Simon E M, Hevner R, Pinter J D, Clegg N J, Miller V S, Kinsman S L, Hahn J S, Barkovich A J
Department of Diagnostic Radiology, University of California, San Francisco 94143, USA.
AJNR Am J Neuroradiol. 2000 Nov-Dec;21(10):1955-61.
Although holoprosencephaly has been known for many years, few detailed analyses have been performed in a large series of patients to outline the range of morphology in this disorder, particularly regarding the deep gray nuclear structures. We reviewed a large patient cohort to elucidate the combinations of morphologic aberrations of the deep gray nuclei and to correlate those findings with recent discoveries in embryology and developmental neurogenetics.
A retrospective review of the imaging records of 57 patients (43 MR studies and 14 high-quality CT studies) to categorize the spectrum of deep gray nuclear malformations. The hypothalami, caudate nuclei, lentiform nuclei, thalami, and mesencephalon were graded as to their degree of noncleavage. Spatial orientation was also evaluated, as was the relationship of the basal ganglia to the diencephalic structures and mesencephalon. The extent of noncleavage of the various nuclei was then assessed for statistical association.
In every study on which it could be accurately assessed, we found some degree of hypothalamic noncleavage. Noncleavage was also common in the caudate nuclei (96%), lentiform nuclei (85%), and thalami (67%). Complete and partial noncleavage were more common in the caudate nuclei than in the lentiform nuclei. The degree of thalamic noncleavage was uniformly less than that in the caudate and lentiform nuclei. Abnormalities in alignment of the long axis of the thalamus were seen in 71% of cases, and were associated with degree of thalamic noncleavage; 27% of patients had some degree of mesencephalic noncleavage.
The hypothalamus and caudate nuclei are the most severely affected structures in holoprosencephaly, and the mesencephalic structures are more commonly involved than previously thought in this "prosencephalic disorder." These findings suggest the lack of induction of the most rostral aspects of the embryonic floor plate as the cause of this disorder.
尽管全前脑畸形已为人所知多年，但在大量患者中进行的详细分析较少，难以勾勒出该疾病的形态学范围，尤其是关于深部灰质核结构。我们回顾了一大组患者，以阐明深部灰质核形态异常的组合，并将这些发现与胚胎学和发育神经遗传学的最新发现相关联。
对57例患者的影像学记录（43例磁共振成像研究和14例高质量计算机断层扫描研究）进行回顾性分析，以对深部灰质核畸形的范围进行分类。下丘脑、尾状核、豆状核、丘脑和中脑根据其未分离程度进行分级。还评估了空间定向以及基底神经节与间脑结构和中脑的关系。然后评估各种核的未分离程度之间的统计关联。
在每项能够准确评估的研究中，我们都发现了一定程度的下丘脑未分离。未分离在尾状核（96%）、豆状核（85%）和丘脑（67%）中也很常见。完全和部分未分离在尾状核中比在豆状核中更常见。丘脑未分离程度始终低于尾状核和豆状核。71%的病例中可见丘脑长轴排列异常，且与丘脑未分离程度相关；27%的患者有一定程度的中脑未分离。
下丘脑和尾状核是全前脑畸形中受影响最严重的结构，并且在这种“前脑疾病”中，中脑结构比以前认为的更常受累。这些发现表明，胚胎底板最前端部分缺乏诱导是该疾病的病因。
