Saeki Naokatsu, Nagai Yuichiro, Matsuura Iichiro, Uchino Yoshio, Kubota Motoo, Murai Hisayuki, Ishikura Hiroshi, Ikehira Hiroo, Yamaura Akira
Department of Neurologic Surgery, Chiba University Graduate School of Medicine, Japan.
AJNR Am J Neuroradiol. 2004 Aug;25(7):1218-22.
Perivascular (PV) spaces are known to distend and cause edema along the optic tract (OT) in pituitary-region tumors. Interstitial fluid may be retained in PV spaces when tumors block their drainage outlets to subarachnoid spaces. However, these spaces and their outlets have not been anatomically elucidated. Our purpose was to evaluate how often large PV spaces are present along the OT and demonstrate their superficial communication points to adjacent subarachnoid spaces.
We examined serial histologic sections of 10 hemispheric blocks obtained from cadavers without cerebral abnormality.
Large PV spaces, 0.5-1.5 mm in maximum height, were always present along the middle portion of the OT. Perforation points of the largest spaces were noted at the medial sulcus of the OT in seven hemispheres and through the OT in three.
Large PV spaces are present along the middle portion of the OT. Their communication point to adjacent subarachnoid spaces was histologically demonstrated. The locations and variations of the outlet of large PV spaces explain the clinical features of edemas; these findings anatomically support the hypothesis that blockage of the outlets to subarachnoid spaces may play a role in distending the PV spaces and in causing edema in pituitary-region tumors. Only MR imaging has revealed this change; further pathologic investigations are awaited.
已知垂体区肿瘤周围血管间隙（PV间隙）会扩张并沿视束（OT）引发水肿。当肿瘤阻塞PV间隙至蛛网膜下腔的引流出口时，间质液可能会潴留在PV间隙中。然而，这些间隙及其出口的解剖结构尚未明确。我们的目的是评估OT沿线大PV间隙出现的频率，并展示其与相邻蛛网膜下腔的浅表连通点。
我们检查了从无脑部异常的尸体获取的10个半球组织块的连续组织学切片。
在OT中部总是存在最大高度为0.5 - 1.5毫米的大PV间隙。在7个半球中，最大间隙的穿孔点位于OT的内侧沟，在3个半球中穿过OT。
在OT中部存在大PV间隙。从组织学上证实了它们与相邻蛛网膜下腔的连通点。大PV间隙出口的位置和变异解释了水肿的临床特征；这些发现从解剖学上支持了以下假说，即蛛网膜下腔出口阻塞可能在PV间隙扩张及垂体区肿瘤引起水肿中起作用。只有磁共振成像揭示了这种变化；有待进一步的病理学研究。
