Bartels R H, Merx J L, van Overbeeke J J
Department of Neurosurgery, University Hospital Nijmegen, The Netherlands.
J Neurosurg. 1998 Nov;89(5):738-41. doi: 10.3171/jns.1998.89.5.0738.
Occipital encephaloceles are relatively frequently encountered. Many investigators have addressed the embryogenesis of these formations, but the dural system has never before been studied. In this retrospective analysis the authors sought to gain a better understanding of the origins of these defects.
The charts and radiological examinations, especially the magnetic resonance venography studies, were reviewed in seven patients. In six patients the straight sinus was absent. Drainage of the galenic system took place through a sinus within the falx, also known as a falcine sinus. The tentorium was not seen in five patients.
The combination of an absent straight sinus and dysplastic tentorium is no coincidence: both develop within the same mesenchyme in the mesencephalic flexure. Distortion of the mesenchyme by a neural tube defect, causing an occipital encephalocele, will lead not only to disorders of the tentorium but also of the straight sinus.
枕部脑膨出相对较为常见。许多研究者探讨过这些结构的胚胎发生，但硬脑膜系统此前从未被研究过。在这项回顾性分析中，作者试图更好地了解这些缺陷的起源。
回顾了7例患者的病历和影像学检查，尤其是磁共振静脉造影研究。6例患者的直窦缺如。大脑大静脉系统通过大脑镰内的一个窦引流，该窦也称为大脑镰窦。5例患者未见到小脑幕。
直窦缺如和发育异常的小脑幕同时出现并非巧合：两者均在中脑曲内的同一间充质中发育。神经管缺陷导致间充质变形，进而引起枕部脑膨出，这不仅会导致小脑幕紊乱，还会导致直窦紊乱。
