DEEPENING THE ROLE OF BODY SCHEMA IN THE PROGRESSION OF ADOLESCENT IDIOPATHIC SCOLIOSIS: A CASE-CONTROL STUDY AND A LONGITUDINAL ANALYSIS

Scoliosis is a three-dimensional spinal deformity and one of the most frequent spinal disorders during growth. In its adolescent idiopathic form, it appears to be influenced by multiple factors, although its precise etiology and the mechanisms underlying curve progression remain largely unknown. In particular, knowledge is limited regarding the potential contribution of central mechanisms, such as sensorimotor integration and the organization of body schema. This doctoral thesis was designed with two main objectives: first, to investigate whether Adolescent Idiopathic Scoliosis (AIS) patients differ from healthy individuals in body schema, considered an indirect index of central neural activity; and second, to identify predictive factors for treatment success in AIS. Chapter 1 provides a general background on scoliosis, focusing on AIS, central nervous system involvement, and common assessment methods in research and clinical practice. Chapter 2 outlines the main objectives of the thesis. Chapter 3 presents two reviews that served as the conceptual foundation for the subsequent clinical investigations. The first literature review confirmed the central role of the Cobb angle as the primary clinical parameter for evaluating AIS severity and treatment response. The second systematic review examined evidence of alterations in sensorimotor integration in AIS, drawing on findings from biomechanical and neurophysiological studies. Together, these reviews emphasized the need for a more in-depth exploration of central mechanisms and the potential influence of conservative treatments, such as bracing, on body representation. Building upon this framework, Chapter 4 describes two clinical studies conducted at the Adolescence Spine Diseases Diagnostic and Therapeutic Center of the Azienda Ospedale Università Padova. The first study was a case-control and longitudinal investigation including AIS patients and age- and sex-matched healthy controls, focusing on body schema assessment in brace-naïve patients. The second, a cross-sectional observational study in a large AIS cohort, combined routine clinical evaluation with assessments of body schema and proprioception, revealing a possible correlation between brace use and body awareness. This chapter also presents a case study of a patient initially diagnosed with AIS but later found to have scoliosis secondary to a rare genetic condition, highlighting the potential of electroencephalography in assessing sensorimotor integration alterations in secondary scoliosis. Chapter 5 describes the development of a database of 630 AIS patients, which served as the basis for constructing a machine learning (ML) model aimed at predicting the success or failure of conservative treatment. A point-based clinical index derived from this model, once further validated, may be applied in clinical practice to support Physical Medicine and Rehabilitation physicians in treatment decision-making. In Chapter 6, the same database was used to analyze adherence to brace treatment before, during, and after the COVID-19 pandemic. Results showed an increase in orthotic prescriptions but a progressive decline in compliance, highlighting the pandemic’s impact on long-term adherence and the need for personalized strategies to enhance compliance. Chapter 7 reports a study on scoliosis in patients with Prader-Willi syndrome, examining its effects on postural and motor milestones, spinal mobility, and caregiver burden. Chapter 8 summarizes the main findings and clinical implications. Overall, the results highlight the possibility of moving beyond a purely structural view of AIS by integrating clinical, neurophysiological, body schema, and predictive approaches. The integration of predictive indices with body schema and neurophysiological assessments may improve understanding of AIS and advance personalized care.