Semi-Circular Canals Anomalies//Idiopathic Scoliosis

Supports: Fondation Yves Cotrel pour la recherche en pathologie rachidienne. Institut de France, Paris. SHFJ/CEA Orsay in the frame of the cooperation through IFR 49 INSERM/CNRS France.-Membranous semi circular canals (SCC) modelling based on MRI revealed significant anomalies in IS patients compared to normal subjects-Frequent aplasias located in the lateral canal were found in IS.-We also discovered a, never described, abnormal communication between lateral and posterior canal.-Lateral SCC is involved in trunk rotation and lateral deviation: these movements are frequently abnormal in IS. Structured Abstract: Study design Are there qualitative and/or quantitative relations between abnormal partitions of the lymph in semicircular canals (SSC) and idiopathic scoliosis (IS)? Objective Comparison of membranous SSC in IS and normal subjects. Methods: We compared a scoliosis group SG (n=95, 75W. 20M.from 10 to 30 Y.) to a control group CG (n=33, 27W. 16 M., from 8 to 51Y.) Then, we divided SG in different subgroups: versus Cobb angle: SG1: 12 to 20°, SG2: 20 to 47°, versus curve type: thoracolumbar (TL), thoracic (T) and lumbar (L). Data were acquired with a T2 MRI (G.E. Excite 1.5T, mode Fiesta). We processed the data with Brainvisa modules (http://brainvisa.info/) and novel automated modules permitting a scale jump and a partition between peri-and endo-lymph. Specific anomalies were scored for statistical study. In SG, we also found abnormal communications between lateral and posterior canals in 54.7% and 3 patients without SSC anomaly. In the CG, we found 9% of SSC anomalies located on the lateral canals (10.5 %), on posterior (9%) and anterior (7.5%) Mann-Whitney U test: sum of anomalies, posterior canals and anterior canals: p<0, 0001; lateral canals: p=0.002). We compared SCC anomalies in the different SG subgroups:-versus Cobb angle: no differences between the different groups (Mann-Whitney U test p= 0, 08),-Versus curve type: no difference between the different groups (Kruskal-Wallis test p= 0,69). Discussion: We found high percent of lateral canal aplasia & abnormal communications also affecting the lateral canal: these canals are known to be implicated in axial body rotation. These results could explain the results of Kramers in 2004 who observed an asymmetrical trunk rotation around the vertical axis and lateral deviations in IS patients of his study. 2 In the text, we bring the proof that abnormal connections also affect the bony canals. This result suggests a congenital origin: bony labyrinths are ossified early in utero. The additional fact that a large percentage of …