原发性颅底凹陷症的CT-病理再研究

目的：探讨颅底凹陷症及颅底凹陷症合并寰枕融合畸形的病理机制。资料与方法：本文分析７２例颅底凹陷症及１００例正常人的ＣＴ表现。结果：病理组单纯颅底凹陷症２９例，伴寰枕融合者４３例，寰枕高度小于３１ｍｍ者３２例，其中寰椎发育不良短小者１３例，枕骨髁发育不良短小者２４例，二者同时存在者６例；寰枕高度大于３１ｍｍ者１１例。寰枢椎脱位１８例，其中枕骨髁发育不良短小者２例，合并寰椎发育不良短小者１５例，仅一例脱位甚轻者为单纯颅底凹陷症。横韧带断裂１１例，全部合并寰椎发育不良短小，齿状突凸入枕大孔者９例，均合并寰椎发育不良。结论：作者认为：单纯颅底凹陷症及颅底凹陷症合并枕骨髁发育不良的主要病理改变为延、颈髓屈曲后弓并与小脑扁桃体相互挤压。颅底凹陷症合并寰椎发育不良的病理机制为齿状突对脑干腹侧面的直接压迫及小脑扁桃体对脑干背侧面的压迫

Investigation of the Mechanism of the Basilar Impression CT

Purpose:Study the mechanism of the Basilar Impression and Basilar impression accompany by agenesis of atlas.Materical and methods:72 patients of the Basilar Impression and 100 no rmal persons were studerted.read films with double blind method.Results:T he basilar Impression were found in 29 patients and the Basilar impression accompany by occipit alization were in 43 patients.Basilar impression accompany by agenesis of atlasin 13 patients.Basilar impression accompany by agenesis of occipital condyle in 24 patients.Dislocation of atlas were found in 18 patients.it occur in 2 patients with agenesis of occipital of condy and occured in 15 patients.Disrupture were found in 11 patients with agenesis of atlas.The dens protruding into foramen magnum in 9 patients with agenesis of atlas.Conclusion:The author ssugg ested that the main mechanism of the basilar impression is over bending of medulla oblonga taand cervical cord,and pressing each ot her with cerebellar to nsil.The main mechanism of the basilar impression accompany by agenesis of atlas is pressing by the dens and cerebellartonsil directly.