Ogura Yoji, Yabuki Shoji, Fujibayashi Shunsuke, Okada Eijiro, Iwanami Akio, Watanabe Kota, Nakamura Masaya, Matsumoto Morio, Ishii Ken, Ikegawa Shiro
Laboratory of Bone and Joint Diseases, RIKEN Center for Integrative Medical Sciences, Tokyo, 108-8639, Japan; Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, 160-8582, Japan.
Department of Orthopaedic Surgery, Fukushima Medical University School of Medicine, Fukushima, Japan.
J Orthop Sci. 2018 May;23(3):455-458. doi: 10.1016/j.jos.2018.01.010. Epub 2018 Feb 16.
Spinal extradural arachnoid cyst (SEDAC) is a cystic lesion that protrudes into the epidural space from a small dural defect. Early diagnosis of SEDAC is important because its expansion causes neurological damage. Two types of SEDAC, syndromic and sporadic, are present. Syndromic SEDAC is inherited as a part of lymphedema-distichiasis syndrome caused by mutations in the FOXC2 gene; however, it is often mistaken as sporadic because of low penetrance. It is not reasonable to conduct a genetic testing for all SEDAC patients and their family members. The aim of this study is to establish an effective screening method to distinguish syndromic SEDAC from sporadic SEDAC.
We performed a retrospective review of medical records and imaging studies of 29 subjects who were diagnosed with SEDAC. Clinical features, family history and magnetic resonance imaging (MRI) were analyzed. Mutations in FOXC2 were examined by Sanger-sequencing of the entire coding region of the genes. SEDAC having a mutation in FOXC2 gene was defined with syndromic SEDAC.
Eleven subjects had a heterozygous mutation in FOXC2. They were all familial and hence syndromic SEDAC. Only one proband had known family history of SEDAC at diagnosis. MRI findings and physical examinations, especially eye and leg examinations, were quite useful to screen syndromic SEDAC. Physical examination often showed accompanying lymphedema and distichiasis in syndromic SEDAC. Syndromic SEDAC tended to have multiple cysts out of the thoracolumbar area.
We established an effective screening method based on physical examinations and MRI findings.
脊髓硬膜外蛛网膜囊肿（SEDAC）是一种从硬脑膜小缺损处突入硬膜外间隙的囊性病变。SEDAC的早期诊断很重要，因为其扩张会导致神经损伤。SEDAC有两种类型，综合征型和散发型。综合征型SEDAC作为由FOXC2基因突变引起的淋巴水肿-双行睫综合征的一部分而遗传；然而，由于其低外显率，它常被误诊为散发型。对所有SEDAC患者及其家庭成员进行基因检测是不合理的。本研究的目的是建立一种有效的筛查方法，以区分综合征型SEDAC和散发型SEDAC。
我们对29例诊断为SEDAC的患者的病历和影像学研究进行了回顾性分析。分析了临床特征、家族史和磁共振成像（MRI）。通过对基因整个编码区进行桑格测序来检测FOXC2基因的突变。FOXC2基因发生突变的SEDAC被定义为综合征型SEDAC。
11例患者的FOXC2基因存在杂合突变。他们均为家族性，因此是综合征型SEDAC。诊断时只有一名先证者有已知的SEDAC家族史。MRI表现和体格检查，尤其是眼部和腿部检查，对筛查综合征型SEDAC非常有用。体格检查常显示综合征型SEDAC伴有淋巴水肿和双行睫。综合征型SEDAC往往在胸腰段区域外有多个囊肿。
我们基于体格检查和MRI表现建立了一种有效的筛查方法。
