Altered EEG activity and body schema representation in adolescent idiopathic scoliosis

Research Objectives: The pathophysiology of Adolescent Idiopathic Scoliosis (AIS) is not yet completely understood, but multi-factorial hypotheses have been proposed. The aim of our study was to compare the electroencephalography (EEG) activity in adolescents with AIS and controls, to examine the brain oscillatory changes related to balance control and inquire possibly related body schema representational alterations.

Design: Case-control study. Subjects with AIS were compared to age-matched healthy subjects.

Setting: We recorded EEG data and balance data, with arms in both the neutral position and laterally elevated with elbow flexed at 90° (with eyes open and closed). A re-adaptation of the Image Marking Procedure was used to assess the body schema.

Participants: Data were acquired in 14 healthy subjects and in 14 subjects with AIS (Cobb angle:b 20°-55°; Risser sign: 0-4; no spine surgery).

Interventions: not applicable.

Main Outcome Measures: EEG relative power; delta body perception index score (BPI); balance and motion parameters.

Results: Results revealed no balance control difference between groups; higher EEG alpha relative power over sensorimotor areas ispilateral to the side of the curve and a significant increase of theta relative powers localized over the central areas in AIS participants. The delta BPI score (BPI shoulder minus BPI waist) resulted significantly different between the two groups. The inclinations of the perceived interacromial axes in girls having thoracic principal curve, and bisiliac axes in girls with lumbar principal curve, was opposite to the real inclination.

Conclusions: Results provide evidence of an increased theta activity, a lateralized alpha activity and an altered body schema perception in AIS subjects. Whether these processes are a cause or a consequence of AIS needs to be further investigated.

Author(s) Disclosures: No conflict of interests to declare.