Asymmetric otolith vestibulo-ocular responses in children with idiopathic scoliosis

A suggested cause of idiopathic scoliosis (IS) in children is a disequilibrium in the vestibulospinal control of trunk muscles. We sought a correlation between otolith vestibular dysfunction and IS.

A recently developed test for evaluation of otolith vestibular function (off-vertical axis rotation, OVAR) was applied to 30 children with IS, 12 control subjects, and 3 with congenital scoliosis as a result of spinal deformities.

Of the patients with IS, 67% had significantly greater values of directional preponderance on the OVAR test (a measure of otolith system imbalance) compared with control subjects. Patients with congenital scoliosis showed normal responses on the OVAR test. No correlation was found between the direction of the preponderance and the side of the spine imbalance, or between the directional preponderance and the curve magnitude. The rate of progression of the scoliosis was not significantly correlated with the amplitude of the directional preponderance.

These results support the hypothesis that central otolith vestibular system disorders lead to a vestibulospinal system imbalance, and may be a factor in the cause of IS.