Del Bigio M R, Crook C R, Buist R
Department of Pathology, University of Manitoba, Winnipeg, Canada.
Exp Neurol. 1997 Nov;148(1):256-64. doi: 10.1006/exnr.1997.6644.
The motor and cognitive dysfunction associated with hydrocephalus remains a clinical problem in children. We hypothesized that young rats with hydrocephalus should exhibit similar dysfunction and that the dysfunction should be reversible by shunting. Hydrocephalus was induced in 3-week-old rats by injection of kaolin into the cisterna magna. Rats were assessed by T2-weighted images obtained with a 7-T magnetic resonance device and by repeated behavioral testing including ability to traverse a narrow beam and ability to find a hidden platform in a water pool. Some of the rats underwent a shunting procedure 1 or 4 weeks after kaolin injection. Magnetic resonance images were used to measure ventricle size. They clearly demonstrated increased signal in periventricular white matter, which corresponded to increased brain water content. A flow-void phenomenon was observed in the cerebral aqueduct. Ability to traverse the beam did not correlate with the degree of ventriculomegaly. Ability to swim to the hidden platform demonstrated a progressive impairment of learning function which may have been accentuated by motor disability. When rats were shunted after 1 week, the behavioral dysfunction was prevented. Late shunting after 4 weeks was associated with gradual recovery of the behavioral disability which was not complete after 4 weeks. We conclude that early shunting is superior to late shunting with regard to behavioral dysfunction. High-resolution MR imaging shows features in hydrocephalic rats similar to those found in hydrocephalic humans.
脑积水相关的运动和认知功能障碍仍是儿童临床中的一个问题。我们推测，患有脑积水的幼鼠应表现出类似的功能障碍，且这种功能障碍应可通过分流术得到逆转。通过向3周龄大鼠的大池内注射高岭土来诱发脑积水。通过使用7-T磁共振设备获得的T2加权图像以及包括穿越窄梁能力和在水池中找到隐藏平台能力在内的重复行为测试对大鼠进行评估。部分大鼠在注射高岭土1周或4周后接受了分流手术。磁共振图像用于测量脑室大小。图像清楚地显示脑室周围白质信号增强，这与脑含水量增加相对应。在大脑导水管中观察到流空现象。穿越窄梁的能力与脑室扩大程度无关。游向隐藏平台的能力显示出学习功能的逐渐受损，这可能因运动障碍而加剧。当大鼠在1周后进行分流时，行为功能障碍得到预防。4周后进行晚期分流与行为障碍的逐渐恢复相关，4周后恢复并不完全。我们得出结论，就行为功能障碍而言，早期分流优于晚期分流。高分辨率磁共振成像显示脑积水大鼠的特征与脑积水人类相似。
