Physical Activity Predicts Performance in an Unpracticed Bimanual Coordination Task

Increased EEG alpha peak frequency in adolescents with idiopathic scoliosis during balance control in normal upright standing

Adolescent idiopathic scoliosis (AIS) is a multifactorial disorder characterized by a tridimensional deformation of the spine. AIS pathophysiology is still unclear and its aetiology is unknown. Results from several studies revealed balance control alterations in adolescents with AIS suggesting cortical sensorimotor processing impairments. Studies assessing cortical activity involved in balance control revealed an increase in alpha peak frequency (APF), which is a neurophysiological marker of thalamo-cortical transmission, related to a more challenging balance task. The objective of this study is to assess APF of adolescents with AIS during balance control in upright standing posture using electroencephalography (EEG). EEG was recorded in 16 girls with AIS and 15 control girls in normal standing posture on a force platform. The participants stood upright for 2 min with eyes open and 2 min with eyes closed. Fast Fourier transformations of EEG data were calculated to obtain APF. Balance performances were assessed through the area of an ellipse covering the center of pressure (COP) displacement and the root mean square value of the COP velocity. Compared to the control group, APF was higher in the AIS group at central, frontal, parietal and occipital regions. Further, COP analyses did not reveal any difference between AIS and control groups. A higher APF may indicate the need for increased cortical processing to maintain balance control in normal upright standing in adolescents with AIS compared to healthy controls. We suggest that this may be a compensatory strategy to overcome balance control challenges.

Cortical dynamics of sensorimotor information processing associated with balance control in adolescents with and without idiopathic scoliosis

OBJECTIVE

This study aims at examining the cortical dynamics of sensorimotor information processing related to balance control in participants with adolescent idiopathic scoliosis (AIS) and in age-matched controls (CTL).

METHODS

Cortical dynamics during standing balance control were assessed in 13 girls with AIS and 13 age-matched controls using electroencephalography. Time-frequency analysis were used to determine frequency power during ankle proprioception alteration (ankle tendons co-vibration interval) or reintegration of ankle proprioception (post-vibration interval) with or without vision.

RESULTS

Balance control did not differ between groups. In the co-vibration interval, a significant suppression 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 the AIS group compared to the CTL group. In the post-vibration interval, significant suppressions in beta (13-30 Hz) and gamma (30-50 Hz) band power were observed in the AIS group in the non-vision condition.

CONCLUSION

Participants with AIS showed brain oscillations differences compared to CTL in the sensorimotor cortex while controlling their balance in various sensory conditions.

SIGNIFICANCE

Future study using evaluation of cortical dynamics could serve documenting whether rehabilitation programs have an effect on sensorimotor function in AIS.