Osaka K, Sato N, Ohbora Y, Tamaki N, Matsumoto S
No Shinkei Geka. 1976 Dec;4(12):1165-76.
The abnormal midline cyst of diencephalic origin was termed "diencephalic cyst" by Brocklehurst in 1973. Since then, several case reports of so-called "diencephalic cyst" have appeared, but its clinical picture, especially its relation to other midline dysraphisms, does not seem to be well understood. Our experience with four cases of so-called "diencephalic cyst" were reported and their relation to holoprosencephaly as well as simple agenesis of corpus callosum was discussed. (1) In all of these cases, there was an abnormal space in the midline which freely communicated with the lateral ventricle. In the first two cases, their clinical pictures as well as the features of contrast studies were typical of alobar holoprosencephaly. In the third case, the absence of the olfactory tract, the incompletely separated cerebrum, and the monoventricle were confirmed at autopsy. In the last case, the ventricle was also incompletely separated. From these observations, such a malformation should better be considered as a variant of holoprosencephaly, and it would not be appropriate to classify this malformation, as Brocklehurst claimed, as "a maldevelopment lying between the group associated with anterior neuropore closure and prosencephalization (anterior encephaloceles and holoprosencephaly) and the group associated with maldevelopment of the hind brain (cerebellar and fourth ventricle encephaloceles and Dandy-Walker cyst of the rhombencephalon)." (2) This malformation is apparently formed before the 40 mm stage of the embryo, since by this time the diencephalic roof has already sunk to the level of the adult form. This maldevelopment should be clearly differenciated from simple agenesis of the corpus callosum which is formed after the 60 mm stage of the embryo. In simple agenesis of the corpus callosum, the deep venous system might take an abnormal course, but is well formed, whereas in holoprosencephaly or so-called "diencephalic cyst", the internal cerebral vein as well as the straight sinus and the inferior sagittal sinus is absent. (3) In all of our cases, there was an abnormal space posterior and inferior to the elevated lateral sinus. Autopsy done in two cases revealed that this abnormal space was a Dandy-Walker cyst in one case, the the dorsal sack of diencephalic origin in the other case. The latter case tells that in the cases of holoprosencephaly the lateral sinus does not necessarily mark the boundary between the cerebrum and the cerebellum. (4) "Diencephalic cyst" often accompanies severe hydrocephalus. However, even with successful surgical treatment of hydrocephalus, the outcome of intelligence in these cases would be grave.
1973年，布罗克赫斯特将起源于间脑的异常中线囊肿称为“间脑囊肿”。从那时起，陆续出现了几例所谓“间脑囊肿”的病例报告，但人们似乎并未充分了解其临床表现，尤其是它与其他中线神经管闭合不全的关系。我们报告了4例所谓“间脑囊肿”的病例，并讨论了它们与前脑无裂畸形以及单纯胼胝体发育不全的关系。（1）在所有这些病例中，中线部位均存在一个与侧脑室自由相通的异常间隙。在前两例中，其临床表现以及造影检查特征均符合无脑叶型前脑无裂畸形。在第三例中，尸检证实嗅束缺如、大脑未完全分离且为单脑室。在最后一例中，脑室也未完全分离。基于这些观察结果来看，这种畸形更应被视为前脑无裂畸形的一种变异型，而像布罗克赫斯特所主张的那样，将这种畸形归类为“一种介于与前神经孔闭合及前脑形成相关的畸形组（前脑膨出和前脑无裂畸形）和与后脑发育异常相关的畸形组（小脑和第四脑室膨出以及菱脑的丹迪-沃克囊肿）之间的发育异常”是不合适的。（2）这种畸形显然是在胚胎40毫米阶段之前形成的，因为此时间脑顶部已经下沉到成人形态的水平。这种发育异常应与单纯胼胝体发育不全明确区分开，后者是在胚胎60毫米阶段之后形成的。在单纯胼胝体发育不全中，深部静脉系统可能走行异常，但结构完好，而在前脑无裂畸形或所谓“间脑囊肿”中，大脑内静脉以及直窦和下矢状窦均缺如。（3）在我们所有的病例中，在抬高的侧窦后方和下方均存在一个异常间隙。对两例进行的尸检显示，在其中一例中这个异常间隙是一个丹迪-沃克囊肿，在另一例中是起源于间脑的背侧囊袋。后一例表明，在前脑无裂畸形的病例中，侧窦不一定标志着大脑和小脑之间的边界。（4）“间脑囊肿”常伴有严重脑积水。然而，即便成功进行了脑积水手术治疗，这些病例的智力预后仍不容乐观。
