Abstract
Introduction
Autonomic nerve system (ANS) regulates intercostal vascular nutrition (internal mammary artery), and its pathological status leads to developmental asymmetry of the trunk and rib cage, and consequently producing scoliotic deformity of the spine. The aim of this study is to investigate the possible causation of idiopathic scoliosis in development abnormalities of ANS.
Methods
We evaluated samples taken from 12 patients with idiopathic scoliotic deformities and a control set of three patients without scoliotic deformity. We examined the samples of autonomic nerves taken from convexity and concavity of the scoliotic deformity during the patients' surgical correction by the transthoracic approach. We used the electronmicroscopic method to analyse samples, and the morphometric method for statistical evaluation.
Results
Evaluation of the samples taken from scoliotic convexity and the control samples of non-scoliotic patients showed normal findings in autonomic nerve structures. We detected significant morphological changes in all scoliotic samples taken from concavity. These changes were mostly in myelin vaginas with abnormalities and compression of the axon fibre, massive lesion and separation of the myelin sheath, vacualisation of cytoplasma of the Schwann cells, and condensation of the cytoblast. By morphometric measurements we found 23·71% of myelinised nerve fibres (MNF), 12·21% of unmyelinised nerve fibres (UNF), and 5·0% of Schwann cells (SC) in samples taken from scoliotic convexity, and 29·9% of MNF, 19·9% of UNF, and 16·7% of SC in control non-scoliotic samples. We recorded 17·36% of MNF, 5·82% of UNF, and 5·27% of SC in samples taken from concavity.
Conclusions
We noted abnormalities in structure of ANS in concave side of scoliotic curves, and statistically significant differences between both sides of scoliotic deformity (convexity and concavity). Furthermore, we recorded discrepancies between scoliotic samples and non-scoliotic control samples. The abnormalities, mostly in the myelinated fibres, might be originated by the primary genetic lesion and thus could affect the development of scoliosis. The abnormalities of ANS can produce changes in internal mammary artery, and consequently can lead to the abnormal blood supply of vertebrae as well as anterior wall chest. These abnormalities of ANS could lead to the scoliotic origin in growing spine.
