The Johns Hopkins Temporal Bone Laboratory, Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland, USA.
Otol Neurotol. 2011 Jun;32(4):602-9. doi: 10.1097/MAO.0b013e3182129026.
Arachnoid granulations (AG) are more prevalent along the middle fossa surface of the temporal bone, where they produce larger bony defects than those occurring on the posterior surface.
Dural and bony defects formed by AGs are proposed to lead to spontaneous meningoencephaloceles and cerebrospinal fluid otorrhea. They most commonly occur at the tegmen and in individuals older than 40 years.
Vertically sectioned temporal bones were evaluated using light microscopy to determine AG histology, distribution, and morphometry and to determine the prevalence of AG penetration in the donor population.
AGs were observed to penetrate the dura mater and make direct contact with cortical surfaces in 12.7% of donors in the Johns Hopkins Temporal Bone Collection. AGs occurred at middle fossa sites 13% more frequently than at posterior fossa sites. At middle fossa sites AGs produced significantly larger bony openings and were more likely to be associated with herniating brain tissue. Donors with AGs were significantly older, and all were in the late 30s or older.
Erosion of the temporal bone by AGs is not a rare occurrence in the population and becomes increasingly prevalent with age. It is estimated that 14 in 1,000 donors were at greatest risk of eventual cerebrospinal fluid leakage at the tegmen. The age and anatomic distribution described in this study strengthens the notion that AG penetration plays a role in the pathophysiology of spontaneous cerebrospinal fluid leaks and meningoencephaloceles of the temporal bone.
蛛网膜颗粒（AG）在颞骨中窝表面更为常见，在那里它们产生的骨缺损比后表面的更大。
AG 形成的硬脑膜和骨缺损被认为会导致自发性脑膜脑膨出和脑脊液耳漏。它们最常发生在天幕和 40 岁以上的个体。
使用光学显微镜对垂直切片的颞骨进行评估，以确定 AG 的组织学、分布和形态计量学，并确定供体人群中 AG 穿透的发生率。
在约翰霍普金斯颞骨库中，12.7%的供体中观察到 AG 穿透硬脑膜并与皮质表面直接接触。AG 在中颅窝的发生率比在后颅窝的发生率高 13%。在中颅窝部位，AG 产生的骨开口明显更大，并且更有可能与突出的脑组织有关。有 AG 的供体年龄明显更大，所有人都在 30 多岁或以上。
AG 对颞骨的侵蚀在人群中并不罕见，而且随着年龄的增长而越来越普遍。据估计，在 1000 名供体中，有 14 名供体在天幕处发生脑脊液漏的风险最大。本研究中描述的年龄和解剖分布加强了这样一种观点，即 AG 穿透在自发性脑脊液漏和颞骨脑膜脑膨出的病理生理学中起作用。
