Understanding the neurophysiological mechanisms associated with balance control in adolescents with idiopathic scoliosis

Introduction Several studies revealed balance control alterations in adolescents with idiopathic scoliosis (AIS) suggesting cortical sensorimotor processing impairments. This study aims at examining the cortical dynamics of sensorimotor information processing related to balance control in different sensory tasks in participants with AIS and in age-matched controls (CTL) using electroencephalography (EEG). Methods Cortical dynamics during normal standing balance and during ankle tendons co-vibration (proprioception alteration) and post-vibration (proprioception reintegration) were assessed in 16 girls with AIS and 15 CTL using EEG. The participants stood on a force platform. Fourier transform and time-frequency analysis were used to determine alpha peak frequency (APF) and band power synchronization/desynchronization in all conditions with and without vision. Balance performances were assessed through the distance covered by the center of pressure (COP). Results COP did not differ between groups in all conditions. APF was larger in the AIS group at central, frontal and parietal regions. In the co-vibration condition, a significant desynchronization in alpha (8–12 Hz) and beta (13–30 Hz) band power and a significant increase in theta (4–7 Hz) band power were found respectively in the vision and non-vision condition in AIS compared to CTL. In the post-vibration condition, significant desynchronization in beta and gamma (30–50 Hz) band power were observed in the AIS group in the non-vision condition. Discussion/conclusion Differences in APF and frequency band power in AIS compared to CTL may indicate the need for increased cortical processing to maintain balance control. Future investigations may help understand the pathomechanism of progressive scoliosis.