Danielpour Moise, Wilcox William R, Alanay Yasemin, Pressman Barry D, Rimoin David L
Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
J Neurosurg. 2007 Dec;107(6 Suppl):504-7. doi: 10.3171/PED-07/12/504.
Achondroplasia is the most common of the heritable skeletal dysplasias. Compression at the cervicomedullary junction can result in myelopathy, hypotonia, sleep apnea, and even sudden death. However, most children with achondroplasia do not suffer from severe neurological symptoms and achieve normal motor and intellectual development without surgical intervention. At the authors' institution, magnetic resonance (MR) imaging and cerebrospinal fluid (CSF) flow studies have been incorporated in the assessment of children with achondroplasia for cervicomedullary junction compression. The authors recently identified four children with achondroplasia who had normal findings on MR imaging and flow studies obtained in the neutral position. On flexion studies, however, three had complete blockage of CSF flow, and more dramatic posterior cervicomedullary compression was demonstrated on extension studies. Some of these patients had severe neurological abnormalities and sleep apnea, while others just developed headaches and/or had apnea episodes when sleeping or in a car seat. Three children underwent decompressive surgery with dramatic improvement or resolution of signs and symptoms. The fourth patient had increased CSF pressure on MR images obtained in the flexed position, possibly due to venous outflow obstruction. Her condition improved dramatically after placement of a ventriculoperitoneal shunt. The increased risk of dynamic cord compression and alterations in CSF dynamics in patients with achondroplasia constitute indications for surgical intervention.
软骨发育不全是最常见的遗传性骨骼发育不良疾病。颈髓交界处受压可导致脊髓病、肌张力减退、睡眠呼吸暂停，甚至猝死。然而，大多数软骨发育不全患儿并无严重神经症状，无需手术干预即可实现正常的运动和智力发育。在作者所在机构，磁共振（MR）成像和脑脊液（CSF）流动研究已被纳入对软骨发育不全患儿颈髓交界处受压情况的评估中。作者最近发现了4例软骨发育不全患儿，他们在中立位进行的MR成像和流动研究结果正常。然而，在屈曲研究中，3例患儿的脑脊液流动完全受阻，伸展研究显示颈髓后部受压更明显。其中一些患者有严重的神经异常和睡眠呼吸暂停，而另一些患者仅出现头痛和/或在睡眠或坐在汽车座椅时出现呼吸暂停发作。3例患儿接受了减压手术，体征和症状得到显著改善或缓解。第4例患者在屈曲位获得的MR图像上显示脑脊液压力升高，可能是由于静脉流出受阻。在置入脑室腹腔分流管后，她的病情显著改善。软骨发育不全患者动态脊髓受压风险增加以及脑脊液动力学改变构成了手术干预的指征。
