29 healthy children of the same age. Caloric labyrinthine stimulation was done in the supine and erect position. The results were analysed with the aim of finding out whether an increased scoliotic deformity might influence the labyrinthine response. For comparison of the nystagmus response in the two different positions a quotient of the values (degrees/second) obtained from cold water stimulation in the erect and supine position was calculated. In the control children the labyrinthine response in erect posture was half of the response in supine posture. In erect posture the scoliotic deformity increased. This obvious change in the spine did not increase the caloric response from the convex side labyrinth. The predominance of the convex side labyrinth observed in the supine position was thus not seen in the erect position. The results of this study did not support the assumption that a postural deformity in the spine can influence a calorically induced labyrinthine response.