严重创伤性脑损伤(TBI)后弥漫性脑肿胀在儿童中比成人更常见;然而，缺乏未成熟动物的弥漫性脑损伤模型。作者通过修改最近描述的成年大鼠闭合性脑损伤模型，建立了一种新的未成熟大鼠弥漫性严重脑外伤模型。共105只Sprague-Dawley幼年大鼠(17日龄;平均体重38.5±5.46 g)，使用不同重量(0 g(假)，75 g, 100 g或125 g)从2 m的高度传递到金属盘上，将其固定在完整的头盖骨上。评估死亡率、生理和神经参数(从早期反射恢复到逃逸)以及早期组织病理学变化。在严重损伤(SI)后的急性期(从2米高度递送100 g;50只大鼠)，经常出现呼吸暂停，死亡率为38%。假损伤动物(11只大鼠)的神经恢复完成时间为4.1±0.23分钟(平均值±标准误差)，但在中度损伤(75 g/2 m;11只大鼠)(14.97±3.99分钟)和SI(20.57±1.31分钟(p < 0.05))大鼠。 In the first 24 hours, the sham-injured animals were more active than the injured ones as reflected by a greater net weight gain: 2.9 ± 1.0 g, 1.2 ± 1.6 g, and −0.6 ± 2.1 g in sham-injured, MI, and SI animals, respectively. Immediately after injury, transient hypertension (lasting < 15 seconds) was followed by hypotension (lasting < 3 minutes) and loss of temperature regulation. Both injuries also induced apnea (0.75 ± 0.7 minutes and 1.27 ± 0.53 minutes in MI and SI groups, respectively), which either resolved or deteriorated to death. Intubation and assisted ventilation in animals with SI for 9.57 ± 3.27 minutes in the peritrauma period eliminated mortality (p < 0.05, intubated vs. nonintubated). Histologically, after SI, there was diffuse edema throughout the corpus callosum below the region of injury and in the thalami. Other injuries included neuronal death in the deep nuclei, bilateral disruption of CA3, diffuse subarachnoid hemorrhage, and, in some, ventriculomegaly. Following a diffuse TBI in immature rats, SI produced a mortality rate, neurological deficit, and histological changes similar to those previously reported for an injury resulting from a 450-g weight dropped from 2 m in adult rats. A graded insult was achieved by maintaining the height of the weight drop but varying the weights. Weight loss, acute physiological instability, and acute neurological deficits were also indicative of an SI. Mortality was eliminated when ventilatory support was used during the peritrauma period. This model should be useful in studying the response of the immature rat to diffuse severe TBI.
