Is the Integration Problem in the Sensoriomotor System the Cause of Adolescent Idiopathic Scoliosis?

Abstract

Purpose: The reason behind the balance control disorder seen in adolescent idiopathic scoliosis (AIS) has been suggested as a central nervous system dysfunction, yet it has not been investigated in detail whether this problem originates from sensory, motor, or from both systems. This study aimed to reveal the differences in the pathways that provide proprioceptive sense, motor control, and coordination between these 2 systems in female individuals with AIS. Methods: Brain Diffusion Tensor Imaging was applied to 30 healthy individuals and 30 Lenke type 1 AIS patients. All of the individuals included in the study were predominantly righthanded and aged between 10 and 18. Diffusion tensor imaging of both groups were performed bilateral tractography on the corticospinal tract (CS tr), medial lemniscus (ML), superior longitudinal fasciculus (SLF), and inferior longitudinal fasciculus (ILF) tracts using DSI Studio software. Results: Significant differences in the parameters of CS tr, ML, SLF, ILF pathways were found between the AIS and the control groups. In the AIS group, significant differences were found in the fiber count and fiber ratio of the ML that carries the proprioceptive sense and CS tr, which is responsible for the somatomotor system. There were also significant differences between the left and right CS tr, ML, SLF, and ILF pathways of the AIS group (P < 0.05). Conclusions: Differences in the CS tr, ML, SLF, and ILF pathways may trigger muscular asymmetry and cause postural instability and thus spinal deformity in AIS.

Comparison of morphometric measurements of lumbar muscles on the convex and concave sides of curvature in idiopathic scoliosis

“…[18][19][20] Payas et al, reported in their study that the number of tractus corticospinalis fibers responsible for the motor control of the muscles in individuals with scoliosis decreased on the right and left sides compared to healthy individuals, and they reported that this would result in bilateral muscle strength and volume loss in individuals with scoliosis. [21] In our study, PM, and QL muscle volume data of individuals with IS were found to be smaller on both the right and left sides compared to the control group. These data support that bilateral muscle weakness is present in individuals with IS compared to the control group.…”

“…However, studies report that muscles on the convex side of curvature are stronger. [19][20][21] As a result of the change in the locomotor system in scoliosis, the origins and insertions of the muscles change, and the anatomical size of the muscles is affected. While the length of the muscles on the concave side shortens and the muscle thickness increases, the muscles on the convex side lengthen and the thickness decreases.…”

“…[ 18 – 20 ] Payas et al, reported in their study that the number of tractus corticospinalis fibers responsible for the motor control of the muscles in individuals with scoliosis decreased on the right and left sides compared to healthy individuals, and they reported that this would result in bilateral muscle strength and volume loss in individuals with scoliosis. [ 21 ]…”