目的　探讨 Ａｒｎｏｌｄ Ｃｈｉａｒｉ 畸形合并脊髓空洞症 （ Ａ Ｃ Ｍ／ Ｓ Ｍ） 的发病 机理， 寻求更好的手术方法。方法　对１４ 例 Ａ Ｃ Ｍ／ Ｓ Ｍ 的患者进行 Ｍ Ｒ Ｉ检查及术前奎科试验， 术中枕大池、空洞及脊髓蛛网膜下腔 （ Ｓ Ｓ Ａ Ｓ） 压力测量， 分析与空洞形成及大小相关的因素， 对单纯 Ａ Ｃ Ｍ 及 Ｈ Ｃ Ｉ（ 正中矢状面最宽处空洞与脊髓直径比值） ＜ ０５ 者行枕下颅骨切除＋ 硬膜扩大修补术 （ Ａ） ； Ａ Ｃ Ｍ／ Ｓ Ｍ 且 Ｈ Ｃ Ｉ≥０５者行 Ａ＋ 空洞蛛网膜下腔（ Ｓ Ｓ） 分流术（ Ｂ） 。结果　１４ 例患者均有不同程度的颈部位置性梗阻。空洞内液体与 Ｃ Ｓ Ｆ蛋白含量无显著差异（ Ｐ ＞ ００５） ， 小脑扁桃体下疝的程度与空洞大小无显著线性关系（ Ｐｒ１ ＞ ０５ ， Ｐｒ２ ＞ ０２） ； 枕大池与椎管蛛网膜下腔压力差与空洞大小呈显著正相关（ Ｐｒ３ ＜ ０１ ， Ｐｒ４＜ ０００５） 。手术有效率为９３８ ％ 。结论　脑脊液动力学改变是脊髓空洞形成的关键， 当后颅窝与椎管内压力梯度达到一定值时， 脊髓空洞开始形成。治疗应根据 Ａ Ｃ Ｍ 是否伴有 Ｓ Ｍ 及 Ｓ Ｃ Ｉ值选择恰当的手术方法。 Objective To explore the pathogenesis of Arnold Chiari malformation associated with syringomyelia (A C M / S M) and to find a better surgical method. Methods M R I test and preoperative Quaker test were performed in 14 cases of A C M / S M patients. The pressure, pressure and volume of the cistern and parietal cavity, Size related factors, simple A C M and H C I (the median sagittal cavity and spinal cord diameter ratio at the widest point) <0.5 were suboccipital skull excision + dilatation repair surgery (A); A C M / S M and H C I ≥ 0.5 5 line A + cavity - subarachnoid (SS) shunt (B). Results All 14 patients had different degrees of cervical positional obstruction. There was no significant difference (P> 005) between the content of liquid and the content of C S F protein in the cavity, and there was no significant linear relationship between the extent of the tonsil herniation and the size of the cavity (Pr 1> 05, Pr 2> 02) Spinal subarachnoid pressure difference was positively correlated with the size of the cavity (Pr3 <01, Pr4 <0005). The operative efficiency was 938%. Conclusions Cerebrospinal fluid dynamics is the key to the formation of syringomyelia. When the pressure gradient in posterior fossa and spinal canal reaches a certain value, syringomyelia begins to form. Treatment should be based on A C M with S M and S C I value to choose the appropriate surgical methods.