title: Comparison of the scoliosis curve patterns and MRI syrinx cord characteristics of idiopathic syringomyelia versus Chiari I malformation.
abstract: OBJECTIVE
  Although the more readily available MR imaging has brought about more incidental findings of idiopathic syringomyelia (IS), no published study has specifically addressed the clinical and imaging features of IS-associated scoliosis. Since IS and Chiari I malformation (CMI)-type syringomyelia are hypothesized to share a common underlying developmental pathomechanism, this study aimed to investigate the scoliosis curve patterns and MRI syrinx cord characteristics of patients with IS comparing with those seen in CMI.
  
  
  METHODS
  Sixty-one patients with scoliosis secondary to IS were identified and reviewed retrospectively. The curve pattern and specific curve features were recorded and compared with historic CMI controls. Location, size, and morphological appearance of the syrinx were systematically assessed on MR images.
  
  
  RESULTS
  The maximal syrinx/cord ratio and rostrocaudal length of the syrinx in IS averaged 0.43 ± 0.16 (range 0.17-0.78) and 4.6 ± 2.5 (range 2-15) vertebral levels, respectively, both of which were smaller than those reported in CMI-type syringomyelia. Regarding the characteristics of IS-related scoliosis, sagittal profiles as well as the frequency of curve patterns and atypical features were all found to resemble those in patients with CMI (P > .05). Among the 47 individuals with a single thoracic curve, Fisher exact test revealed a significant correlation between curve convexity and the dominant side of deviated syrinx (83.3 % concordance rate, P = .021). In addition, apex of the thoracic curve trended toward being significantly correlated with the level of maximum expansion of the syrinx (P = .066).
  
  
  CONCLUSIONS
  Radiological characteristics of scoliosis were found to be similar between idiopathic and CMI-type syrinx in both the coronal and sagittal planes, adding further evidence to the concept that these entities may be part of a spectrum of disease sharing a common pathophysiological mechanism. The thoracic spine in IS patients tended to be convex to the deviated side of syrinx, which indirectly supported the likely role of spinal cord dysfunction in the pathogenesis of syrinx-associated spinal deformities.
authors.affiliation: Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road No. 321, Nanjing, 210008, China.|Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China.
authors.forename: Zezhang
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road No. 321, Nanjing, 210008, China.|Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China.
authors.forename: Shifu
authors.initials: S
authors.lastname: Sha
authors.affiliation: Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China.|Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, 5/F, Clinical Science Building, Shatin, NT, Hong Kong, China.
authors.forename: Winnie C C
authors.initials: WC
authors.lastname: Chu
authors.affiliation: Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road No. 321, Nanjing, 210008, China.|Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China.
authors.forename: Huang
authors.initials: H
authors.lastname: Yan
authors.affiliation: Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road No. 321, Nanjing, 210008, China.|Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China.
authors.forename: Dingding
authors.initials: D
authors.lastname: Xie
authors.affiliation: Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road No. 321, Nanjing, 210008, China.|Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road No. 321, Nanjing, 210008, China.|Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road No. 321, Nanjing, 210008, China.|Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China. jackcheng@cuhk.edu.hk.
authors.forename: Jack C Y
authors.initials: JC
authors.lastname: Cheng
authors.affiliation: Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road No. 321, Nanjing, 210008, China. scoliosis2002@sina.com.|Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, China. scoliosis2002@sina.com.
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D000293:Adolescent; D001139:Arnold-Chiari Malformation / Q000150:complications / Q000473:pathology*; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D012600:Scoliosis / Q000150:complications / Q000473:pathology*; D013131:Spine / Q000473:pathology*; D013595:Syringomyelia / Q000150:complications / Q000473:pathology*; D055815:Young Adult
keywords: Chiari I malformation; Coronal asymmetry; Idiopathic syringomyelia; Imaging feature; Scoliosis