3rd Chair and Department of Gynecology, Medical University of Lublin, Lublin, Poland.
Chair and Department of Obstetrics and Pathology of Pregnancy, Medical University of Lublin, Lublin, Poland.
Arch Gynecol Obstet. 2020 Sep;302(3):619-628. doi: 10.1007/s00404-020-05650-y. Epub 2020 Jun 15.
Neural tube defects (NTDs) are a group of heterogeneous congenital anomalies of the central nervous system (CNS). Acrania is a non-NTD congenital disorder related to the CNS. It can transform into anencephaly through the acrania-exencephaly-anencephaly sequence (AEAS). In AEAS, the cerebral tissue is not protected and is gradually destroyed due to exposure to the harmful effect of amniotic fluid and mechanical injuries. These lead to exencephaly and then into anencephaly. In contrast to primary anencephaly (NTDs), this type of anencephaly authors suggests calling secondary anencephaly.
Analysis of the known prenatal ultrasonography (US) signs associated with AEAS. Simultaneously, the authors propose a new sign in the differentiation of acrania from exencephaly and anencephaly, called the "beret" sign.
It is a two-centre retrospective observational study. As part of the study, 4060 US scans were analyzed.
In 10 cases, the absence of calvarium was diagnosed, allowing recognition of either AEAS stages or primary anencephaly. In 5 cases, cerebral structures were enclosed by an inertial rippled thin membrane, with a smooth outer contour. Between the described membrane and the brain structures, a thin anechoic space corresponding to cerebrospinal fluid was observed. This sign was defined as the "beret" sign. In these cases, acrania was diagnosed. In three cases calvarium was missing. The brain structures had an irregular appearance, did not wave and remained motionless. The outer contour was unequal as if divided into lobes. Amniotic fluid was anechoic. Exencephaly was diagnosed in these cases. In two cases calvarium, brain structures, and meninges were missing. The "frog eyes" sign and slightly echogenic amniotic fluid were visible. In this case, anencephaly was diagnosed.
The "beret" sign seems to be a promising tool in the diagnosis of acrania. Furthermore, echogenicity of amniotic fluid could be useful during differentiation between primary and secondary anencephaly.
神经管缺陷（NTDs）是一组异质性的中枢神经系统（CNS）先天性异常。颅缝早闭是一种与 CNS 相关的非 NTD 先天性疾病。它可以通过颅缝早闭-无脑-无脑畸形序列（AEAS）转化为无脑畸形。在 AEAS 中，由于羊水的有害影响和机械损伤，脑组织没有得到保护并逐渐被破坏。这导致无脑畸形，然后是无脑畸形。与原发性无脑畸形（NTDs）不同，作者建议将这种类型的无脑畸形称为继发性无脑畸形。
分析与 AEAS 相关的已知产前超声（US）征象。同时，作者提出了一种新的征象，用于区分颅缝早闭和无脑畸形与无脑畸形，称为“贝雷帽”征象。
这是一项两中心回顾性观察性研究。作为研究的一部分，分析了 4060 次 US 扫描。
在 10 例病例中，诊断为颅骨缺失，能够识别 AEAS 阶段或原发性无脑畸形。在 5 例病例中，大脑结构被惯性波纹状薄膜包围，外轮廓光滑。在描述的膜和脑结构之间，观察到一个薄的无回声空间，对应于脑脊液。该征象定义为“贝雷帽”征象。在这些病例中，诊断为颅缝早闭。在 3 例病例中，颅骨缺失。脑结构外观不规则，无波动且保持静止。外轮廓不均匀，似乎分为叶。羊水呈无回声。在这些病例中，诊断为无脑畸形。在 2 例病例中，颅骨、脑结构和脑膜缺失。可见“青蛙眼”征和稍高回声羊水。在这种情况下，诊断为无脑畸形。
“贝雷帽”征象似乎是诊断颅缝早闭的一种很有前途的工具。此外，在原发性和继发性无脑畸形的鉴别中，羊水的回声性可能有用。
