Objective To set up and to evaluate an acute closed brain injury model in rats. Methods The acute closed brain injury was produced in rats by using an impactor consisting of a stand, a guide tube, a weight and a footplate. Ninetysix SD rats were divided into a control group(n＝32, no impact), a mild injury group(n＝32, impact once at force level of 400 g·cm) and a severe injury group(n＝32, impact once at force level of 800 g·cm) to elucidate the physiological responses, the pathophysiological changes and brain edema after brain injury at different injury levels. Results In the mild injury group and the severe injury group, a sudden rise or reduction of blood pressure, deep and fast breath apnea, and pain reflects inhibition were observed. The responses were more obvious in the severe injury group than in the mild injury group. The water content of the brain increased after 6 hours of injury. The pathological contusion and edema of brain were noted or above the impact force level of 800 g·cm. When the impact force rose to or over 1200g·cm, the animals died of persistent apnea mostly. Conclusion Although the established closed brain injury model with different biomechanical mechanisms as the clinical brain injury, it is in conformity with pathological changes and pathophysiological characteristics of acute clinical brain injury, it can be utilized extensively because of its convenient and practice.
Fifteen rabbits were given a second degree scald on the back, then a large amount of fluid were given rapidly. In this way an acute diluted hyponatremia and a brain edema model were produced. In one group, the magnetotherapy was instituted immediately following the acut injury, while in the other group, it was started after the brain edema being developed. After giving a large quantity of fluid, the Na~+, CI~-, and K~+ concentrations in the blood were decreased and the quantity of water in the brain tissue was increased evidentely. The phenomena of neuron edema and widening of the perivascular space were also found. It was proved that the model of experimental brain edema could be produced on animals and the treatment and the prevention for brain edema could be obtained to advantage to certaiin degree. Also,it was better to use the magnetotherapy in brain edema as early as possidle.
Massive cerebral infarction with malignant brain edema has poor prognosis with very high mortality, despite aggressive medical treatment. Surgical decompression is recommended by Chinese and international clinical guidelines for patients with massive cerebral infarction, however, there is no standardized diagnosis and treatment protocol in clinical practice. Following the principle of evidence-based medicine and based on the diagnosis and treatment norms of the participating hospitals of Severe Ischaemic Stroke Collaboration in recent years, we recommend this consensus statement of the standardized surgical decompression for malignant brain edema in massive cerebral infarction.