透明中隔の発生異常—神経放射線学的および臨床的研究

DEVELOPEMENTAL ANOMALIES OF SEPTUM PELLUCIDUM:Neuroradiological and Clinical Study

Ｉ．緒言

　透明中隔は，両側の側脳室体部を分離している薄い垂直状，吻状の膜様組織であり，これは2層の薄い膜で構成され，三角形状を呈し，前部および上部は脳梁に接し，後部および下部は脳弓の前交連およびその前縁と接している。

　発生学的に透明中隔はmid-line structureとして，脳梁と同一時期すなわち胎生3カ月頃に構成が始じまり，胎生6カ月頃に完成するといわれている^18）。この透明中隔の発生過程において種々の発生異常を生ずる。

The developemental anonalies of the septum pel-lucidum was studied and presented with special re-ference to its neuroradiological and clinical consider-ations, classifying the developemental anomalies of the septum pellucidum into the absence of the septum pellucidum, the cavum of the septum pellucidum associated with the cavum of Verga, and the fusion of the cavum of the septum pellucidum with the third ventricle complicated by the agenesis of the corpus callosum.

Four cases of the absence of the septum pellucidum, two cases of the cavum of the septum pellucidum-communicating and noncommunicating type-, one case of the fusion of the cavum of the septum pellucidum with third ventricle complicated by the agenesis of the corpus callosum were reported and presented. One case of the absence of the septum pellucidum was complicated by the primitive tri-geminal artery, one case of the noncommunicating cavum of the septum pellucidum by the cavum velum interpositum, one case of the communicating cavum of the septum pellucidum by the occipital menin-gocele, one case of the fusion of the cavum of the septum pellucidum with the third ventricle by the agenesis of the corpus callosum.

The historical background, anatomy, embryology, incidence, pneumographic study, clinical pictures, and other associated malformations of the developemental anomalies of the septum pellucidum were discussed with review of the literatures on these anomalies.