Portnoy H D, Croissant P D
Arch Neurol. 1978 May;35(5):306-16. doi: 10.1001/archneur.1978.00500290052009.
Seven children studied because of clinical macrocephaly and suspected hydrocephalus ultimately proved to have megalencephaly apparently due to an increase in sagittal sinus venous pressure as established from infusion studies. Unexplainably, these patients were all males. All were seen initially between 2 and 8 months of age. Head enlargement exceeded two standard deviations in all seven. Pneumoencephalography, ventriculography, or computerized tomography demonstrated normal or minimally enlarged ventricles that did not progress in size. Isotope cisternography was abnormal. Studies of CSF formation and absorption demonstrated normal absorption rates but high calculated sagittal sinus pressures. Though therapy was usually not required, in one unusual infant, severe progressive macrocephaly with minimal hydrocephalus required a shunt. Another had a transient episode of acute hydrocephalus associated with a low CSF absorption rate and ventricular enlargement. In this report, we review the intracranial hydrodynamics of benign intracranial hypertension (BIH), communicating hydrocephalus, and the pathogenesis of megalencephaly. Benign intracranial hypertension and the type of megalencephaly demonstrated by our patients appear to develop similarly except that the presence of open cranial sutures may allow a transient nonhydrostatic loading of brain parenchyma in infants, resulting in mild, nonprogressive macrocephaly.
七名儿童因临床巨头畸形和疑似脑积水接受研究，最终证实患有巨脑症，显然是由于从灌注研究确定的矢状窦静脉压升高所致。令人费解的是，这些患者均为男性。所有患者最初就诊时年龄在2至8个月之间。七名患者的头部增大均超过两个标准差。气脑造影、脑室造影或计算机断层扫描显示脑室正常或仅轻度扩大，且大小无进展。同位素脑池造影异常。脑脊液形成和吸收研究显示吸收速率正常，但计算得出的矢状窦压力较高。尽管通常不需要治疗，但在一名特殊婴儿中，严重进行性巨头畸形伴轻度脑积水需要进行分流手术。另一名患者出现了与脑脊液低吸收速率和脑室扩大相关的急性脑积水短暂发作。在本报告中，我们回顾了良性颅内高压（BIH）、交通性脑积水的颅内流体动力学以及巨脑症的发病机制。我们患者所表现出的良性颅内高压和巨脑症类型似乎发展方式相似，只是开放颅缝的存在可能使婴儿脑实质出现短暂的非静水压力负荷，导致轻度、非进行性巨头畸形。
